diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 377d417ec15..2e034a0b89a 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -225,7 +225,9 @@ vma_address(struct page *page, struct vm_area_struct *vma) /* * At what user virtual address is page expected in vma? checking that the - * page matches the vma: currently only used by unuse_process, on anon pages. + * page matches the vma: currently only used on anon pages, by unuse_vma; + * and by extraordinary checks on anon pages in VM_UNPAGED vmas, taking + * care that an mmap of /dev/mem might window free and foreign pages. */ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma) { @@ -234,7 +236,8 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma) (void *)page->mapping - PAGE_MAPPING_ANON) return -EFAULT; } else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) { - if (vma->vm_file->f_mapping != page->mapping) + if (!vma->vm_file || + vma->vm_file->f_mapping != page->mapping) return -EFAULT; } else return -EFAULT; |