From 98f6ef64b15a48f15062aff5d143b5d9a6ae7711 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 11 Oct 2012 13:20:00 +0000 Subject: [PATCH] vfs: bogus warnings in fs/namei.c The follow_link() function always initializes its *p argument, or returns an error, but when building with 'gcc -s', the compiler gets confused by the __always_inline attribute to the function and can no longer detect where the cookie was initialized. The solution is to always initialize the pointer from follow_link, even in the error path. When building with -O2, this has zero impact on generated code and adds a single instruction in the error path for a -Os build on ARM. Without this patch, building with gcc-4.6 through gcc-4.8 and CONFIG_CC_OPTIMIZE_FOR_SIZE results in: fs/namei.c: In function 'link_path_walk': fs/namei.c:649:24: warning: 'cookie' may be used uninitialized in this function [-Wuninitialized] fs/namei.c:1544:9: note: 'cookie' was declared here fs/namei.c: In function 'path_lookupat': fs/namei.c:649:24: warning: 'cookie' may be used uninitialized in this function [-Wuninitialized] fs/namei.c:1934:10: note: 'cookie' was declared here fs/namei.c: In function 'path_openat': fs/namei.c:649:24: warning: 'cookie' may be used uninitialized in this function [-Wuninitialized] fs/namei.c:2899:9: note: 'cookie' was declared here Signed-off-by: Arnd Bergmann Signed-off-by: Al Viro --- fs/namei.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/namei.c b/fs/namei.c index 6d47fac64292..c1f18e4f034c 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -810,6 +810,7 @@ follow_link(struct path *link, struct nameidata *nd, void **p) return error; out_put_nd_path: + *p = NULL; path_put(&nd->path); path_put(link); return error; -- 2.39.2