Make the position an in/out argument like all the other read/write
helpers and and make the buf argument a void pointer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Use proper ssize_t and size_t types for the return value and count
argument, move the offset last and make it an in/out argument like
all other read/write helpers, and make the buf argument a void pointer
to get rid of lots of casts in the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Prevent use of uninitialized memory (originating from the stack frame of
do_sysctl()) by verifying that the name array is filled with sufficient
input data before comparing its specific entries with integer constants.
Through timing measurement or analyzing the kernel debug logs, a
user-mode program could potentially infer the results of comparisons
against the uninitialized memory, and acquire some (very limited)
information about the state of the kernel stack. The change also
eliminates possible future warnings by tools such as KMSAN and other
code checkers / instrumentations.
Link: http://lkml.kernel.org/r/20170524122139.21333-1-mjurczyk@google.com
Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Matthew Whitehead <tedheadster@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Do not break lines while printk()ing values.
kernel: warning: process `tomoyo_file_tes' used the deprecated sysctl system call with
kernel: 3.
kernel: 5.
kernel: 56.
kernel:
Link: http://lkml.kernel.org/r/1480814833-4976-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit fixes the following security hole affecting systems where
all of the following conditions are fulfilled:
- The fs.suid_dumpable sysctl is set to 2.
- The kernel.core_pattern sysctl's value starts with "/". (Systems
where kernel.core_pattern starts with "|/" are not affected.)
- Unprivileged user namespace creation is permitted. (This is
true on Linux >=3.8, but some distributions disallow it by
default using a distro patch.)
Under these conditions, if a program executes under secure exec rules,
causing it to run with the SUID_DUMP_ROOT flag, then unshares its user
namespace, changes its root directory and crashes, the coredump will be
written using fsuid=0 and a path derived from kernel.core_pattern - but
this path is interpreted relative to the root directory of the process,
allowing the attacker to control where a coredump will be written with
root privileges.
To fix the security issue, always interpret core_pattern for dumps that
are written under SUID_DUMP_ROOT relative to the root directory of init.
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There have been several times where I have had to rebuild a kernel to
cause a panic when hitting a WARN() in the code in order to get a crash
dump from a system. Sometimes this is easy to do, other times (such as
in the case of a remote admin) it is not trivial to send new images to
the user.
A much easier method would be a switch to change the WARN() over to a
panic. This makes debugging easier in that I can now test the actual
image the WARN() was seen on and I do not have to engage in remote
debugging.
This patch adds a panic_on_warn kernel parameter and
/proc/sys/kernel/panic_on_warn calls panic() in the
warn_slowpath_common() path. The function will still print out the
location of the warning.
An example of the panic_on_warn output:
The first line below is from the WARN_ON() to output the WARN_ON()'s
location. After that the panic() output is displayed.
WARNING: CPU: 30 PID: 11698 at /home/prarit/dummy_module/dummy-module.c:25 init_dummy+0x1f/0x30 [dummy_module]()
Kernel panic - not syncing: panic_on_warn set ...
CPU: 30 PID: 11698 Comm: insmod Tainted: G W OE 3.17.0+ #57
Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013
0000000000000000 000000008e3f87df ffff88080f093c38 ffffffff81665190
0000000000000000 ffffffff818aea3d ffff88080f093cb8 ffffffff8165e2ec
ffffffff00000008 ffff88080f093cc8 ffff88080f093c68 000000008e3f87df
Call Trace:
[<ffffffff81665190>] dump_stack+0x46/0x58
[<ffffffff8165e2ec>] panic+0xd0/0x204
[<ffffffffa038e05f>] ? init_dummy+0x1f/0x30 [dummy_module]
[<ffffffff81076b90>] warn_slowpath_common+0xd0/0xd0
[<ffffffffa038e040>] ? dummy_greetings+0x40/0x40 [dummy_module]
[<ffffffff81076c8a>] warn_slowpath_null+0x1a/0x20
[<ffffffffa038e05f>] init_dummy+0x1f/0x30 [dummy_module]
[<ffffffff81002144>] do_one_initcall+0xd4/0x210
[<ffffffff811b52c2>] ? __vunmap+0xc2/0x110
[<ffffffff810f8889>] load_module+0x16a9/0x1b30
[<ffffffff810f3d30>] ? store_uevent+0x70/0x70
[<ffffffff810f49b9>] ? copy_module_from_fd.isra.44+0x129/0x180
[<ffffffff810f8ec6>] SyS_finit_module+0xa6/0xd0
[<ffffffff8166cf29>] system_call_fastpath+0x12/0x17
Successfully tested by me.
hpa said: There is another very valid use for this: many operators would
rather a machine shuts down than being potentially compromised either
functionally or security-wise.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1/ Step down as dmaengine maintainer see commit 08223d80df "dmaengine
maintainer update"
2/ Removal of net_dma, as it has been marked 'broken' since 3.13 (commit
7787380336 "net_dma: mark broken"), without reports of performance
regression.
3/ Miscellaneous fixes
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Merge tag 'dmaengine-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine
Pull dmaengine updates from Dan Williams:
"Even though this has fixes marked for -stable, given the size and the
needed conflict resolutions this is 3.18-rc1/merge-window material.
These patches have been languishing in my tree for a long while. The
fact that I do not have the time to do proper/prompt maintenance of
this tree is a primary factor in the decision to step down as
dmaengine maintainer. That and the fact that the bulk of drivers/dma/
activity is going through Vinod these days.
The net_dma removal has not been in -next. It has developed simple
conflicts against mainline and net-next (for-3.18).
Continuing thanks to Vinod for staying on top of drivers/dma/.
Summary:
1/ Step down as dmaengine maintainer see commit 08223d80df
"dmaengine maintainer update"
2/ Removal of net_dma, as it has been marked 'broken' since 3.13
(commit 7787380336 "net_dma: mark broken"), without reports of
performance regression.
3/ Miscellaneous fixes"
* tag 'dmaengine-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine:
net: make tcp_cleanup_rbuf private
net_dma: revert 'copied_early'
net_dma: simple removal
dmaengine maintainer update
dmatest: prevent memory leakage on error path in thread
ioat: Use time_before_jiffies()
dmaengine: fix xor sources continuation
dma: mv_xor: Rename __mv_xor_slot_cleanup() to mv_xor_slot_cleanup()
dma: mv_xor: Remove all callers of mv_xor_slot_cleanup()
dma: mv_xor: Remove unneeded mv_xor_clean_completed_slots() call
ioat: Use pci_enable_msix_exact() instead of pci_enable_msix()
drivers: dma: Include appropriate header file in dca.c
drivers: dma: Mark functions as static in dma_v3.c
dma: mv_xor: Add DMA API error checks
ioat/dca: Use dev_is_pci() to check whether it is pci device
Per commit "77873803363c net_dma: mark broken" net_dma is no longer used
and there is no plan to fix it.
This is the mechanical removal of bits in CONFIG_NET_DMA ifdef guards.
Reverting the remainder of the net_dma induced changes is deferred to
subsequent patches.
Marked for stable due to Roman's report of a memory leak in
dma_pin_iovec_pages():
https://lkml.org/lkml/2014/9/3/177
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: David Whipple <whipple@securedatainnovations.ch>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: <stable@vger.kernel.org>
Reported-by: Roman Gushchin <klamm@yandex-team.ru>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This can be used in virtual networking applications, and
may have other uses as well. The option is disabled by
default.
A specific use case is setting up virtual routers, bridges, and
hosts on a single OS without the use of network namespaces or
virtual machines. With proper use of ip rules, routing tables,
veth interface pairs and/or other virtual interfaces,
and applications that can bind to interfaces and/or IP addresses,
it is possibly to create one or more virtual routers with multiple
hosts attached. The host interfaces can act as IPv6 systems,
with radvd running on the ports in the virtual routers. With the
option provided in this patch enabled, those hosts can now properly
obtain IPv6 addresses from the radvd.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
snprintf() will return the 'ideal' length which may be larger than real
buffer length, if we only want to use real length, need use scnprintf()
instead of.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ip_vs.h is not necessary for sysctl_binary.c.
prepare for the next patch to avoid compile issue.
Signed-off-by: JunweiZhang <junwei.zhang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
The null check of `strchr() + 1' is broken, which is always non-null,
leading to OOB read. Instead, check the result of strchr().
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs pile (part one) from Al Viro:
"Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
locking violations, etc.
The most visible changes here are death of FS_REVAL_DOT (replaced with
"has ->d_weak_revalidate()") and a new helper getting from struct file
to inode. Some bits of preparation to xattr method interface changes.
Misc patches by various people sent this cycle *and* ocfs2 fixes from
several cycles ago that should've been upstream right then.
PS: the next vfs pile will be xattr stuff."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
saner proc_get_inode() calling conventions
proc: avoid extra pde_put() in proc_fill_super()
fs: change return values from -EACCES to -EPERM
fs/exec.c: make bprm_mm_init() static
ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
ocfs2: fix possible use-after-free with AIO
ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
target: writev() on single-element vector is pointless
export kernel_write(), convert open-coded instances
fs: encode_fh: return FILEID_INVALID if invalid fid_type
kill f_vfsmnt
vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
nfsd: handle vfs_getattr errors in acl protocol
switch vfs_getattr() to struct path
default SET_PERSONALITY() in linux/elf.h
ceph: prepopulate inodes only when request is aborted
d_hash_and_lookup(): export, switch open-coded instances
9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
9p: split dropping the acls from v9fs_set_create_acl()
...
TCP Appropriate Byte Count was added by me, but later disabled.
There is no point in maintaining it since it is a potential source
of bugs and Linux already implements other better window protection
heuristics.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The expressions tsk->nsproxy->pid_ns and task_active_pid_ns
aka ns_of_pid(task_pid(tsk)) should have the same number of
cache line misses with the practical difference that
ns_of_pid(task_pid(tsk)) is released later in a processes life.
Furthermore by using task_active_pid_ns it becomes trivial
to write an unshare implementation for the the pid namespace.
So I have used task_active_pid_ns everywhere I can.
In fork since the pid has not yet been attached to the
process I use ns_of_pid, to achieve the same effect.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Since per-BDI flusher threads were introduced in 2.6, the pdflush
mechanism is not used any more. But the old interface exported through
/proc/sys/vm/nr_pdflush_threads still exists and is obviously useless.
For back-compatibility, printk warning information and return 2 to notify
the users that the interface is removed.
Signed-off-by: Wanpeng Li <liwp@linux.vnet.ibm.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
binary_sysctl() calls sysctl_getname() which allocates from names_cache
slab usin __getname()
The matching function to free the name is __putname(), and not putname()
which should be used only to match getname() allocations.
This is because when auditing is enabled, putname() calls audit_putname
*instead* (not in addition) to __putname(). Then, if a syscall is in
progress, audit_putname does not release the name - instead, it expects
the name to get released when the syscall completes, but that will happen
only if audit_getname() was called previously, i.e. if the name was
allocated with getname() rather than the naked __getname(). So,
__getname() followed by putname() ends up leaking memory.
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
removing obsoleted sysctl,
ip_rt_gc_interval variable no longer used since 2.6.38
Signed-off-by: Vasily Averin <vvs@sw.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the move from Linux 2.6 to Linux 3.x as an excuse to kill the
annoying subdirectories in the XFS source code. Besides the large
amount of file rename the only changes are to the Makefile, a few
files including headers with the subdirectory prefix, and the binary
sysctl compat code that includes a header under fs/xfs/ from
kernel/.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
new function: file_open_root(dentry, mnt, name, flags) opens the file
vfs_path_lookup would arrive to.
Note that name can be empty; in that case the usual requirement that
dentry should be a directory is lifted.
open-coded equivalents switched to it, may_open() got down exactly
one caller and became static.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Originally adapted from Huang Ying's patch which moved the
unknown_nmi_panic to the traps.c file. Because the old nmi
watchdog was deleted before this change happened, the
unknown_nmi_panic sysctl was lost. This re-adds it.
Also, the nmi_watchdog sysctl was re-implemented and its
documentation updated accordingly.
Patch-inspired-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1291068437-5331-3-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove own implementation of hex_to_bin().
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A while back there was a discussion regarding the rt_secret_interval timer.
Given that we've had the ability to do emergency route cache rebuilds for awhile
now, based on a statistical analysis of the various hash chain lengths in the
cache, the use of the flush timer is somewhat redundant. This patch removes the
rt_secret_interval sysctl, allowing us to rely solely on the statistical
analysis mechanism to determine the need for route cache flushes.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
When printing legacy sysctls print the warning message
for each of them only once. This way there is a guarantee
the syslog won't be flooded for any sane program.
The original attempt at this made the tables non const and stored
the flag inline.
Linus suggested using a separate hash table for this, this is based on a
code snippet from him.
The hash implies this is not exact and can sometimes not print a
new sysctl due to a hash collision, but in practice this should not
be a problem
I used a FNV32 hash over the binary string with a 32byte bitmap. This
gives relatively little collisions when all the predefined binary sysctls
are hashed:
size 256
bucket
length number
0: [25]
1: [67]
2: [88]
3: [47]
4: [22]
5: [6]
6: [1]
The worst case is a single collision of 6 hash values.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
As predicted during code review, the sysctl(2) changes made systems with
old glibc nearly unusable. About every command gives a:
warning: process `ls' used the deprecated sysctl system call with 1.4
warning in the log.
I see this on a SUSE 10.0 system with glibc 2.3.5.
Don't warn for this common case.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A malicious user could have passed in a ctl_name of 0 and triggered
the well know ctl_name to procname mapping code, instead of the wild
card matching code. This is a slight problem as wild card entries don't
have procnames, and because in some alternate universe a network device
might have ifindex 0. So test for and handle wild card entries first.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
dev_get_by_index does not exist when the network stack is not
compiled in, so only include the code to follow wild card paths
when the network stack is present.
I have shuffled the code around a little to make it clear
that dev_put is called after dev_get_by_index showing that
there is no leak.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Now that the glibc pthread implemenation no longers uses sysctl() users
of sysctl are as rare as hen's teeth. So remove the glibc exception
from the warning, and use the standard printk_ratelimit instead of
rolling our own.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
To simply maintenance and to be able to remove all of the binary
sysctl support from various subsystems I have rewritten the binary
sysctl code as a compatibility wrapper around proc/sys.
The code is built around a hard coded table based on the table
in sysctl_check.c that lists all of our current binary sysctls
and provides enough information to convert from the sysctl
binary input into into ascii and back again. New in this
patch is the realization that the only dynamic entries
that need to be handled have ifname as the asscii string
and ifindex as their ctl_name.
When a sys_sysctl is called the code now looks in the
translation table converting the binary name to the
path under /proc where the value is to be found. Opens
that file, and calls into a format conversion wrapper
that calls fop->read and then fop->write as appropriate.
Since in practice the practically no one uses or tests
sys_sysctl rewritting the code to be beautiful is a little
silly. The redeeming merit of this work is it allows us to
rip out all of the binary sysctl syscall support from
everywhere else in the tree. Allowing us to remove
a lot of dead (after this patch) and barely maintained code.
In addition it becomes much easier to optimize the sysctl
implementation for being the backing store of /proc/sys,
without having to worry about sys_sysctl.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This uses compat_alloc_userspace to remove the various
hacks to allow do_sysctl to write to throuh oldlenp.
The rest of our mature compat syscall helper facitilies
are used as well to ensure we have a nice clean maintainable
compat syscall that can be used on all architectures.
The motiviation for a generic compat sysctl (besides the
obvious hack removal) is to reduce the number of compat
sysctl defintions out there so I can refactor the
binary sysctl implementation.
ppc already used the name compat_sys_sysctl so I remove the
ppcs version here.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Read in the binary sysctl path once, instead of reread it
from user space each time the code needs to access a path
element.
The deprecated sysctl warning is moved to do_sysctl so
that the compat_sysctl entries syscalls will also warn.
The return of -ENOSYS when !CONFIG_SYSCTL_SYSCALL is moved
to binary_sysctl. Always leaving a do_sysctl available
that handles !CONFIG_SYSCTL_SYSCALL and printing the
deprecated sysctl warning allows for a single defitition
of the sysctl syscall.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
In preparation for more invasive cleanups separate the core
binary sysctl logic into it's own file.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
