The follow_link() function always initializes its *p argument,
or returns an error, but not all versions of gcc figure this
out, so we have to work around this using the uninitialized_var()
macro.

Without this patch, building with arm-linux-gnueabi-gcc-4.6 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 <a...@arndb.de>
Cc: Al Viro <v...@zeniv.linux.org.uk>
Cc: linux-fsde...@vger.kernel.org
Cc: Jan Kara <j...@suse.cz>
---
 fs/namei.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index dd1ed1b..62a1725 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1543,7 +1543,7 @@ static inline int nested_symlink(struct path *path, 
struct nameidata *nd)
 
        do {
                struct path link = *path;
-               void *cookie;
+               void *uninitialized_var(cookie);
 
                res = follow_link(&link, nd, &cookie);
                if (res)
@@ -1933,7 +1933,7 @@ static int path_lookupat(int dfd, const char *name,
        if (!err && !(flags & LOOKUP_PARENT)) {
                err = lookup_last(nd, &path);
                while (err > 0) {
-                       void *cookie;
+                       void *uninitialized_var(cookie);
                        struct path link = path;
                        err = may_follow_link(&link, nd);
                        if (unlikely(err))
@@ -2902,7 +2902,7 @@ static struct file *path_openat(int dfd, const char 
*pathname,
        error = do_last(nd, &path, file, op, &opened, pathname);
        while (unlikely(error > 0)) { /* trailing symlink */
                struct path link = path;
-               void *cookie;
+               void *uninitialized_var(cookie);
                if (!(nd->flags & LOOKUP_FOLLOW)) {
                        path_put_conditional(&path, nd);
                        path_put(&nd->path);
-- 
1.7.10

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to