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-rw-r--r--mm/memory.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/mm/memory.c b/mm/memory.c
index b6e5fd2..2ed2267 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2770,11 +2770,18 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo
{
address &= PAGE_MASK;
if ((vma->vm_flags & VM_GROWSDOWN) && address == vma->vm_start) {
- address -= PAGE_SIZE;
- if (find_vma(vma->vm_mm, address) != vma)
- return -ENOMEM;
+ struct vm_area_struct *prev = vma->vm_prev;
+
+ /*
+ * Is there a mapping abutting this one below?
+ *
+ * That's only ok if it's the same stack mapping
+ * that has gotten split..
+ */
+ if (prev && prev->vm_end == address)
+ return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM;
- expand_stack(vma, address);
+ expand_stack(vma, address - PAGE_SIZE);
}
return 0;
}
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