4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * proc root directory handling functions
9 #include <asm/uaccess.h>
11 #include <linux/errno.h>
12 #include <linux/time.h>
13 #include <linux/proc_fs.h>
14 #include <linux/stat.h>
15 #include <linux/init.h>
16 #include <linux/sched.h>
17 #include <linux/module.h>
18 #include <linux/bitops.h>
19 #include <linux/mount.h>
20 #include <linux/pid_namespace.h>
21 #include <linux/parser.h>
25 static int proc_test_super(struct super_block
*sb
, void *data
)
27 return sb
->s_fs_info
== data
;
30 static int proc_set_super(struct super_block
*sb
, void *data
)
32 int err
= set_anon_super(sb
, NULL
);
34 struct pid_namespace
*ns
= (struct pid_namespace
*)data
;
35 sb
->s_fs_info
= get_pid_ns(ns
);
41 Opt_gid
, Opt_hidepid
, Opt_err
,
44 static const match_table_t tokens
= {
45 {Opt_hidepid
, "hidepid=%u"},
50 static int proc_parse_options(char *options
, struct pid_namespace
*pid
)
53 substring_t args
[MAX_OPT_ARGS
];
59 while ((p
= strsep(&options
, ",")) != NULL
) {
64 args
[0].to
= args
[0].from
= 0;
65 token
= match_token(p
, tokens
, args
);
68 if (match_int(&args
[0], &option
))
70 pid
->pid_gid
= make_kgid(current_user_ns(), option
);
73 if (match_int(&args
[0], &option
))
75 if (option
< 0 || option
> 2) {
76 pr_err("proc: hidepid value must be between 0 and 2.\n");
79 pid
->hide_pid
= option
;
82 pr_err("proc: unrecognized mount option \"%s\" "
83 "or missing value\n", p
);
91 int proc_remount(struct super_block
*sb
, int *flags
, char *data
)
93 struct pid_namespace
*pid
= sb
->s_fs_info
;
94 return !proc_parse_options(data
, pid
);
97 static struct dentry
*proc_mount(struct file_system_type
*fs_type
,
98 int flags
, const char *dev_name
, void *data
)
101 struct super_block
*sb
;
102 struct pid_namespace
*ns
;
103 struct proc_inode
*ei
;
106 if (flags
& MS_KERNMOUNT
) {
107 ns
= (struct pid_namespace
*)data
;
110 ns
= current
->nsproxy
->pid_ns
;
114 sb
= sget(fs_type
, proc_test_super
, proc_set_super
, flags
, ns
);
118 if (!proc_parse_options(options
, ns
)) {
119 deactivate_locked_super(sb
);
120 return ERR_PTR(-EINVAL
);
124 err
= proc_fill_super(sb
);
126 deactivate_locked_super(sb
);
130 sb
->s_flags
|= MS_ACTIVE
;
133 ei
= PROC_I(sb
->s_root
->d_inode
);
136 ei
->pid
= get_pid(find_pid_ns(1, ns
));
140 return dget(sb
->s_root
);
143 static void proc_kill_sb(struct super_block
*sb
)
145 struct pid_namespace
*ns
;
147 ns
= (struct pid_namespace
*)sb
->s_fs_info
;
152 static struct file_system_type proc_fs_type
= {
155 .kill_sb
= proc_kill_sb
,
158 void __init
proc_root_init(void)
162 proc_init_inodecache();
163 err
= register_filesystem(&proc_fs_type
);
166 err
= pid_ns_prepare_proc(&init_pid_ns
);
168 unregister_filesystem(&proc_fs_type
);
172 proc_symlink("mounts", NULL
, "self/mounts");
176 #ifdef CONFIG_SYSVIPC
177 proc_mkdir("sysvipc", NULL
);
179 proc_mkdir("fs", NULL
);
180 proc_mkdir("driver", NULL
);
181 proc_mkdir("fs/nfsd", NULL
); /* somewhere for the nfsd filesystem to be mounted */
182 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
183 /* just give it a mountpoint */
184 proc_mkdir("openprom", NULL
);
187 #ifdef CONFIG_PROC_DEVICETREE
188 proc_device_tree_init();
190 proc_mkdir("bus", NULL
);
194 static int proc_root_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
, struct kstat
*stat
197 generic_fillattr(dentry
->d_inode
, stat
);
198 stat
->nlink
= proc_root
.nlink
+ nr_processes();
202 static struct dentry
*proc_root_lookup(struct inode
* dir
, struct dentry
* dentry
, unsigned int flags
)
204 if (!proc_lookup(dir
, dentry
, flags
))
207 return proc_pid_lookup(dir
, dentry
, flags
);
210 static int proc_root_readdir(struct file
* filp
,
211 void * dirent
, filldir_t filldir
)
213 unsigned int nr
= filp
->f_pos
;
216 if (nr
< FIRST_PROCESS_ENTRY
) {
217 int error
= proc_readdir(filp
, dirent
, filldir
);
220 filp
->f_pos
= FIRST_PROCESS_ENTRY
;
223 ret
= proc_pid_readdir(filp
, dirent
, filldir
);
228 * The root /proc directory is special, as it has the
229 * <pid> directories. Thus we don't use the generic
230 * directory handling functions for that..
232 static const struct file_operations proc_root_operations
= {
233 .read
= generic_read_dir
,
234 .readdir
= proc_root_readdir
,
235 .llseek
= default_llseek
,
239 * proc root can do almost nothing..
241 static const struct inode_operations proc_root_inode_operations
= {
242 .lookup
= proc_root_lookup
,
243 .getattr
= proc_root_getattr
,
247 * This is the root "inode" in the /proc tree..
249 struct proc_dir_entry proc_root
= {
250 .low_ino
= PROC_ROOT_INO
,
252 .mode
= S_IFDIR
| S_IRUGO
| S_IXUGO
,
254 .count
= ATOMIC_INIT(1),
255 .proc_iops
= &proc_root_inode_operations
,
256 .proc_fops
= &proc_root_operations
,
257 .parent
= &proc_root
,
261 int pid_ns_prepare_proc(struct pid_namespace
*ns
)
263 struct vfsmount
*mnt
;
265 mnt
= kern_mount_data(&proc_fs_type
, ns
);
273 void pid_ns_release_proc(struct pid_namespace
*ns
)
275 kern_unmount(ns
->proc_mnt
);