Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit 8aacc9f550feb09c8b26470498345c192996a68e

Authored by Caspar Zhang
Committed by Linus Torvalds
1 parent bcd438be3b
Exists in master and in 6 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

mm/mempolicy.c: fix pgoff in mbind vma merge 

commit 9d8cebd4bcd7 ("mm: fix mbind vma merge problem") didn't really
fix the mbind vma merge problem due to wrong pgoff value passing to
vma_merge(), which made vma_merge() always return NULL.

Before the patch applied, we are getting a result like:

  addr = 0x7fa58f00c000
  [snip]
  7fa58f00c000-7fa58f00d000 rw-p 00000000 00:00 0
  7fa58f00d000-7fa58f00e000 rw-p 00000000 00:00 0
  7fa58f00e000-7fa58f00f000 rw-p 00000000 00:00 0

here 7fa58f00c000->7fa58f00f000 we get 3 VMAs which are expected to be
merged described as described in commit 9d8cebd.

Re-testing the patched kernel with the reproducer provided in commit
9d8cebd, we get the correct result:

  addr = 0x7ffa5aaa2000
  [snip]
  7ffa5aaa2000-7ffa5aaa6000 rw-p 00000000 00:00 0
  7fffd556f000-7fffd5584000 rw-p 00000000 00:00 0                          [stack]

Signed-off-by: Caspar Zhang <caspar@casparzhang.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 2 additions and 3 deletions Side-by-side Diff

... ... @@ -636,7 +636,6 @@
636 636 struct vm_area_struct *prev;
637 637 struct vm_area_struct *vma;
638 638 int err = 0;
639   - pgoff_t pgoff;
640 639 unsigned long vmstart;
641 640 unsigned long vmend;
642 641  
643 642  
... ... @@ -649,9 +648,9 @@
649 648 vmstart = max(start, vma->vm_start);
650 649 vmend = min(end, vma->vm_end);
651 650  
652   - pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
653 651 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
654   - vma->anon_vma, vma->vm_file, pgoff, new_pol);
  652 + vma->anon_vma, vma->vm_file, vma->vm_pgoff,
  653 + new_pol);
655 654 if (prev) {
656 655 vma = prev;
657 656 next = vma->vm_next;