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-rw-r--r--include/linux/pagemap.h11
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 */
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