diff options
Diffstat (limited to 'include/linux/pagemap.h')
| -rw-r--r-- | include/linux/pagemap.h | 11 |
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 */ |