diff options
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 13 |
1 files changed, 9 insertions, 4 deletions
@@ -531,7 +531,7 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma, * reCOWed by userspace write). */ if ((ret & VM_FAULT_WRITE) && !(vma->vm_flags & VM_WRITE)) - *flags |= FOLL_COW; + *flags |= FOLL_COW; return 0; } @@ -1638,7 +1638,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, PMD_SHIFT, next, write, pages, nr)) return 0; } else if (!gup_pte_range(pmd, addr, next, write, pages, nr)) - return 0; + return 0; } while (pmdp++, addr = next, addr != end); return 1; @@ -1740,7 +1740,9 @@ bool gup_fast_permitted(unsigned long start, int nr_pages, int write) /* * Like get_user_pages_fast() except it's IRQ-safe in that it won't fall back to - * the regular GUP. It will only return non-negative values. + * the regular GUP. + * Note a difference with get_user_pages_fast: this always returns the + * number of pages pinned, 0 if no pages were pinned. */ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages) @@ -1806,9 +1808,12 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, len = (unsigned long) nr_pages << PAGE_SHIFT; end = start + len; + if (nr_pages <= 0) + return 0; + if (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ, (void __user *)start, len))) - return 0; + return -EFAULT; if (gup_fast_permitted(start, nr_pages, write)) { local_irq_disable(); |