mm/mmap.c:insert_vm_struct(): check for failure before setting values

There's no point in initializing vma->vm_pgoff if the insertion attempt
will be failing anyway.  Run the checks before performing the
initialization.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
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 15:04:08 -07:00 committed by Linus Torvalds
parent bde43c6c9f
commit c9d13f5fc7

View File

@ -2871,6 +2871,13 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
struct vm_area_struct *prev;
struct rb_node **rb_link, *rb_parent;
if (find_vma_links(mm, vma->vm_start, vma->vm_end,
&prev, &rb_link, &rb_parent))
return -ENOMEM;
if ((vma->vm_flags & VM_ACCOUNT) &&
security_vm_enough_memory_mm(mm, vma_pages(vma)))
return -ENOMEM;
/*
* The vm_pgoff of a purely anonymous vma should be irrelevant
* until its first write fault, when page's anon_vma and index
@ -2887,12 +2894,6 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
BUG_ON(vma->anon_vma);
vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
}
if (find_vma_links(mm, vma->vm_start, vma->vm_end,
&prev, &rb_link, &rb_parent))
return -ENOMEM;
if ((vma->vm_flags & VM_ACCOUNT) &&
security_vm_enough_memory_mm(mm, vma_pages(vma)))
return -ENOMEM;
vma_link(mm, vma, prev, rb_link, rb_parent);
return 0;