From 42c36f63ac1366ab0ecc2d5717821362c259f517 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 9 May 2011 17:44:42 -0700 Subject: [PATCH] vm: fix vm_pgoff wrap in upward expansion 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 Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- mm/mmap.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index e27e0cf..772140c 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1767,10 +1767,13 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) 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; - perf_event_mmap(vma); + 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; + perf_event_mmap(vma); + } } } vma_unlock_anon_vma(vma); -- 2.7.4