Commit 42c36f63 authored May 09, 2011 by Hugh Dickins Committed by Linus Torvalds May 09, 2011

vm: fix vm_pgoff wrap in upward expansion



Commit a626ca6a ("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>

parent c191f6cc

mm/mmap.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -1767,12 +1767,15 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
		size = address - vma->vm_start;
		grow = (address - vma->vm_end) >> PAGE_SHIFT;

		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);
		khugepaged_enter_vma_merge(vma);
		return error;