4.5-stable review patch. If anyone has any objections, please let me know.
------------------ From: Kirill A. Shutemov <[email protected]> commit 0798d3c022dc63eb0ec02b511e1f76ca8411ef8e upstream. 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.shute...@linux.intel.com Fixes: 6d0a07edd17c ("mm: thp: calculate the mapcount correctly for THP pages during WP faults") Signed-off-by: Kirill A. Shutemov <[email protected]> Reported-by: Mika Westerberg <[email protected]> Tested-by: Mika Westerberg <[email protected]> Reviewed-by: Andrea Arcangeli <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- mm/rmap.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1112,6 +1112,8 @@ void page_move_anon_rmap(struct page *pa 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;
