diff options
| -rw-r--r-- | mm/memory.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/mm/memory.c b/mm/memory.c index b6e5fd23cc5..2ed2267439d 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; } |