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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2016-05-28 00:27:38 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-28 00:49:37 +0300
commit0798d3c022dc63eb0ec02b511e1f76ca8411ef8e (patch)
tree64fd1d7fe4f727f319d34904a5a587f07a95d18e
parente2fe14564d3316d1625ed20bf1083995f4960893 (diff)
downloadlinux-0798d3c022dc63eb0ec02b511e1f76ca8411ef8e.tar.xz
mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()
If page_move_anon_rmap() is refiling a pmd-splitted THP mapped in a tail page from a pte, the "address" must be THP aligned in order for the page->index bugcheck to pass in the CONFIG_DEBUG_VM=y builds. Link: http://lkml.kernel.org/r/1464253620-106404-1-git-send-email-kirill.shutemov@linux.intel.com Fixes: 6d0a07edd17c ("mm: thp: calculate the mapcount correctly for THP pages during WP faults") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> [4.5] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/rmap.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 8a839935b18c..0ea5d9071b32 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1098,6 +1098,8 @@ void page_move_anon_rmap(struct page *page,
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_VMA(!anon_vma, vma);
+ if (IS_ENABLED(CONFIG_DEBUG_VM) && PageTransHuge(page))
+ address &= HPAGE_PMD_MASK;
VM_BUG_ON_PAGE(page->index != linear_page_index(vma, address), page);
anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;