Commit Graph

215 Commits

Author SHA1 Message Date
Vincent Li
cba8aafe1e fs/proc/base.c: fix proc_fault_inject_write() input sanity check
Remove obfuscated zero-length input check and return -EINVAL instead of
-EIO error to make the error message clear to user.  Add whitespace
stripping.  No functionality changes.

The old code:

echo  1  > /proc/pid/make-it-fail (ok)
echo 1foo > /proc/pid/make-it-fail (-bash: echo: write error: Input/output error)

The new code:

echo  1  > /proc/pid/make-it-fail (ok)
echo 1foo > /proc/pid/make-it-fail (-bash: echo: write error: Invalid argument)

This patch is conservative in changes to not breaking existing
scripts/applications.

Signed-off-by: Vincent Li <macli@brc.ubc.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 07:39:40 -07:00
Oleg Nesterov
9b4d1cbef8 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>
2009-09-23 07:39:40 -07:00
Kees Cook
cff4edb591 proc: fix reported unit for RLIMIT_CPU
/proc/$pid/limits should show RLIMIT_CPU as seconds, which is the unit
used in kernel/posix-cpu-timers.c:

        unsigned long psecs = cputime_to_secs(ptime);
        ...
        if (psecs >= sig->rlim[RLIMIT_CPU].rlim_max) {
                ...
                __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);

Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 07:39:40 -07:00
KOSAKI Motohiro
5d863b8968 oom: fix oom_adjust_write() input sanity check
Andrew Morton pointed out oom_adjust_write() has very strange EIO
and new line handling. this patch fixes it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2009-09-22 07:17:39 -07:00
KOSAKI Motohiro
495789a51a oom: make oom_score to per-process value
oom-killer kills a process, not task.  Then oom_score should be calculated
as per-process too.  it makes consistency more and makes speed up
select_bad_process().

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2009-09-22 07:17:39 -07:00
KOSAKI Motohiro
28b83c5193 oom: move oom_adj value from task_struct to signal_struct
Currently, OOM logic callflow is here.

    __out_of_memory()
        select_bad_process()            for each task
            badness()                   calculate badness of one task
                oom_kill_process()      search child
                    oom_kill_task()     kill target task and mm shared tasks with it

example, process-A have two thread, thread-A and thread-B and it have very
fat memory and each thread have following oom_adj and oom_score.

     thread-A: oom_adj = OOM_DISABLE, oom_score = 0
     thread-B: oom_adj = 0,           oom_score = very-high

Then, select_bad_process() select thread-B, but oom_kill_task() refuse
kill the task because thread-A have OOM_DISABLE.  Thus __out_of_memory()
call select_bad_process() again.  but select_bad_process() select the same
task.  It mean kernel fall in livelock.

The fact is, select_bad_process() must select killable task.  otherwise
OOM logic go into livelock.

And root cause is, oom_adj shouldn't be per-thread value.  it should be
per-process value because OOM-killer kill a process, not thread.  Thus
This patch moves oomkilladj (now more appropriately named oom_adj) from
struct task_struct to struct signal_struct.  it naturally prevent
select_bad_process() choose wrong task.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.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>
2009-09-22 07:17:39 -07:00
KOSAKI Motohiro
0753ba01e1 mm: revert "oom: move oom_adj value"
The commit 2ff05b2b (oom: move oom_adj value) moveed the oom_adj value to
the mm_struct.  It was a very good first step for sanitize OOM.

However Paul Menage reported the commit makes regression to his job
scheduler.  Current OOM logic can kill OOM_DISABLED process.

Why? His program has the code of similar to the following.

	...
	set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */
	...
	if (vfork() == 0) {
		set_oom_adj(0); /* Invoked child can be killed */
		execve("foo-bar-cmd");
	}
	....

vfork() parent and child are shared the same mm_struct.  then above
set_oom_adj(0) doesn't only change oom_adj for vfork() child, it's also
change oom_adj for vfork() parent.  Then, vfork() parent (job scheduler)
lost OOM immune and it was killed.

Actually, fork-setting-exec idiom is very frequently used in userland program.
We must not break this assumption.

Then, this patch revert commit 2ff05b2b and related commit.

Reverted commit list
---------------------
- commit 2ff05b2b4e (oom: move oom_adj value from task_struct to mm_struct)
- commit 4d8b9135c3 (oom: avoid unnecessary mm locking and scanning for OOM_DISABLE)
- commit 8123681022 (oom: only oom kill exiting tasks with attached memory)
- commit 933b787b57 (mm: copy over oom_adj value at fork time)

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-18 16:31:13 -07:00
Oleg Nesterov
704b836cbf mm_for_maps: take ->cred_guard_mutex to fix the race with exec
The problem is minor, but without ->cred_guard_mutex held we can race
with exec() and get the new ->mm but check old creds.

Now we do not need to re-check task->mm after ptrace_may_access(), it
can't be changed to the new mm under us.

Strictly speaking, this also fixes another very minor problem. Unless
security check fails or the task exits mm_for_maps() should never
return NULL, the caller should get either old or new ->mm.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-10 20:49:26 +10:00
Oleg Nesterov
00f89d2185 mm_for_maps: shift down_read(mmap_sem) to the caller
mm_for_maps() takes ->mmap_sem after security checks, this looks
strange and obfuscates the locking rules. Move this lock to its
single caller, m_start().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-10 20:48:32 +10:00
Oleg Nesterov
13f0feafa6 mm_for_maps: simplify, use ptrace_may_access()
It would be nice to kill __ptrace_may_access(). It requires task_lock(),
but this lock is only needed to read mm->flags in the middle.

Convert mm_for_maps() to use ptrace_may_access(), this also simplifies
the code a little bit.

Also, we do not need to take ->mmap_sem in advance. In fact I think
mm_for_maps() should not play with ->mmap_sem at all, the caller should
take this lock.

With or without this patch, without ->cred_guard_mutex held we can race
with exec() and get the new ->mm but check old creds.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-10 20:47:42 +10:00
David Rientjes
2ff05b2b4e oom: move oom_adj value from task_struct to mm_struct
The per-task oom_adj value is a characteristic of its mm more than the
task itself since it's not possible to oom kill any thread that shares the
mm.  If a task were to be killed while attached to an mm that could not be
freed because another thread were set to OOM_DISABLE, it would have
needlessly been terminated since there is no potential for future memory
freeing.

This patch moves oomkilladj (now more appropriately named oom_adj) from
struct task_struct to struct mm_struct.  This requires task_lock() on a
task to check its oom_adj value to protect against exec, but it's already
necessary to take the lock when dereferencing the mm to find the total VM
size for the badness heuristic.

This fixes a livelock if the oom killer chooses a task and another thread
sharing the same memory has an oom_adj value of OOM_DISABLE.  This occurs
because oom_kill_task() repeatedly returns 1 and refuses to kill the
chosen task while select_bad_process() will repeatedly choose the same
task during the next retry.

Taking task_lock() in select_bad_process() to check for OOM_DISABLE and in
oom_kill_task() to check for threads sharing the same memory will be
removed in the next patch in this series where it will no longer be
necessary.

Writing to /proc/pid/oom_adj for a kthread will now return -EINVAL since
these threads are immune from oom killing already.  They simply report an
oom_adj value of OOM_DISABLE.

Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:43 -07:00
James Morris
0b4ec6e4e0 Merge branch 'master' into next 2009-06-09 09:27:53 +10:00
KOSAKI Motohiro
bd6daba909 procfs: make errno values consistent when open pident vs exit(2) race occurs
proc_pident_instantiate() has following call flow.

proc_pident_lookup()
  proc_pident_instantiate()
    proc_pid_make_inode()

And, proc_pident_lookup() has following error handling.

	const struct pid_entry *p, *last;
	error = ERR_PTR(-ENOENT);
	if (!task)
		goto out_no_task;

Then, proc_pident_instantiate should return ENOENT too when racing against
exit(2) occur.

EINAL has two bad reason.
  - it implies caller is wrong. bad the race isn't caller's mistake.
  - man 2 open don't explain EINVAL. user often don't handle it.

Note: Other proc_pid_make_inode() caller already use ENOENT properly.

Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-29 08:40:02 -07:00
David Howells
107db7c7dd CRED: Guard the setprocattr security hook against ptrace
Guard the setprocattr security hook against ptrace by taking the target task's
cred_guard_mutex around it.  The problem is that setprocattr() may otherwise
note the lack of a debugger, and then perform an action on that basis whilst
letting a debugger attach between the two points.  Holding cred_guard_mutex
across the test and the action prevents ptrace_attach() from doing that.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-05-11 08:15:39 +10:00
Jake Edge
f83ce3e6b0 proc: avoid information leaks to non-privileged processes
By using the same test as is used for /proc/pid/maps and /proc/pid/smaps,
only allow processes that can ptrace() a given process to see information
that might be used to bypass address space layout randomization (ASLR).
These include eip, esp, wchan, and start_stack in /proc/pid/stat as well
as the non-symbolic output from /proc/pid/wchan.

ASLR can be bypassed by sampling eip as shown by the proof-of-concept
code at http://code.google.com/p/fuzzyaslr/ As part of a presentation
(http://www.cr0.org/paper/to-jt-linux-alsr-leak.pdf) esp and wchan were
also noted as possibly usable information leaks as well.  The
start_stack address also leaks potentially useful information.

Cc: Stable Team <stable@kernel.org>
Signed-off-by: Jake Edge <jake@lwn.net>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-04 15:14:23 -07:00
KOSAKI Motohiro
31b07093c4 proc: mounts_poll() make consistent to mdstat_poll
In recently sysfs_poll discussion, Neil Brown pointed out /proc/mounts
also should be fixed.

SUSv3 says "Regular files shall always poll TRUE for reading and
writing".  see
http://www.opengroup.org/onlinepubs/009695399/functions/poll.html

Then, mounts_poll()'s default should be "POLLIN | POLLRDNORM".  it mean
always readable.

In addition, event trigger should use "POLLERR | POLLPRI" instead
POLLERR.  it makes consistent to mdstat_poll() and sysfs_poll(). and,
select(2) can handle POLLPRI easily.


Reported-by: Neil Brown <neilb@suse.de>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-16 16:17:10 -07:00
Al Viro
5ad4e53bd5 Get rid of indirect include of fs_struct.h
Don't pull it in sched.h; very few files actually need it and those
can include directly.  sched.h itself only needs forward declaration
of struct fs_struct;

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:27 -04:00
Hugh Dickins
7c2c7d9930 fix setuid sometimes wouldn't
check_unsafe_exec() also notes whether the fs_struct is being
shared by more threads than will get killed by the exec, and if so
sets LSM_UNSAFE_SHARE to make bprm_set_creds() careful about euid.
But /proc/<pid>/cwd and /proc/<pid>/root lookups make transient
use of get_fs_struct(), which also raises that sharing count.

This might occasionally cause a setuid program not to change euid,
in the same way as happened with files->count (check_unsafe_exec
also looks at sighand->count, but /proc doesn't raise that one).

We'd prefer exec not to unshare fs_struct: so fix this in procfs,
replacing get_fs_struct() by get_fs_path(), which does path_get
while still holding task_lock, instead of raising fs->count.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: stable@kernel.org
___

 fs/proc/base.c |   50 +++++++++++++++--------------------------------
 1 file changed, 16 insertions(+), 34 deletions(-)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-28 17:30:00 -07:00
Al Viro
d72f71eb0e constify dentry_operations: procfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:44:01 -04:00
Linus Torvalds
ee568b25ee Avoid 64-bit "switch()" statements on 32-bit architectures
Commit ee6f779b9e ("filp->f_pos not
correctly updated in proc_task_readdir") changed the proc code to use
filp->f_pos directly, rather than through a temporary variable.  In the
process, that caused the operations to be done on the full 64 bits, even
though the offset is never that big.

That's all fine and dandy per se, but for some unfathomable reason gcc
generates absolutely horrid code when using 64-bit values in switch()
statements.  To the point of actually calling out to gcc helper
functions like __cmpdi2 rather than just doing the trivial comparisons
directly the way gcc does for normal compares.  At which point we get
link failures, because we really don't want to support that kind of
crazy code.

Fix this by just casting the f_pos value to "unsigned long", which
is plenty big enough for /proc, and avoids the gcc code generation issue.

Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Zhang Le <r0bertz@gentoo.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-17 10:02:35 -07:00
Zhang Le
ee6f779b9e filp->f_pos not correctly updated in proc_task_readdir
filp->f_pos only get updated at the end of the function. Thus d_off of those
dirents who are in the middle will be 0, and this will cause a problem in
glibc's readdir implementation, specifically endless loop. Because when overflow
occurs, f_pos will be set to next dirent to read, however it will be 0, unless
the next one is the last one. So it will start over again and again.

There is a sample program in man 2 gendents. This is the output of the program
running on a multithread program's task dir before this patch is applied:

  $ ./a.out /proc/3807/task
  --------------- nread=128 ---------------
  i-node#  file type  d_reclen  d_off   d_name
    506442  directory    16          1  .
    506441  directory    16          0  ..
    506443  directory    16          0  3807
    506444  directory    16          0  3809
    506445  directory    16          0  3812
    506446  directory    16          0  3861
    506447  directory    16          0  3862
    506448  directory    16          8  3863

This is the output after this patch is applied

  $ ./a.out /proc/3807/task
  --------------- nread=128 ---------------
  i-node#  file type  d_reclen  d_off   d_name
    506442  directory    16          1  .
    506441  directory    16          2  ..
    506443  directory    16          3  3807
    506444  directory    16          4  3809
    506445  directory    16          5  3812
    506446  directory    16          6  3861
    506447  directory    16          7  3862
    506448  directory    16          8  3863

Signed-off-by: Zhang Le <r0bertz@gentoo.org>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-16 07:51:33 -07:00
Linus Torvalds
a0c9f240a9 Merge branch 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc
* 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc:
  proc: remove write-only variable in proc_pident_lookup()
  proc: fix sparse warning
  proc: add /proc/*/stack
  proc: remove '##' usage
  proc: remove useless WARN_ONs
  proc: stop using BKL
2009-01-07 12:01:06 -08:00
Al Viro
56ff5efad9 zero i_uid/i_gid on inode allocation
... and don't bother in callers.  Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.

i_mode is not worth the effort; it has no common default value.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:28 -05:00
WANG Cong
230e40fbda proc: remove write-only variable in proc_pident_lookup()
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-05 12:27:45 +03:00
Hannes Eder
dfe6b7d940 proc: fix sparse warning
fs/proc/base.c:312:4: warning: do-while statement is not a compound statement

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-05 12:27:45 +03:00
Ken Chen
2ec220e27f proc: add /proc/*/stack
/proc/*/stack adds the ability to query a task's stack trace. It is more
useful than /proc/*/wchan as it provides full stack trace instead of single
depth. Example output:

	$ cat /proc/self/stack
	[<c010a271>] save_stack_trace_tsk+0x17/0x35
	[<c01827b4>] proc_pid_stack+0x4a/0x76
	[<c018312d>] proc_single_show+0x4a/0x5e
	[<c016bdec>] seq_read+0xf3/0x29f
	[<c015a004>] vfs_read+0x6d/0x91
	[<c015a0c1>] sys_read+0x3b/0x60
	[<c0102eda>] syscall_call+0x7/0xb
	[<ffffffff>] 0xffffffff

[add save_stack_trace_tsk() on mips, ACK Ralf --adobriyan]
Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-05 12:27:44 +03:00
Alexey Dobriyan
631f9c1868 proc: remove '##' usage
Inability to jump to /proc/*/foo handlers with ctags is annoying.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-05 12:27:44 +03:00
Alexey Dobriyan
ecae934edc proc: remove useless WARN_ONs
NULL "struct inode *" means VFS passed NULL inode to ->open.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-05 12:27:44 +03:00
Linus Torvalds
a39b863342 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits)
  sched: fix warning in fs/proc/base.c
  schedstat: consolidate per-task cpu runtime stats
  sched: use RCU variant of list traversal in for_each_leaf_rt_rq()
  sched, cpuacct: export percpu cpuacct cgroup stats
  sched, cpuacct: refactoring cpuusage_read / cpuusage_write
  sched: optimize update_curr()
  sched: fix wakeup preemption clock
  sched: add missing arch_update_cpu_topology() call
  sched: let arch_update_cpu_topology indicate if topology changed
  sched: idle_balance() does not call load_balance_newidle()
  sched: fix sd_parent_degenerate on non-numa smp machine
  sched: add uid information to sched_debug for CONFIG_USER_SCHED
  sched: move double_unlock_balance() higher
  sched: update comment for move_task_off_dead_cpu
  sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares
  sched/rt: removed unneeded defintion
  sched: add hierarchical accounting to cpu accounting controller
  sched: include group statistics in /proc/sched_debug
  sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER
  sched: clean up SCHED_CPUMASK_ALLOC
  ...
2008-12-28 12:27:58 -08:00
James Morris
cbacc2c7f0 Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
Ingo Molnar
826e08b015 sched: fix warning in fs/proc/base.c
Stephen Rothwell reported this new (harmless) build warning on platforms that
define u64 to long:

 fs/proc/base.c: In function 'proc_pid_schedstat':
 fs/proc/base.c:352: warning: format '%llu' expects type 'long long unsigned int', but argument 3 has type 'u64'

asm-generic/int-l64.h platforms strike again: that file should be eliminated.

Fix it by casting the parameters to long long.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-22 07:41:06 +01:00
Ken Chen
9c2c48020e schedstat: consolidate per-task cpu runtime stats
Impact: simplify code

When we turn on CONFIG_SCHEDSTATS, per-task cpu runtime is accumulated
twice. Once in task->se.sum_exec_runtime and once in sched_info.cpu_time.
These two stats are exactly the same.

Given that task->se.sum_exec_runtime is always accumulated by the core
scheduler, sched_info can reuse that data instead of duplicate the accounting.

Signed-off-by: Ken Chen <kenchen@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 13:54:01 +01:00
Hugh Dickins
9c24624727 KSYM_SYMBOL_LEN fixes
Miles Lane tailing /sys files hit a BUG which Pekka Enberg has tracked
to my 966c8c12dc sprint_symbol(): use
less stack exposing a bug in slub's list_locations() -
kallsyms_lookup() writes a 0 to namebuf[KSYM_NAME_LEN-1], but that was
beyond the end of page provided.

The 100 slop which list_locations() allows at end of page looks roughly
enough for all the other stuff it might print after the symbol before
it checks again: break out KSYM_SYMBOL_LEN earlier than before.

Latencytop and ftrace and are using KSYM_NAME_LEN buffers where they
need KSYM_SYMBOL_LEN buffers, and vmallocinfo a 2*KSYM_NAME_LEN buffer
where it wants a KSYM_SYMBOL_LEN buffer: fix those before anyone copies
them.

[akpm@linux-foundation.org: ftrace.h needs module.h]
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc Miles Lane <miles.lane@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10 08:01:54 -08:00
David Howells
c69e8d9c01 CRED: Use RCU to access another task's creds and to release a task's own creds
Use RCU to access another task's creds and to release a task's own creds.
This means that it will be possible for the credentials of a task to be
replaced without another task (a) requiring a full lock to read them, and (b)
seeing deallocated memory.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:19 +11:00
David Howells
b6dff3ec5e CRED: Separate task security context from task_struct
Separate the task security context from task_struct.  At this point, the
security data is temporarily embedded in the task_struct with two pointers
pointing to it.

Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in
entry.S via asm-offsets.

With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:16 +11:00
Al Viro
aeb5d72706 [PATCH] introduce fmode_t, do annotations
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21 07:47:06 -04:00
Alexey Dobriyan
3bbfe05967 proc: remove kernel.maps_protect
After commit 831830b5a2 aka
"restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace"
sysctl stopped being relevant because commit moved security checks from ->show
time to ->start time (mm_for_maps()).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
2008-10-10 04:24:51 +04:00
Kees Cook
4783072308 [PATCH] proc: show personality via /proc/pid/personality
Make process personality flags visible in /proc.  Since a process's
personality is potentially sensitive (e.g. READ_IMPLIES_EXEC), make this
file only readable by the process owner.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-10 04:18:57 +04:00
Lai Jiangshan
a6bebbc87a [PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock()
lock_task_sighand() make sure task->sighand is being protected,
so we do not need rcu_read_lock().
[ exec() will get task->sighand->siglock before change task->sighand! ]

But code using rcu_read_lock() _just_ to protect lock_task_sighand()
only appear in procfs. (and some code in procfs use lock_task_sighand()
without such redundant protection.)

Other subsystem may put lock_task_sighand() into rcu_read_lock()
critical region, but these rcu_read_lock() are used for protecting
"for_each_process()", "find_task_by_vpid()" etc. , not for protecting
lock_task_sighand().

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
[ok from Oleg]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-10 04:18:57 +04:00
Alexander Beregalov
7c44319dc6 proc: fix warnings
proc: fix warnings

 fs/proc/base.c:2429: warning: format '%llu' expects type 'long long unsigned int', but argument 3 has type 'u64'
 fs/proc/base.c:2429: warning: format '%llu' expects type 'long long unsigned int', but argument 4 has type 'u64'
 fs/proc/base.c:2429: warning: format '%llu' expects type 'long long unsigned int', but argument 5 has type 'u64'
 fs/proc/base.c:2429: warning: format '%llu' expects type 'long long unsigned int', but argument 6 has type 'u64'
 fs/proc/base.c:2429: warning: format '%llu' expects type 'long long unsigned int', but argument 7 has type 'u64'
 fs/proc/base.c:2429: warning: format '%llu' expects type 'long long unsigned int', but argument 8 has type 'u64'
 fs/proc/base.c:2429: warning: format '%llu' expects type 'long long unsigned int', but argument 9 has type 'u64'

Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Acked-by: Andrea Righi <righi.andrea@gmail.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-05 14:33:50 -07:00
Andrea Righi
940389b8af task IO accounting: move all IO statistics in struct task_io_accounting
Simplify the code of include/linux/task_io_accounting.h.

It is also more reasonable to have all the task i/o-related statistics in a
single struct (task_io_accounting).

Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-27 16:12:28 -07:00
Andrea Righi
5995477ab7 task IO accounting: improve code readability
Put all i/o statistics in struct proc_io_accounting and use inline functions to
initialize and increment statistics, removing a lot of single variable
assignments.

This also reduces the kernel size as following (with CONFIG_TASK_XACCT=y and
CONFIG_TASK_IO_ACCOUNTING=y).

    text    data     bss     dec     hex filename
   11651       0       0   11651    2d83 kernel/exit.o.before
   11619       0       0   11619    2d63 kernel/exit.o.after
   10886     132     136   11154    2b92 kernel/fork.o.before
   10758     132     136   11026    2b12 kernel/fork.o.after

 3082029  807968 4818600 8708597  84e1f5 vmlinux.o.before
 3081869  807968 4818600 8708437  84e155 vmlinux.o.after

Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-27 09:58:20 -07:00
Linus Torvalds
4836e30078 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (39 commits)
  [PATCH] fix RLIM_NOFILE handling
  [PATCH] get rid of corner case in dup3() entirely
  [PATCH] remove remaining namei_{32,64}.h crap
  [PATCH] get rid of indirect users of namei.h
  [PATCH] get rid of __user_path_lookup_open
  [PATCH] f_count may wrap around
  [PATCH] dup3 fix
  [PATCH] don't pass nameidata to __ncp_lookup_validate()
  [PATCH] don't pass nameidata to gfs2_lookupi()
  [PATCH] new (local) helper: user_path_parent()
  [PATCH] sanitize __user_walk_fd() et.al.
  [PATCH] preparation to __user_walk_fd cleanup
  [PATCH] kill nameidata passing to permission(), rename to inode_permission()
  [PATCH] take noexec checks to very few callers that care
  Re: [PATCH 3/6] vfs: open_exec cleanup
  [patch 4/4] vfs: immutable inode checking cleanup
  [patch 3/4] fat: dont call notify_change
  [patch 2/4] vfs: utimes cleanup
  [patch 1/4] vfs: utimes: move owner check into inode_change_ok()
  [PATCH] vfs: use kstrdup() and check failing allocation
  ...
2008-07-26 20:23:44 -07:00
Andrea Righi
b2d002dba5 task IO accounting: correctly account threads IO statistics
Oleg Nesterov points out that we should check that the task is still alive
before we iterate over the threads.  This patch includes a fixup for this.

Also simplify do_io_accounting() implementation.

Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 20:16:47 -07:00
Al Viro
e6305c43ed [PATCH] sanitize ->permission() prototype
* kill nameidata * argument; map the 3 bits in ->flags anybody cares
  about to new MAY_... ones and pass with the mask.
* kill redundant gfs2_iop_permission()
* sanitize ecryptfs_permission()
* fix remaining places where ->permission() instances might barf on new
  MAY_... found in mask.

The obvious next target in that direction is permission(9)

folded fix for nfs_permission() breakage from Miklos Szeredi <mszeredi@suse.cz>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:14 -04:00
Roland McGrath
ebcb67341f /proc/PID/syscall
This adds /proc/PID/syscall and /proc/PID/task/TID/syscall magic files.
These use task_current_syscall() to show the task's current system call
number and argument registers, stack pointer and PC.  For a task blocked
but not in a syscall, the file shows "-1" in place of the syscall number,
followed by only the SP and PC.  For a task that's not blocked, it shows
"running".

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:10 -07:00
Roland McGrath
0d094efeb1 tracehook: tracehook_tracer_task
This adds the tracehook_tracer_task() hook to consolidate all forms of
"Who is using ptrace on me?" logic.  This is used for "TracerPid:" in
/proc and for permission checks.  We also clean up the selinux code the
called an identical accessor.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:08 -07:00
Andrea Righi
297c5d9263 task IO accounting: provide distinct tgid/tid I/O statistics
Report per-thread I/O statistics in /proc/pid/task/tid/io and aggregate
parent I/O statistics in /proc/pid/io.  This approach follows the same
model used to account per-process and per-thread CPU times.

As a practial application, this allows for example to quickly find the top
I/O consumer when a process spawns many child threads that perform the
actual I/O work, because the aggregated I/O statistics can always be found
in /proc/pid/io.

[ Oleg Nesterov points out that we should check that the task is still
  alive before we iterate over the threads, but also says that we can do
  that fixup on top of this later.  - Linus ]

Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Cc: Matt Heaton <matt@hostmonster.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Acked-by-with-comments: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:47 -07:00
Stephen Smalley
006ebb40d3 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>
2008-07-14 15:01:47 +10:00
Vegard Nossum
aed5417593 proc: calculate the correct /proc/<pid> link count
This patch:

  commit e9720acd72
  Author: Pavel Emelyanov <xemul@openvz.org>
  Date:   Fri Mar 7 11:08:40 2008 -0800

    [NET]: Make /proc/net a symlink on /proc/self/net (v3)

introduced a /proc/self/net directory without bumping the corresponding
link count for /proc/self.

This patch replaces the static link count initializations with a call that
counts the number of directory entries in the given pid_entry table
whenever it is instantiated, and thus relieves the burden of manually
keeping the two in sync.

[akpm@linux-foundation.org: cleanup]
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:13 -07:00