Ensure FMODE_NONOTIFY is not set by userspace

[net-next-2.6.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 4b218a46ddd3d631e1ec92ded13e01b548aba346..5cf366965d0ca5ec8766781367135838f3b2eac0 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1074,7 +1074,8 @@ struct cgroup_sb_opts {
  */
 static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
 {
-       char *token, *o = data ?: "all";
+       char *token, *o = data;
+       bool all_ss = false, one_ss = false;
        unsigned long mask = (unsigned long)-1;
        int i;
        bool module_pin_failed = false;
@@ -1090,24 +1091,27 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
        while ((token = strsep(&o, ",")) != NULL) {
                if (!*token)
                        return -EINVAL;
-               if (!strcmp(token, "all")) {
-                       /* Add all non-disabled subsystems */
-                       opts->subsys_bits = 0;
-                       for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
-                               struct cgroup_subsys *ss = subsys[i];
-                               if (ss == NULL)
-                                       continue;
-                               if (!ss->disabled)
-                                       opts->subsys_bits |= 1ul << i;
-                       }
-               } else if (!strcmp(token, "none")) {
+               if (!strcmp(token, "none")) {
                        /* Explicitly have no subsystems */
                        opts->none = true;
-               } else if (!strcmp(token, "noprefix")) {
+                       continue;
+               }
+               if (!strcmp(token, "all")) {
+                       /* Mutually exclusive option 'all' + subsystem name */
+                       if (one_ss)
+                               return -EINVAL;
+                       all_ss = true;
+                       continue;
+               }
+               if (!strcmp(token, "noprefix")) {
                        set_bit(ROOT_NOPREFIX, &opts->flags);
-               } else if (!strcmp(token, "clone_children")) {
+                       continue;
+               }
+               if (!strcmp(token, "clone_children")) {
                        opts->clone_children = true;
-               } else if (!strncmp(token, "release_agent=", 14)) {
+                       continue;
+               }
+               if (!strncmp(token, "release_agent=", 14)) {
                        /* Specifying two release agents is forbidden */
                        if (opts->release_agent)
                                return -EINVAL;
@@ -1115,7 +1119,9 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
                                kstrndup(token + 14, PATH_MAX - 1, GFP_KERNEL);
                        if (!opts->release_agent)
                                return -ENOMEM;
-               } else if (!strncmp(token, "name=", 5)) {
+                       continue;
+               }
+               if (!strncmp(token, "name=", 5)) {
                        const char *name = token + 5;
                        /* Can't specify an empty name */
                        if (!strlen(name))
@@ -1137,20 +1143,44 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
                                              GFP_KERNEL);
                        if (!opts->name)
                                return -ENOMEM;
-               } else {
-                       struct cgroup_subsys *ss;
-                       for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
-                               ss = subsys[i];
-                               if (ss == NULL)
-                                       continue;
-                               if (!strcmp(token, ss->name)) {
-                                       if (!ss->disabled)
-                                               set_bit(i, &opts->subsys_bits);
-                                       break;
-                               }
-                       }
-                       if (i == CGROUP_SUBSYS_COUNT)
-                               return -ENOENT;
+
+                       continue;
+               }
+
+               for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
+                       struct cgroup_subsys *ss = subsys[i];
+                       if (ss == NULL)
+                               continue;
+                       if (strcmp(token, ss->name))
+                               continue;
+                       if (ss->disabled)
+                               continue;
+
+                       /* Mutually exclusive option 'all' + subsystem name */
+                       if (all_ss)
+                               return -EINVAL;
+                       set_bit(i, &opts->subsys_bits);
+                       one_ss = true;
+
+                       break;
+               }
+               if (i == CGROUP_SUBSYS_COUNT)
+                       return -ENOENT;
+       }
+
+       /*
+        * If the 'all' option was specified select all the subsystems,
+        * otherwise 'all, 'none' and a subsystem name options were not
+        * specified, let's default to 'all'
+        */
+       if (all_ss || (!all_ss && !one_ss && !opts->none)) {
+               for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
+                       struct cgroup_subsys *ss = subsys[i];
+                       if (ss == NULL)
+                               continue;
+                       if (ss->disabled)
+                               continue;
+                       set_bit(i, &opts->subsys_bits);
                }
        }
 
@@ -1892,6 +1922,8 @@ static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft,
                                      const char *buffer)
 {
        BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
+       if (strlen(buffer) >= PATH_MAX)
+               return -EINVAL;
        if (!cgroup_lock_live_group(cgrp))
                return -ENODEV;
        strcpy(cgrp->root->release_agent_path, buffer);