Patch "mm/hugetlb: use pmd_page() in follow_huge_pmd()" has been added to the 4.0-stable tree

Patch "mm/hugetlb: use pmd_page() in follow_huge_pmd()" has been added to the 4.0-stable tree

[gregkh]

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

    mm/hugetlb: use pmd_page() in follow_huge_pmd()

to the 4.0-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-hugetlb-use-pmd_page-in-follow_huge_pmd.patch
and it can be found in the queue-4.0 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 97534127012f0e396eddea4691f4c9b170aed74b Mon Sep 17 00:00:00 2001
From: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Date: Tue, 14 Apr 2015 15:42:30 -0700
Subject: mm/hugetlb: use pmd_page() in follow_huge_pmd()

From: Gerald Schaefer <gerald.schaefer@de.ibm.com>

commit 97534127012f0e396eddea4691f4c9b170aed74b upstream.

Commit 61f77eda9bbf ("mm/hugetlb: reduce arch dependent code around
follow_huge_*") broke follow_huge_pmd() on s390, where pmd and pte
layout differ and using pte_page() on a huge pmd will return wrong
results.  Using pmd_page() instead fixes this.

All architectures that were touched by that commit have pmd_page()
defined, so this should not break anything on other architectures.

Fixes: 61f77eda "mm/hugetlb: reduce arch dependent code around follow_huge_*"
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.cz>, Andrea Arcangeli <aarcange@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: David Rientjes <rientjes@google.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/hugetlb.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3735,8 +3735,7 @@ retry:
 	if (!pmd_huge(*pmd))
 		goto out;
 	if (pmd_present(*pmd)) {
-		page = pte_page(*(pte_t *)pmd) +
-			((address & ~PMD_MASK) >> PAGE_SHIFT);
+		page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT);
 		if (flags & FOLL_GET)
 			get_page(page);
 	} else {


Patches currently in stable-queue which might be from gerald.schaefer@de.ibm.com are

queue-4.0/mm-hugetlb-use-pmd_page-in-follow_huge_pmd.patch