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1/*
2 * linux/fs/proc/root.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc root directory handling functions
7 */
8
9#include <asm/uaccess.h>
10
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
22#include "internal.h"
23
24static int proc_test_super(struct super_block *sb, void *data)
25{
26 return sb->s_fs_info == data;
27}
28
29static int proc_set_super(struct super_block *sb, void *data)
30{
31 int err = set_anon_super(sb, NULL);
32 if (!err) {
33 struct pid_namespace *ns = (struct pid_namespace *)data;
34 sb->s_fs_info = get_pid_ns(ns);
35 }
36 return err;
37}
38
39static struct dentry *proc_mount(struct file_system_type *fs_type,
40 int flags, const char *dev_name, void *data)
41{
42 int err;
43 struct super_block *sb;
44 struct pid_namespace *ns;
45 struct proc_inode *ei;
46
47 if (flags & MS_KERNMOUNT)
48 ns = (struct pid_namespace *)data;
49 else
50 ns = current->nsproxy->pid_ns;
51
52 sb = sget(fs_type, proc_test_super, proc_set_super, ns);
53 if (IS_ERR(sb))
54 return ERR_CAST(sb);
55
56 if (!sb->s_root) {
57 sb->s_flags = flags;
58 err = proc_fill_super(sb);
59 if (err) {
60 deactivate_locked_super(sb);
61 return ERR_PTR(err);
62 }
63
64 sb->s_flags |= MS_ACTIVE;
65 }
66
67 ei = PROC_I(sb->s_root->d_inode);
68 if (!ei->pid) {
69 rcu_read_lock();
70 ei->pid = get_pid(find_pid_ns(1, ns));
71 rcu_read_unlock();
72 }
73
74 return dget(sb->s_root);
75}
76
77static void proc_kill_sb(struct super_block *sb)
78{
79 struct pid_namespace *ns;
80
81 ns = (struct pid_namespace *)sb->s_fs_info;
82 kill_anon_super(sb);
83 put_pid_ns(ns);
84}
85
86static struct file_system_type proc_fs_type = {
87 .name = "proc",
88 .mount = proc_mount,
89 .kill_sb = proc_kill_sb,
90};
91
92void __init proc_root_init(void)
93{
94 struct vfsmount *mnt;
95 int err;
96
97 proc_init_inodecache();
98 err = register_filesystem(&proc_fs_type);
99 if (err)
100 return;
101 mnt = kern_mount_data(&proc_fs_type, &init_pid_ns);
102 if (IS_ERR(mnt)) {
103 unregister_filesystem(&proc_fs_type);
104 return;
105 }
106
107 init_pid_ns.proc_mnt = mnt;
108 proc_symlink("mounts", NULL, "self/mounts");
109
110 proc_net_init();
111
112#ifdef CONFIG_SYSVIPC
113 proc_mkdir("sysvipc", NULL);
114#endif
115 proc_mkdir("fs", NULL);
116 proc_mkdir("driver", NULL);
117 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
118#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
119 /* just give it a mountpoint */
120 proc_mkdir("openprom", NULL);
121#endif
122 proc_tty_init();
123#ifdef CONFIG_PROC_DEVICETREE
124 proc_device_tree_init();
125#endif
126 proc_mkdir("bus", NULL);
127 proc_sys_init();
128}
129
130static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
131)
132{
133 generic_fillattr(dentry->d_inode, stat);
134 stat->nlink = proc_root.nlink + nr_processes();
135 return 0;
136}
137
138static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
139{
140 if (!proc_lookup(dir, dentry, nd)) {
141 return NULL;
142 }
143
144 return proc_pid_lookup(dir, dentry, nd);
145}
146
147static int proc_root_readdir(struct file * filp,
148 void * dirent, filldir_t filldir)
149{
150 unsigned int nr = filp->f_pos;
151 int ret;
152
153 if (nr < FIRST_PROCESS_ENTRY) {
154 int error = proc_readdir(filp, dirent, filldir);
155 if (error <= 0)
156 return error;
157 filp->f_pos = FIRST_PROCESS_ENTRY;
158 }
159
160 ret = proc_pid_readdir(filp, dirent, filldir);
161 return ret;
162}
163
164/*
165 * The root /proc directory is special, as it has the
166 * <pid> directories. Thus we don't use the generic
167 * directory handling functions for that..
168 */
169static const struct file_operations proc_root_operations = {
170 .read = generic_read_dir,
171 .readdir = proc_root_readdir,
172 .llseek = default_llseek,
173};
174
175/*
176 * proc root can do almost nothing..
177 */
178static const struct inode_operations proc_root_inode_operations = {
179 .lookup = proc_root_lookup,
180 .getattr = proc_root_getattr,
181};
182
183/*
184 * This is the root "inode" in the /proc tree..
185 */
186struct proc_dir_entry proc_root = {
187 .low_ino = PROC_ROOT_INO,
188 .namelen = 5,
189 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
190 .nlink = 2,
191 .count = ATOMIC_INIT(1),
192 .proc_iops = &proc_root_inode_operations,
193 .proc_fops = &proc_root_operations,
194 .parent = &proc_root,
195 .name = "/proc",
196};
197
198int pid_ns_prepare_proc(struct pid_namespace *ns)
199{
200 struct vfsmount *mnt;
201
202 mnt = kern_mount_data(&proc_fs_type, ns);
203 if (IS_ERR(mnt))
204 return PTR_ERR(mnt);
205
206 ns->proc_mnt = mnt;
207 return 0;
208}
209
210void pid_ns_release_proc(struct pid_namespace *ns)
211{
212 mntput(ns->proc_mnt);
213}
1/*
2 * linux/fs/proc/root.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc root directory handling functions
7 */
8
9#include <asm/uaccess.h>
10
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>
22
23#include "internal.h"
24
25static int proc_test_super(struct super_block *sb, void *data)
26{
27 return sb->s_fs_info == data;
28}
29
30static int proc_set_super(struct super_block *sb, void *data)
31{
32 int err = set_anon_super(sb, NULL);
33 if (!err) {
34 struct pid_namespace *ns = (struct pid_namespace *)data;
35 sb->s_fs_info = get_pid_ns(ns);
36 }
37 return err;
38}
39
40enum {
41 Opt_gid, Opt_hidepid, Opt_err,
42};
43
44static const match_table_t tokens = {
45 {Opt_hidepid, "hidepid=%u"},
46 {Opt_gid, "gid=%u"},
47 {Opt_err, NULL},
48};
49
50static int proc_parse_options(char *options, struct pid_namespace *pid)
51{
52 char *p;
53 substring_t args[MAX_OPT_ARGS];
54 int option;
55
56 if (!options)
57 return 1;
58
59 while ((p = strsep(&options, ",")) != NULL) {
60 int token;
61 if (!*p)
62 continue;
63
64 args[0].to = args[0].from = 0;
65 token = match_token(p, tokens, args);
66 switch (token) {
67 case Opt_gid:
68 if (match_int(&args[0], &option))
69 return 0;
70 pid->pid_gid = make_kgid(current_user_ns(), option);
71 break;
72 case Opt_hidepid:
73 if (match_int(&args[0], &option))
74 return 0;
75 if (option < 0 || option > 2) {
76 pr_err("proc: hidepid value must be between 0 and 2.\n");
77 return 0;
78 }
79 pid->hide_pid = option;
80 break;
81 default:
82 pr_err("proc: unrecognized mount option \"%s\" "
83 "or missing value\n", p);
84 return 0;
85 }
86 }
87
88 return 1;
89}
90
91int proc_remount(struct super_block *sb, int *flags, char *data)
92{
93 struct pid_namespace *pid = sb->s_fs_info;
94 return !proc_parse_options(data, pid);
95}
96
97static struct dentry *proc_mount(struct file_system_type *fs_type,
98 int flags, const char *dev_name, void *data)
99{
100 int err;
101 struct super_block *sb;
102 struct pid_namespace *ns;
103 struct proc_inode *ei;
104 char *options;
105
106 if (flags & MS_KERNMOUNT) {
107 ns = (struct pid_namespace *)data;
108 options = NULL;
109 } else {
110 ns = current->nsproxy->pid_ns;
111 options = data;
112 }
113
114 sb = sget(fs_type, proc_test_super, proc_set_super, ns);
115 if (IS_ERR(sb))
116 return ERR_CAST(sb);
117
118 if (!proc_parse_options(options, ns)) {
119 deactivate_locked_super(sb);
120 return ERR_PTR(-EINVAL);
121 }
122
123 if (!sb->s_root) {
124 sb->s_flags = flags;
125 err = proc_fill_super(sb);
126 if (err) {
127 deactivate_locked_super(sb);
128 return ERR_PTR(err);
129 }
130
131 sb->s_flags |= MS_ACTIVE;
132 }
133
134 ei = PROC_I(sb->s_root->d_inode);
135 if (!ei->pid) {
136 rcu_read_lock();
137 ei->pid = get_pid(find_pid_ns(1, ns));
138 rcu_read_unlock();
139 }
140
141 return dget(sb->s_root);
142}
143
144static void proc_kill_sb(struct super_block *sb)
145{
146 struct pid_namespace *ns;
147
148 ns = (struct pid_namespace *)sb->s_fs_info;
149 kill_anon_super(sb);
150 put_pid_ns(ns);
151}
152
153static struct file_system_type proc_fs_type = {
154 .name = "proc",
155 .mount = proc_mount,
156 .kill_sb = proc_kill_sb,
157};
158
159void __init proc_root_init(void)
160{
161 int err;
162
163 proc_init_inodecache();
164 err = register_filesystem(&proc_fs_type);
165 if (err)
166 return;
167 err = pid_ns_prepare_proc(&init_pid_ns);
168 if (err) {
169 unregister_filesystem(&proc_fs_type);
170 return;
171 }
172
173 proc_symlink("mounts", NULL, "self/mounts");
174
175 proc_net_init();
176
177#ifdef CONFIG_SYSVIPC
178 proc_mkdir("sysvipc", NULL);
179#endif
180 proc_mkdir("fs", NULL);
181 proc_mkdir("driver", NULL);
182 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
183#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
184 /* just give it a mountpoint */
185 proc_mkdir("openprom", NULL);
186#endif
187 proc_tty_init();
188#ifdef CONFIG_PROC_DEVICETREE
189 proc_device_tree_init();
190#endif
191 proc_mkdir("bus", NULL);
192 proc_sys_init();
193}
194
195static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
196)
197{
198 generic_fillattr(dentry->d_inode, stat);
199 stat->nlink = proc_root.nlink + nr_processes();
200 return 0;
201}
202
203static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
204{
205 if (!proc_lookup(dir, dentry, nd)) {
206 return NULL;
207 }
208
209 return proc_pid_lookup(dir, dentry, nd);
210}
211
212static int proc_root_readdir(struct file * filp,
213 void * dirent, filldir_t filldir)
214{
215 unsigned int nr = filp->f_pos;
216 int ret;
217
218 if (nr < FIRST_PROCESS_ENTRY) {
219 int error = proc_readdir(filp, dirent, filldir);
220 if (error <= 0)
221 return error;
222 filp->f_pos = FIRST_PROCESS_ENTRY;
223 }
224
225 ret = proc_pid_readdir(filp, dirent, filldir);
226 return ret;
227}
228
229/*
230 * The root /proc directory is special, as it has the
231 * <pid> directories. Thus we don't use the generic
232 * directory handling functions for that..
233 */
234static const struct file_operations proc_root_operations = {
235 .read = generic_read_dir,
236 .readdir = proc_root_readdir,
237 .llseek = default_llseek,
238};
239
240/*
241 * proc root can do almost nothing..
242 */
243static const struct inode_operations proc_root_inode_operations = {
244 .lookup = proc_root_lookup,
245 .getattr = proc_root_getattr,
246};
247
248/*
249 * This is the root "inode" in the /proc tree..
250 */
251struct proc_dir_entry proc_root = {
252 .low_ino = PROC_ROOT_INO,
253 .namelen = 5,
254 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
255 .nlink = 2,
256 .count = ATOMIC_INIT(1),
257 .proc_iops = &proc_root_inode_operations,
258 .proc_fops = &proc_root_operations,
259 .parent = &proc_root,
260 .name = "/proc",
261};
262
263int pid_ns_prepare_proc(struct pid_namespace *ns)
264{
265 struct vfsmount *mnt;
266
267 mnt = kern_mount_data(&proc_fs_type, ns);
268 if (IS_ERR(mnt))
269 return PTR_ERR(mnt);
270
271 ns->proc_mnt = mnt;
272 return 0;
273}
274
275void pid_ns_release_proc(struct pid_namespace *ns)
276{
277 kern_unmount(ns->proc_mnt);
278}