1 files changed, 9 insertions, 2 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 862fc07dc6c0..8f1e390fd71b 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -219,6 +219,9 @@ static inline int fault_in_pages_writeable(char __user *uaddr, int size)
 {
         int ret;
 
+        if (unlikely(size == 0))
+                return 0;
+
         /*
          * Writing zeroes into userspace here is OK, because we know that if
          * the zero gets there, we'll be overwriting it.
@@ -238,19 +241,23 @@ static inline int fault_in_pages_writeable(char __user *uaddr, int size)
         return ret;
 }
 
-static inline void fault_in_pages_readable(const char __user *uaddr, int size)
+static inline int fault_in_pages_readable(const char __user *uaddr, int size)
 {
         volatile char c;
         int ret;
 
+        if (unlikely(size == 0))
+                return 0;
+
         ret = __get_user(c, uaddr);
         if (ret == 0) {
                 const char __user *end = uaddr + size - 1;
 
                 if (((unsigned long)uaddr & PAGE_MASK) !=
                                 ((unsigned long)end & PAGE_MASK))
-                        __get_user(c, end);
+                        ret = __get_user(c, end);
         }
+        return ret;
 }
 
 #endif /* _LINUX_PAGEMAP_H */