* reCOWed by userspace write).
*/
if ((ret & VM_FAULT_WRITE) && !(vma->vm_flags & VM_WRITE))
- *flags |= FOLL_COW;
+ *flags |= FOLL_COW;
return 0;
}
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;
/*
* 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)
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();