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: [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 <hughd@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/mmap.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index e27e0cf0de03..772140c53ab1 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);