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@xxxxxxxxxxx>
Cc: stable@xxxxxxxxxx
---
On April 12th you asked "Guys, can you think of any other thing
that might expand a mapping?": this is the only one I thought of.
mm/mmap.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
--- 2.6.39-rc6/mm/mmap.c 2011-05-04 12:10:31.477543104 -0700
+++ linux/mm/mmap.c 2011-05-09 17:16:34.251725877 -0700
@@ -1767,10 +1767,13 @@ 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;
- 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);
--
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