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| author | Pekka Enberg <penberg@kernel.org> | 2010-11-08 21:29:07 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-11-09 10:19:38 -0800 |
| commit | 63bfd7384b119409685a17d5c58f0b56e5dc03da (patch) | |
| tree | b01a10267b8e702af948e571801f02ee70ff1794 | |
| parent | 814ce2521121c2459e16cea8c7221e157edbeddd (diff) | |
| download | op-kernel-dev-63bfd7384b119409685a17d5c58f0b56e5dc03da.zip op-kernel-dev-63bfd7384b119409685a17d5c58f0b56e5dc03da.tar.gz | |
perf_events: Fix perf_counter_mmap() hook in mprotect()
As pointed out by Linus, commit dab5855 ("perf_counter: Add mmap event hooks to
mprotect()") is fundamentally wrong as mprotect_fixup() can free 'vma' due to
merging. Fix the problem by moving perf_event_mmap() hook to
mprotect_fixup().
Note: there's another successful return path from mprotect_fixup() if old
flags equal to new flags. We don't, however, need to call
perf_event_mmap() there because 'perf' already knows the VMA is
executable.
Reported-by: Dave Jones <davej@redhat.com>
Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/mprotect.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index 2d1bf7c..4c51338 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -211,6 +211,7 @@ success: mmu_notifier_invalidate_range_end(mm, start, end); vm_stat_account(mm, oldflags, vma->vm_file, -nrpages); vm_stat_account(mm, newflags, vma->vm_file, nrpages); + perf_event_mmap(vma); return 0; fail: @@ -299,7 +300,6 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); if (error) goto out; - perf_event_mmap(vma); nstart = tmp; if (nstart < prev->vm_end) |
