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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-07-21 14:48:45 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-24 13:07:14 +0200 |
| commit | ae97be30fa7d9e99359598fcef22db0415e10181 (patch) | |
| tree | 5881b42dc3862f0fa90b48dcb5ad608a4ff5fd3d | |
| parent | 5aac8b553059deec6d5d628f6da9271e247a0aac (diff) | |
| download | linux-ae97be30fa7d9e99359598fcef22db0415e10181.tar.gz | |
mm: make vm_area_dup() actually copy the old vma data
[ Upstream commit 95faf6992df468f617edb788da8c21c6eed0dfa7 ]
.. 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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/fork.c | 10 | ||||
| -rw-r--r-- | mm/mmap.c | 7 | ||||
| -rw-r--r-- | mm/nommu.c | 1 |
3 files changed, 7 insertions, 11 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index a6659f4451f1cf..bee870a48149d6 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -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; diff --git a/mm/mmap.c b/mm/mmap.c index 065f27a3ee7af3..6d0a6973e00838 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -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) diff --git a/mm/nommu.c b/mm/nommu.c index 8e2598a6e55672..5eaa3f5722f90c 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -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; |