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| author | Vladimir Davydov <vdavydov@parallels.com> | 2014-08-09 01:22:01 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-09 02:57:23 +0400 |
| commit | 4f7d461433bb4a4deee61baefdac6cd1a1ecb546 (patch) | |
| tree | fe3609c5e750d4a06876f61ab217503e56b4e182 /fs/jfs/jfs_txnmgr.h | |
| parent | ce65cefa5debefc0e81d0a533bda467f0aa67350 (diff) | |
| download | linux-4f7d461433bb4a4deee61baefdac6cd1a1ecb546.tar.xz | |
fork: copy mm's vm usage counters under mmap_sem
If a forking process has a thread calling (un)mmap (silly but still),
the child process may have some of its mm's vm usage counters (total_vm
and friends) screwed up, because currently they are copied from oldmm
w/o holding any locks (memcpy in dup_mm).
This patch moves the counters initialization to dup_mmap() to be called
under oldmm->mmap_sem, which eliminates any possibility of race.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/jfs/jfs_txnmgr.h')
0 files changed, 0 insertions, 0 deletions