Patch "mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()" has been added to the 4.5-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()

to the 4.5-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:
     mm-thp-avoid-false-positive-vm_bug_on_page-in-page_move_anon_rmap.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 0798d3c022dc63eb0ec02b511e1f76ca8411ef8e Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Fri, 27 May 2016 14:27:38 -0700
Subject: mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()

From: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

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.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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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;


Patches currently in stable-queue which might be from kirill.shutemov@linux.intel.com are

queue-4.5/mips-handle-highmem-pages-in-__update_cache.patch
queue-4.5/mips-sync-icache-dcache-in-set_pte_at.patch
queue-4.5/mm-thp-avoid-false-positive-vm_bug_on_page-in-page_move_anon_rmap.patch