From: Paul Gortmaker Date: Tue, 29 May 2012 22:06:14 +0000 (-0700) Subject: pagemap.h: fix warning about possibly used before init var X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=af2e840971dee21ba9b87e9ecee7d5cc6109baaa;p=linux-beck.git pagemap.h: fix warning about possibly used before init var Commit f56f821feb7b ("mm: extend prefault helpers to fault in more than PAGE_SIZE") added in the new functions: fault_in_multipages_writeable() and fault_in_multipages_readable(). However, we currently see: include/linux/pagemap.h:492: warning: 'ret' may be used uninitialized in this function include/linux/pagemap.h:492: note: 'ret' was declared here Unlike a lot of gcc nags, this one appears somewhat legit. i.e. passing in an invalid negative value of "size" does make it look like all the conditionals in there would be bypassed and the uninitialized value would be returned. Signed-off-by: Paul Gortmaker Cc: Daniel Vetter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index efa26b4da8d2..7cfad3bbb0cc 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -460,11 +460,11 @@ 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; + int ret = 0; char __user *end = uaddr + size - 1; if (unlikely(size == 0)) - return 0; + return ret; /* * Writing zeroes into userspace here is OK, because we know that if @@ -489,11 +489,11 @@ static inline int fault_in_multipages_readable(const char __user *uaddr, int size) { volatile char c; - int ret; + int ret = 0; const char __user *end = uaddr + size - 1; if (unlikely(size == 0)) - return 0; + return ret; while (uaddr <= end) { ret = __get_user(c, uaddr);