linux/fs/proc/base.c

3243 lines
76 KiB
C
Raw Normal View History

/*
* linux/fs/proc/base.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* proc base directory handling functions
*
* 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
* Instead of using magical inumbers to determine the kind of object
* we allocate and fill in-core inodes upon lookup. They don't even
* go into icache. We cache the reference to task_struct upon lookup too.
* Eventually it should become a filesystem in its own. We don't use the
* rest of procfs anymore.
[PATCH] add /proc/pid/smaps Add a "smaps" entry to /proc/pid: show howmuch memory is resident in each mapping. People that want to perform a memory consumption analysing can use it mainly if someone needs to figure out which libraries can be reduced for embedded systems. So the new features are the physical size of shared and clean [or dirty]; private and clean [or dirty]. Take a look the example below: # cat /proc/4576/smaps 08048000-080dc000 r-xp /bin/bash Size: 592 KB Rss: 500 KB Shared_Clean: 500 KB Shared_Dirty: 0 KB Private_Clean: 0 KB Private_Dirty: 0 KB 080dc000-080e2000 rw-p /bin/bash Size: 24 KB Rss: 24 KB Shared_Clean: 0 KB Shared_Dirty: 0 KB Private_Clean: 0 KB Private_Dirty: 24 KB 080e2000-08116000 rw-p Size: 208 KB Rss: 208 KB Shared_Clean: 0 KB Shared_Dirty: 0 KB Private_Clean: 0 KB Private_Dirty: 208 KB b7e2b000-b7e34000 r-xp /lib/tls/libnss_files-2.3.2.so Size: 36 KB Rss: 12 KB Shared_Clean: 12 KB Shared_Dirty: 0 KB Private_Clean: 0 KB Private_Dirty: 0 KB ... (Includes a cleanup from "Richard Purdie" <rpurdie@rpsys.net>) From: Torsten Foertsch <torsten.foertsch@gmx.net> show_smap calls first show_map and then prints its additional information to the seq_file. show_map checks if all it has to print fits into the buffer and if yes marks the current vma as written. While that is correct for show_map it is not for show_smap. Here the vma should be marked as written only after the additional information is also written. The attached patch cures the problem. It moves the functionality of the show_map function to a new function show_map_internal that is called with an additional struct mem_size_stats* argument. Then show_map calls show_map_internal with NULL as struct mem_size_stats* whereas show_smap calls it with a real pointer. Now the final if (m->count < m->size) /* vma is copied successfully */ m->version = (vma != get_gate_vma(task))? vma->vm_start: 0; is done only if the whole entry fits into the buffer. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 22:55:10 +00:00
*
*
* Changelog:
* 17-Jan-2005
* Allan Bezerra
* Bruna Moreira <bruna.moreira@indt.org.br>
* Edjard Mota <edjard.mota@indt.org.br>
* Ilias Biris <ilias.biris@indt.org.br>
* Mauricio Lin <mauricio.lin@indt.org.br>
*
* Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
*
* A new process specific entry (smaps) included in /proc. It shows the
* size of rss for each memory area. The maps entry lacks information
* about physical memory size (rss) for each mapped file, i.e.,
* rss information for executables and library files.
* This additional information is useful for any tools that need to know
* about physical memory consumption for a process specific library.
*
* Changelog:
* 21-Feb-2005
* Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
* Pud inclusion in the page table walking.
*
* ChangeLog:
* 10-Mar-2005
* 10LE Instituto Nokia de Tecnologia - INdT:
* A better way to walks through the page table as suggested by Hugh Dickins.
*
* Simo Piiroinen <simo.piiroinen@nokia.com>:
* Smaps information related to shared, private, clean and dirty pages.
*
* Paul Mundt <paul.mundt@nokia.com>:
* Overall revision about smaps.
*/
#include <asm/uaccess.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/namei.h>
#include <linux/mnt_namespace.h>
#include <linux/mm.h>
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
#include <linux/swap.h>
#include <linux/rcupdate.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>
#include <linux/resource.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
#include <linux/cgroup.h>
#include <linux/cpuset.h>
#include <linux/audit.h>
#include <linux/poll.h>
#include <linux/nsproxy.h>
#include <linux/oom.h>
#include <linux/elf.h>
#include <linux/pid_namespace.h>
userns: Rework the user_namespace adding uid/gid mapping support - Convert the old uid mapping functions into compatibility wrappers - Add a uid/gid mapping layer from user space uid and gids to kernel internal uids and gids that is extent based for simplicty and speed. * Working with number space after mapping uids/gids into their kernel internal version adds only mapping complexity over what we have today, leaving the kernel code easy to understand and test. - Add proc files /proc/self/uid_map /proc/self/gid_map These files display the mapping and allow a mapping to be added if a mapping does not exist. - Allow entering the user namespace without a uid or gid mapping. Since we are starting with an existing user our uids and gids still have global mappings so are still valid and useful they just don't have local mappings. The requirement for things to work are global uid and gid so it is odd but perfectly fine not to have a local uid and gid mapping. Not requiring global uid and gid mappings greatly simplifies the logic of setting up the uid and gid mappings by allowing the mappings to be set after the namespace is created which makes the slight weirdness worth it. - Make the mappings in the initial user namespace to the global uid/gid space explicit. Today it is an identity mapping but in the future we may want to twist this for debugging, similar to what we do with jiffies. - Document the memory ordering requirements of setting the uid and gid mappings. We only allow the mappings to be set once and there are no pointers involved so the requirments are trivial but a little atypical. Performance: In this scheme for the permission checks the performance is expected to stay the same as the actuall machine instructions should remain the same. The worst case I could think of is ls -l on a large directory where all of the stat results need to be translated with from kuids and kgids to uids and gids. So I benchmarked that case on my laptop with a dual core hyperthread Intel i5-2520M cpu with 3M of cpu cache. My benchmark consisted of going to single user mode where nothing else was running. On an ext4 filesystem opening 1,000,000 files and looping through all of the files 1000 times and calling fstat on the individuals files. This was to ensure I was benchmarking stat times where the inodes were in the kernels cache, but the inode values were not in the processors cache. My results: v3.4-rc1: ~= 156ns (unmodified v3.4-rc1 with user namespace support disabled) v3.4-rc1-userns-: ~= 155ns (v3.4-rc1 with my user namespace patches and user namespace support disabled) v3.4-rc1-userns+: ~= 164ns (v3.4-rc1 with my user namespace patches and user namespace support enabled) All of the configurations ran in roughly 120ns when I performed tests that ran in the cpu cache. So in summary the performance impact is: 1ns improvement in the worst case with user namespace support compiled out. 8ns aka 5% slowdown in the worst case with user namespace support compiled in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-17 08:11:58 +00:00
#include <linux/user_namespace.h>
#include <linux/fs_struct.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
#include <linux/flex_array.h>
arch/tile: more /proc and /sys file support This change introduces a few of the less controversial /proc and /proc/sys interfaces for tile, along with sysfs attributes for various things that were originally proposed as /proc/tile files. It also adjusts the "hardwall" proc API. Arnd Bergmann reviewed the initial arch/tile submission, which included a complete set of all the /proc/tile and /proc/sys/tile knobs that we had added in a somewhat ad hoc way during initial development, and provided feedback on where most of them should go. One knob turned out to be similar enough to the existing /proc/sys/debug/exception-trace that it was re-implemented to use that model instead. Another knob was /proc/tile/grid, which reported the "grid" dimensions of a tile chip (e.g. 8x8 processors = 64-core chip). Arnd suggested looking at sysfs for that, so this change moves that information to a pair of sysfs attributes (chip_width and chip_height) in the /sys/devices/system/cpu directory. We also put the "chip_serial" and "chip_revision" information from our old /proc/tile/board file as attributes in /sys/devices/system/cpu. Other information collected via hypervisor APIs is now placed in /sys/hypervisor. We create a /sys/hypervisor/type file (holding the constant string "tilera") to be parallel with the Xen use of /sys/hypervisor/type holding "xen". We create three top-level files, "version" (the hypervisor's own version), "config_version" (the version of the configuration file), and "hvconfig" (the contents of the configuration file). The remaining information from our old /proc/tile/board and /proc/tile/switch files becomes an attribute group appearing under /sys/hypervisor/board/. Finally, after some feedback from Arnd Bergmann for the previous version of this patch, the /proc/tile/hardwall file is split up into two conceptual parts. First, a directory /proc/tile/hardwall/ which contains one file per active hardwall, each file named after the hardwall's ID and holding a cpulist that says which cpus are enclosed by the hardwall. Second, a /proc/PID file "hardwall" that is either empty (for non-hardwall-using processes) or contains the hardwall ID. Finally, this change pushes the /proc/sys/tile/unaligned_fixup/ directory, with knobs controlling the kernel code for handling the fixup of unaligned exceptions. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-26 16:40:09 +00:00
#ifdef CONFIG_HARDWALL
#include <asm/hardwall.h>
#endif
tracepoint: add tracepoints for debugging oom_score_adj oom_score_adj is used for guarding processes from OOM-Killer. One of problem is that it's inherited at fork(). When a daemon set oom_score_adj and make children, it's hard to know where the value is set. This patch adds some tracepoints useful for debugging. This patch adds 3 trace points. - creating new task - renaming a task (exec) - set oom_score_adj To debug, users need to enable some trace pointer. Maybe filtering is useful as # EVENT=/sys/kernel/debug/tracing/events/task/ # echo "oom_score_adj != 0" > $EVENT/task_newtask/filter # echo "oom_score_adj != 0" > $EVENT/task_rename/filter # echo 1 > $EVENT/enable # EVENT=/sys/kernel/debug/tracing/events/oom/ # echo 1 > $EVENT/enable output will be like this. # grep oom /sys/kernel/debug/tracing/trace bash-7699 [007] d..3 5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000 bash-7699 [007] ...1 5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000 ls-7729 [003] ...2 5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000 bash-7699 [002] ...1 5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000 grep-7730 [007] ...2 5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000 Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:08:09 +00:00
#include <trace/events/oom.h>
#include "internal.h"
#include "fd.h"
/* NOTE:
* Implementing inode permission operations in /proc is almost
* certainly an error. Permission checks need to happen during
* each system call not at open time. The reason is that most of
* what we wish to check for permissions in /proc varies at runtime.
*
* The classic example of a problem is opening file descriptors
* in /proc for a task before it execs a suid executable.
*/
struct pid_entry {
char *name;
int len;
umode_t mode;
const struct inode_operations *iop;
const struct file_operations *fop;
union proc_op op;
};
#define NOD(NAME, MODE, IOP, FOP, OP) { \
.name = (NAME), \
.len = sizeof(NAME) - 1, \
.mode = MODE, \
.iop = IOP, \
.fop = FOP, \
.op = OP, \
}
#define DIR(NAME, MODE, iops, fops) \
NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
#define LNK(NAME, get_link) \
NOD(NAME, (S_IFLNK|S_IRWXUGO), \
&proc_pid_link_inode_operations, NULL, \
{ .proc_get_link = get_link } )
#define REG(NAME, MODE, fops) \
NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
#define INF(NAME, MODE, read) \
NOD(NAME, (S_IFREG|(MODE)), \
NULL, &proc_info_file_operations, \
{ .proc_read = read } )
#define ONE(NAME, MODE, show) \
NOD(NAME, (S_IFREG|(MODE)), \
NULL, &proc_single_file_operations, \
{ .proc_show = show } )
/*
* Count the number of hardlinks for the pid_entry table, excluding the .
* and .. links.
*/
static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
unsigned int n)
{
unsigned int i;
unsigned int count;
count = 0;
for (i = 0; i < n; ++i) {
if (S_ISDIR(entries[i].mode))
++count;
}
return count;
}
static int get_task_root(struct task_struct *task, struct path *root)
{
int result = -ENOENT;
task_lock(task);
if (task->fs) {
get_fs_root(task->fs, root);
result = 0;
}
task_unlock(task);
return result;
}
static int proc_cwd_link(struct dentry *dentry, struct path *path)
{
struct task_struct *task = get_proc_task(dentry->d_inode);
int result = -ENOENT;
if (task) {
task_lock(task);
if (task->fs) {
get_fs_pwd(task->fs, path);
result = 0;
}
task_unlock(task);
put_task_struct(task);
}
return result;
}
static int proc_root_link(struct dentry *dentry, struct path *path)
{
struct task_struct *task = get_proc_task(dentry->d_inode);
int result = -ENOENT;
if (task) {
result = get_task_root(task, path);
put_task_struct(task);
}
return result;
}
static int proc_pid_cmdline(struct task_struct *task, char * buffer)
{
int res = 0;
unsigned int len;
struct mm_struct *mm = get_task_mm(task);
if (!mm)
goto out;
if (!mm->arg_end)
goto out_mm; /* Shh! No looking before we're done */
len = mm->arg_end - mm->arg_start;
if (len > PAGE_SIZE)
len = PAGE_SIZE;
res = access_process_vm(task, mm->arg_start, buffer, len, 0);
// If the nul at the end of args has been overwritten, then
// assume application is using setproctitle(3).
if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
len = strnlen(buffer, res);
if (len < res) {
res = len;
} else {
len = mm->env_end - mm->env_start;
if (len > PAGE_SIZE - res)
len = PAGE_SIZE - res;
res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
res = strnlen(buffer, res);
}
}
out_mm:
mmput(mm);
out:
return res;
}
static int proc_pid_auxv(struct task_struct *task, char *buffer)
{
struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ);
int res = PTR_ERR(mm);
if (mm && !IS_ERR(mm)) {
unsigned int nwords = 0;
do {
nwords += 2;
} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
res = nwords * sizeof(mm->saved_auxv[0]);
if (res > PAGE_SIZE)
res = PAGE_SIZE;
memcpy(buffer, mm->saved_auxv, res);
mmput(mm);
}
return res;
}
#ifdef CONFIG_KALLSYMS
/*
* Provides a wchan file via kallsyms in a proper one-value-per-file format.
* Returns the resolved symbol. If that fails, simply return the address.
*/
static int proc_pid_wchan(struct task_struct *task, char *buffer)
{
unsigned long wchan;
char symname[KSYM_NAME_LEN];
wchan = get_wchan(task);
if (lookup_symbol_name(wchan, symname) < 0)
if (!ptrace_may_access(task, PTRACE_MODE_READ))
return 0;
else
return sprintf(buffer, "%lu", wchan);
else
return sprintf(buffer, "%s", symname);
}
#endif /* CONFIG_KALLSYMS */
static int lock_trace(struct task_struct *task)
{
int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
if (err)
return err;
if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
mutex_unlock(&task->signal->cred_guard_mutex);
return -EPERM;
}
return 0;
}
static void unlock_trace(struct task_struct *task)
{
mutex_unlock(&task->signal->cred_guard_mutex);
}
#ifdef CONFIG_STACKTRACE
#define MAX_STACK_TRACE_DEPTH 64
static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
struct stack_trace trace;
unsigned long *entries;
int err;
int i;
entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
if (!entries)
return -ENOMEM;
trace.nr_entries = 0;
trace.max_entries = MAX_STACK_TRACE_DEPTH;
trace.entries = entries;
trace.skip = 0;
err = lock_trace(task);
if (!err) {
save_stack_trace_tsk(task, &trace);
for (i = 0; i < trace.nr_entries; i++) {
seq_printf(m, "[<%pK>] %pS\n",
(void *)entries[i], (void *)entries[i]);
}
unlock_trace(task);
}
kfree(entries);
return err;
}
#endif
#ifdef CONFIG_SCHEDSTATS
/*
* Provides /proc/PID/schedstat
*/
static int proc_pid_schedstat(struct task_struct *task, char *buffer)
{
return sprintf(buffer, "%llu %llu %lu\n",
(unsigned long long)task->se.sum_exec_runtime,
(unsigned long long)task->sched_info.run_delay,
task->sched_info.pcount);
}
#endif
#ifdef CONFIG_LATENCYTOP
static int lstats_show_proc(struct seq_file *m, void *v)
{
int i;
struct inode *inode = m->private;
struct task_struct *task = get_proc_task(inode);
if (!task)
return -ESRCH;
seq_puts(m, "Latency Top version : v0.1\n");
for (i = 0; i < 32; i++) {
struct latency_record *lr = &task->latency_record[i];
if (lr->backtrace[0]) {
int q;
seq_printf(m, "%i %li %li",
lr->count, lr->time, lr->max);
for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
unsigned long bt = lr->backtrace[q];
if (!bt)
break;
if (bt == ULONG_MAX)
break;
seq_printf(m, " %ps", (void *)bt);
}
seq_putc(m, '\n');
}
}
put_task_struct(task);
return 0;
}
static int lstats_open(struct inode *inode, struct file *file)
{
return single_open(file, lstats_show_proc, inode);
}
static ssize_t lstats_write(struct file *file, const char __user *buf,
size_t count, loff_t *offs)
{
struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
if (!task)
return -ESRCH;
clear_all_latency_tracing(task);
put_task_struct(task);
return count;
}
static const struct file_operations proc_lstats_operations = {
.open = lstats_open,
.read = seq_read,
.write = lstats_write,
.llseek = seq_lseek,
.release = single_release,
};
#endif
static int proc_oom_score(struct task_struct *task, char *buffer)
{
unsigned long totalpages = totalram_pages + total_swap_pages;
unsigned long points = 0;
read_lock(&tasklist_lock);
if (pid_alive(task))
points = oom_badness(task, NULL, NULL, totalpages) *
1000 / totalpages;
read_unlock(&tasklist_lock);
return sprintf(buffer, "%lu\n", points);
}
struct limit_names {
char *name;
char *unit;
};
static const struct limit_names lnames[RLIM_NLIMITS] = {
[RLIMIT_CPU] = {"Max cpu time", "seconds"},
[RLIMIT_FSIZE] = {"Max file size", "bytes"},
[RLIMIT_DATA] = {"Max data size", "bytes"},
[RLIMIT_STACK] = {"Max stack size", "bytes"},
[RLIMIT_CORE] = {"Max core file size", "bytes"},
[RLIMIT_RSS] = {"Max resident set", "bytes"},
[RLIMIT_NPROC] = {"Max processes", "processes"},
[RLIMIT_NOFILE] = {"Max open files", "files"},
[RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
[RLIMIT_AS] = {"Max address space", "bytes"},
[RLIMIT_LOCKS] = {"Max file locks", "locks"},
[RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
[RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
[RLIMIT_NICE] = {"Max nice priority", NULL},
[RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
[RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
};
/* Display limits for a process */
static int proc_pid_limits(struct task_struct *task, char *buffer)
{
unsigned int i;
int count = 0;
unsigned long flags;
char *bufptr = buffer;
struct rlimit rlim[RLIM_NLIMITS];
if (!lock_task_sighand(task, &flags))
return 0;
memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
unlock_task_sighand(task, &flags);
/*
* print the file header
*/
count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
"Limit", "Soft Limit", "Hard Limit", "Units");
for (i = 0; i < RLIM_NLIMITS; i++) {
if (rlim[i].rlim_cur == RLIM_INFINITY)
count += sprintf(&bufptr[count], "%-25s %-20s ",
lnames[i].name, "unlimited");
else
count += sprintf(&bufptr[count], "%-25s %-20lu ",
lnames[i].name, rlim[i].rlim_cur);
if (rlim[i].rlim_max == RLIM_INFINITY)
count += sprintf(&bufptr[count], "%-20s ", "unlimited");
else
count += sprintf(&bufptr[count], "%-20lu ",
rlim[i].rlim_max);
if (lnames[i].unit)
count += sprintf(&bufptr[count], "%-10s\n",
lnames[i].unit);
else
count += sprintf(&bufptr[count], "\n");
}
return count;
}
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
static int proc_pid_syscall(struct task_struct *task, char *buffer)
{
long nr;
unsigned long args[6], sp, pc;
int res = lock_trace(task);
if (res)
return res;
if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
res = sprintf(buffer, "running\n");
else if (nr < 0)
res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
else
res = sprintf(buffer,
"%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
nr,
args[0], args[1], args[2], args[3], args[4], args[5],
sp, pc);
unlock_trace(task);
return res;
}
#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
/************************************************************************/
/* Here the fs part begins */
/************************************************************************/
/* permission checks */
[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 07:25:58 +00:00
static int proc_fd_access_allowed(struct inode *inode)
{
[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 07:25:58 +00:00
struct task_struct *task;
int allowed = 0;
/* Allow access to a task's file descriptors if it is us or we
* may use ptrace attach to the process and find out that
* information.
[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 07:25:58 +00:00
*/
task = get_proc_task(inode);
if (task) {
Security: split proc ptrace checking into read vs. attach Enable security modules to distinguish reading of process state via proc from full ptrace access by renaming ptrace_may_attach to ptrace_may_access and adding a mode argument indicating whether only read access or full attach access is requested. This allows security modules to permit access to reading process state without granting full ptrace access. The base DAC/capability checking remains unchanged. Read access to /proc/pid/mem continues to apply a full ptrace attach check since check_mem_permission() already requires the current task to already be ptracing the target. The other ptrace checks within proc for elements like environ, maps, and fds are changed to pass the read mode instead of attach. In the SELinux case, we model such reading of process state as a reading of a proc file labeled with the target process' label. This enables SELinux policy to permit such reading of process state without permitting control or manipulation of the target process, as there are a number of cases where programs probe for such information via proc but do not need to be able to control the target (e.g. procps, lsof, PolicyKit, ConsoleKit). At present we have to choose between allowing full ptrace in policy (more permissive than required/desired) or breaking functionality (or in some cases just silencing the denials via dontaudit rules but this can hide genuine attacks). This version of the patch incorporates comments from Casey Schaufler (change/replace existing ptrace_may_attach interface, pass access mode), and Chris Wright (provide greater consistency in the checking). Note that like their predecessors __ptrace_may_attach and ptrace_may_attach, the __ptrace_may_access and ptrace_may_access interfaces use different return value conventions from each other (0 or -errno vs. 1 or 0). I retained this difference to avoid any changes to the caller logic but made the difference clearer by changing the latter interface to return a bool rather than an int and by adding a comment about it to ptrace.h for any future callers. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: James Morris <jmorris@namei.org>
2008-05-19 12:32:49 +00:00
allowed = ptrace_may_access(task, PTRACE_MODE_READ);
[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 07:25:58 +00:00
put_task_struct(task);
}
[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 07:25:58 +00:00
return allowed;
}
int proc_setattr(struct dentry *dentry, struct iattr *attr)
{
int error;
struct inode *inode = dentry->d_inode;
if (attr->ia_valid & ATTR_MODE)
return -EPERM;
error = inode_change_ok(inode, attr);
if (error)
return error;
if ((attr->ia_valid & ATTR_SIZE) &&
attr->ia_size != i_size_read(inode)) {
error = vmtruncate(inode, attr->ia_size);
if (error)
return error;
}
setattr_copy(inode, attr);
mark_inode_dirty(inode);
return 0;
}
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
/*
* May current process learn task's sched/cmdline info (for hide_pid_min=1)
* or euid/egid (for hide_pid_min=2)?
*/
static bool has_pid_permissions(struct pid_namespace *pid,
struct task_struct *task,
int hide_pid_min)
{
if (pid->hide_pid < hide_pid_min)
return true;
if (in_group_p(pid->pid_gid))
return true;
return ptrace_may_access(task, PTRACE_MODE_READ);
}
static int proc_pid_permission(struct inode *inode, int mask)
{
struct pid_namespace *pid = inode->i_sb->s_fs_info;
struct task_struct *task;
bool has_perms;
task = get_proc_task(inode);
if (!task)
return -ESRCH;
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
has_perms = has_pid_permissions(pid, task, 1);
put_task_struct(task);
if (!has_perms) {
if (pid->hide_pid == 2) {
/*
* Let's make getdents(), stat(), and open()
* consistent with each other. If a process
* may not stat() a file, it shouldn't be seen
* in procfs at all.
*/
return -ENOENT;
}
return -EPERM;
}
return generic_permission(inode, mask);
}
static const struct inode_operations proc_def_inode_operations = {
.setattr = proc_setattr,
};
#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
static ssize_t proc_info_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file->f_path.dentry->d_inode;
unsigned long page;
ssize_t length;
struct task_struct *task = get_proc_task(inode);
length = -ESRCH;
if (!task)
goto out_no_task;
if (count > PROC_BLOCK_SIZE)
count = PROC_BLOCK_SIZE;
length = -ENOMEM;
if (!(page = __get_free_page(GFP_TEMPORARY)))
goto out;
length = PROC_I(inode)->op.proc_read(task, (char*)page);
if (length >= 0)
length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
free_page(page);
out:
put_task_struct(task);
out_no_task:
return length;
}
static const struct file_operations proc_info_file_operations = {
.read = proc_info_read,
.llseek = generic_file_llseek,
};
static int proc_single_show(struct seq_file *m, void *v)
{
struct inode *inode = m->private;
struct pid_namespace *ns;
struct pid *pid;
struct task_struct *task;
int ret;
ns = inode->i_sb->s_fs_info;
pid = proc_pid(inode);
task = get_pid_task(pid, PIDTYPE_PID);
if (!task)
return -ESRCH;
ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
put_task_struct(task);
return ret;
}
static int proc_single_open(struct inode *inode, struct file *filp)
{
return single_open(filp, proc_single_show, inode);
}
static const struct file_operations proc_single_file_operations = {
.open = proc_single_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
{
struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
struct mm_struct *mm;
if (!task)
return -ESRCH;
mm = mm_access(task, mode);
put_task_struct(task);
if (IS_ERR(mm))
return PTR_ERR(mm);
if (mm) {
/* ensure this mm_struct can't be freed */
atomic_inc(&mm->mm_count);
/* but do not pin its memory */
mmput(mm);
}
file->private_data = mm;
return 0;
}
static int mem_open(struct inode *inode, struct file *file)
{
int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
/* OK to pass negative loff_t, we can catch out-of-range */
file->f_mode |= FMODE_UNSIGNED_OFFSET;
return ret;
}
static ssize_t mem_rw(struct file *file, char __user *buf,
size_t count, loff_t *ppos, int write)
{
struct mm_struct *mm = file->private_data;
unsigned long addr = *ppos;
ssize_t copied;
char *page;
if (!mm)
return 0;
page = (char *)__get_free_page(GFP_TEMPORARY);
if (!page)
return -ENOMEM;
copied = 0;
if (!atomic_inc_not_zero(&mm->mm_users))
goto free;
while (count > 0) {
int this_len = min_t(int, count, PAGE_SIZE);
if (write && copy_from_user(page, buf, this_len)) {
copied = -EFAULT;
break;
}
this_len = access_remote_vm(mm, addr, page, this_len, write);
if (!this_len) {
if (!copied)
copied = -EIO;
break;
}
if (!write && copy_to_user(buf, page, this_len)) {
copied = -EFAULT;
break;
}
buf += this_len;
addr += this_len;
copied += this_len;
count -= this_len;
}
*ppos = addr;
mmput(mm);
free:
free_page((unsigned long) page);
return copied;
}
static ssize_t mem_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
return mem_rw(file, buf, count, ppos, 0);
}
static ssize_t mem_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return mem_rw(file, (char __user*)buf, count, ppos, 1);
}
loff_t mem_lseek(struct file *file, loff_t offset, int orig)
{
switch (orig) {
case 0:
file->f_pos = offset;
break;
case 1:
file->f_pos += offset;
break;
default:
return -EINVAL;
}
force_successful_syscall_return();
return file->f_pos;
}
static int mem_release(struct inode *inode, struct file *file)
{
struct mm_struct *mm = file->private_data;
if (mm)
mmdrop(mm);
return 0;
}
static const struct file_operations proc_mem_operations = {
.llseek = mem_lseek,
.read = mem_read,
.write = mem_write,
.open = mem_open,
.release = mem_release,
};
static int environ_open(struct inode *inode, struct file *file)
{
return __mem_open(inode, file, PTRACE_MODE_READ);
}
static ssize_t environ_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
char *page;
unsigned long src = *ppos;
int ret = 0;
struct mm_struct *mm = file->private_data;
if (!mm)
return 0;
page = (char *)__get_free_page(GFP_TEMPORARY);
if (!page)
return -ENOMEM;
ret = 0;
if (!atomic_inc_not_zero(&mm->mm_users))
goto free;
while (count > 0) {
proc: environ_read() make sure offset points to environment address range Currently the following offset and environment address range check in environ_read() of /proc/<pid>/environ is buggy: int this_len = mm->env_end - (mm->env_start + src); if (this_len <= 0) break; Large or negative offsets on /proc/<pid>/environ converted to 'unsigned long' may pass this check since '(mm->env_start + src)' can overflow and 'this_len' will be positive. This can turn /proc/<pid>/environ to act like /proc/<pid>/mem since (mm->env_start + src) will point and read from another VMA. There are two fixes here plus some code cleaning: 1) Fix the overflow by checking if the offset that was converted to unsigned long will always point to the [mm->env_start, mm->env_end] address range. 2) Remove the truncation that was made to the result of the check, storing the result in 'int this_len' will alter its value and we can not depend on it. For kernels that have commit b409e578d ("proc: clean up /proc/<pid>/environ handling") which adds the appropriate ptrace check and saves the 'mm' at ->open() time, this is not a security issue. This patch is taken from the grsecurity patch since it was just made available. Signed-off-by: Djalal Harouni <tixxdz@opendz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Brad Spengler <spender@grsecurity.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 21:42:26 +00:00
size_t this_len, max_len;
int retval;
proc: environ_read() make sure offset points to environment address range Currently the following offset and environment address range check in environ_read() of /proc/<pid>/environ is buggy: int this_len = mm->env_end - (mm->env_start + src); if (this_len <= 0) break; Large or negative offsets on /proc/<pid>/environ converted to 'unsigned long' may pass this check since '(mm->env_start + src)' can overflow and 'this_len' will be positive. This can turn /proc/<pid>/environ to act like /proc/<pid>/mem since (mm->env_start + src) will point and read from another VMA. There are two fixes here plus some code cleaning: 1) Fix the overflow by checking if the offset that was converted to unsigned long will always point to the [mm->env_start, mm->env_end] address range. 2) Remove the truncation that was made to the result of the check, storing the result in 'int this_len' will alter its value and we can not depend on it. For kernels that have commit b409e578d ("proc: clean up /proc/<pid>/environ handling") which adds the appropriate ptrace check and saves the 'mm' at ->open() time, this is not a security issue. This patch is taken from the grsecurity patch since it was just made available. Signed-off-by: Djalal Harouni <tixxdz@opendz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Brad Spengler <spender@grsecurity.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 21:42:26 +00:00
if (src >= (mm->env_end - mm->env_start))
break;
proc: environ_read() make sure offset points to environment address range Currently the following offset and environment address range check in environ_read() of /proc/<pid>/environ is buggy: int this_len = mm->env_end - (mm->env_start + src); if (this_len <= 0) break; Large or negative offsets on /proc/<pid>/environ converted to 'unsigned long' may pass this check since '(mm->env_start + src)' can overflow and 'this_len' will be positive. This can turn /proc/<pid>/environ to act like /proc/<pid>/mem since (mm->env_start + src) will point and read from another VMA. There are two fixes here plus some code cleaning: 1) Fix the overflow by checking if the offset that was converted to unsigned long will always point to the [mm->env_start, mm->env_end] address range. 2) Remove the truncation that was made to the result of the check, storing the result in 'int this_len' will alter its value and we can not depend on it. For kernels that have commit b409e578d ("proc: clean up /proc/<pid>/environ handling") which adds the appropriate ptrace check and saves the 'mm' at ->open() time, this is not a security issue. This patch is taken from the grsecurity patch since it was just made available. Signed-off-by: Djalal Harouni <tixxdz@opendz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Brad Spengler <spender@grsecurity.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 21:42:26 +00:00
this_len = mm->env_end - (mm->env_start + src);
max_len = min_t(size_t, PAGE_SIZE, count);
this_len = min(max_len, this_len);
retval = access_remote_vm(mm, (mm->env_start + src),
page, this_len, 0);
if (retval <= 0) {
ret = retval;
break;
}
if (copy_to_user(buf, page, retval)) {
ret = -EFAULT;
break;
}
ret += retval;
src += retval;
buf += retval;
count -= retval;
}
*ppos = src;
mmput(mm);
free:
free_page((unsigned long) page);
return ret;
}
static const struct file_operations proc_environ_operations = {
.open = environ_open,
.read = environ_read,
.llseek = generic_file_llseek,
.release = mem_release,
};
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
char buffer[PROC_NUMBUF];
int oom_score_adj = OOM_SCORE_ADJ_MIN;
unsigned long flags;
size_t len;
if (!task)
return -ESRCH;
if (lock_task_sighand(task, &flags)) {
oom_score_adj = task->signal->oom_score_adj;
unlock_task_sighand(task, &flags);
}
put_task_struct(task);
len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
return simple_read_from_buffer(buf, count, ppos, buffer, len);
}
static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct task_struct *task;
char buffer[PROC_NUMBUF];
unsigned long flags;
int oom_score_adj;
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
int err;
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count)) {
err = -EFAULT;
goto out;
}
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
if (err)
goto out;
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
oom_score_adj > OOM_SCORE_ADJ_MAX) {
err = -EINVAL;
goto out;
}
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
task = get_proc_task(file->f_path.dentry->d_inode);
if (!task) {
err = -ESRCH;
goto out;
}
task_lock(task);
if (!task->mm) {
err = -EINVAL;
goto err_task_lock;
}
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
if (!lock_task_sighand(task, &flags)) {
err = -ESRCH;
goto err_task_lock;
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
}
if (oom_score_adj < task->signal->oom_score_adj_min &&
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
!capable(CAP_SYS_RESOURCE)) {
err = -EACCES;
goto err_sighand;
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
}
task->signal->oom_score_adj = oom_score_adj;
if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
task->signal->oom_score_adj_min = oom_score_adj;
tracepoint: add tracepoints for debugging oom_score_adj oom_score_adj is used for guarding processes from OOM-Killer. One of problem is that it's inherited at fork(). When a daemon set oom_score_adj and make children, it's hard to know where the value is set. This patch adds some tracepoints useful for debugging. This patch adds 3 trace points. - creating new task - renaming a task (exec) - set oom_score_adj To debug, users need to enable some trace pointer. Maybe filtering is useful as # EVENT=/sys/kernel/debug/tracing/events/task/ # echo "oom_score_adj != 0" > $EVENT/task_newtask/filter # echo "oom_score_adj != 0" > $EVENT/task_rename/filter # echo 1 > $EVENT/enable # EVENT=/sys/kernel/debug/tracing/events/oom/ # echo 1 > $EVENT/enable output will be like this. # grep oom /sys/kernel/debug/tracing/trace bash-7699 [007] d..3 5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000 bash-7699 [007] ...1 5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000 ls-7729 [003] ...2 5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000 bash-7699 [002] ...1 5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000 grep-7730 [007] ...2 5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000 Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:08:09 +00:00
trace_oom_score_adj_update(task);
err_sighand:
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
unlock_task_sighand(task, &flags);
err_task_lock:
task_unlock(task);
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
put_task_struct(task);
out:
return err < 0 ? err : count;
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
}
static const struct file_operations proc_oom_score_adj_operations = {
.read = oom_score_adj_read,
.write = oom_score_adj_write,
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-15 16:52:59 +00:00
.llseek = default_llseek,
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
};
#ifdef CONFIG_AUDITSYSCALL
#define TMPBUFLEN 21
static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file->f_path.dentry->d_inode;
struct task_struct *task = get_proc_task(inode);
ssize_t length;
char tmpbuf[TMPBUFLEN];
if (!task)
return -ESRCH;
length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
from_kuid(file->f_cred->user_ns,
audit_get_loginuid(task)));
put_task_struct(task);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file->f_path.dentry->d_inode;
char *page, *tmp;
ssize_t length;
uid_t loginuid;
kuid_t kloginuid;
rcu_read_lock();
if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
rcu_read_unlock();
return -EPERM;
}
rcu_read_unlock();
if (count >= PAGE_SIZE)
count = PAGE_SIZE - 1;
if (*ppos != 0) {
/* No partial writes. */
return -EINVAL;
}
page = (char*)__get_free_page(GFP_TEMPORARY);
if (!page)
return -ENOMEM;
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out_free_page;
page[count] = '\0';
loginuid = simple_strtoul(page, &tmp, 10);
if (tmp == page) {
length = -EINVAL;
goto out_free_page;
}
kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
if (!uid_valid(kloginuid)) {
length = -EINVAL;
goto out_free_page;
}
length = audit_set_loginuid(kloginuid);
if (likely(length == 0))
length = count;
out_free_page:
free_page((unsigned long) page);
return length;
}
static const struct file_operations proc_loginuid_operations = {
.read = proc_loginuid_read,
.write = proc_loginuid_write,
.llseek = generic_file_llseek,
};
static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file->f_path.dentry->d_inode;
struct task_struct *task = get_proc_task(inode);
ssize_t length;
char tmpbuf[TMPBUFLEN];
if (!task)
return -ESRCH;
length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
audit_get_sessionid(task));
put_task_struct(task);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static const struct file_operations proc_sessionid_operations = {
.read = proc_sessionid_read,
.llseek = generic_file_llseek,
};
#endif
#ifdef CONFIG_FAULT_INJECTION
static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
char buffer[PROC_NUMBUF];
size_t len;
int make_it_fail;
if (!task)
return -ESRCH;
make_it_fail = task->make_it_fail;
put_task_struct(task);
len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
return simple_read_from_buffer(buf, count, ppos, buffer, len);
}
static ssize_t proc_fault_inject_write(struct file * file,
const char __user * buf, size_t count, loff_t *ppos)
{
struct task_struct *task;
char buffer[PROC_NUMBUF], *end;
int make_it_fail;
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count))
return -EFAULT;
make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
if (*end)
return -EINVAL;
task = get_proc_task(file->f_dentry->d_inode);
if (!task)
return -ESRCH;
task->make_it_fail = make_it_fail;
put_task_struct(task);
return count;
}
static const struct file_operations proc_fault_inject_operations = {
.read = proc_fault_inject_read,
.write = proc_fault_inject_write,
.llseek = generic_file_llseek,
};
#endif
#ifdef CONFIG_SCHED_DEBUG
/*
* Print out various scheduling related per-task fields:
*/
static int sched_show(struct seq_file *m, void *v)
{
struct inode *inode = m->private;
struct task_struct *p;
p = get_proc_task(inode);
if (!p)
return -ESRCH;
proc_sched_show_task(p, m);
put_task_struct(p);
return 0;
}
static ssize_t
sched_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct task_struct *p;
p = get_proc_task(inode);
if (!p)
return -ESRCH;
proc_sched_set_task(p);
put_task_struct(p);
return count;
}
static int sched_open(struct inode *inode, struct file *filp)
{
return single_open(filp, sched_show, inode);
}
static const struct file_operations proc_pid_sched_operations = {
.open = sched_open,
.read = seq_read,
.write = sched_write,
.llseek = seq_lseek,
.release = single_release,
};
#endif
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
#ifdef CONFIG_SCHED_AUTOGROUP
/*
* Print out autogroup related information:
*/
static int sched_autogroup_show(struct seq_file *m, void *v)
{
struct inode *inode = m->private;
struct task_struct *p;
p = get_proc_task(inode);
if (!p)
return -ESRCH;
proc_sched_autogroup_show_task(p, m);
put_task_struct(p);
return 0;
}
static ssize_t
sched_autogroup_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct task_struct *p;
char buffer[PROC_NUMBUF];
int nice;
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
int err;
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count))
return -EFAULT;
err = kstrtoint(strstrip(buffer), 0, &nice);
if (err < 0)
return err;
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
p = get_proc_task(inode);
if (!p)
return -ESRCH;
err = proc_sched_autogroup_set_nice(p, nice);
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
if (err)
count = err;
put_task_struct(p);
return count;
}
static int sched_autogroup_open(struct inode *inode, struct file *filp)
{
int ret;
ret = single_open(filp, sched_autogroup_show, NULL);
if (!ret) {
struct seq_file *m = filp->private_data;
m->private = inode;
}
return ret;
}
static const struct file_operations proc_pid_sched_autogroup_operations = {
.open = sched_autogroup_open,
.read = seq_read,
.write = sched_autogroup_write,
.llseek = seq_lseek,
.release = single_release,
};
#endif /* CONFIG_SCHED_AUTOGROUP */
static ssize_t comm_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct task_struct *p;
char buffer[TASK_COMM_LEN];
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count))
return -EFAULT;
p = get_proc_task(inode);
if (!p)
return -ESRCH;
if (same_thread_group(current, p))
set_task_comm(p, buffer);
else
count = -EINVAL;
put_task_struct(p);
return count;
}
static int comm_show(struct seq_file *m, void *v)
{
struct inode *inode = m->private;
struct task_struct *p;
p = get_proc_task(inode);
if (!p)
return -ESRCH;
task_lock(p);
seq_printf(m, "%s\n", p->comm);
task_unlock(p);
put_task_struct(p);
return 0;
}
static int comm_open(struct inode *inode, struct file *filp)
{
return single_open(filp, comm_show, inode);
}
static const struct file_operations proc_pid_set_comm_operations = {
.open = comm_open,
.read = seq_read,
.write = comm_write,
.llseek = seq_lseek,
.release = single_release,
};
static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
{
struct task_struct *task;
struct mm_struct *mm;
struct file *exe_file;
task = get_proc_task(dentry->d_inode);
if (!task)
return -ENOENT;
mm = get_task_mm(task);
put_task_struct(task);
if (!mm)
return -ENOENT;
exe_file = get_mm_exe_file(mm);
mmput(mm);
if (exe_file) {
*exe_path = exe_file->f_path;
path_get(&exe_file->f_path);
fput(exe_file);
return 0;
} else
return -ENOENT;
}
static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
struct path path;
int error = -EACCES;
[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 07:25:58 +00:00
/* Are we allowed to snoop on the tasks file descriptors? */
if (!proc_fd_access_allowed(inode))
goto out;
error = PROC_I(inode)->op.proc_get_link(dentry, &path);
if (error)
goto out;
nd_jump_link(nd, &path);
return NULL;
out:
return ERR_PTR(error);
}
static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
{
char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
char *pathname;
int len;
if (!tmp)
return -ENOMEM;
pathname = d_path(path, tmp, PAGE_SIZE);
len = PTR_ERR(pathname);
if (IS_ERR(pathname))
goto out;
len = tmp + PAGE_SIZE - 1 - pathname;
if (len > buflen)
len = buflen;
if (copy_to_user(buffer, pathname, len))
len = -EFAULT;
out:
free_page((unsigned long)tmp);
return len;
}
static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
{
int error = -EACCES;
struct inode *inode = dentry->d_inode;
struct path path;
[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 07:25:58 +00:00
/* Are we allowed to snoop on the tasks file descriptors? */
if (!proc_fd_access_allowed(inode))
goto out;
error = PROC_I(inode)->op.proc_get_link(dentry, &path);
if (error)
goto out;
error = do_proc_readlink(&path, buffer, buflen);
path_put(&path);
out:
return error;
}
const struct inode_operations proc_pid_link_inode_operations = {
.readlink = proc_pid_readlink,
.follow_link = proc_pid_follow_link,
.setattr = proc_setattr,
};
/* building an inode */
struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
{
struct inode * inode;
struct proc_inode *ei;
const struct cred *cred;
/* We need a new inode */
inode = new_inode(sb);
if (!inode)
goto out;
/* Common stuff */
ei = PROC_I(inode);
inode->i_ino = get_next_ino();
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_op = &proc_def_inode_operations;
/*
* grab the reference to task.
*/
ei->pid = get_task_pid(task, PIDTYPE_PID);
if (!ei->pid)
goto out_unlock;
if (task_dumpable(task)) {
rcu_read_lock();
cred = __task_cred(task);
inode->i_uid = cred->euid;
inode->i_gid = cred->egid;
rcu_read_unlock();
}
security_task_to_inode(task, inode);
out:
return inode;
out_unlock:
iput(inode);
return NULL;
}
int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
struct task_struct *task;
const struct cred *cred;
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
struct pid_namespace *pid = dentry->d_sb->s_fs_info;
generic_fillattr(inode, stat);
rcu_read_lock();
stat->uid = GLOBAL_ROOT_UID;
stat->gid = GLOBAL_ROOT_GID;
task = pid_task(proc_pid(inode), PIDTYPE_PID);
if (task) {
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
if (!has_pid_permissions(pid, task, 2)) {
rcu_read_unlock();
/*
* This doesn't prevent learning whether PID exists,
* it only makes getattr() consistent with readdir().
*/
return -ENOENT;
}
if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
task_dumpable(task)) {
cred = __task_cred(task);
stat->uid = cred->euid;
stat->gid = cred->egid;
}
}
rcu_read_unlock();
[PATCH] setuid core dump Add a new `suid_dumpable' sysctl: This value can be used to query and set the core dump mode for setuid or otherwise protected/tainted binaries. The modes are 0 - (default) - traditional behaviour. Any process which has changed privilege levels or is execute only will not be dumped 1 - (debug) - all processes dump core when possible. The core dump is owned by the current user and no security is applied. This is intended for system debugging situations only. Ptrace is unchecked. 2 - (suidsafe) - any binary which normally would not be dumped is dumped readable by root only. This allows the end user to remove such a dump but not access it directly. For security reasons core dumps in this mode will not overwrite one another or other files. This mode is appropriate when adminstrators are attempting to debug problems in a normal environment. (akpm: > > +EXPORT_SYMBOL(suid_dumpable); > > EXPORT_SYMBOL_GPL? No problem to me. > > if (current->euid == current->uid && current->egid == current->gid) > > current->mm->dumpable = 1; > > Should this be SUID_DUMP_USER? Actually the feedback I had from last time was that the SUID_ defines should go because its clearer to follow the numbers. They can go everywhere (and there are lots of places where dumpable is tested/used as a bool in untouched code) > Maybe this should be renamed to `dump_policy' or something. Doing that > would help us catch any code which isn't using the #defines, too. Fair comment. The patch was designed to be easy to maintain for Red Hat rather than for merging. Changing that field would create a gigantic diff because it is used all over the place. ) Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 07:09:43 +00:00
return 0;
}
/* dentry stuff */
/*
* Exceptional case: normally we are not allowed to unhash a busy
* directory. In this case, however, we can do it - no aliasing problems
* due to the way we treat inodes.
*
* Rewrite the inode's ownerships here because the owning task may have
* performed a setuid(), etc.
*
* Before the /proc/pid/status file was created the only way to read
* the effective uid of a /process was to stat /proc/pid. Reading
* /proc/pid/status is slow enough that procps and other packages
* kept stating /proc/pid. To keep the rules in /proc simple I have
* made this apply to all per process world readable and executable
* directories.
*/
int pid_revalidate(struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct task_struct *task;
const struct cred *cred;
if (flags & LOOKUP_RCU)
return -ECHILD;
inode = dentry->d_inode;
task = get_proc_task(inode);
if (task) {
if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
task_dumpable(task)) {
rcu_read_lock();
cred = __task_cred(task);
inode->i_uid = cred->euid;
inode->i_gid = cred->egid;
rcu_read_unlock();
} else {
inode->i_uid = GLOBAL_ROOT_UID;
inode->i_gid = GLOBAL_ROOT_GID;
}
inode->i_mode &= ~(S_ISUID | S_ISGID);
security_task_to_inode(task, inode);
put_task_struct(task);
return 1;
}
d_drop(dentry);
return 0;
}
const struct dentry_operations pid_dentry_operations =
{
.d_revalidate = pid_revalidate,
.d_delete = pid_delete_dentry,
};
/* Lookups */
/*
* Fill a directory entry.
*
* If possible create the dcache entry and derive our inode number and
* file type from dcache entry.
*
* Since all of the proc inode numbers are dynamically generated, the inode
* numbers do not exist until the inode is cache. This means creating the
* the dcache entry in readdir is necessary to keep the inode numbers
* reported by readdir in sync with the inode numbers reported
* by stat.
*/
int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
const char *name, int len,
instantiate_t instantiate, struct task_struct *task, const void *ptr)
{
struct dentry *child, *dir = filp->f_path.dentry;
struct inode *inode;
struct qstr qname;
ino_t ino = 0;
unsigned type = DT_UNKNOWN;
qname.name = name;
qname.len = len;
qname.hash = full_name_hash(name, len);
child = d_lookup(dir, &qname);
if (!child) {
struct dentry *new;
new = d_alloc(dir, &qname);
if (new) {
child = instantiate(dir->d_inode, new, task, ptr);
if (child)
dput(new);
else
child = new;
}
}
if (!child || IS_ERR(child) || !child->d_inode)
goto end_instantiate;
inode = child->d_inode;
if (inode) {
ino = inode->i_ino;
type = inode->i_mode >> 12;
}
dput(child);
end_instantiate:
if (!ino)
ino = find_inode_number(dir, &qname);
if (!ino)
ino = 1;
return filldir(dirent, name, len, filp->f_pos, ino, type);
}
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
#ifdef CONFIG_CHECKPOINT_RESTORE
/*
* dname_to_vma_addr - maps a dentry name into two unsigned longs
* which represent vma start and end addresses.
*/
static int dname_to_vma_addr(struct dentry *dentry,
unsigned long *start, unsigned long *end)
{
if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
return -EINVAL;
return 0;
}
static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
{
unsigned long vm_start, vm_end;
bool exact_vma_exists = false;
struct mm_struct *mm = NULL;
struct task_struct *task;
const struct cred *cred;
struct inode *inode;
int status = 0;
if (flags & LOOKUP_RCU)
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
return -ECHILD;
if (!capable(CAP_SYS_ADMIN)) {
status = -EACCES;
goto out_notask;
}
inode = dentry->d_inode;
task = get_proc_task(inode);
if (!task)
goto out_notask;
mm = mm_access(task, PTRACE_MODE_READ);
if (IS_ERR_OR_NULL(mm))
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
goto out;
if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
down_read(&mm->mmap_sem);
exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
up_read(&mm->mmap_sem);
}
mmput(mm);
if (exact_vma_exists) {
if (task_dumpable(task)) {
rcu_read_lock();
cred = __task_cred(task);
inode->i_uid = cred->euid;
inode->i_gid = cred->egid;
rcu_read_unlock();
} else {
inode->i_uid = GLOBAL_ROOT_UID;
inode->i_gid = GLOBAL_ROOT_GID;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
}
security_task_to_inode(task, inode);
status = 1;
}
out:
put_task_struct(task);
out_notask:
if (status <= 0)
d_drop(dentry);
return status;
}
static const struct dentry_operations tid_map_files_dentry_operations = {
.d_revalidate = map_files_d_revalidate,
.d_delete = pid_delete_dentry,
};
static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
{
unsigned long vm_start, vm_end;
struct vm_area_struct *vma;
struct task_struct *task;
struct mm_struct *mm;
int rc;
rc = -ENOENT;
task = get_proc_task(dentry->d_inode);
if (!task)
goto out;
mm = get_task_mm(task);
put_task_struct(task);
if (!mm)
goto out;
rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
if (rc)
goto out_mmput;
down_read(&mm->mmap_sem);
vma = find_exact_vma(mm, vm_start, vm_end);
if (vma && vma->vm_file) {
*path = vma->vm_file->f_path;
path_get(path);
rc = 0;
}
up_read(&mm->mmap_sem);
out_mmput:
mmput(mm);
out:
return rc;
}
struct map_files_info {
fmode_t mode;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
unsigned long len;
unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
};
static struct dentry *
proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
fmode_t mode = (fmode_t)(unsigned long)ptr;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
struct proc_inode *ei;
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)
return ERR_PTR(-ENOENT);
ei = PROC_I(inode);
ei->op.proc_get_link = proc_map_files_get_link;
inode->i_op = &proc_pid_link_inode_operations;
inode->i_size = 64;
inode->i_mode = S_IFLNK;
if (mode & FMODE_READ)
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
inode->i_mode |= S_IRUSR;
if (mode & FMODE_WRITE)
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
inode->i_mode |= S_IWUSR;
d_set_d_op(dentry, &tid_map_files_dentry_operations);
d_add(dentry, inode);
return NULL;
}
static struct dentry *proc_map_files_lookup(struct inode *dir,
struct dentry *dentry, unsigned int flags)
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
{
unsigned long vm_start, vm_end;
struct vm_area_struct *vma;
struct task_struct *task;
struct dentry *result;
struct mm_struct *mm;
result = ERR_PTR(-EACCES);
if (!capable(CAP_SYS_ADMIN))
goto out;
result = ERR_PTR(-ENOENT);
task = get_proc_task(dir);
if (!task)
goto out;
result = ERR_PTR(-EACCES);
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries map_files/ entries are never supposed to be executed, still curious minds might try to run them, which leads to the following deadlock ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc4-24406-g841e6a6 #121 Not tainted ------------------------------------------------------- bash/1556 is trying to acquire lock: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: do_lookup+0x267/0x2b1 but task is already holding lock: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds+0x2d/0x69 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sig->cred_guard_mutex){+.+.+.}: validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_killable_nested+0x40/0x45 lock_trace+0x24/0x59 proc_map_files_lookup+0x5a/0x165 __lookup_hash+0x52/0x73 do_lookup+0x276/0x2b1 walk_component+0x3d/0x114 do_last+0xfc/0x540 path_openat+0xd3/0x306 do_filp_open+0x3d/0x89 do_sys_open+0x74/0x106 sys_open+0x21/0x23 tracesys+0xdd/0xe2 -> #0 (&sb->s_type->i_mutex_key#8){+.+.+.}: check_prev_add+0x6a/0x1ef validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_nested+0x40/0x45 do_lookup+0x267/0x2b1 walk_component+0x3d/0x114 link_path_walk+0x1f9/0x48f path_openat+0xb6/0x306 do_filp_open+0x3d/0x89 open_exec+0x25/0xa0 do_execve_common+0xea/0x2f9 do_execve+0x43/0x45 sys_execve+0x43/0x5a stub_execve+0x6c/0xc0 This is because prepare_bprm_creds grabs task->signal->cred_guard_mutex and when do_lookup happens we try to grab task->signal->cred_guard_mutex again in lock_trace. Fix it using plain ptrace_may_access() helper in proc_map_files_lookup() and in proc_map_files_readdir() instead of lock_trace(), the caller must be CAP_SYS_ADMIN granted anyway. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Jones <davej@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-18 00:03:25 +00:00
if (!ptrace_may_access(task, PTRACE_MODE_READ))
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
goto out_put_task;
result = ERR_PTR(-ENOENT);
if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries map_files/ entries are never supposed to be executed, still curious minds might try to run them, which leads to the following deadlock ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc4-24406-g841e6a6 #121 Not tainted ------------------------------------------------------- bash/1556 is trying to acquire lock: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: do_lookup+0x267/0x2b1 but task is already holding lock: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds+0x2d/0x69 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sig->cred_guard_mutex){+.+.+.}: validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_killable_nested+0x40/0x45 lock_trace+0x24/0x59 proc_map_files_lookup+0x5a/0x165 __lookup_hash+0x52/0x73 do_lookup+0x276/0x2b1 walk_component+0x3d/0x114 do_last+0xfc/0x540 path_openat+0xd3/0x306 do_filp_open+0x3d/0x89 do_sys_open+0x74/0x106 sys_open+0x21/0x23 tracesys+0xdd/0xe2 -> #0 (&sb->s_type->i_mutex_key#8){+.+.+.}: check_prev_add+0x6a/0x1ef validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_nested+0x40/0x45 do_lookup+0x267/0x2b1 walk_component+0x3d/0x114 link_path_walk+0x1f9/0x48f path_openat+0xb6/0x306 do_filp_open+0x3d/0x89 open_exec+0x25/0xa0 do_execve_common+0xea/0x2f9 do_execve+0x43/0x45 sys_execve+0x43/0x5a stub_execve+0x6c/0xc0 This is because prepare_bprm_creds grabs task->signal->cred_guard_mutex and when do_lookup happens we try to grab task->signal->cred_guard_mutex again in lock_trace. Fix it using plain ptrace_may_access() helper in proc_map_files_lookup() and in proc_map_files_readdir() instead of lock_trace(), the caller must be CAP_SYS_ADMIN granted anyway. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Jones <davej@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-18 00:03:25 +00:00
goto out_put_task;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
mm = get_task_mm(task);
if (!mm)
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries map_files/ entries are never supposed to be executed, still curious minds might try to run them, which leads to the following deadlock ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc4-24406-g841e6a6 #121 Not tainted ------------------------------------------------------- bash/1556 is trying to acquire lock: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: do_lookup+0x267/0x2b1 but task is already holding lock: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds+0x2d/0x69 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sig->cred_guard_mutex){+.+.+.}: validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_killable_nested+0x40/0x45 lock_trace+0x24/0x59 proc_map_files_lookup+0x5a/0x165 __lookup_hash+0x52/0x73 do_lookup+0x276/0x2b1 walk_component+0x3d/0x114 do_last+0xfc/0x540 path_openat+0xd3/0x306 do_filp_open+0x3d/0x89 do_sys_open+0x74/0x106 sys_open+0x21/0x23 tracesys+0xdd/0xe2 -> #0 (&sb->s_type->i_mutex_key#8){+.+.+.}: check_prev_add+0x6a/0x1ef validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_nested+0x40/0x45 do_lookup+0x267/0x2b1 walk_component+0x3d/0x114 link_path_walk+0x1f9/0x48f path_openat+0xb6/0x306 do_filp_open+0x3d/0x89 open_exec+0x25/0xa0 do_execve_common+0xea/0x2f9 do_execve+0x43/0x45 sys_execve+0x43/0x5a stub_execve+0x6c/0xc0 This is because prepare_bprm_creds grabs task->signal->cred_guard_mutex and when do_lookup happens we try to grab task->signal->cred_guard_mutex again in lock_trace. Fix it using plain ptrace_may_access() helper in proc_map_files_lookup() and in proc_map_files_readdir() instead of lock_trace(), the caller must be CAP_SYS_ADMIN granted anyway. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Jones <davej@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-18 00:03:25 +00:00
goto out_put_task;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
down_read(&mm->mmap_sem);
vma = find_exact_vma(mm, vm_start, vm_end);
if (!vma)
goto out_no_vma;
result = proc_map_files_instantiate(dir, dentry, task,
(void *)(unsigned long)vma->vm_file->f_mode);
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
out_no_vma:
up_read(&mm->mmap_sem);
mmput(mm);
out_put_task:
put_task_struct(task);
out:
return result;
}
static const struct inode_operations proc_map_files_inode_operations = {
.lookup = proc_map_files_lookup,
.permission = proc_fd_permission,
.setattr = proc_setattr,
};
static int
proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
struct vm_area_struct *vma;
struct task_struct *task;
struct mm_struct *mm;
ino_t ino;
int ret;
ret = -EACCES;
if (!capable(CAP_SYS_ADMIN))
goto out;
ret = -ENOENT;
task = get_proc_task(inode);
if (!task)
goto out;
ret = -EACCES;
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries map_files/ entries are never supposed to be executed, still curious minds might try to run them, which leads to the following deadlock ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc4-24406-g841e6a6 #121 Not tainted ------------------------------------------------------- bash/1556 is trying to acquire lock: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: do_lookup+0x267/0x2b1 but task is already holding lock: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds+0x2d/0x69 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sig->cred_guard_mutex){+.+.+.}: validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_killable_nested+0x40/0x45 lock_trace+0x24/0x59 proc_map_files_lookup+0x5a/0x165 __lookup_hash+0x52/0x73 do_lookup+0x276/0x2b1 walk_component+0x3d/0x114 do_last+0xfc/0x540 path_openat+0xd3/0x306 do_filp_open+0x3d/0x89 do_sys_open+0x74/0x106 sys_open+0x21/0x23 tracesys+0xdd/0xe2 -> #0 (&sb->s_type->i_mutex_key#8){+.+.+.}: check_prev_add+0x6a/0x1ef validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_nested+0x40/0x45 do_lookup+0x267/0x2b1 walk_component+0x3d/0x114 link_path_walk+0x1f9/0x48f path_openat+0xb6/0x306 do_filp_open+0x3d/0x89 open_exec+0x25/0xa0 do_execve_common+0xea/0x2f9 do_execve+0x43/0x45 sys_execve+0x43/0x5a stub_execve+0x6c/0xc0 This is because prepare_bprm_creds grabs task->signal->cred_guard_mutex and when do_lookup happens we try to grab task->signal->cred_guard_mutex again in lock_trace. Fix it using plain ptrace_may_access() helper in proc_map_files_lookup() and in proc_map_files_readdir() instead of lock_trace(), the caller must be CAP_SYS_ADMIN granted anyway. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Jones <davej@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-18 00:03:25 +00:00
if (!ptrace_may_access(task, PTRACE_MODE_READ))
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
goto out_put_task;
ret = 0;
switch (filp->f_pos) {
case 0:
ino = inode->i_ino;
if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries map_files/ entries are never supposed to be executed, still curious minds might try to run them, which leads to the following deadlock ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc4-24406-g841e6a6 #121 Not tainted ------------------------------------------------------- bash/1556 is trying to acquire lock: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: do_lookup+0x267/0x2b1 but task is already holding lock: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds+0x2d/0x69 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sig->cred_guard_mutex){+.+.+.}: validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_killable_nested+0x40/0x45 lock_trace+0x24/0x59 proc_map_files_lookup+0x5a/0x165 __lookup_hash+0x52/0x73 do_lookup+0x276/0x2b1 walk_component+0x3d/0x114 do_last+0xfc/0x540 path_openat+0xd3/0x306 do_filp_open+0x3d/0x89 do_sys_open+0x74/0x106 sys_open+0x21/0x23 tracesys+0xdd/0xe2 -> #0 (&sb->s_type->i_mutex_key#8){+.+.+.}: check_prev_add+0x6a/0x1ef validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_nested+0x40/0x45 do_lookup+0x267/0x2b1 walk_component+0x3d/0x114 link_path_walk+0x1f9/0x48f path_openat+0xb6/0x306 do_filp_open+0x3d/0x89 open_exec+0x25/0xa0 do_execve_common+0xea/0x2f9 do_execve+0x43/0x45 sys_execve+0x43/0x5a stub_execve+0x6c/0xc0 This is because prepare_bprm_creds grabs task->signal->cred_guard_mutex and when do_lookup happens we try to grab task->signal->cred_guard_mutex again in lock_trace. Fix it using plain ptrace_may_access() helper in proc_map_files_lookup() and in proc_map_files_readdir() instead of lock_trace(), the caller must be CAP_SYS_ADMIN granted anyway. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Jones <davej@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-18 00:03:25 +00:00
goto out_put_task;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
filp->f_pos++;
case 1:
ino = parent_ino(dentry);
if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries map_files/ entries are never supposed to be executed, still curious minds might try to run them, which leads to the following deadlock ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc4-24406-g841e6a6 #121 Not tainted ------------------------------------------------------- bash/1556 is trying to acquire lock: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: do_lookup+0x267/0x2b1 but task is already holding lock: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds+0x2d/0x69 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sig->cred_guard_mutex){+.+.+.}: validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_killable_nested+0x40/0x45 lock_trace+0x24/0x59 proc_map_files_lookup+0x5a/0x165 __lookup_hash+0x52/0x73 do_lookup+0x276/0x2b1 walk_component+0x3d/0x114 do_last+0xfc/0x540 path_openat+0xd3/0x306 do_filp_open+0x3d/0x89 do_sys_open+0x74/0x106 sys_open+0x21/0x23 tracesys+0xdd/0xe2 -> #0 (&sb->s_type->i_mutex_key#8){+.+.+.}: check_prev_add+0x6a/0x1ef validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_nested+0x40/0x45 do_lookup+0x267/0x2b1 walk_component+0x3d/0x114 link_path_walk+0x1f9/0x48f path_openat+0xb6/0x306 do_filp_open+0x3d/0x89 open_exec+0x25/0xa0 do_execve_common+0xea/0x2f9 do_execve+0x43/0x45 sys_execve+0x43/0x5a stub_execve+0x6c/0xc0 This is because prepare_bprm_creds grabs task->signal->cred_guard_mutex and when do_lookup happens we try to grab task->signal->cred_guard_mutex again in lock_trace. Fix it using plain ptrace_may_access() helper in proc_map_files_lookup() and in proc_map_files_readdir() instead of lock_trace(), the caller must be CAP_SYS_ADMIN granted anyway. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Jones <davej@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-18 00:03:25 +00:00
goto out_put_task;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
filp->f_pos++;
default:
{
unsigned long nr_files, pos, i;
struct flex_array *fa = NULL;
struct map_files_info info;
struct map_files_info *p;
mm = get_task_mm(task);
if (!mm)
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries map_files/ entries are never supposed to be executed, still curious minds might try to run them, which leads to the following deadlock ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc4-24406-g841e6a6 #121 Not tainted ------------------------------------------------------- bash/1556 is trying to acquire lock: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: do_lookup+0x267/0x2b1 but task is already holding lock: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds+0x2d/0x69 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sig->cred_guard_mutex){+.+.+.}: validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_killable_nested+0x40/0x45 lock_trace+0x24/0x59 proc_map_files_lookup+0x5a/0x165 __lookup_hash+0x52/0x73 do_lookup+0x276/0x2b1 walk_component+0x3d/0x114 do_last+0xfc/0x540 path_openat+0xd3/0x306 do_filp_open+0x3d/0x89 do_sys_open+0x74/0x106 sys_open+0x21/0x23 tracesys+0xdd/0xe2 -> #0 (&sb->s_type->i_mutex_key#8){+.+.+.}: check_prev_add+0x6a/0x1ef validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_nested+0x40/0x45 do_lookup+0x267/0x2b1 walk_component+0x3d/0x114 link_path_walk+0x1f9/0x48f path_openat+0xb6/0x306 do_filp_open+0x3d/0x89 open_exec+0x25/0xa0 do_execve_common+0xea/0x2f9 do_execve+0x43/0x45 sys_execve+0x43/0x5a stub_execve+0x6c/0xc0 This is because prepare_bprm_creds grabs task->signal->cred_guard_mutex and when do_lookup happens we try to grab task->signal->cred_guard_mutex again in lock_trace. Fix it using plain ptrace_may_access() helper in proc_map_files_lookup() and in proc_map_files_readdir() instead of lock_trace(), the caller must be CAP_SYS_ADMIN granted anyway. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Jones <davej@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-18 00:03:25 +00:00
goto out_put_task;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
down_read(&mm->mmap_sem);
nr_files = 0;
/*
* We need two passes here:
*
* 1) Collect vmas of mapped files with mmap_sem taken
* 2) Release mmap_sem and instantiate entries
*
* otherwise we get lockdep complained, since filldir()
* routine might require mmap_sem taken in might_fault().
*/
for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
if (vma->vm_file && ++pos > filp->f_pos)
nr_files++;
}
if (nr_files) {
fa = flex_array_alloc(sizeof(info), nr_files,
GFP_KERNEL);
if (!fa || flex_array_prealloc(fa, 0, nr_files,
GFP_KERNEL)) {
ret = -ENOMEM;
if (fa)
flex_array_free(fa);
up_read(&mm->mmap_sem);
mmput(mm);
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries map_files/ entries are never supposed to be executed, still curious minds might try to run them, which leads to the following deadlock ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc4-24406-g841e6a6 #121 Not tainted ------------------------------------------------------- bash/1556 is trying to acquire lock: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: do_lookup+0x267/0x2b1 but task is already holding lock: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds+0x2d/0x69 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sig->cred_guard_mutex){+.+.+.}: validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_killable_nested+0x40/0x45 lock_trace+0x24/0x59 proc_map_files_lookup+0x5a/0x165 __lookup_hash+0x52/0x73 do_lookup+0x276/0x2b1 walk_component+0x3d/0x114 do_last+0xfc/0x540 path_openat+0xd3/0x306 do_filp_open+0x3d/0x89 do_sys_open+0x74/0x106 sys_open+0x21/0x23 tracesys+0xdd/0xe2 -> #0 (&sb->s_type->i_mutex_key#8){+.+.+.}: check_prev_add+0x6a/0x1ef validate_chain+0x444/0x4f4 __lock_acquire+0x387/0x3f8 lock_acquire+0x12b/0x158 __mutex_lock_common+0x56/0x3a9 mutex_lock_nested+0x40/0x45 do_lookup+0x267/0x2b1 walk_component+0x3d/0x114 link_path_walk+0x1f9/0x48f path_openat+0xb6/0x306 do_filp_open+0x3d/0x89 open_exec+0x25/0xa0 do_execve_common+0xea/0x2f9 do_execve+0x43/0x45 sys_execve+0x43/0x5a stub_execve+0x6c/0xc0 This is because prepare_bprm_creds grabs task->signal->cred_guard_mutex and when do_lookup happens we try to grab task->signal->cred_guard_mutex again in lock_trace. Fix it using plain ptrace_may_access() helper in proc_map_files_lookup() and in proc_map_files_readdir() instead of lock_trace(), the caller must be CAP_SYS_ADMIN granted anyway. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Jones <davej@redhat.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-18 00:03:25 +00:00
goto out_put_task;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
}
for (i = 0, vma = mm->mmap, pos = 2; vma;
vma = vma->vm_next) {
if (!vma->vm_file)
continue;
if (++pos <= filp->f_pos)
continue;
info.mode = vma->vm_file->f_mode;
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
info.len = snprintf(info.name,
sizeof(info.name), "%lx-%lx",
vma->vm_start, vma->vm_end);
if (flex_array_put(fa, i++, &info, GFP_KERNEL))
BUG();
}
}
up_read(&mm->mmap_sem);
for (i = 0; i < nr_files; i++) {
p = flex_array_get(fa, i);
ret = proc_fill_cache(filp, dirent, filldir,
p->name, p->len,
proc_map_files_instantiate,
task,
(void *)(unsigned long)p->mode);
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
if (ret)
break;
filp->f_pos++;
}
if (fa)
flex_array_free(fa);
mmput(mm);
}
}
out_put_task:
put_task_struct(task);
out:
return ret;
}
static const struct file_operations proc_map_files_operations = {
.read = generic_read_dir,
.readdir = proc_map_files_readdir,
.llseek = default_llseek,
};
#endif /* CONFIG_CHECKPOINT_RESTORE */
static struct dentry *proc_pident_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
{
const struct pid_entry *p = ptr;
struct inode *inode;
struct proc_inode *ei;
struct dentry *error = ERR_PTR(-ENOENT);
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)
goto out;
ei = PROC_I(inode);
inode->i_mode = p->mode;
if (S_ISDIR(inode->i_mode))
set_nlink(inode, 2); /* Use getattr to fix if necessary */
if (p->iop)
inode->i_op = p->iop;
if (p->fop)
inode->i_fop = p->fop;
ei->op = p->op;
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, 0))
error = NULL;
out:
return error;
}
static struct dentry *proc_pident_lookup(struct inode *dir,
struct dentry *dentry,
const struct pid_entry *ents,
unsigned int nents)
{
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
const struct pid_entry *p, *last;
error = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
/*
* Yes, it does not scale. And it should not. Don't add
* new entries into /proc/<tgid>/ without very good reasons.
*/
last = &ents[nents - 1];
for (p = ents; p <= last; p++) {
if (p->len != dentry->d_name.len)
continue;
if (!memcmp(dentry->d_name.name, p->name, p->len))
break;
}
if (p > last)
goto out;
error = proc_pident_instantiate(dir, dentry, task, p);
out:
put_task_struct(task);
out_no_task:
return error;
}
static int proc_pident_fill_cache(struct file *filp, void *dirent,
filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
{
return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
proc_pident_instantiate, task, p);
}
static int proc_pident_readdir(struct file *filp,
void *dirent, filldir_t filldir,
const struct pid_entry *ents, unsigned int nents)
{
int i;
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
struct task_struct *task = get_proc_task(inode);
const struct pid_entry *p, *last;
ino_t ino;
int ret;
ret = -ENOENT;
if (!task)
goto out_no_task;
ret = 0;
i = filp->f_pos;
switch (i) {
case 0:
ino = inode->i_ino;
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
goto out;
i++;
filp->f_pos++;
/* fall through */
case 1:
ino = parent_ino(dentry);
if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
goto out;
i++;
filp->f_pos++;
/* fall through */
default:
i -= 2;
if (i >= nents) {
ret = 1;
goto out;
}
p = ents + i;
last = &ents[nents - 1];
while (p <= last) {
if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
goto out;
filp->f_pos++;
p++;
}
}
ret = 1;
out:
put_task_struct(task);
out_no_task:
return ret;
}
#ifdef CONFIG_SECURITY
static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file->f_path.dentry->d_inode;
char *p = NULL;
ssize_t length;
struct task_struct *task = get_proc_task(inode);
if (!task)
return -ESRCH;
length = security_getprocattr(task,
(char*)file->f_path.dentry->d_name.name,
&p);
put_task_struct(task);
if (length > 0)
length = simple_read_from_buffer(buf, count, ppos, p, length);
kfree(p);
return length;
}
static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file->f_path.dentry->d_inode;
char *page;
ssize_t length;
struct task_struct *task = get_proc_task(inode);
length = -ESRCH;
if (!task)
goto out_no_task;
if (count > PAGE_SIZE)
count = PAGE_SIZE;
/* No partial writes. */
length = -EINVAL;
if (*ppos != 0)
goto out;
length = -ENOMEM;
page = (char*)__get_free_page(GFP_TEMPORARY);
if (!page)
goto out;
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out_free;
/* Guard against adverse ptrace interaction */
length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
if (length < 0)
goto out_free;
length = security_setprocattr(task,
(char*)file->f_path.dentry->d_name.name,
(void*)page, count);
mutex_unlock(&task->signal->cred_guard_mutex);
out_free:
free_page((unsigned long) page);
out:
put_task_struct(task);
out_no_task:
return length;
}
static const struct file_operations proc_pid_attr_operations = {
.read = proc_pid_attr_read,
.write = proc_pid_attr_write,
.llseek = generic_file_llseek,
};
static const struct pid_entry attr_dir_stuff[] = {
REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
REG("prev", S_IRUGO, proc_pid_attr_operations),
REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
};
static int proc_attr_dir_readdir(struct file * filp,
void * dirent, filldir_t filldir)
{
return proc_pident_readdir(filp,dirent,filldir,
attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
}
static const struct file_operations proc_attr_dir_operations = {
.read = generic_read_dir,
.readdir = proc_attr_dir_readdir,
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-15 16:52:59 +00:00
.llseek = default_llseek,
};
static struct dentry *proc_attr_dir_lookup(struct inode *dir,
struct dentry *dentry, unsigned int flags)
{
return proc_pident_lookup(dir, dentry,
attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
}
static const struct inode_operations proc_attr_dir_inode_operations = {
.lookup = proc_attr_dir_lookup,
.getattr = pid_getattr,
.setattr = proc_setattr,
};
#endif
#ifdef CONFIG_ELF_CORE
static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
struct mm_struct *mm;
char buffer[PROC_NUMBUF];
size_t len;
int ret;
if (!task)
return -ESRCH;
ret = 0;
mm = get_task_mm(task);
if (mm) {
len = snprintf(buffer, sizeof(buffer), "%08lx\n",
((mm->flags & MMF_DUMP_FILTER_MASK) >>
MMF_DUMP_FILTER_SHIFT));
mmput(mm);
ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
}
put_task_struct(task);
return ret;
}
static ssize_t proc_coredump_filter_write(struct file *file,
const char __user *buf,
size_t count,
loff_t *ppos)
{
struct task_struct *task;
struct mm_struct *mm;
char buffer[PROC_NUMBUF], *end;
unsigned int val;
int ret;
int i;
unsigned long mask;
ret = -EFAULT;
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count))
goto out_no_task;
ret = -EINVAL;
val = (unsigned int)simple_strtoul(buffer, &end, 0);
if (*end == '\n')
end++;
if (end - buffer == 0)
goto out_no_task;
ret = -ESRCH;
task = get_proc_task(file->f_dentry->d_inode);
if (!task)
goto out_no_task;
ret = end - buffer;
mm = get_task_mm(task);
if (!mm)
goto out_no_mm;
for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
if (val & mask)
set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
else
clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
}
mmput(mm);
out_no_mm:
put_task_struct(task);
out_no_task:
return ret;
}
static const struct file_operations proc_coredump_filter_operations = {
.read = proc_coredump_filter_read,
.write = proc_coredump_filter_write,
.llseek = generic_file_llseek,
};
#endif
/*
* /proc/self:
*/
static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
int buflen)
{
struct pid_namespace *ns = dentry->d_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
char tmp[PROC_NUMBUF];
if (!tgid)
return -ENOENT;
sprintf(tmp, "%d", tgid);
return vfs_readlink(dentry,buffer,buflen,tmp);
}
static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct pid_namespace *ns = dentry->d_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
char *name = ERR_PTR(-ENOENT);
if (tgid) {
name = __getname();
if (!name)
name = ERR_PTR(-ENOMEM);
else
sprintf(name, "%d", tgid);
}
nd_set_link(nd, name);
return NULL;
}
static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
void *cookie)
{
char *s = nd_get_link(nd);
if (!IS_ERR(s))
__putname(s);
}
static const struct inode_operations proc_self_inode_operations = {
.readlink = proc_self_readlink,
.follow_link = proc_self_follow_link,
.put_link = proc_self_put_link,
};
/*
* proc base
*
* These are the directory entries in the root directory of /proc
* that properly belong to the /proc filesystem, as they describe
* describe something that is process related.
*/
static const struct pid_entry proc_base_stuff[] = {
NOD("self", S_IFLNK|S_IRWXUGO,
&proc_self_inode_operations, NULL, {}),
};
static struct dentry *proc_base_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
{
const struct pid_entry *p = ptr;
struct inode *inode;
struct proc_inode *ei;
struct dentry *error;
/* Allocate the inode */
error = ERR_PTR(-ENOMEM);
inode = new_inode(dir->i_sb);
if (!inode)
goto out;
/* Initialize the inode */
ei = PROC_I(inode);
inode->i_ino = get_next_ino();
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
/*
* grab the reference to the task.
*/
ei->pid = get_task_pid(task, PIDTYPE_PID);
if (!ei->pid)
goto out_iput;
inode->i_mode = p->mode;
if (S_ISDIR(inode->i_mode))
set_nlink(inode, 2);
if (S_ISLNK(inode->i_mode))
inode->i_size = 64;
if (p->iop)
inode->i_op = p->iop;
if (p->fop)
inode->i_fop = p->fop;
ei->op = p->op;
d_add(dentry, inode);
error = NULL;
out:
return error;
out_iput:
iput(inode);
goto out;
}
static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
{
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
const struct pid_entry *p, *last;
error = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
/* Lookup the directory entry */
last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
for (p = proc_base_stuff; p <= last; p++) {
if (p->len != dentry->d_name.len)
continue;
if (!memcmp(dentry->d_name.name, p->name, p->len))
break;
}
if (p > last)
goto out;
error = proc_base_instantiate(dir, dentry, task, p);
out:
put_task_struct(task);
out_no_task:
return error;
}
static int proc_base_fill_cache(struct file *filp, void *dirent,
filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
{
return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
proc_base_instantiate, task, p);
}
#ifdef CONFIG_TASK_IO_ACCOUNTING
static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
{
struct task_io_accounting acct = task->ioac;
unsigned long flags;
int result;
result = mutex_lock_killable(&task->signal->cred_guard_mutex);
if (result)
return result;
if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
result = -EACCES;
goto out_unlock;
}
if (whole && lock_task_sighand(task, &flags)) {
struct task_struct *t = task;
task_io_accounting_add(&acct, &task->signal->ioac);
while_each_thread(task, t)
task_io_accounting_add(&acct, &t->ioac);
unlock_task_sighand(task, &flags);
}
result = sprintf(buffer,
"rchar: %llu\n"
"wchar: %llu\n"
"syscr: %llu\n"
"syscw: %llu\n"
"read_bytes: %llu\n"
"write_bytes: %llu\n"
"cancelled_write_bytes: %llu\n",
(unsigned long long)acct.rchar,
(unsigned long long)acct.wchar,
(unsigned long long)acct.syscr,
(unsigned long long)acct.syscw,
(unsigned long long)acct.read_bytes,
(unsigned long long)acct.write_bytes,
(unsigned long long)acct.cancelled_write_bytes);
out_unlock:
mutex_unlock(&task->signal->cred_guard_mutex);
return result;
}
static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
{
return do_io_accounting(task, buffer, 0);
}
static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
{
return do_io_accounting(task, buffer, 1);
}
#endif /* CONFIG_TASK_IO_ACCOUNTING */
userns: Rework the user_namespace adding uid/gid mapping support - Convert the old uid mapping functions into compatibility wrappers - Add a uid/gid mapping layer from user space uid and gids to kernel internal uids and gids that is extent based for simplicty and speed. * Working with number space after mapping uids/gids into their kernel internal version adds only mapping complexity over what we have today, leaving the kernel code easy to understand and test. - Add proc files /proc/self/uid_map /proc/self/gid_map These files display the mapping and allow a mapping to be added if a mapping does not exist. - Allow entering the user namespace without a uid or gid mapping. Since we are starting with an existing user our uids and gids still have global mappings so are still valid and useful they just don't have local mappings. The requirement for things to work are global uid and gid so it is odd but perfectly fine not to have a local uid and gid mapping. Not requiring global uid and gid mappings greatly simplifies the logic of setting up the uid and gid mappings by allowing the mappings to be set after the namespace is created which makes the slight weirdness worth it. - Make the mappings in the initial user namespace to the global uid/gid space explicit. Today it is an identity mapping but in the future we may want to twist this for debugging, similar to what we do with jiffies. - Document the memory ordering requirements of setting the uid and gid mappings. We only allow the mappings to be set once and there are no pointers involved so the requirments are trivial but a little atypical. Performance: In this scheme for the permission checks the performance is expected to stay the same as the actuall machine instructions should remain the same. The worst case I could think of is ls -l on a large directory where all of the stat results need to be translated with from kuids and kgids to uids and gids. So I benchmarked that case on my laptop with a dual core hyperthread Intel i5-2520M cpu with 3M of cpu cache. My benchmark consisted of going to single user mode where nothing else was running. On an ext4 filesystem opening 1,000,000 files and looping through all of the files 1000 times and calling fstat on the individuals files. This was to ensure I was benchmarking stat times where the inodes were in the kernels cache, but the inode values were not in the processors cache. My results: v3.4-rc1: ~= 156ns (unmodified v3.4-rc1 with user namespace support disabled) v3.4-rc1-userns-: ~= 155ns (v3.4-rc1 with my user namespace patches and user namespace support disabled) v3.4-rc1-userns+: ~= 164ns (v3.4-rc1 with my user namespace patches and user namespace support enabled) All of the configurations ran in roughly 120ns when I performed tests that ran in the cpu cache. So in summary the performance impact is: 1ns improvement in the worst case with user namespace support compiled out. 8ns aka 5% slowdown in the worst case with user namespace support compiled in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-17 08:11:58 +00:00
#ifdef CONFIG_USER_NS
static int proc_id_map_open(struct inode *inode, struct file *file,
struct seq_operations *seq_ops)
{
struct user_namespace *ns = NULL;
struct task_struct *task;
struct seq_file *seq;
int ret = -EINVAL;
task = get_proc_task(inode);
if (task) {
rcu_read_lock();
ns = get_user_ns(task_cred_xxx(task, user_ns));
rcu_read_unlock();
put_task_struct(task);
}
if (!ns)
goto err;
ret = seq_open(file, seq_ops);
if (ret)
goto err_put_ns;
seq = file->private_data;
seq->private = ns;
return 0;
err_put_ns:
put_user_ns(ns);
err:
return ret;
}
static int proc_id_map_release(struct inode *inode, struct file *file)
{
struct seq_file *seq = file->private_data;
struct user_namespace *ns = seq->private;
put_user_ns(ns);
return seq_release(inode, file);
}
static int proc_uid_map_open(struct inode *inode, struct file *file)
{
return proc_id_map_open(inode, file, &proc_uid_seq_operations);
}
static int proc_gid_map_open(struct inode *inode, struct file *file)
{
return proc_id_map_open(inode, file, &proc_gid_seq_operations);
}
static int proc_projid_map_open(struct inode *inode, struct file *file)
{
return proc_id_map_open(inode, file, &proc_projid_seq_operations);
}
userns: Rework the user_namespace adding uid/gid mapping support - Convert the old uid mapping functions into compatibility wrappers - Add a uid/gid mapping layer from user space uid and gids to kernel internal uids and gids that is extent based for simplicty and speed. * Working with number space after mapping uids/gids into their kernel internal version adds only mapping complexity over what we have today, leaving the kernel code easy to understand and test. - Add proc files /proc/self/uid_map /proc/self/gid_map These files display the mapping and allow a mapping to be added if a mapping does not exist. - Allow entering the user namespace without a uid or gid mapping. Since we are starting with an existing user our uids and gids still have global mappings so are still valid and useful they just don't have local mappings. The requirement for things to work are global uid and gid so it is odd but perfectly fine not to have a local uid and gid mapping. Not requiring global uid and gid mappings greatly simplifies the logic of setting up the uid and gid mappings by allowing the mappings to be set after the namespace is created which makes the slight weirdness worth it. - Make the mappings in the initial user namespace to the global uid/gid space explicit. Today it is an identity mapping but in the future we may want to twist this for debugging, similar to what we do with jiffies. - Document the memory ordering requirements of setting the uid and gid mappings. We only allow the mappings to be set once and there are no pointers involved so the requirments are trivial but a little atypical. Performance: In this scheme for the permission checks the performance is expected to stay the same as the actuall machine instructions should remain the same. The worst case I could think of is ls -l on a large directory where all of the stat results need to be translated with from kuids and kgids to uids and gids. So I benchmarked that case on my laptop with a dual core hyperthread Intel i5-2520M cpu with 3M of cpu cache. My benchmark consisted of going to single user mode where nothing else was running. On an ext4 filesystem opening 1,000,000 files and looping through all of the files 1000 times and calling fstat on the individuals files. This was to ensure I was benchmarking stat times where the inodes were in the kernels cache, but the inode values were not in the processors cache. My results: v3.4-rc1: ~= 156ns (unmodified v3.4-rc1 with user namespace support disabled) v3.4-rc1-userns-: ~= 155ns (v3.4-rc1 with my user namespace patches and user namespace support disabled) v3.4-rc1-userns+: ~= 164ns (v3.4-rc1 with my user namespace patches and user namespace support enabled) All of the configurations ran in roughly 120ns when I performed tests that ran in the cpu cache. So in summary the performance impact is: 1ns improvement in the worst case with user namespace support compiled out. 8ns aka 5% slowdown in the worst case with user namespace support compiled in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-17 08:11:58 +00:00
static const struct file_operations proc_uid_map_operations = {
.open = proc_uid_map_open,
.write = proc_uid_map_write,
.read = seq_read,
.llseek = seq_lseek,
.release = proc_id_map_release,
};
static const struct file_operations proc_gid_map_operations = {
.open = proc_gid_map_open,
.write = proc_gid_map_write,
.read = seq_read,
.llseek = seq_lseek,
.release = proc_id_map_release,
};
static const struct file_operations proc_projid_map_operations = {
.open = proc_projid_map_open,
.write = proc_projid_map_write,
.read = seq_read,
.llseek = seq_lseek,
.release = proc_id_map_release,
};
userns: Rework the user_namespace adding uid/gid mapping support - Convert the old uid mapping functions into compatibility wrappers - Add a uid/gid mapping layer from user space uid and gids to kernel internal uids and gids that is extent based for simplicty and speed. * Working with number space after mapping uids/gids into their kernel internal version adds only mapping complexity over what we have today, leaving the kernel code easy to understand and test. - Add proc files /proc/self/uid_map /proc/self/gid_map These files display the mapping and allow a mapping to be added if a mapping does not exist. - Allow entering the user namespace without a uid or gid mapping. Since we are starting with an existing user our uids and gids still have global mappings so are still valid and useful they just don't have local mappings. The requirement for things to work are global uid and gid so it is odd but perfectly fine not to have a local uid and gid mapping. Not requiring global uid and gid mappings greatly simplifies the logic of setting up the uid and gid mappings by allowing the mappings to be set after the namespace is created which makes the slight weirdness worth it. - Make the mappings in the initial user namespace to the global uid/gid space explicit. Today it is an identity mapping but in the future we may want to twist this for debugging, similar to what we do with jiffies. - Document the memory ordering requirements of setting the uid and gid mappings. We only allow the mappings to be set once and there are no pointers involved so the requirments are trivial but a little atypical. Performance: In this scheme for the permission checks the performance is expected to stay the same as the actuall machine instructions should remain the same. The worst case I could think of is ls -l on a large directory where all of the stat results need to be translated with from kuids and kgids to uids and gids. So I benchmarked that case on my laptop with a dual core hyperthread Intel i5-2520M cpu with 3M of cpu cache. My benchmark consisted of going to single user mode where nothing else was running. On an ext4 filesystem opening 1,000,000 files and looping through all of the files 1000 times and calling fstat on the individuals files. This was to ensure I was benchmarking stat times where the inodes were in the kernels cache, but the inode values were not in the processors cache. My results: v3.4-rc1: ~= 156ns (unmodified v3.4-rc1 with user namespace support disabled) v3.4-rc1-userns-: ~= 155ns (v3.4-rc1 with my user namespace patches and user namespace support disabled) v3.4-rc1-userns+: ~= 164ns (v3.4-rc1 with my user namespace patches and user namespace support enabled) All of the configurations ran in roughly 120ns when I performed tests that ran in the cpu cache. So in summary the performance impact is: 1ns improvement in the worst case with user namespace support compiled out. 8ns aka 5% slowdown in the worst case with user namespace support compiled in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-17 08:11:58 +00:00
#endif /* CONFIG_USER_NS */
static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
int err = lock_trace(task);
if (!err) {
seq_printf(m, "%08x\n", task->personality);
unlock_trace(task);
}
return err;
}
/*
* Thread groups
*/
static const struct file_operations proc_task_operations;
static const struct inode_operations proc_task_inode_operations;
static const struct pid_entry tgid_base_stuff[] = {
DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
procfs: introduce the /proc/<pid>/map_files/ directory This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink results in a file that point exactly to the same inode as them vma's one. For example the ls -l of some arbitrary /proc/<pid>/map_files/ | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so This *helps* checkpointing process in three ways: 1. When dumping a task mappings we do know exact file that is mapped by particular region. We do this by opening /proc/$pid/map_files/$address symlink the way we do with file descriptors. 2. This also helps in determining which anonymous shared mappings are shared with each other by comparing the inodes of them. 3. When restoring a set of processes in case two of them has a mapping shared, we map the memory by the 1st one and then open its /proc/$pid/map_files/$address file and map it by the 2nd task. Using /proc/$pid/maps for this is quite inconvenient since it brings repeatable re-reading and reparsing for this text file which slows down restore procedure significantly. Also as being pointed in (3) it is a way easier to use top level shared mapping in children as /proc/$pid/map_files/$address when needed. [akpm@linux-foundation.org: coding-style fixes] [gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:23 +00:00
#ifdef CONFIG_CHECKPOINT_RESTORE
DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
#endif
DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
#ifdef CONFIG_NET
DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
#endif
REG("environ", S_IRUSR, proc_environ_operations),
INF("auxv", S_IRUSR, proc_pid_auxv),
ONE("status", S_IRUGO, proc_pid_status),
ONE("personality", S_IRUGO, proc_pid_personality),
INF("limits", S_IRUGO, proc_pid_limits),
#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
#endif
#ifdef CONFIG_SCHED_AUTOGROUP
REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
#endif
REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
INF("syscall", S_IRUGO, proc_pid_syscall),
#endif
INF("cmdline", S_IRUGO, proc_pid_cmdline),
ONE("stat", S_IRUGO, proc_tgid_stat),
ONE("statm", S_IRUGO, proc_pid_statm),
procfs: mark thread stack correctly in proc/<pid>/maps Stack for a new thread is mapped by userspace code and passed via sys_clone. This memory is currently seen as anonymous in /proc/<pid>/maps, which makes it difficult to ascertain which mappings are being used for thread stacks. This patch uses the individual task stack pointers to determine which vmas are actually thread stacks. For a multithreaded program like the following: #include <pthread.h> void *thread_main(void *foo) { while(1); } int main() { pthread_t t; pthread_create(&t, NULL, thread_main, NULL); pthread_join(t, NULL); } proc/PID/maps looks like the following: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Here, one could guess that 7f8a44492000-7f8a44c92000 is a stack since the earlier vma that has no permissions (7f8a44e3d000-7f8a4503d000) but that is not always a reliable way to find out which vma is a thread stack. Also, /proc/PID/maps and /proc/PID/task/TID/maps has the same content. With this patch in place, /proc/PID/task/TID/maps are treated as 'maps as the task would see it' and hence, only the vma that that task uses as stack is marked as [stack]. All other 'stack' vmas are marked as anonymous memory. /proc/PID/maps acts as a thread group level view, where all thread stack vmas are marked as [stack:TID] where TID is the process ID of the task that uses that vma as stack, while the process stack is marked as [stack]. So /proc/PID/maps will look like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Thus marking all vmas that are used as stacks by the threads in the thread group along with the process stack. The task level maps will however like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] where only the vma that is being used as a stack by *that* task is marked as [stack]. Analogous changes have been made to /proc/PID/smaps, /proc/PID/numa_maps, /proc/PID/task/TID/smaps and /proc/PID/task/TID/numa_maps. Relevant snippets from smaps and numa_maps: [siddhesh@localhost ~ ]$ pgrep a.out 1441 [siddhesh@localhost ~ ]$ cat /proc/1441/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/smaps | grep "\[stack" 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/numa_maps | grep "stack" 7f8a44492000 default stack:1442 anon=2 dirty=2 N0=2 7fff6273a000 default stack anon=3 dirty=3 N0=3 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/numa_maps | grep "stack" 7f8a44492000 default stack anon=2 dirty=2 N0=2 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/numa_maps | grep "stack" 7fff6273a000 default stack anon=3 dirty=3 N0=3 [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix build] Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jamie Lokier <jamie@shareable.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21 23:34:04 +00:00
REG("maps", S_IRUGO, proc_pid_maps_operations),
#ifdef CONFIG_NUMA
procfs: mark thread stack correctly in proc/<pid>/maps Stack for a new thread is mapped by userspace code and passed via sys_clone. This memory is currently seen as anonymous in /proc/<pid>/maps, which makes it difficult to ascertain which mappings are being used for thread stacks. This patch uses the individual task stack pointers to determine which vmas are actually thread stacks. For a multithreaded program like the following: #include <pthread.h> void *thread_main(void *foo) { while(1); } int main() { pthread_t t; pthread_create(&t, NULL, thread_main, NULL); pthread_join(t, NULL); } proc/PID/maps looks like the following: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Here, one could guess that 7f8a44492000-7f8a44c92000 is a stack since the earlier vma that has no permissions (7f8a44e3d000-7f8a4503d000) but that is not always a reliable way to find out which vma is a thread stack. Also, /proc/PID/maps and /proc/PID/task/TID/maps has the same content. With this patch in place, /proc/PID/task/TID/maps are treated as 'maps as the task would see it' and hence, only the vma that that task uses as stack is marked as [stack]. All other 'stack' vmas are marked as anonymous memory. /proc/PID/maps acts as a thread group level view, where all thread stack vmas are marked as [stack:TID] where TID is the process ID of the task that uses that vma as stack, while the process stack is marked as [stack]. So /proc/PID/maps will look like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Thus marking all vmas that are used as stacks by the threads in the thread group along with the process stack. The task level maps will however like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] where only the vma that is being used as a stack by *that* task is marked as [stack]. Analogous changes have been made to /proc/PID/smaps, /proc/PID/numa_maps, /proc/PID/task/TID/smaps and /proc/PID/task/TID/numa_maps. Relevant snippets from smaps and numa_maps: [siddhesh@localhost ~ ]$ pgrep a.out 1441 [siddhesh@localhost ~ ]$ cat /proc/1441/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/smaps | grep "\[stack" 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/numa_maps | grep "stack" 7f8a44492000 default stack:1442 anon=2 dirty=2 N0=2 7fff6273a000 default stack anon=3 dirty=3 N0=3 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/numa_maps | grep "stack" 7f8a44492000 default stack anon=2 dirty=2 N0=2 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/numa_maps | grep "stack" 7fff6273a000 default stack anon=3 dirty=3 N0=3 [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix build] Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jamie Lokier <jamie@shareable.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21 23:34:04 +00:00
REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
#endif
REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
LNK("cwd", proc_cwd_link),
LNK("root", proc_root_link),
LNK("exe", proc_exe_link),
REG("mounts", S_IRUGO, proc_mounts_operations),
REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
REG("mountstats", S_IRUSR, proc_mountstats_operations),
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
procfs: mark thread stack correctly in proc/<pid>/maps Stack for a new thread is mapped by userspace code and passed via sys_clone. This memory is currently seen as anonymous in /proc/<pid>/maps, which makes it difficult to ascertain which mappings are being used for thread stacks. This patch uses the individual task stack pointers to determine which vmas are actually thread stacks. For a multithreaded program like the following: #include <pthread.h> void *thread_main(void *foo) { while(1); } int main() { pthread_t t; pthread_create(&t, NULL, thread_main, NULL); pthread_join(t, NULL); } proc/PID/maps looks like the following: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Here, one could guess that 7f8a44492000-7f8a44c92000 is a stack since the earlier vma that has no permissions (7f8a44e3d000-7f8a4503d000) but that is not always a reliable way to find out which vma is a thread stack. Also, /proc/PID/maps and /proc/PID/task/TID/maps has the same content. With this patch in place, /proc/PID/task/TID/maps are treated as 'maps as the task would see it' and hence, only the vma that that task uses as stack is marked as [stack]. All other 'stack' vmas are marked as anonymous memory. /proc/PID/maps acts as a thread group level view, where all thread stack vmas are marked as [stack:TID] where TID is the process ID of the task that uses that vma as stack, while the process stack is marked as [stack]. So /proc/PID/maps will look like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Thus marking all vmas that are used as stacks by the threads in the thread group along with the process stack. The task level maps will however like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] where only the vma that is being used as a stack by *that* task is marked as [stack]. Analogous changes have been made to /proc/PID/smaps, /proc/PID/numa_maps, /proc/PID/task/TID/smaps and /proc/PID/task/TID/numa_maps. Relevant snippets from smaps and numa_maps: [siddhesh@localhost ~ ]$ pgrep a.out 1441 [siddhesh@localhost ~ ]$ cat /proc/1441/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/smaps | grep "\[stack" 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/numa_maps | grep "stack" 7f8a44492000 default stack:1442 anon=2 dirty=2 N0=2 7fff6273a000 default stack anon=3 dirty=3 N0=3 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/numa_maps | grep "stack" 7f8a44492000 default stack anon=2 dirty=2 N0=2 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/numa_maps | grep "stack" 7fff6273a000 default stack anon=3 dirty=3 N0=3 [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix build] Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jamie Lokier <jamie@shareable.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21 23:34:04 +00:00
REG("smaps", S_IRUGO, proc_pid_smaps_operations),
REG("pagemap", S_IRUGO, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
#endif
#ifdef CONFIG_KALLSYMS
INF("wchan", S_IRUGO, proc_pid_wchan),
#endif
#ifdef CONFIG_STACKTRACE
ONE("stack", S_IRUGO, proc_pid_stack),
#endif
#ifdef CONFIG_SCHEDSTATS
INF("schedstat", S_IRUGO, proc_pid_schedstat),
#endif
#ifdef CONFIG_LATENCYTOP
REG("latency", S_IRUGO, proc_lstats_operations),
#endif
#ifdef CONFIG_PROC_PID_CPUSET
REG("cpuset", S_IRUGO, proc_cpuset_operations),
#endif
#ifdef CONFIG_CGROUPS
REG("cgroup", S_IRUGO, proc_cgroup_operations),
#endif
INF("oom_score", S_IRUGO, proc_oom_score),
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
#ifdef CONFIG_AUDITSYSCALL
REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
REG("sessionid", S_IRUGO, proc_sessionid_operations),
#endif
#ifdef CONFIG_FAULT_INJECTION
REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
#endif
#ifdef CONFIG_ELF_CORE
REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
#endif
#ifdef CONFIG_TASK_IO_ACCOUNTING
INF("io", S_IRUSR, proc_tgid_io_accounting),
#endif
arch/tile: more /proc and /sys file support This change introduces a few of the less controversial /proc and /proc/sys interfaces for tile, along with sysfs attributes for various things that were originally proposed as /proc/tile files. It also adjusts the "hardwall" proc API. Arnd Bergmann reviewed the initial arch/tile submission, which included a complete set of all the /proc/tile and /proc/sys/tile knobs that we had added in a somewhat ad hoc way during initial development, and provided feedback on where most of them should go. One knob turned out to be similar enough to the existing /proc/sys/debug/exception-trace that it was re-implemented to use that model instead. Another knob was /proc/tile/grid, which reported the "grid" dimensions of a tile chip (e.g. 8x8 processors = 64-core chip). Arnd suggested looking at sysfs for that, so this change moves that information to a pair of sysfs attributes (chip_width and chip_height) in the /sys/devices/system/cpu directory. We also put the "chip_serial" and "chip_revision" information from our old /proc/tile/board file as attributes in /sys/devices/system/cpu. Other information collected via hypervisor APIs is now placed in /sys/hypervisor. We create a /sys/hypervisor/type file (holding the constant string "tilera") to be parallel with the Xen use of /sys/hypervisor/type holding "xen". We create three top-level files, "version" (the hypervisor's own version), "config_version" (the version of the configuration file), and "hvconfig" (the contents of the configuration file). The remaining information from our old /proc/tile/board and /proc/tile/switch files becomes an attribute group appearing under /sys/hypervisor/board/. Finally, after some feedback from Arnd Bergmann for the previous version of this patch, the /proc/tile/hardwall file is split up into two conceptual parts. First, a directory /proc/tile/hardwall/ which contains one file per active hardwall, each file named after the hardwall's ID and holding a cpulist that says which cpus are enclosed by the hardwall. Second, a /proc/PID file "hardwall" that is either empty (for non-hardwall-using processes) or contains the hardwall ID. Finally, this change pushes the /proc/sys/tile/unaligned_fixup/ directory, with knobs controlling the kernel code for handling the fixup of unaligned exceptions. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-26 16:40:09 +00:00
#ifdef CONFIG_HARDWALL
INF("hardwall", S_IRUGO, proc_pid_hardwall),
#endif
userns: Rework the user_namespace adding uid/gid mapping support - Convert the old uid mapping functions into compatibility wrappers - Add a uid/gid mapping layer from user space uid and gids to kernel internal uids and gids that is extent based for simplicty and speed. * Working with number space after mapping uids/gids into their kernel internal version adds only mapping complexity over what we have today, leaving the kernel code easy to understand and test. - Add proc files /proc/self/uid_map /proc/self/gid_map These files display the mapping and allow a mapping to be added if a mapping does not exist. - Allow entering the user namespace without a uid or gid mapping. Since we are starting with an existing user our uids and gids still have global mappings so are still valid and useful they just don't have local mappings. The requirement for things to work are global uid and gid so it is odd but perfectly fine not to have a local uid and gid mapping. Not requiring global uid and gid mappings greatly simplifies the logic of setting up the uid and gid mappings by allowing the mappings to be set after the namespace is created which makes the slight weirdness worth it. - Make the mappings in the initial user namespace to the global uid/gid space explicit. Today it is an identity mapping but in the future we may want to twist this for debugging, similar to what we do with jiffies. - Document the memory ordering requirements of setting the uid and gid mappings. We only allow the mappings to be set once and there are no pointers involved so the requirments are trivial but a little atypical. Performance: In this scheme for the permission checks the performance is expected to stay the same as the actuall machine instructions should remain the same. The worst case I could think of is ls -l on a large directory where all of the stat results need to be translated with from kuids and kgids to uids and gids. So I benchmarked that case on my laptop with a dual core hyperthread Intel i5-2520M cpu with 3M of cpu cache. My benchmark consisted of going to single user mode where nothing else was running. On an ext4 filesystem opening 1,000,000 files and looping through all of the files 1000 times and calling fstat on the individuals files. This was to ensure I was benchmarking stat times where the inodes were in the kernels cache, but the inode values were not in the processors cache. My results: v3.4-rc1: ~= 156ns (unmodified v3.4-rc1 with user namespace support disabled) v3.4-rc1-userns-: ~= 155ns (v3.4-rc1 with my user namespace patches and user namespace support disabled) v3.4-rc1-userns+: ~= 164ns (v3.4-rc1 with my user namespace patches and user namespace support enabled) All of the configurations ran in roughly 120ns when I performed tests that ran in the cpu cache. So in summary the performance impact is: 1ns improvement in the worst case with user namespace support compiled out. 8ns aka 5% slowdown in the worst case with user namespace support compiled in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-17 08:11:58 +00:00
#ifdef CONFIG_USER_NS
REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
userns: Rework the user_namespace adding uid/gid mapping support - Convert the old uid mapping functions into compatibility wrappers - Add a uid/gid mapping layer from user space uid and gids to kernel internal uids and gids that is extent based for simplicty and speed. * Working with number space after mapping uids/gids into their kernel internal version adds only mapping complexity over what we have today, leaving the kernel code easy to understand and test. - Add proc files /proc/self/uid_map /proc/self/gid_map These files display the mapping and allow a mapping to be added if a mapping does not exist. - Allow entering the user namespace without a uid or gid mapping. Since we are starting with an existing user our uids and gids still have global mappings so are still valid and useful they just don't have local mappings. The requirement for things to work are global uid and gid so it is odd but perfectly fine not to have a local uid and gid mapping. Not requiring global uid and gid mappings greatly simplifies the logic of setting up the uid and gid mappings by allowing the mappings to be set after the namespace is created which makes the slight weirdness worth it. - Make the mappings in the initial user namespace to the global uid/gid space explicit. Today it is an identity mapping but in the future we may want to twist this for debugging, similar to what we do with jiffies. - Document the memory ordering requirements of setting the uid and gid mappings. We only allow the mappings to be set once and there are no pointers involved so the requirments are trivial but a little atypical. Performance: In this scheme for the permission checks the performance is expected to stay the same as the actuall machine instructions should remain the same. The worst case I could think of is ls -l on a large directory where all of the stat results need to be translated with from kuids and kgids to uids and gids. So I benchmarked that case on my laptop with a dual core hyperthread Intel i5-2520M cpu with 3M of cpu cache. My benchmark consisted of going to single user mode where nothing else was running. On an ext4 filesystem opening 1,000,000 files and looping through all of the files 1000 times and calling fstat on the individuals files. This was to ensure I was benchmarking stat times where the inodes were in the kernels cache, but the inode values were not in the processors cache. My results: v3.4-rc1: ~= 156ns (unmodified v3.4-rc1 with user namespace support disabled) v3.4-rc1-userns-: ~= 155ns (v3.4-rc1 with my user namespace patches and user namespace support disabled) v3.4-rc1-userns+: ~= 164ns (v3.4-rc1 with my user namespace patches and user namespace support enabled) All of the configurations ran in roughly 120ns when I performed tests that ran in the cpu cache. So in summary the performance impact is: 1ns improvement in the worst case with user namespace support compiled out. 8ns aka 5% slowdown in the worst case with user namespace support compiled in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-17 08:11:58 +00:00
#endif
};
static int proc_tgid_base_readdir(struct file * filp,
void * dirent, filldir_t filldir)
{
return proc_pident_readdir(filp,dirent,filldir,
tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
}
static const struct file_operations proc_tgid_base_operations = {
.read = generic_read_dir,
.readdir = proc_tgid_base_readdir,
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-15 16:52:59 +00:00
.llseek = default_llseek,
};
static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
return proc_pident_lookup(dir, dentry,
tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
}
static const struct inode_operations proc_tgid_base_inode_operations = {
.lookup = proc_tgid_base_lookup,
.getattr = pid_getattr,
.setattr = proc_setattr,
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
.permission = proc_pid_permission,
};
static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
{
struct dentry *dentry, *leader, *dir;
char buf[PROC_NUMBUF];
struct qstr name;
name.name = buf;
name.len = snprintf(buf, sizeof(buf), "%d", pid);
dentry = d_hash_and_lookup(mnt->mnt_root, &name);
if (dentry) {
pidns: fix a leak in /proc dentries and inodes with pid namespaces. Daniel Lezcano reported a leak in 'struct pid' and 'struct pid_namespace' that is discussed in: http://lkml.org/lkml/2009/10/2/159. To summarize the thread, when container-init is terminated, it sets the PF_EXITING flag, zaps other processes in the container and waits to reap them. As a part of reaping, the container-init should flush any /proc dentries associated with the processes. But because the container-init is itself exiting and the following PF_EXITING check, the dentries are not flushed, resulting in leak in /proc inodes and dentries. This fix reverts the commit 7766755a2f249e7e0 ("Fix /proc dcache deadlock in do_exit") which introduced the check for PF_EXITING. At the time of the commit, shrink_dcache_parent() flushed dentries from other filesystems also and could have caused a deadlock which the commit fixed. But as pointed out by Eric Biederman, after commit 0feae5c47aabdde59, shrink_dcache_parent() no longer affects other filesystems. So reverting the commit is now safe. As pointed out by Jan Kara, the leak is not as critical since the unclaimed space will be reclaimed under memory pressure or by: echo 3 > /proc/sys/vm/drop_caches But since this check is no longer required, its best to remove it. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Reported-by: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Jan Kara <jack@ucw.cz> Cc: Andrea Arcangeli <andrea@cpushare.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-11 22:26:32 +00:00
shrink_dcache_parent(dentry);
d_drop(dentry);
dput(dentry);
}
name.name = buf;
name.len = snprintf(buf, sizeof(buf), "%d", tgid);
leader = d_hash_and_lookup(mnt->mnt_root, &name);
if (!leader)
goto out;
name.name = "task";
name.len = strlen(name.name);
dir = d_hash_and_lookup(leader, &name);
if (!dir)
goto out_put_leader;
name.name = buf;
name.len = snprintf(buf, sizeof(buf), "%d", pid);
dentry = d_hash_and_lookup(dir, &name);
if (dentry) {
shrink_dcache_parent(dentry);
d_drop(dentry);
dput(dentry);
}
dput(dir);
out_put_leader:
dput(leader);
out:
return;
}
/**
* proc_flush_task - Remove dcache entries for @task from the /proc dcache.
* @task: task that should be flushed.
*
* When flushing dentries from proc, one needs to flush them from global
* proc (proc_mnt) and from all the namespaces' procs this task was seen
* in. This call is supposed to do all of this job.
*
* Looks in the dcache for
* /proc/@pid
* /proc/@tgid/task/@pid
* if either directory is present flushes it and all of it'ts children
* from the dcache.
*
* It is safe and reasonable to cache /proc entries for a task until
* that task exits. After that they just clog up the dcache with
* useless entries, possibly causing useful dcache entries to be
* flushed instead. This routine is proved to flush those useless
* dcache entries at process exit time.
*
* NOTE: This routine is just an optimization so it does not guarantee
* that no dcache entries will exist at process exit time it
* just makes it very unlikely that any will persist.
*/
void proc_flush_task(struct task_struct *task)
{
int i;
proc_flush_task: flush /proc/tid/task/pid when a sub-thread exits The exiting sub-thread flushes /proc/pid only, but this doesn't buy too much: ps and friends mostly use /proc/tid/task/pid. Remove "if (thread_group_leader())" checks from proc_flush_task() path, this means we always remove /proc/tid/task/pid dentry on exit, and this actually matches the comment above proc_flush_task(). The test-case: static void* tfunc(void *arg) { char name[256]; sprintf(name, "/proc/%d/task/%ld/status", getpid(), gettid()); close(open(name, O_RDONLY)); return NULL; } int main(void) { pthread_t t; for (;;) { if (!pthread_create(&t, NULL, &tfunc, NULL)) pthread_join(t, NULL); } } slabtop shows that pid/proc_inode_cache/etc grow quickly and "indefinitely" until the task is killed or shrink_slab() is called, not good. And the main thread needs a lot of time to exit. The same can happen if something like "ps -efL" runs continuously, while some application spawns short-living threads. Reported-by: "James M. Leddy" <jleddy@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dominic Duval <dduval@redhat.com> Cc: Frank Hirtz <fhirtz@redhat.com> Cc: "Fuller, Johnray" <Johnray.Fuller@gs.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Paul Batkowski <pbatkowski@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 23:45:34 +00:00
struct pid *pid, *tgid;
struct upid *upid;
pid = task_pid(task);
proc_flush_task: flush /proc/tid/task/pid when a sub-thread exits The exiting sub-thread flushes /proc/pid only, but this doesn't buy too much: ps and friends mostly use /proc/tid/task/pid. Remove "if (thread_group_leader())" checks from proc_flush_task() path, this means we always remove /proc/tid/task/pid dentry on exit, and this actually matches the comment above proc_flush_task(). The test-case: static void* tfunc(void *arg) { char name[256]; sprintf(name, "/proc/%d/task/%ld/status", getpid(), gettid()); close(open(name, O_RDONLY)); return NULL; } int main(void) { pthread_t t; for (;;) { if (!pthread_create(&t, NULL, &tfunc, NULL)) pthread_join(t, NULL); } } slabtop shows that pid/proc_inode_cache/etc grow quickly and "indefinitely" until the task is killed or shrink_slab() is called, not good. And the main thread needs a lot of time to exit. The same can happen if something like "ps -efL" runs continuously, while some application spawns short-living threads. Reported-by: "James M. Leddy" <jleddy@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dominic Duval <dduval@redhat.com> Cc: Frank Hirtz <fhirtz@redhat.com> Cc: "Fuller, Johnray" <Johnray.Fuller@gs.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Paul Batkowski <pbatkowski@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 23:45:34 +00:00
tgid = task_tgid(task);
for (i = 0; i <= pid->level; i++) {
upid = &pid->numbers[i];
proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
proc_flush_task: flush /proc/tid/task/pid when a sub-thread exits The exiting sub-thread flushes /proc/pid only, but this doesn't buy too much: ps and friends mostly use /proc/tid/task/pid. Remove "if (thread_group_leader())" checks from proc_flush_task() path, this means we always remove /proc/tid/task/pid dentry on exit, and this actually matches the comment above proc_flush_task(). The test-case: static void* tfunc(void *arg) { char name[256]; sprintf(name, "/proc/%d/task/%ld/status", getpid(), gettid()); close(open(name, O_RDONLY)); return NULL; } int main(void) { pthread_t t; for (;;) { if (!pthread_create(&t, NULL, &tfunc, NULL)) pthread_join(t, NULL); } } slabtop shows that pid/proc_inode_cache/etc grow quickly and "indefinitely" until the task is killed or shrink_slab() is called, not good. And the main thread needs a lot of time to exit. The same can happen if something like "ps -efL" runs continuously, while some application spawns short-living threads. Reported-by: "James M. Leddy" <jleddy@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dominic Duval <dduval@redhat.com> Cc: Frank Hirtz <fhirtz@redhat.com> Cc: "Fuller, Johnray" <Johnray.Fuller@gs.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Paul Batkowski <pbatkowski@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 23:45:34 +00:00
tgid->numbers[i].nr);
}
upid = &pid->numbers[pid->level];
if (upid->nr == 1)
pid_ns_release_proc(upid->ns);
}
static struct dentry *proc_pid_instantiate(struct inode *dir,
struct dentry * dentry,
struct task_struct *task, const void *ptr)
{
struct dentry *error = ERR_PTR(-ENOENT);
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)
goto out;
inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
inode->i_op = &proc_tgid_base_inode_operations;
inode->i_fop = &proc_tgid_base_operations;
inode->i_flags|=S_IMMUTABLE;
set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
ARRAY_SIZE(tgid_base_stuff)));
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, 0))
error = NULL;
out:
return error;
}
struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
{
struct dentry *result;
struct task_struct *task;
unsigned tgid;
struct pid_namespace *ns;
result = proc_base_lookup(dir, dentry);
if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
goto out;
tgid = name_to_int(dentry);
if (tgid == ~0U)
goto out;
ns = dentry->d_sb->s_fs_info;
rcu_read_lock();
task = find_task_by_pid_ns(tgid, ns);
if (task)
get_task_struct(task);
rcu_read_unlock();
if (!task)
goto out;
result = proc_pid_instantiate(dir, dentry, task, NULL);
put_task_struct(task);
out:
return result;
}
/*
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
* Find the first task with tgid >= tgid
2006-06-26 07:25:50 +00:00
*
*/
struct tgid_iter {
unsigned int tgid;
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
struct task_struct *task;
};
static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
{
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
struct pid *pid;
if (iter.task)
put_task_struct(iter.task);
rcu_read_lock();
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
retry:
iter.task = NULL;
pid = find_ge_pid(iter.tgid, ns);
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
if (pid) {
iter.tgid = pid_nr_ns(pid, ns);
iter.task = pid_task(pid, PIDTYPE_PID);
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
/* What we to know is if the pid we have find is the
* pid of a thread_group_leader. Testing for task
* being a thread_group_leader is the obvious thing
* todo but there is a window when it fails, due to
* the pid transfer logic in de_thread.
*
* So we perform the straight forward test of seeing
* if the pid we have found is the pid of a thread
* group leader, and don't worry if the task we have
* found doesn't happen to be a thread group leader.
* As we don't care in the case of readdir.
*/
if (!iter.task || !has_group_leader_pid(iter.task)) {
iter.tgid += 1;
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
goto retry;
}
get_task_struct(iter.task);
2006-06-26 07:25:50 +00:00
}
rcu_read_unlock();
return iter;
}
#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
struct tgid_iter iter)
{
char name[PROC_NUMBUF];
int len = snprintf(name, sizeof(name), "%d", iter.tgid);
return proc_fill_cache(filp, dirent, filldir, name, len,
proc_pid_instantiate, iter.task, NULL);
}
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
static int fake_filldir(void *buf, const char *name, int namelen,
loff_t offset, u64 ino, unsigned d_type)
{
return 0;
}
/* for the /proc/ directory itself, after non-process stuff has been done */
int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
unsigned int nr;
struct task_struct *reaper;
struct tgid_iter iter;
struct pid_namespace *ns;
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
filldir_t __filldir;
if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
goto out_no_task;
nr = filp->f_pos - FIRST_PROCESS_ENTRY;
reaper = get_proc_task(filp->f_path.dentry->d_inode);
if (!reaper)
goto out_no_task;
for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
const struct pid_entry *p = &proc_base_stuff[nr];
if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
goto out;
}
ns = filp->f_dentry->d_sb->s_fs_info;
iter.task = NULL;
iter.tgid = filp->f_pos - TGID_OFFSET;
for (iter = next_tgid(ns, iter);
iter.task;
iter.tgid += 1, iter = next_tgid(ns, iter)) {
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
if (has_pid_permissions(ns, iter.task, 2))
__filldir = filldir;
else
__filldir = fake_filldir;
filp->f_pos = iter.tgid + TGID_OFFSET;
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
put_task_struct(iter.task);
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
goto out;
}
2006-06-26 07:25:50 +00:00
}
[PATCH] proc: readdir race fix (take 3) The problem: An opendir, readdir, closedir sequence can fail to report process ids that are continually in use throughout the sequence of system calls. For this race to trigger the process that proc_pid_readdir stops at must exit before readdir is called again. This can cause ps to fail to report processes, and it is in violation of posix guarantees and normal application expectations with respect to readdir. Currently there is no way to work around this problem in user space short of providing a gargantuan buffer to user space so the directory read all happens in on system call. This patch implements the normal directory semantics for proc, that guarantee that a directory entry that is neither created nor destroyed while reading the directory entry will be returned. For directory that are either created or destroyed during the readdir you may or may not see them. Furthermore you may seek to a directory offset you have previously seen. These are the guarantee that ext[23] provides and that posix requires, and more importantly that user space expects. Plus it is a simple semantic to implement reliable service. It is just a matter of calling readdir a second time if you are wondering if something new has show up. These better semantics are implemented by scanning through the pids in numerical order and by making the file offset a pid plus a fixed offset. The pid scan happens on the pid bitmap, which when you look at it is remarkably efficient for a brute force algorithm. Given that a typical cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There are only 40 cache lines for the entire 32K pid space. A typical system will have 100 pids or more so this is actually fewer cache lines we have to look at to scan a linked list, and the worst case of having to scan the entire pid bitmap is pretty reasonable. If we need something more efficient we can go to a more efficient data structure for indexing the pids, but for now what we have should be sufficient. In addition this takes no additional locks and is actually less code than what we are doing now. Also another very subtle bug in this area has been fixed. It is possible to catch a task in the middle of de_thread where a thread is assuming the thread of it's thread group leader. This patch carefully handles that case so if we hit it we don't fail to return the pid, that is undergoing the de_thread dance. Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for providing the first fix, pointing this out and working on it. [oleg@tv-sign.ru: fix it] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 09:17:04 +00:00
filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
out:
put_task_struct(reaper);
out_no_task:
2006-06-26 07:25:50 +00:00
return 0;
}
/*
* Tasks
*/
static const struct pid_entry tid_base_stuff[] = {
DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
REG("environ", S_IRUSR, proc_environ_operations),
INF("auxv", S_IRUSR, proc_pid_auxv),
ONE("status", S_IRUGO, proc_pid_status),
ONE("personality", S_IRUGO, proc_pid_personality),
INF("limits", S_IRUGO, proc_pid_limits),
#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
#endif
REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
INF("syscall", S_IRUGO, proc_pid_syscall),
#endif
INF("cmdline", S_IRUGO, proc_pid_cmdline),
ONE("stat", S_IRUGO, proc_tid_stat),
ONE("statm", S_IRUGO, proc_pid_statm),
procfs: mark thread stack correctly in proc/<pid>/maps Stack for a new thread is mapped by userspace code and passed via sys_clone. This memory is currently seen as anonymous in /proc/<pid>/maps, which makes it difficult to ascertain which mappings are being used for thread stacks. This patch uses the individual task stack pointers to determine which vmas are actually thread stacks. For a multithreaded program like the following: #include <pthread.h> void *thread_main(void *foo) { while(1); } int main() { pthread_t t; pthread_create(&t, NULL, thread_main, NULL); pthread_join(t, NULL); } proc/PID/maps looks like the following: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Here, one could guess that 7f8a44492000-7f8a44c92000 is a stack since the earlier vma that has no permissions (7f8a44e3d000-7f8a4503d000) but that is not always a reliable way to find out which vma is a thread stack. Also, /proc/PID/maps and /proc/PID/task/TID/maps has the same content. With this patch in place, /proc/PID/task/TID/maps are treated as 'maps as the task would see it' and hence, only the vma that that task uses as stack is marked as [stack]. All other 'stack' vmas are marked as anonymous memory. /proc/PID/maps acts as a thread group level view, where all thread stack vmas are marked as [stack:TID] where TID is the process ID of the task that uses that vma as stack, while the process stack is marked as [stack]. So /proc/PID/maps will look like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Thus marking all vmas that are used as stacks by the threads in the thread group along with the process stack. The task level maps will however like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] where only the vma that is being used as a stack by *that* task is marked as [stack]. Analogous changes have been made to /proc/PID/smaps, /proc/PID/numa_maps, /proc/PID/task/TID/smaps and /proc/PID/task/TID/numa_maps. Relevant snippets from smaps and numa_maps: [siddhesh@localhost ~ ]$ pgrep a.out 1441 [siddhesh@localhost ~ ]$ cat /proc/1441/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/smaps | grep "\[stack" 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/numa_maps | grep "stack" 7f8a44492000 default stack:1442 anon=2 dirty=2 N0=2 7fff6273a000 default stack anon=3 dirty=3 N0=3 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/numa_maps | grep "stack" 7f8a44492000 default stack anon=2 dirty=2 N0=2 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/numa_maps | grep "stack" 7fff6273a000 default stack anon=3 dirty=3 N0=3 [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix build] Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jamie Lokier <jamie@shareable.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21 23:34:04 +00:00
REG("maps", S_IRUGO, proc_tid_maps_operations),
#ifdef CONFIG_CHECKPOINT_RESTORE
REG("children", S_IRUGO, proc_tid_children_operations),
#endif
#ifdef CONFIG_NUMA
procfs: mark thread stack correctly in proc/<pid>/maps Stack for a new thread is mapped by userspace code and passed via sys_clone. This memory is currently seen as anonymous in /proc/<pid>/maps, which makes it difficult to ascertain which mappings are being used for thread stacks. This patch uses the individual task stack pointers to determine which vmas are actually thread stacks. For a multithreaded program like the following: #include <pthread.h> void *thread_main(void *foo) { while(1); } int main() { pthread_t t; pthread_create(&t, NULL, thread_main, NULL); pthread_join(t, NULL); } proc/PID/maps looks like the following: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Here, one could guess that 7f8a44492000-7f8a44c92000 is a stack since the earlier vma that has no permissions (7f8a44e3d000-7f8a4503d000) but that is not always a reliable way to find out which vma is a thread stack. Also, /proc/PID/maps and /proc/PID/task/TID/maps has the same content. With this patch in place, /proc/PID/task/TID/maps are treated as 'maps as the task would see it' and hence, only the vma that that task uses as stack is marked as [stack]. All other 'stack' vmas are marked as anonymous memory. /proc/PID/maps acts as a thread group level view, where all thread stack vmas are marked as [stack:TID] where TID is the process ID of the task that uses that vma as stack, while the process stack is marked as [stack]. So /proc/PID/maps will look like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Thus marking all vmas that are used as stacks by the threads in the thread group along with the process stack. The task level maps will however like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] where only the vma that is being used as a stack by *that* task is marked as [stack]. Analogous changes have been made to /proc/PID/smaps, /proc/PID/numa_maps, /proc/PID/task/TID/smaps and /proc/PID/task/TID/numa_maps. Relevant snippets from smaps and numa_maps: [siddhesh@localhost ~ ]$ pgrep a.out 1441 [siddhesh@localhost ~ ]$ cat /proc/1441/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/smaps | grep "\[stack" 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/numa_maps | grep "stack" 7f8a44492000 default stack:1442 anon=2 dirty=2 N0=2 7fff6273a000 default stack anon=3 dirty=3 N0=3 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/numa_maps | grep "stack" 7f8a44492000 default stack anon=2 dirty=2 N0=2 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/numa_maps | grep "stack" 7fff6273a000 default stack anon=3 dirty=3 N0=3 [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix build] Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jamie Lokier <jamie@shareable.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21 23:34:04 +00:00
REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
#endif
REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
LNK("cwd", proc_cwd_link),
LNK("root", proc_root_link),
LNK("exe", proc_exe_link),
REG("mounts", S_IRUGO, proc_mounts_operations),
REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
procfs: mark thread stack correctly in proc/<pid>/maps Stack for a new thread is mapped by userspace code and passed via sys_clone. This memory is currently seen as anonymous in /proc/<pid>/maps, which makes it difficult to ascertain which mappings are being used for thread stacks. This patch uses the individual task stack pointers to determine which vmas are actually thread stacks. For a multithreaded program like the following: #include <pthread.h> void *thread_main(void *foo) { while(1); } int main() { pthread_t t; pthread_create(&t, NULL, thread_main, NULL); pthread_join(t, NULL); } proc/PID/maps looks like the following: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Here, one could guess that 7f8a44492000-7f8a44c92000 is a stack since the earlier vma that has no permissions (7f8a44e3d000-7f8a4503d000) but that is not always a reliable way to find out which vma is a thread stack. Also, /proc/PID/maps and /proc/PID/task/TID/maps has the same content. With this patch in place, /proc/PID/task/TID/maps are treated as 'maps as the task would see it' and hence, only the vma that that task uses as stack is marked as [stack]. All other 'stack' vmas are marked as anonymous memory. /proc/PID/maps acts as a thread group level view, where all thread stack vmas are marked as [stack:TID] where TID is the process ID of the task that uses that vma as stack, while the process stack is marked as [stack]. So /proc/PID/maps will look like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Thus marking all vmas that are used as stacks by the threads in the thread group along with the process stack. The task level maps will however like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] where only the vma that is being used as a stack by *that* task is marked as [stack]. Analogous changes have been made to /proc/PID/smaps, /proc/PID/numa_maps, /proc/PID/task/TID/smaps and /proc/PID/task/TID/numa_maps. Relevant snippets from smaps and numa_maps: [siddhesh@localhost ~ ]$ pgrep a.out 1441 [siddhesh@localhost ~ ]$ cat /proc/1441/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/smaps | grep "\[stack" 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/numa_maps | grep "stack" 7f8a44492000 default stack:1442 anon=2 dirty=2 N0=2 7fff6273a000 default stack anon=3 dirty=3 N0=3 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/numa_maps | grep "stack" 7f8a44492000 default stack anon=2 dirty=2 N0=2 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/numa_maps | grep "stack" 7fff6273a000 default stack anon=3 dirty=3 N0=3 [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix build] Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jamie Lokier <jamie@shareable.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21 23:34:04 +00:00
REG("smaps", S_IRUGO, proc_tid_smaps_operations),
REG("pagemap", S_IRUGO, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
#endif
#ifdef CONFIG_KALLSYMS
INF("wchan", S_IRUGO, proc_pid_wchan),
#endif
#ifdef CONFIG_STACKTRACE
ONE("stack", S_IRUGO, proc_pid_stack),
#endif
#ifdef CONFIG_SCHEDSTATS
INF("schedstat", S_IRUGO, proc_pid_schedstat),
#endif
#ifdef CONFIG_LATENCYTOP
REG("latency", S_IRUGO, proc_lstats_operations),
#endif
#ifdef CONFIG_PROC_PID_CPUSET
REG("cpuset", S_IRUGO, proc_cpuset_operations),
#endif
#ifdef CONFIG_CGROUPS
REG("cgroup", S_IRUGO, proc_cgroup_operations),
#endif
INF("oom_score", S_IRUGO, proc_oom_score),
oom: badness heuristic rewrite This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 00:19:46 +00:00
REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
#ifdef CONFIG_AUDITSYSCALL
REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
REG("sessionid", S_IRUGO, proc_sessionid_operations),
#endif
#ifdef CONFIG_FAULT_INJECTION
REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
#endif
#ifdef CONFIG_TASK_IO_ACCOUNTING
INF("io", S_IRUSR, proc_tid_io_accounting),
#endif
arch/tile: more /proc and /sys file support This change introduces a few of the less controversial /proc and /proc/sys interfaces for tile, along with sysfs attributes for various things that were originally proposed as /proc/tile files. It also adjusts the "hardwall" proc API. Arnd Bergmann reviewed the initial arch/tile submission, which included a complete set of all the /proc/tile and /proc/sys/tile knobs that we had added in a somewhat ad hoc way during initial development, and provided feedback on where most of them should go. One knob turned out to be similar enough to the existing /proc/sys/debug/exception-trace that it was re-implemented to use that model instead. Another knob was /proc/tile/grid, which reported the "grid" dimensions of a tile chip (e.g. 8x8 processors = 64-core chip). Arnd suggested looking at sysfs for that, so this change moves that information to a pair of sysfs attributes (chip_width and chip_height) in the /sys/devices/system/cpu directory. We also put the "chip_serial" and "chip_revision" information from our old /proc/tile/board file as attributes in /sys/devices/system/cpu. Other information collected via hypervisor APIs is now placed in /sys/hypervisor. We create a /sys/hypervisor/type file (holding the constant string "tilera") to be parallel with the Xen use of /sys/hypervisor/type holding "xen". We create three top-level files, "version" (the hypervisor's own version), "config_version" (the version of the configuration file), and "hvconfig" (the contents of the configuration file). The remaining information from our old /proc/tile/board and /proc/tile/switch files becomes an attribute group appearing under /sys/hypervisor/board/. Finally, after some feedback from Arnd Bergmann for the previous version of this patch, the /proc/tile/hardwall file is split up into two conceptual parts. First, a directory /proc/tile/hardwall/ which contains one file per active hardwall, each file named after the hardwall's ID and holding a cpulist that says which cpus are enclosed by the hardwall. Second, a /proc/PID file "hardwall" that is either empty (for non-hardwall-using processes) or contains the hardwall ID. Finally, this change pushes the /proc/sys/tile/unaligned_fixup/ directory, with knobs controlling the kernel code for handling the fixup of unaligned exceptions. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-26 16:40:09 +00:00
#ifdef CONFIG_HARDWALL
INF("hardwall", S_IRUGO, proc_pid_hardwall),
#endif
userns: Rework the user_namespace adding uid/gid mapping support - Convert the old uid mapping functions into compatibility wrappers - Add a uid/gid mapping layer from user space uid and gids to kernel internal uids and gids that is extent based for simplicty and speed. * Working with number space after mapping uids/gids into their kernel internal version adds only mapping complexity over what we have today, leaving the kernel code easy to understand and test. - Add proc files /proc/self/uid_map /proc/self/gid_map These files display the mapping and allow a mapping to be added if a mapping does not exist. - Allow entering the user namespace without a uid or gid mapping. Since we are starting with an existing user our uids and gids still have global mappings so are still valid and useful they just don't have local mappings. The requirement for things to work are global uid and gid so it is odd but perfectly fine not to have a local uid and gid mapping. Not requiring global uid and gid mappings greatly simplifies the logic of setting up the uid and gid mappings by allowing the mappings to be set after the namespace is created which makes the slight weirdness worth it. - Make the mappings in the initial user namespace to the global uid/gid space explicit. Today it is an identity mapping but in the future we may want to twist this for debugging, similar to what we do with jiffies. - Document the memory ordering requirements of setting the uid and gid mappings. We only allow the mappings to be set once and there are no pointers involved so the requirments are trivial but a little atypical. Performance: In this scheme for the permission checks the performance is expected to stay the same as the actuall machine instructions should remain the same. The worst case I could think of is ls -l on a large directory where all of the stat results need to be translated with from kuids and kgids to uids and gids. So I benchmarked that case on my laptop with a dual core hyperthread Intel i5-2520M cpu with 3M of cpu cache. My benchmark consisted of going to single user mode where nothing else was running. On an ext4 filesystem opening 1,000,000 files and looping through all of the files 1000 times and calling fstat on the individuals files. This was to ensure I was benchmarking stat times where the inodes were in the kernels cache, but the inode values were not in the processors cache. My results: v3.4-rc1: ~= 156ns (unmodified v3.4-rc1 with user namespace support disabled) v3.4-rc1-userns-: ~= 155ns (v3.4-rc1 with my user namespace patches and user namespace support disabled) v3.4-rc1-userns+: ~= 164ns (v3.4-rc1 with my user namespace patches and user namespace support enabled) All of the configurations ran in roughly 120ns when I performed tests that ran in the cpu cache. So in summary the performance impact is: 1ns improvement in the worst case with user namespace support compiled out. 8ns aka 5% slowdown in the worst case with user namespace support compiled in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-17 08:11:58 +00:00
#ifdef CONFIG_USER_NS
REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
userns: Rework the user_namespace adding uid/gid mapping support - Convert the old uid mapping functions into compatibility wrappers - Add a uid/gid mapping layer from user space uid and gids to kernel internal uids and gids that is extent based for simplicty and speed. * Working with number space after mapping uids/gids into their kernel internal version adds only mapping complexity over what we have today, leaving the kernel code easy to understand and test. - Add proc files /proc/self/uid_map /proc/self/gid_map These files display the mapping and allow a mapping to be added if a mapping does not exist. - Allow entering the user namespace without a uid or gid mapping. Since we are starting with an existing user our uids and gids still have global mappings so are still valid and useful they just don't have local mappings. The requirement for things to work are global uid and gid so it is odd but perfectly fine not to have a local uid and gid mapping. Not requiring global uid and gid mappings greatly simplifies the logic of setting up the uid and gid mappings by allowing the mappings to be set after the namespace is created which makes the slight weirdness worth it. - Make the mappings in the initial user namespace to the global uid/gid space explicit. Today it is an identity mapping but in the future we may want to twist this for debugging, similar to what we do with jiffies. - Document the memory ordering requirements of setting the uid and gid mappings. We only allow the mappings to be set once and there are no pointers involved so the requirments are trivial but a little atypical. Performance: In this scheme for the permission checks the performance is expected to stay the same as the actuall machine instructions should remain the same. The worst case I could think of is ls -l on a large directory where all of the stat results need to be translated with from kuids and kgids to uids and gids. So I benchmarked that case on my laptop with a dual core hyperthread Intel i5-2520M cpu with 3M of cpu cache. My benchmark consisted of going to single user mode where nothing else was running. On an ext4 filesystem opening 1,000,000 files and looping through all of the files 1000 times and calling fstat on the individuals files. This was to ensure I was benchmarking stat times where the inodes were in the kernels cache, but the inode values were not in the processors cache. My results: v3.4-rc1: ~= 156ns (unmodified v3.4-rc1 with user namespace support disabled) v3.4-rc1-userns-: ~= 155ns (v3.4-rc1 with my user namespace patches and user namespace support disabled) v3.4-rc1-userns+: ~= 164ns (v3.4-rc1 with my user namespace patches and user namespace support enabled) All of the configurations ran in roughly 120ns when I performed tests that ran in the cpu cache. So in summary the performance impact is: 1ns improvement in the worst case with user namespace support compiled out. 8ns aka 5% slowdown in the worst case with user namespace support compiled in. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-17 08:11:58 +00:00
#endif
};
static int proc_tid_base_readdir(struct file * filp,
void * dirent, filldir_t filldir)
{
return proc_pident_readdir(filp,dirent,filldir,
tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
}
static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
return proc_pident_lookup(dir, dentry,
tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
}
static const struct file_operations proc_tid_base_operations = {
.read = generic_read_dir,
.readdir = proc_tid_base_readdir,
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-15 16:52:59 +00:00
.llseek = default_llseek,
};
static const struct inode_operations proc_tid_base_inode_operations = {
.lookup = proc_tid_base_lookup,
.getattr = pid_getattr,
.setattr = proc_setattr,
};
static struct dentry *proc_task_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
{
struct dentry *error = ERR_PTR(-ENOENT);
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)
goto out;
inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
inode->i_op = &proc_tid_base_inode_operations;
inode->i_fop = &proc_tid_base_operations;
inode->i_flags|=S_IMMUTABLE;
set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
ARRAY_SIZE(tid_base_stuff)));
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, 0))
error = NULL;
out:
return error;
}
static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
{
struct dentry *result = ERR_PTR(-ENOENT);
struct task_struct *task;
struct task_struct *leader = get_proc_task(dir);
unsigned tid;
struct pid_namespace *ns;
if (!leader)
goto out_no_task;
tid = name_to_int(dentry);
if (tid == ~0U)
goto out;
ns = dentry->d_sb->s_fs_info;
rcu_read_lock();
task = find_task_by_pid_ns(tid, ns);
if (task)
get_task_struct(task);
rcu_read_unlock();
if (!task)
goto out;
if (!same_thread_group(leader, task))
goto out_drop_task;
result = proc_task_instantiate(dir, dentry, task, NULL);
out_drop_task:
put_task_struct(task);
out:
put_task_struct(leader);
out_no_task:
return result;
}
2006-06-26 07:25:50 +00:00
/*
* Find the first tid of a thread group to return to user space.
*
* Usually this is just the thread group leader, but if the users
* buffer was too small or there was a seek into the middle of the
* directory we have more work todo.
*
* In the case of a short read we start with find_task_by_pid.
*
* In the case of a seek we start with the leader and walk nr
* threads past it.
*/
static struct task_struct *first_tid(struct task_struct *leader,
int tid, int nr, struct pid_namespace *ns)
2006-06-26 07:25:50 +00:00
{
struct task_struct *pos;
rcu_read_lock();
2006-06-26 07:25:50 +00:00
/* Attempt to start with the pid of a thread */
if (tid && (nr > 0)) {
pos = find_task_by_pid_ns(tid, ns);
if (pos && (pos->group_leader == leader))
goto found;
2006-06-26 07:25:50 +00:00
}
2006-06-26 07:25:50 +00:00
/* If nr exceeds the number of threads there is nothing todo */
pos = NULL;
if (nr && nr >= get_nr_threads(leader))
goto out;
/* If we haven't found our starting place yet start
* with the leader and walk nr threads forward.
2006-06-26 07:25:50 +00:00
*/
for (pos = leader; nr > 0; --nr) {
pos = next_thread(pos);
if (pos == leader) {
pos = NULL;
goto out;
}
}
found:
get_task_struct(pos);
out:
rcu_read_unlock();
2006-06-26 07:25:50 +00:00
return pos;
}
/*
* Find the next thread in the thread list.
* Return NULL if there is an error or no next thread.
*
* The reference to the input task_struct is released.
*/
static struct task_struct *next_tid(struct task_struct *start)
{
struct task_struct *pos = NULL;
rcu_read_lock();
if (pid_alive(start)) {
2006-06-26 07:25:50 +00:00
pos = next_thread(start);
if (thread_group_leader(pos))
pos = NULL;
else
get_task_struct(pos);
}
rcu_read_unlock();
2006-06-26 07:25:50 +00:00
put_task_struct(start);
return pos;
}
static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
struct task_struct *task, int tid)
{
char name[PROC_NUMBUF];
int len = snprintf(name, sizeof(name), "%d", tid);
return proc_fill_cache(filp, dirent, filldir, name, len,
proc_task_instantiate, task, NULL);
}
/* for the /proc/TGID/task/ directories */
static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
struct task_struct *leader = NULL;
2006-06-26 07:25:50 +00:00
struct task_struct *task;
int retval = -ENOENT;
ino_t ino;
2006-06-26 07:25:50 +00:00
int tid;
struct pid_namespace *ns;
task = get_proc_task(inode);
if (!task)
goto out_no_task;
rcu_read_lock();
if (pid_alive(task)) {
leader = task->group_leader;
get_task_struct(leader);
}
rcu_read_unlock();
put_task_struct(task);
if (!leader)
goto out_no_task;
retval = 0;
switch ((unsigned long)filp->f_pos) {
case 0:
ino = inode->i_ino;
if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
goto out;
filp->f_pos++;
/* fall through */
case 1:
ino = parent_ino(dentry);
if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
goto out;
filp->f_pos++;
/* fall through */
}
2006-06-26 07:25:50 +00:00
/* f_version caches the tgid value that the last readdir call couldn't
* return. lseek aka telldir automagically resets f_version to 0.
*/
ns = filp->f_dentry->d_sb->s_fs_info;
tid = (int)filp->f_version;
2006-06-26 07:25:50 +00:00
filp->f_version = 0;
for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
2006-06-26 07:25:50 +00:00
task;
task = next_tid(task), filp->f_pos++) {
tid = task_pid_nr_ns(task, ns);
if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
2006-06-26 07:25:50 +00:00
/* returning this tgid failed, save it as the first
* pid for the next readir call */
filp->f_version = (u64)tid;
2006-06-26 07:25:50 +00:00
put_task_struct(task);
break;
2006-06-26 07:25:50 +00:00
}
}
out:
put_task_struct(leader);
out_no_task:
return retval;
}
static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
struct task_struct *p = get_proc_task(inode);
generic_fillattr(inode, stat);
if (p) {
stat->nlink += get_nr_threads(p);
put_task_struct(p);
}
return 0;
}
static const struct inode_operations proc_task_inode_operations = {
.lookup = proc_task_lookup,
.getattr = proc_task_getattr,
.setattr = proc_setattr,
procfs: add hidepid= and gid= mount options Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc/<pid>/ directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg KH <greg@kroah.com> Cc: Theodore Tso <tytso@MIT.EDU> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 23:11:31 +00:00
.permission = proc_pid_permission,
};
static const struct file_operations proc_task_operations = {
.read = generic_read_dir,
.readdir = proc_task_readdir,
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-15 16:52:59 +00:00
.llseek = default_llseek,
};