umd: Stop using split_argv

There is exactly one argument so there is nothing to split.  All
split_argv does now is cause confusion and avoid the need for a cast
when passing a "const char *" string to call_usermodehelper_setup.

So avoid confusion and the possibility of an odd driver name causing
problems by just using a fixed argv array with a cast in the call to
call_usermodehelper_setup.

v1: https://lkml.kernel.org/r/87sged3a9n.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-16-ebiederm@xmission.com
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

diff --git a/kernel/usermode_driver.c b/kernel/usermode_driver.c
index cd136f8..0b35212 100644 (file)
--- a/kernel/usermode_driver.c
+++ b/kernel/usermode_driver.c
@@ -160,27 +160,21 @@ static void umd_cleanup(struct subprocess_info *info)
 int fork_usermode_driver(struct umd_info *info)
 {
        struct subprocess_info *sub_info;
-       char **argv = NULL;
+       const char *argv[] = { info->driver_name, NULL };
        int err;
 
        if (WARN_ON_ONCE(info->tgid))
                return -EBUSY;
 
        err = -ENOMEM;
-       argv = argv_split(GFP_KERNEL, info->driver_name, NULL);
-       if (!argv)
-               goto out;
-
-       sub_info = call_usermodehelper_setup(info->driver_name, argv, NULL,
-                                            GFP_KERNEL,
+       sub_info = call_usermodehelper_setup(info->driver_name,
+                                            (char **)argv, NULL, GFP_KERNEL,
                                             umd_setup, umd_cleanup, info);
        if (!sub_info)
                goto out;
 
        err = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
 out:
-       if (argv)
-               argv_free(argv);
        return err;
 }
 EXPORT_SYMBOL_GPL(fork_usermode_driver);