fs: namespace: suppress 'may be used uninitialized' warnings

The gcc version 4.9.1 compiler complains Even though it isn't possible for
these variables to not get initialized before they are used.

fs/namespace.c: In function ‘SyS_mount’:
fs/namespace.c:2720:8: warning: ‘kernel_dev’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  ret = do_mount(kernel_dev, kernel_dir->name, kernel_type, flags,
        ^
fs/namespace.c:2699:8: note: ‘kernel_dev’ was declared here
  char *kernel_dev;
        ^
fs/namespace.c:2720:8: warning: ‘kernel_type’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  ret = do_mount(kernel_dev, kernel_dir->name, kernel_type, flags,
        ^
fs/namespace.c:2697:8: note: ‘kernel_type’ was declared here
  char *kernel_type;
        ^

Fix the warnings by simplifying copy_mount_string() as suggested by Al Viro.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/compat.c b/fs/compat.c
index 66d3d3c..6205c24 100644 (file)
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -797,8 +797,9 @@ COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
        struct filename *dir;
        int retval;
 
-       retval = copy_mount_string(type, &kernel_type);
-       if (retval < 0)
+       kernel_type = copy_mount_string(type);
+       retval = PTR_ERR(kernel_type);
+       if (IS_ERR(kernel_type))
                goto out;
 
        dir = getname(dir_name);
@@ -806,8 +807,9 @@ COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
        if (IS_ERR(dir))
                goto out1;
 
-       retval = copy_mount_string(dev_name, &kernel_dev);
-       if (retval < 0)
+       kernel_dev = copy_mount_string(dev_name);
+       retval = PTR_ERR(kernel_dev);
+       if (IS_ERR(kernel_dev))
                goto out2;
 
        retval = copy_mount_options(data, &data_page);

diff --cc fs/internal.h
Simple merge

diff --cc fs/namespace.c
Simple merge