Commit | Line | Data |
---|---|---|
1da177e4 LT |
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> | |
1da177e4 | 15 | #include <linux/init.h> |
914e2637 | 16 | #include <linux/sched.h> |
1da177e4 LT |
17 | #include <linux/module.h> |
18 | #include <linux/bitops.h> | |
f6c7a1f3 | 19 | #include <linux/mount.h> |
07543f5c | 20 | #include <linux/pid_namespace.h> |
97412950 | 21 | #include <linux/parser.h> |
1da177e4 | 22 | |
fee781e6 AB |
23 | #include "internal.h" |
24 | ||
07543f5c PE |
25 | static int proc_test_super(struct super_block *sb, void *data) |
26 | { | |
27 | return sb->s_fs_info == data; | |
28 | } | |
29 | ||
30 | static int proc_set_super(struct super_block *sb, void *data) | |
31 | { | |
ff78fca2 AV |
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; | |
07543f5c PE |
38 | } |
39 | ||
97412950 | 40 | enum { |
0499680a | 41 | Opt_gid, Opt_hidepid, Opt_err, |
97412950 VK |
42 | }; |
43 | ||
44 | static const match_table_t tokens = { | |
0499680a VK |
45 | {Opt_hidepid, "hidepid=%u"}, |
46 | {Opt_gid, "gid=%u"}, | |
97412950 VK |
47 | {Opt_err, NULL}, |
48 | }; | |
49 | ||
50 | static int proc_parse_options(char *options, struct pid_namespace *pid) | |
51 | { | |
52 | char *p; | |
53 | substring_t args[MAX_OPT_ARGS]; | |
0499680a | 54 | int option; |
97412950 VK |
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) { | |
0499680a VK |
67 | case Opt_gid: |
68 | if (match_int(&args[0], &option)) | |
69 | return 0; | |
dcb0f222 | 70 | pid->pid_gid = make_kgid(current_user_ns(), option); |
0499680a VK |
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; | |
97412950 VK |
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 | ||
91 | int 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 | ||
aed1d84f AV |
97 | static struct dentry *proc_mount(struct file_system_type *fs_type, |
98 | int flags, const char *dev_name, void *data) | |
1da177e4 | 99 | { |
07543f5c PE |
100 | int err; |
101 | struct super_block *sb; | |
102 | struct pid_namespace *ns; | |
103 | struct proc_inode *ei; | |
97412950 | 104 | char *options; |
07543f5c | 105 | |
97412950 | 106 | if (flags & MS_KERNMOUNT) { |
07543f5c | 107 | ns = (struct pid_namespace *)data; |
97412950 VK |
108 | options = NULL; |
109 | } else { | |
07543f5c | 110 | ns = current->nsproxy->pid_ns; |
97412950 VK |
111 | options = data; |
112 | } | |
07543f5c | 113 | |
9249e17f | 114 | sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns); |
07543f5c | 115 | if (IS_ERR(sb)) |
aed1d84f | 116 | return ERR_CAST(sb); |
07543f5c | 117 | |
99663be7 VK |
118 | if (!proc_parse_options(options, ns)) { |
119 | deactivate_locked_super(sb); | |
120 | return ERR_PTR(-EINVAL); | |
121 | } | |
122 | ||
07543f5c | 123 | if (!sb->s_root) { |
07543f5c PE |
124 | err = proc_fill_super(sb); |
125 | if (err) { | |
6f5bbff9 | 126 | deactivate_locked_super(sb); |
aed1d84f | 127 | return ERR_PTR(err); |
07543f5c PE |
128 | } |
129 | ||
07543f5c | 130 | sb->s_flags |= MS_ACTIVE; |
07543f5c PE |
131 | } |
132 | ||
4308eebb EB |
133 | ei = PROC_I(sb->s_root->d_inode); |
134 | if (!ei->pid) { | |
135 | rcu_read_lock(); | |
136 | ei->pid = get_pid(find_pid_ns(1, ns)); | |
137 | rcu_read_unlock(); | |
138 | } | |
139 | ||
aed1d84f | 140 | return dget(sb->s_root); |
07543f5c PE |
141 | } |
142 | ||
143 | static void proc_kill_sb(struct super_block *sb) | |
144 | { | |
145 | struct pid_namespace *ns; | |
146 | ||
147 | ns = (struct pid_namespace *)sb->s_fs_info; | |
148 | kill_anon_super(sb); | |
149 | put_pid_ns(ns); | |
1da177e4 LT |
150 | } |
151 | ||
c2319540 | 152 | static struct file_system_type proc_fs_type = { |
1da177e4 | 153 | .name = "proc", |
aed1d84f | 154 | .mount = proc_mount, |
07543f5c | 155 | .kill_sb = proc_kill_sb, |
1da177e4 LT |
156 | }; |
157 | ||
1da177e4 LT |
158 | void __init proc_root_init(void) |
159 | { | |
5bcd7ff9 AD |
160 | int err; |
161 | ||
162 | proc_init_inodecache(); | |
1da177e4 LT |
163 | err = register_filesystem(&proc_fs_type); |
164 | if (err) | |
165 | return; | |
905ad269 AV |
166 | err = pid_ns_prepare_proc(&init_pid_ns); |
167 | if (err) { | |
1da177e4 LT |
168 | unregister_filesystem(&proc_fs_type); |
169 | return; | |
170 | } | |
07543f5c | 171 | |
59c7572e | 172 | proc_symlink("mounts", NULL, "self/mounts"); |
457c4cbc EB |
173 | |
174 | proc_net_init(); | |
1da177e4 LT |
175 | |
176 | #ifdef CONFIG_SYSVIPC | |
177 | proc_mkdir("sysvipc", NULL); | |
1da177e4 | 178 | #endif |
36a5aeb8 | 179 | proc_mkdir("fs", NULL); |
928b4d8c | 180 | proc_mkdir("driver", NULL); |
1da177e4 LT |
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); | |
185 | #endif | |
186 | proc_tty_init(); | |
187 | #ifdef CONFIG_PROC_DEVICETREE | |
188 | proc_device_tree_init(); | |
189 | #endif | |
9c37066d | 190 | proc_mkdir("bus", NULL); |
77b14db5 | 191 | proc_sys_init(); |
1da177e4 LT |
192 | } |
193 | ||
76b6159b AV |
194 | static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat |
195 | ) | |
1da177e4 | 196 | { |
76b6159b AV |
197 | generic_fillattr(dentry->d_inode, stat); |
198 | stat->nlink = proc_root.nlink + nr_processes(); | |
199 | return 0; | |
200 | } | |
1da177e4 | 201 | |
00cd8dd3 | 202 | static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags) |
76b6159b | 203 | { |
00cd8dd3 | 204 | if (!proc_lookup(dir, dentry, flags)) |
1da177e4 | 205 | return NULL; |
1da177e4 | 206 | |
00cd8dd3 | 207 | return proc_pid_lookup(dir, dentry, flags); |
1da177e4 LT |
208 | } |
209 | ||
210 | static int proc_root_readdir(struct file * filp, | |
211 | void * dirent, filldir_t filldir) | |
212 | { | |
213 | unsigned int nr = filp->f_pos; | |
214 | int ret; | |
215 | ||
1da177e4 LT |
216 | if (nr < FIRST_PROCESS_ENTRY) { |
217 | int error = proc_readdir(filp, dirent, filldir); | |
b4df2b92 | 218 | if (error <= 0) |
1da177e4 | 219 | return error; |
1da177e4 LT |
220 | filp->f_pos = FIRST_PROCESS_ENTRY; |
221 | } | |
1da177e4 LT |
222 | |
223 | ret = proc_pid_readdir(filp, dirent, filldir); | |
224 | return ret; | |
225 | } | |
226 | ||
227 | /* | |
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.. | |
231 | */ | |
00977a59 | 232 | static const struct file_operations proc_root_operations = { |
1da177e4 LT |
233 | .read = generic_read_dir, |
234 | .readdir = proc_root_readdir, | |
6038f373 | 235 | .llseek = default_llseek, |
1da177e4 LT |
236 | }; |
237 | ||
238 | /* | |
239 | * proc root can do almost nothing.. | |
240 | */ | |
c5ef1c42 | 241 | static const struct inode_operations proc_root_inode_operations = { |
1da177e4 | 242 | .lookup = proc_root_lookup, |
76b6159b | 243 | .getattr = proc_root_getattr, |
1da177e4 LT |
244 | }; |
245 | ||
246 | /* | |
247 | * This is the root "inode" in the /proc tree.. | |
248 | */ | |
249 | struct proc_dir_entry proc_root = { | |
250 | .low_ino = PROC_ROOT_INO, | |
251 | .namelen = 5, | |
1da177e4 LT |
252 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
253 | .nlink = 2, | |
5a622f2d | 254 | .count = ATOMIC_INIT(1), |
1da177e4 LT |
255 | .proc_iops = &proc_root_inode_operations, |
256 | .proc_fops = &proc_root_operations, | |
257 | .parent = &proc_root, | |
09570f91 | 258 | .name = "/proc", |
1da177e4 LT |
259 | }; |
260 | ||
6f4e6433 PE |
261 | int pid_ns_prepare_proc(struct pid_namespace *ns) |
262 | { | |
263 | struct vfsmount *mnt; | |
264 | ||
265 | mnt = kern_mount_data(&proc_fs_type, ns); | |
266 | if (IS_ERR(mnt)) | |
267 | return PTR_ERR(mnt); | |
268 | ||
579441a3 | 269 | ns->proc_mnt = mnt; |
6f4e6433 PE |
270 | return 0; |
271 | } | |
272 | ||
273 | void pid_ns_release_proc(struct pid_namespace *ns) | |
274 | { | |
905ad269 | 275 | kern_unmount(ns->proc_mnt); |
6f4e6433 | 276 | } |