linux/include
Glauber Costa 2ad306b17c fork: protect architectures where THREAD_SIZE >= PAGE_SIZE against fork bombs
Because those architectures will draw their stacks directly from the page
allocator, rather than the slab cache, we can directly pass __GFP_KMEMCG
flag, and issue the corresponding free_pages.

This code path is taken when the architecture doesn't define
CONFIG_ARCH_THREAD_INFO_ALLOCATOR (only ia64 seems to), and has
THREAD_SIZE >= PAGE_SIZE.  Luckily, most - if not all - of the remaining
architectures fall in this category.

This will guarantee that every stack page is accounted to the memcg the
process currently lives on, and will have the allocations to fail if they
go over limit.

For the time being, I am defining a new variant of THREADINFO_GFP, not to
mess with the other path.  Once the slab is also tracked by memcg, we can
get rid of that flag.

Tested to successfully protect against :(){ :|:& };:

Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Frederic Weisbecker <fweisbec@redhat.com>
Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 15:02:13 -08:00
..
acpi PCI changes for the v3.8 merge window: 2012-12-13 12:14:47 -08:00
asm-generic asm-generic: io: don't perform swab during {in,out} string functions 2012-12-17 17:15:13 -08:00
clocksource
crypto crypto: cast5/cast6 - move lookup tables to shared module 2012-12-06 17:16:26 +08:00
drm Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel into drm-next 2012-12-16 06:05:03 +00:00
keys
linux fork: protect architectures where THREAD_SIZE >= PAGE_SIZE against fork bombs 2012-12-18 15:02:13 -08:00
math-emu
media [media] V4L: Add driver for S3C24XX/S3C64XX SoC series camera interface 2012-11-28 09:43:34 -02:00
memory
misc
net Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-17 15:44:47 -08:00
pcmcia
ras
rdma UAPI: (Scripted) Disintegrate include/rdma 2012-11-22 00:43:10 -08:00
rxrpc
scsi SCSI misc on 20121212 2012-12-13 19:20:31 -08:00
sound Merge remote-tracking branch 'asoc/topic/tlv320aic32x4' into asoc-next 2012-12-10 00:22:20 +09:00
target target/iscsi_target: Add NodeACL tags for initiator group support 2012-12-13 14:18:09 -08:00
trace mm: add a __GFP_KMEMCG flag 2012-12-18 15:02:12 -08:00
uapi ptrace: introduce PTRACE_O_EXITKILL 2012-12-17 17:15:22 -08:00
video Merge tag 'omapdss-for-3.8' of git://gitorious.org/linux-omap-dss2/linux into for-linus 2012-12-13 14:30:56 +02:00
xen Features: 2012-12-13 14:29:16 -08:00
Kbuild