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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-07-21 14:48:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-07-21 14:48:45 -0700 |
| commit | 95faf6992df468f617edb788da8c21c6eed0dfa7 (patch) | |
| tree | 121683c4e94117b9e41d31b0bc359c01a05412ba | |
| parent | 3928d4f5ee37cdc523894f6e549e6aae521d8980 (diff) | |
| download | linux-stable-95faf6992df468f617edb788da8c21c6eed0dfa7.tar.gz linux-stable-95faf6992df468f617edb788da8c21c6eed0dfa7.tar.bz2 linux-stable-95faf6992df468f617edb788da8c21c6eed0dfa7.zip | |
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>
| -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 0e23deb5acfc..67253e41bfb0 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 4286ad2dd1f5..b0ed8ce1b67e 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 006e3fe65017..c2560e9cc803 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; |