This is a note to let you know that I've just added the patch titled
perf_events: Fix perf_counter_mmap() hook in mprotect()
to the 2.6.36-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf_events-fix-perf_counter_mmap-hook-in-mprotect.patch
and it can be found in the queue-2.6.36 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 63bfd7384b119409685a17d5c58f0b56e5dc03da Mon Sep 17 00:00:00 2001
From: Pekka Enberg <[email protected]>
Date: Mon, 8 Nov 2010 21:29:07 +0200
Subject: perf_events: Fix perf_counter_mmap() hook in mprotect()
From: Pekka Enberg <[email protected]>
commit 63bfd7384b119409685a17d5c58f0b56e5dc03da upstream.
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 <[email protected]>
Analyzed-by: Linus Torvalds <[email protected]>
Cc: Ingo Molnar <[email protected]>
Reviewed-by: Peter Zijlstra <[email protected]>
Signed-off-by: Pekka Enberg <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
mm/mprotect.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- 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,
error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
if (error)
goto out;
- perf_event_mmap(vma);
nstart = tmp;
if (nstart < prev->vm_end)
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.36/perf_events-fix-perf_counter_mmap-hook-in-mprotect.patch
queue-2.6.36/um-fix-global-timer-issue-when-using-config_no_hz.patch
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