Btrfs: fix max chunk size check in chunk allocator

[linux.git] / fs / proc / root.c

diff --git a/fs/proc/root.c b/fs/proc/root.c
index 03102d978180eba68469ef01d13ad25465f5b796..46a15d8a29ca74d9ca0a68a57e416108e6b599f3 100644 (file)
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -18,6 +18,7 @@
 #include <linux/bitops.h>
 #include <linux/mount.h>
 #include <linux/pid_namespace.h>
+#include <linux/parser.h>
 
 #include "internal.h"
 
@@ -36,6 +37,63 @@ static int proc_set_super(struct super_block *sb, void *data)
        return err;
 }
 
+enum {
+       Opt_gid, Opt_hidepid, Opt_err,
+};
+
+static const match_table_t tokens = {
+       {Opt_hidepid, "hidepid=%u"},
+       {Opt_gid, "gid=%u"},
+       {Opt_err, NULL},
+};
+
+static int proc_parse_options(char *options, struct pid_namespace *pid)
+{
+       char *p;
+       substring_t args[MAX_OPT_ARGS];
+       int option;
+
+       if (!options)
+               return 1;
+
+       while ((p = strsep(&options, ",")) != NULL) {
+               int token;
+               if (!*p)
+                       continue;
+
+               args[0].to = args[0].from = 0;
+               token = match_token(p, tokens, args);
+               switch (token) {
+               case Opt_gid:
+                       if (match_int(&args[0], &option))
+                               return 0;
+                       pid->pid_gid = option;
+                       break;
+               case Opt_hidepid:
+                       if (match_int(&args[0], &option))
+                               return 0;
+                       if (option < 0 || option > 2) {
+                               pr_err("proc: hidepid value must be between 0 and 2.\n");
+                               return 0;
+                       }
+                       pid->hide_pid = option;
+                       break;
+               default:
+                       pr_err("proc: unrecognized mount option \"%s\" "
+                              "or missing value\n", p);
+                       return 0;
+               }
+       }
+
+       return 1;
+}
+
+int proc_remount(struct super_block *sb, int *flags, char *data)
+{
+       struct pid_namespace *pid = sb->s_fs_info;
+       return !proc_parse_options(data, pid);
+}
+
 static struct dentry *proc_mount(struct file_system_type *fs_type,
        int flags, const char *dev_name, void *data)
 {
@@ -43,11 +101,15 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
        struct super_block *sb;
        struct pid_namespace *ns;
        struct proc_inode *ei;
+       char *options;
 
-       if (flags & MS_KERNMOUNT)
+       if (flags & MS_KERNMOUNT) {
                ns = (struct pid_namespace *)data;
-       else
+               options = NULL;
+       } else {
                ns = current->nsproxy->pid_ns;
+               options = data;
+       }
 
        sb = sget(fs_type, proc_test_super, proc_set_super, ns);
        if (IS_ERR(sb))
@@ -55,6 +117,10 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
 
        if (!sb->s_root) {
                sb->s_flags = flags;
+               if (!proc_parse_options(options, ns)) {
+                       deactivate_locked_super(sb);
+                       return ERR_PTR(-EINVAL);
+               }
                err = proc_fill_super(sb);
                if (err) {
                        deactivate_locked_super(sb);