2.6.36-stable review patch. If anyone has any objections, please let us know.
------------------ 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) _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
