linux/include/uapi
Manfred Spraul e843e7d2c8 ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM
a)

SysV can be abused to allocate locked kernel memory.  For most systems, a
small limit doesn't make sense, see the discussion with regards to SHMMAX.

Therefore: Increase the sysv sem limits so that all known applications
will work with these defaults.

b)

With regards to the maximum supported:
Some of the specified hard limits are not correct anymore, therefore the
patch updates the documentation.

- SEMMNI must stay below IPCMNI, which is 32768.
  As for SHMMAX: Stay a bit below this limit.

- SEMMSL was limited to 8k, to ensure that the kmalloc for the kernel array
  was limited to 16 kB (order=2)

  This doesn't apply anymore:
   - the allocation size isn't sizeof(short)*nsems anymore.
   - ipc_alloc falls back to vmalloc

- SEMOPM should stay below 1000, to limit the kmalloc in semtimedop() to an
  order=1 allocation.
  Therefore: Leave it at 500 (order=0 allocation).

Note:
If an administrator must limit the memory allocations, then he can set the
values as necessary.

Or he can disable sysv entirely (as e.g. done by Android).

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
..
asm-generic syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
drm drm/exynos: use drm generic mmap interface 2014-09-20 01:00:13 +09:00
linux ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM 2014-12-13 12:42:52 -08:00
misc cxl: Add documentation for userspace APIs 2014-10-08 20:16:19 +11:00
mtd mtd: lpddr: add driver for LPDDR2-NVM PCM memories 2014-05-20 17:45:17 -07:00
rdma Merge branches 'core', 'cxgb4', 'ipoib', 'iser', 'iwcm', 'mad', 'misc', 'mlx4', 'mlx5', 'ocrdma' and 'srp' into for-next 2014-08-14 08:58:04 -07:00
scsi
sound ALSA: oxfw: Add hwdep interface 2014-12-10 10:50:00 +01:00
video
xen
Kbuild cxl: Add userspace header file 2014-10-08 20:15:57 +11:00