| From 42c36f63ac1366ab0ecc2d5717821362c259f517 Mon Sep 17 00:00:00 2001 |
| From: Hugh Dickins <hughd@google.com> |
| Date: Mon, 9 May 2011 17:44:42 -0700 |
| Subject: vm: fix vm_pgoff wrap in upward expansion |
| |
| From: Hugh Dickins <hughd@google.com> |
| |
| commit 42c36f63ac1366ab0ecc2d5717821362c259f517 upstream. |
| |
| Commit a626ca6a6564 ("vm: fix vm_pgoff wrap in stack expansion") fixed |
| the case of an expanding mapping causing vm_pgoff wrapping when you had |
| downward stack expansion. But there was another case where IA64 and |
| PA-RISC expand mappings: upward expansion. |
| |
| This fixes that case too. |
| |
| Signed-off-by: Hugh Dickins <hughd@google.com> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| mm/mmap.c | 9 ++++++--- |
| 1 file changed, 6 insertions(+), 3 deletions(-) |
| |
| --- a/mm/mmap.c |
| +++ b/mm/mmap.c |
| @@ -1677,9 +1677,12 @@ int expand_upwards(struct vm_area_struct |
| size = address - vma->vm_start; |
| grow = (address - vma->vm_end) >> PAGE_SHIFT; |
| |
| - error = acct_stack_growth(vma, size, grow); |
| - if (!error) |
| - vma->vm_end = address; |
| + error = -ENOMEM; |
| + if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) { |
| + error = acct_stack_growth(vma, size, grow); |
| + if (!error) |
| + vma->vm_end = address; |
| + } |
| } |
| anon_vma_unlock(vma); |
| return error; |