smack: take the guts of smack_parse_opts_str() into a new helper

smack_add_opt() adds an already matched option to growing smack_mnt_options

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b607b1151e30d16f552fbff81cfb586303b4852c..dba7bc53d86a5d9e32663a56e46390511ad4fbec 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -629,6 +629,54 @@ static int smack_sb_copy_data(char *orig, char *smackopts)
        return 0;
 }
 
+static int smack_add_opt(int token, const char *s, void **mnt_opts)
+{
+       struct smack_mnt_opts *opts = *mnt_opts;
+
+       if (!opts) {
+               opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
+               if (!opts)
+                       return -ENOMEM;
+               *mnt_opts = opts;
+       }
+
+       if (!s)
+               return -ENOMEM;
+
+       switch (token) {
+       case Opt_fsdefault:
+               if (opts->fsdefault)
+                       goto out_opt_err;
+               opts->fsdefault = s;
+               break;
+       case Opt_fsfloor:
+               if (opts->fsfloor)
+                       goto out_opt_err;
+               opts->fsfloor = s;
+               break;
+       case Opt_fshat:
+               if (opts->fshat)
+                       goto out_opt_err;
+               opts->fshat = s;
+               break;
+       case Opt_fsroot:
+               if (opts->fsroot)
+                       goto out_opt_err;
+               opts->fsroot = s;
+               break;
+       case Opt_fstransmute:
+               if (opts->fstransmute)
+                       goto out_opt_err;
+               opts->fstransmute = s;
+               break;
+       }
+       return 0;
+
+out_opt_err:
+       pr_warn("Smack: duplicate mount options\n");
+       return -EINVAL;
+}
+
 /**
  * smack_parse_opts_str - parse Smack specific mount options
  * @options: mount options string
@@ -641,7 +689,6 @@ static int smack_sb_copy_data(char *orig, char *smackopts)
 static int smack_parse_opts_str(char *options,
                void **mnt_opts)
 {
-       struct smack_mnt_opts *opts = *mnt_opts;
        char *p;
        int rc = -ENOMEM;
        int token;
@@ -651,71 +698,24 @@ static int smack_parse_opts_str(char *options,
 
        while ((p = strsep(&options, ",")) != NULL) {
                substring_t args[MAX_OPT_ARGS];
+               const char *arg;
 
                if (!*p)
                        continue;
 
                token = match_token(p, smk_mount_tokens, args);
 
-               if (!opts) {
-                       opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
-                       if (!opts)
-                               return -ENOMEM;
-               }
-
-               switch (token) {
-               case Opt_fsdefault:
-                       if (opts->fsdefault)
-                               goto out_opt_err;
-                       opts->fsdefault = match_strdup(&args[0]);
-                       if (!opts->fsdefault)
-                               goto out_err;
-                       break;
-               case Opt_fsfloor:
-                       if (opts->fsfloor)
-                               goto out_opt_err;
-                       opts->fsfloor = match_strdup(&args[0]);
-                       if (!opts->fsfloor)
-                               goto out_err;
-                       break;
-               case Opt_fshat:
-                       if (opts->fshat)
-                               goto out_opt_err;
-                       opts->fshat = match_strdup(&args[0]);
-                       if (!opts->fshat)
-                               goto out_err;
-                       break;
-               case Opt_fsroot:
-                       if (opts->fsroot)
-                               goto out_opt_err;
-                       opts->fsroot = match_strdup(&args[0]);
-                       if (!opts->fsroot)
-                               goto out_err;
-                       break;
-               case Opt_fstransmute:
-                       if (opts->fstransmute)
-                               goto out_opt_err;
-                       opts->fstransmute = match_strdup(&args[0]);
-                       if (!opts->fstransmute)
-                               goto out_err;
-                       break;
-               default:
-                       rc = -EINVAL;
-                       pr_warn("Smack:  unknown mount option\n");
-                       goto out_err;
+               arg = match_strdup(&args[0]);
+               rc = smack_add_opt(token, arg, mnt_opts);
+               if (unlikely(rc)) {
+                       kfree(arg);
+                       if (*mnt_opts)
+                               smack_free_mnt_opts(*mnt_opts);
+                       *mnt_opts = NULL;
+                       return rc;
                }
        }
-       *mnt_opts = opts;
        return 0;
-
-out_opt_err:
-       rc = -EINVAL;
-       pr_warn("Smack: duplicate mount options\n");
-
-out_err:
-       if (opts)
-               smack_free_mnt_opts(opts);
-       return rc;
 }
 
 static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)