| Date | Wed, 02 Nov 2011 15:15:10 -0700 | From | Greg KH <> | Subject | [104/107] vm: fix vm_pgoff wrap in upward expansion |
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2.6.32-longterm review patch. If anyone has any objections, please let us know.
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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 @@ -1636,9 +1636,12 @@ 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;
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