diff options
| -rw-r--r-- | mm/rmap.c | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index fe2fd9ab0dea..3c5fb8fb105f 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -313,6 +313,9 @@ int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src) check_anon_vma_clone(dst, src); + if (!src->anon_vma) + return 0; + list_for_each_entry_reverse(pavc, &src->anon_vma_chain, same_vma) { struct anon_vma *anon_vma; @@ -478,7 +481,10 @@ void unlink_anon_vmas(struct vm_area_struct *vma) mmap_assert_locked(vma->vm_mm); /* Unfaulted is a no-op. */ - VM_WARN_ON_ONCE(!vma->anon_vma && !list_empty(&vma->anon_vma_chain)); + if (!vma->anon_vma) { + VM_WARN_ON_ONCE(!list_empty(&vma->anon_vma_chain)); + return; + } /* * Unlink each anon_vma chained to the VMA. This list is ordered @@ -502,15 +508,13 @@ void unlink_anon_vmas(struct vm_area_struct *vma) list_del(&avc->same_vma); anon_vma_chain_free(avc); } - if (vma->anon_vma) { - vma->anon_vma->num_active_vmas--; - /* - * vma would still be needed after unlink, and anon_vma will be prepared - * when handle fault. - */ - vma->anon_vma = NULL; - } + vma->anon_vma->num_active_vmas--; + /* + * vma would still be needed after unlink, and anon_vma will be prepared + * when handle fault. + */ + vma->anon_vma = NULL; unlock_anon_vma_root(root); /* |