diff options
Diffstat (limited to 'mm/frame_vector.c')
| -rw-r--r-- | mm/frame_vector.c | 31 |
1 files changed, 6 insertions, 25 deletions
diff --git a/mm/frame_vector.c b/mm/frame_vector.c index c431ca81dad5..5779c1bc6f44 100644 --- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -37,7 +37,6 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, struct mm_struct *mm = current->mm; struct vm_area_struct *vma; int ret = 0; - int err; int locked; if (nr_frames == 0) @@ -74,32 +73,14 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, vec->is_pfns = false; ret = get_user_pages_locked(start, nr_frames, gup_flags, (struct page **)(vec->ptrs), &locked); - goto out; + if (likely(ret > 0)) + goto out; } - vec->got_ref = false; - vec->is_pfns = true; - do { - unsigned long *nums = frame_vector_pfns(vec); - - while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { - err = follow_pfn(vma, start, &nums[ret]); - if (err) { - if (ret == 0) - ret = err; - goto out; - } - start += PAGE_SIZE; - ret++; - } - /* - * We stop if we have enough pages or if VMA doesn't completely - * cover the tail page. - */ - if (ret >= nr_frames || start < vma->vm_end) - break; - vma = find_vma_intersection(mm, start, start + 1); - } while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP)); + /* This used to (racily) return non-refcounted pfns. Let people know */ + WARN_ONCE(1, "get_vaddr_frames() cannot follow VM_IO mapping"); + vec->nr_frames = 0; + out: if (locked) up_read(&mm->mmap_sem); |