linux-toradex.git/ipc/ipc_sysctl.c, branch v3.14.57

ipc: always handle a new value of auto_msgmni

2014-11-21T17:23:04+00:00

commit 1195d94e006b23c6292e78857e154872e33b6d7e upstream.

proc_dointvec_minmax() returns zero if a new value has been set.  So we
don't need to check all charecters have been handled.

Below you can find two examples.  In the new value has not been handled
properly.

$ strace ./a.out
open("/proc/sys/kernel/auto_msgmni", O_WRONLY) = 3
write(3, "0\n\0", 3)                    = 2
close(3)                                = 0
exit_group(0)
$ cat /sys/kernel/debug/tracing/trace

$strace ./a.out
open("/proc/sys/kernel/auto_msgmni", O_WRONLY) = 3
write(3, "0\n", 2)                      = 2
close(3)                                = 0

$ cat /sys/kernel/debug/tracing/trace
a.out-697   [000] ....  3280.998235: unregister_ipcns_notifier <-proc_ipcauto_dointvec_minmax

Fixes: 9eefe520c814 ("ipc: do not use a negative value to re-enable msgmni automatic recomputin")
Signed-off-by: Andrey Vagin 
Cc: Mathias Krause 
Cc: Manfred Spraul 
Cc: Joe Perches 
Cc: Davidlohr Bueso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ipc: whitespace cleanup

2014-01-28T05:02:39+00:00

The ipc code does not adhere the typical linux coding style.
This patch fixes lots of simple whitespace errors.

- mostly autogenerated by
  scripts/checkpatch.pl -f --fix \
	--types=pointer_location,spacing,space_before_tab
- one manual fixup (keep structure members tab-aligned)
- removal of additional space_before_tab that were not found by --fix

Tested with some of my msg and sem test apps.

Andrew: Could you include it in -mm and move it towards Linus' tree?

Signed-off-by: Manfred Spraul 
Suggested-by: Li Bin 
Cc: Joe Perches 
Acked-by: Rafael Aquini 
Cc: Davidlohr Bueso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc, msg: forbid negative values for "msg{max,mnb,mni}"

2013-11-03T18:53:11+00:00

Negative message lengths make no sense -- so don't do negative queue
lenghts or identifier counts. Prevent them from getting negative.

Also change the underlying data types to be unsigned to avoid hairy
surprises with sign extensions in cases where those variables get
evaluated in unsigned expressions with bigger data types, e.g size_t.

In case a user still wants to have "unlimited" sizes she could just use
INT_MAX instead.

Signed-off-by: Mathias Krause 
Cc: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: add sysctl to specify desired next object id

2013-01-05T00:11:45+00:00

Add 3 new variables and sysctls to tune them (by one "next_id" variable
for messages, semaphores and shared memory respectively).  This variable
can be used to set desired id for next allocated IPC object.  By default
it's equal to -1 and old behaviour is preserved.  If this variable is
non-negative, then desired idr will be extracted from it and used as a
start value to search for free IDR slot.

Notes:

1) this patch doesn't guarantee that the new object will have desired
   id.  So it's up to user space how to handle new object with wrong id.

2) After a sucessful id allocation attempt, "next_id" will be set back
   to -1 (if it was non-negative).

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stanislav Kinsbursky 
Cc: Serge Hallyn 
Cc: "Eric W. Biederman" 
Cc: Pavel Emelyanov 
Cc: Al Viro 
Cc: KOSAKI Motohiro 
Cc: Michael Kerrisk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: introduce shm_rmid_forced sysctl

2011-07-26T23:49:44+00:00

Add support for the shm_rmid_forced sysctl.  If set to 1, all shared
memory objects in current ipc namespace will be automatically forced to
use IPC_RMID.

The POSIX way of handling shmem allows one to create shm objects and
call shmdt(), leaving shm object associated with no process, thus
consuming memory not counted via rlimits.

With shm_rmid_forced=1 the shared memory object is counted at least for
one process, so OOM killer may effectively kill the fat process holding
the shared memory.

It obviously breaks POSIX - some programs relying on the feature would
stop working.  So set shm_rmid_forced=1 only if you're sure nobody uses
"orphaned" memory.  Use shm_rmid_forced=0 by default for compatability
reasons.

The feature was previously impemented in -ow as a configure option.

[akpm@linux-foundation.org: fix documentation, per Randy]
[akpm@linux-foundation.org: fix warning]
[akpm@linux-foundation.org: readability/conventionality tweaks]
[akpm@linux-foundation.org: fix shm_rmid_forced/shm_forced_rmid confusion, use standard comment layout]
Signed-off-by: Vasiliy Kulikov 
Cc: Randy Dunlap 
Cc: "Eric W. Biederman" 
Cc: "Serge E. Hallyn" 
Cc: Daniel Lezcano 
Cc: Oleg Nesterov 
Cc: Tejun Heo 
Cc: Ingo Molnar 
Cc: Alan Cox 
Cc: Solar Designer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysctl ipc: Remove dead binary sysctl support code.

2009-11-12T10:04:54+00:00

Now that sys_sysctl is a generic wrapper around /proc/sys  .ctl_name
and .strategy members of sysctl tables are dead code.  Remove them.

Signed-off-by: Eric W. Biederman

sysctl: remove "struct file *" argument of ->proc_handler

2009-09-24T14:21:04+00:00

It's unused.

It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.

It _was_ used in two places at arch/frv for some reason.

Signed-off-by: Alexey Dobriyan 
Cc: David Howells 
Cc: "Eric W. Biederman" 
Cc: Al Viro 
Cc: Ralf Baechle 
Cc: Martin Schwidefsky 
Cc: Ingo Molnar 
Cc: "David S. Miller" 
Cc: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc_sysctl: use CONFIG_PROC_SYSCTL around ipc and utsname proc_handlers

2009-04-03T02:05:01+00:00

As pointed out by Cedric Le Goater (in response to Alexey's original
comment wrt mqns), ipc_sysctl.c and utsname_sysctl.c are using
CONFIG_PROC_FS, not CONFIG_PROC_SYSCTL, to determine whether to define
the proc_handlers.  Change that.

Signed-off-by: Serge E. Hallyn 
Cc: Cedric Le Goater 
Acked-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc/ipc_sysctl.c: move the definition of ipc_auto_callback()

2009-01-06T23:59:29+00:00

proc_ipcauto_dointvec_minmax() is the only user of ipc_auto_callback(),
since the former function is protected by CONFIG_PROC_FS, so should be the
latter one.

Just move its definition down.

Signed-off-by: WANG Cong 
Cc: Eric Biederman 
Cc: Nadia Derbey 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysctl: simplify ->strategy

2008-10-16T18:21:47+00:00

name and nlen parameters passed to ->strategy hook are unused, remove
them.  In general ->strategy hook should know what it's doing, and don't
do something tricky for which, say, pointer to original userspace array
may be needed (name).

Signed-off-by: Alexey Dobriyan 
Acked-by: David S. Miller  [ networking bits ]
Cc: Ralf Baechle 
Cc: David Howells 
Cc: Matt Mackall 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds