mm: make vm_area_dup() actually copy the old vma data
.. and re-initialize th eanon_vma_chain head.
This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/fork.c b/kernel/fork.c
index 0e23deb..67253e4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -315,7 +315,13 @@
struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)
{
- return kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+ struct vm_area_struct *new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+
+ if (new) {
+ *new = *orig;
+ INIT_LIST_HEAD(&new->anon_vma_chain);
+ }
+ return new;
}
void vm_area_free(struct vm_area_struct *vma)
@@ -473,8 +479,6 @@
tmp = vm_area_dup(mpnt);
if (!tmp)
goto fail_nomem;
- *tmp = *mpnt;
- INIT_LIST_HEAD(&tmp->anon_vma_chain);
retval = vma_dup_policy(mpnt, tmp);
if (retval)
goto fail_nomem_policy;