mm/mmap.c: simplify the failure return working flow

__split_vma() doesn't need out_err label, neither need initializing err.

copy_vma() can return NULL directly when kmem_cache_alloc() fails.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Chen Gang 2015-09-08 15:03:38 -07:00 committed by Linus Torvalds
parent 44a30220bc
commit e397589125

View File

@ -2455,7 +2455,7 @@ static int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr, int new_below)
{
struct vm_area_struct *new;
int err = -ENOMEM;
int err;
if (is_vm_hugetlb_page(vma) && (addr &
~(huge_page_mask(hstate_vma(vma)))))
@ -2463,7 +2463,7 @@ static int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
if (!new)
goto out_err;
return -ENOMEM;
/* most fields are the same, copy all, and then fixup */
*new = *vma;
@ -2511,7 +2511,6 @@ static int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
mpol_put(vma_policy(new));
out_free_vma:
kmem_cache_free(vm_area_cachep, new);
out_err:
return err;
}
@ -2952,30 +2951,31 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
*need_rmap_locks = (new_vma->vm_pgoff <= vma->vm_pgoff);
} else {
new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
if (new_vma) {
*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)
get_file(new_vma->vm_file);
if (new_vma->vm_ops && new_vma->vm_ops->open)
new_vma->vm_ops->open(new_vma);
vma_link(mm, new_vma, prev, rb_link, rb_parent);
*need_rmap_locks = false;
}
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)
get_file(new_vma->vm_file);
if (new_vma->vm_ops && new_vma->vm_ops->open)
new_vma->vm_ops->open(new_vma);
vma_link(mm, new_vma, prev, rb_link, rb_parent);
*need_rmap_locks = false;
}
return new_vma;
out_free_mempol:
out_free_mempol:
mpol_put(vma_policy(new_vma));
out_free_vma:
out_free_vma:
kmem_cache_free(vm_area_cachep, new_vma);
out:
return NULL;
}