diff options
| -rw-r--r-- | mm/rmap.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index ca254f5e4337..4adae0e53f32 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -269,6 +269,19 @@ int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src) { struct anon_vma_chain *avc, *pavc; struct anon_vma *root = NULL; + struct vm_area_struct *prev = dst->vm_prev, *pprev = src->vm_prev; + + /* + * If parent share anon_vma with its vm_prev, keep this sharing in in + * child. + * + * 1. Parent has vm_prev, which implies we have vm_prev. + * 2. Parent and its vm_prev have the same anon_vma. + */ + if (!dst->anon_vma && src->anon_vma && + pprev && pprev->anon_vma == src->anon_vma) + dst->anon_vma = prev->anon_vma; + list_for_each_entry_reverse(pavc, &src->anon_vma_chain, same_vma) { struct anon_vma *anon_vma; |