Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 95faf699 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3928d4f5

kernel/fork.c

+7 −3
Original line number Diff line number Diff line
@@ -315,7 +315,13 @@ struct vm_area_struct *vm_area_alloc(void) 


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 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, 
		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;

mm/mmap.c

+0 −7
Original line number Diff line number Diff line
@@ -2624,11 +2624,6 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma, 
	if (!new)

		return -ENOMEM;



	/* most fields are the same, copy all, and then fixup */

	*new = *vma;



	INIT_LIST_HEAD(&new->anon_vma_chain);



	if (new_below)

		new->vm_end = addr;

	else {
@@ -3205,13 +3200,11 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, 
		new_vma = vm_area_dup(vma);

		if (!new_vma)

			goto out;

		*new_vma = *vma;

		new_vma->vm_start = addr;

		new_vma->vm_end = addr + len;

		new_vma->vm_pgoff = pgoff;

		if (vma_dup_policy(vma, new_vma))

			goto out_free_vma;

		INIT_LIST_HEAD(&new_vma->anon_vma_chain);

		if (anon_vma_clone(new_vma, vma))

			goto out_free_mempol;

		if (new_vma->vm_file)

mm/nommu.c

+0 −1
Original line number Diff line number Diff line
@@ -1476,7 +1476,6 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, 
	}



	/* most fields are the same, copy all, and then fixup */

	*new = *vma;

	*region = *vma->vm_region;

	new->vm_region = region;