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-rw-r--r--include/linux/pagemap.h39
1 files changed, 20 insertions, 19 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 66a1260b33de..01e84436cddf 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -571,56 +571,57 @@ static inline int fault_in_pages_readable(const char __user *uaddr, int size)
*/
static inline int fault_in_multipages_writeable(char __user *uaddr, int size)
{
- int ret = 0;
char __user *end = uaddr + size - 1;
if (unlikely(size == 0))
- return ret;
+ return 0;
+ if (unlikely(uaddr > end))
+ return -EFAULT;
/*
* Writing zeroes into userspace here is OK, because we know that if
* the zero gets there, we'll be overwriting it.
*/
- while (uaddr <= end) {
- ret = __put_user(0, uaddr);
- if (ret != 0)
- return ret;
+ do {
+ if (unlikely(__put_user(0, uaddr) != 0))
+ return -EFAULT;
uaddr += PAGE_SIZE;
- }
+ } while (uaddr <= end);
/* Check whether the range spilled into the next page. */
if (((unsigned long)uaddr & PAGE_MASK) ==
((unsigned long)end & PAGE_MASK))
- ret = __put_user(0, end);
+ return __put_user(0, end);
- return ret;
+ return 0;
}
static inline int fault_in_multipages_readable(const char __user *uaddr,
int size)
{
volatile char c;
- int ret = 0;
const char __user *end = uaddr + size - 1;
if (unlikely(size == 0))
- return ret;
+ return 0;
- while (uaddr <= end) {
- ret = __get_user(c, uaddr);
- if (ret != 0)
- return ret;
+ if (unlikely(uaddr > end))
+ return -EFAULT;
+
+ do {
+ if (unlikely(__get_user(c, uaddr) != 0))
+ return -EFAULT;
uaddr += PAGE_SIZE;
- }
+ } while (uaddr <= end);
/* Check whether the range spilled into the next page. */
if (((unsigned long)uaddr & PAGE_MASK) ==
((unsigned long)end & PAGE_MASK)) {
- ret = __get_user(c, end);
- (void)c;
+ return __get_user(c, end);
}
- return ret;
+ (void)c;
+ return 0;
}
int add_to_page_cache_locked(struct page *page, struct address_space *mapping,