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> | |
87a8ebd6 | 19 | #include <linux/user_namespace.h> |
f6c7a1f3 | 20 | #include <linux/mount.h> |
07543f5c | 21 | #include <linux/pid_namespace.h> |
97412950 | 22 | #include <linux/parser.h> |
1da177e4 | 23 | |
fee781e6 AB |
24 | #include "internal.h" |
25 | ||
07543f5c PE |
26 | static int proc_test_super(struct super_block *sb, void *data) |
27 | { | |
28 | return sb->s_fs_info == data; | |
29 | } | |
30 | ||
31 | static int proc_set_super(struct super_block *sb, void *data) | |
32 | { | |
ff78fca2 AV |
33 | int err = set_anon_super(sb, NULL); |
34 | if (!err) { | |
35 | struct pid_namespace *ns = (struct pid_namespace *)data; | |
36 | sb->s_fs_info = get_pid_ns(ns); | |
37 | } | |
38 | return err; | |
07543f5c PE |
39 | } |
40 | ||
97412950 | 41 | enum { |
0499680a | 42 | Opt_gid, Opt_hidepid, Opt_err, |
97412950 VK |
43 | }; |
44 | ||
45 | static const match_table_t tokens = { | |
0499680a VK |
46 | {Opt_hidepid, "hidepid=%u"}, |
47 | {Opt_gid, "gid=%u"}, | |
97412950 VK |
48 | {Opt_err, NULL}, |
49 | }; | |
50 | ||
51 | static int proc_parse_options(char *options, struct pid_namespace *pid) | |
52 | { | |
53 | char *p; | |
54 | substring_t args[MAX_OPT_ARGS]; | |
0499680a | 55 | int option; |
97412950 VK |
56 | |
57 | if (!options) | |
58 | return 1; | |
59 | ||
60 | while ((p = strsep(&options, ",")) != NULL) { | |
61 | int token; | |
62 | if (!*p) | |
63 | continue; | |
64 | ||
9fb88442 | 65 | args[0].to = args[0].from = NULL; |
97412950 VK |
66 | token = match_token(p, tokens, args); |
67 | switch (token) { | |
0499680a VK |
68 | case Opt_gid: |
69 | if (match_int(&args[0], &option)) | |
70 | return 0; | |
dcb0f222 | 71 | pid->pid_gid = make_kgid(current_user_ns(), option); |
0499680a VK |
72 | break; |
73 | case Opt_hidepid: | |
74 | if (match_int(&args[0], &option)) | |
75 | return 0; | |
76 | if (option < 0 || option > 2) { | |
77 | pr_err("proc: hidepid value must be between 0 and 2.\n"); | |
78 | return 0; | |
79 | } | |
80 | pid->hide_pid = option; | |
81 | break; | |
97412950 VK |
82 | default: |
83 | pr_err("proc: unrecognized mount option \"%s\" " | |
84 | "or missing value\n", p); | |
85 | return 0; | |
86 | } | |
87 | } | |
88 | ||
89 | return 1; | |
90 | } | |
91 | ||
92 | int proc_remount(struct super_block *sb, int *flags, char *data) | |
93 | { | |
94 | struct pid_namespace *pid = sb->s_fs_info; | |
95 | return !proc_parse_options(data, pid); | |
96 | } | |
97 | ||
aed1d84f AV |
98 | static struct dentry *proc_mount(struct file_system_type *fs_type, |
99 | int flags, const char *dev_name, void *data) | |
1da177e4 | 100 | { |
07543f5c PE |
101 | int err; |
102 | struct super_block *sb; | |
103 | struct pid_namespace *ns; | |
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 { | |
17cf22c3 | 110 | ns = task_active_pid_ns(current); |
97412950 | 111 | options = data; |
87a8ebd6 | 112 | |
1ca91545 EB |
113 | if (!current_user_ns()->may_mount_proc || |
114 | !ns_capable(ns->user_ns, CAP_SYS_ADMIN)) | |
87a8ebd6 | 115 | return ERR_PTR(-EPERM); |
97412950 | 116 | } |
07543f5c | 117 | |
9249e17f | 118 | sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns); |
07543f5c | 119 | if (IS_ERR(sb)) |
aed1d84f | 120 | return ERR_CAST(sb); |
07543f5c | 121 | |
99663be7 VK |
122 | if (!proc_parse_options(options, ns)) { |
123 | deactivate_locked_super(sb); | |
124 | return ERR_PTR(-EINVAL); | |
125 | } | |
126 | ||
07543f5c | 127 | if (!sb->s_root) { |
07543f5c PE |
128 | err = proc_fill_super(sb); |
129 | if (err) { | |
6f5bbff9 | 130 | deactivate_locked_super(sb); |
aed1d84f | 131 | return ERR_PTR(err); |
07543f5c PE |
132 | } |
133 | ||
07543f5c | 134 | sb->s_flags |= MS_ACTIVE; |
07543f5c PE |
135 | } |
136 | ||
aed1d84f | 137 | return dget(sb->s_root); |
07543f5c PE |
138 | } |
139 | ||
140 | static void proc_kill_sb(struct super_block *sb) | |
141 | { | |
142 | struct pid_namespace *ns; | |
143 | ||
144 | ns = (struct pid_namespace *)sb->s_fs_info; | |
021ada7d AV |
145 | if (ns->proc_self) |
146 | dput(ns->proc_self); | |
07543f5c PE |
147 | kill_anon_super(sb); |
148 | put_pid_ns(ns); | |
1da177e4 LT |
149 | } |
150 | ||
c2319540 | 151 | static struct file_system_type proc_fs_type = { |
1da177e4 | 152 | .name = "proc", |
aed1d84f | 153 | .mount = proc_mount, |
07543f5c | 154 | .kill_sb = proc_kill_sb, |
4f326c00 | 155 | .fs_flags = FS_USERNS_MOUNT, |
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; | |
07543f5c | 166 | |
e656d8a6 | 167 | proc_self_init(); |
59c7572e | 168 | proc_symlink("mounts", NULL, "self/mounts"); |
457c4cbc EB |
169 | |
170 | proc_net_init(); | |
1da177e4 LT |
171 | |
172 | #ifdef CONFIG_SYSVIPC | |
173 | proc_mkdir("sysvipc", NULL); | |
1da177e4 | 174 | #endif |
36a5aeb8 | 175 | proc_mkdir("fs", NULL); |
928b4d8c | 176 | proc_mkdir("driver", NULL); |
1da177e4 LT |
177 | proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */ |
178 | #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE) | |
179 | /* just give it a mountpoint */ | |
180 | proc_mkdir("openprom", NULL); | |
181 | #endif | |
182 | proc_tty_init(); | |
183 | #ifdef CONFIG_PROC_DEVICETREE | |
184 | proc_device_tree_init(); | |
185 | #endif | |
9c37066d | 186 | proc_mkdir("bus", NULL); |
77b14db5 | 187 | proc_sys_init(); |
1da177e4 LT |
188 | } |
189 | ||
76b6159b AV |
190 | static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat |
191 | ) | |
1da177e4 | 192 | { |
76b6159b AV |
193 | generic_fillattr(dentry->d_inode, stat); |
194 | stat->nlink = proc_root.nlink + nr_processes(); | |
195 | return 0; | |
196 | } | |
1da177e4 | 197 | |
00cd8dd3 | 198 | static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags) |
76b6159b | 199 | { |
00cd8dd3 | 200 | if (!proc_lookup(dir, dentry, flags)) |
1da177e4 | 201 | return NULL; |
1da177e4 | 202 | |
00cd8dd3 | 203 | return proc_pid_lookup(dir, dentry, flags); |
1da177e4 LT |
204 | } |
205 | ||
206 | static int proc_root_readdir(struct file * filp, | |
207 | void * dirent, filldir_t filldir) | |
208 | { | |
209 | unsigned int nr = filp->f_pos; | |
210 | int ret; | |
211 | ||
1da177e4 LT |
212 | if (nr < FIRST_PROCESS_ENTRY) { |
213 | int error = proc_readdir(filp, dirent, filldir); | |
b4df2b92 | 214 | if (error <= 0) |
1da177e4 | 215 | return error; |
1da177e4 LT |
216 | filp->f_pos = FIRST_PROCESS_ENTRY; |
217 | } | |
1da177e4 LT |
218 | |
219 | ret = proc_pid_readdir(filp, dirent, filldir); | |
220 | return ret; | |
221 | } | |
222 | ||
223 | /* | |
224 | * The root /proc directory is special, as it has the | |
225 | * <pid> directories. Thus we don't use the generic | |
226 | * directory handling functions for that.. | |
227 | */ | |
00977a59 | 228 | static const struct file_operations proc_root_operations = { |
1da177e4 LT |
229 | .read = generic_read_dir, |
230 | .readdir = proc_root_readdir, | |
6038f373 | 231 | .llseek = default_llseek, |
1da177e4 LT |
232 | }; |
233 | ||
234 | /* | |
235 | * proc root can do almost nothing.. | |
236 | */ | |
c5ef1c42 | 237 | static const struct inode_operations proc_root_inode_operations = { |
1da177e4 | 238 | .lookup = proc_root_lookup, |
76b6159b | 239 | .getattr = proc_root_getattr, |
1da177e4 LT |
240 | }; |
241 | ||
242 | /* | |
243 | * This is the root "inode" in the /proc tree.. | |
244 | */ | |
245 | struct proc_dir_entry proc_root = { | |
246 | .low_ino = PROC_ROOT_INO, | |
247 | .namelen = 5, | |
1da177e4 LT |
248 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
249 | .nlink = 2, | |
5a622f2d | 250 | .count = ATOMIC_INIT(1), |
1da177e4 LT |
251 | .proc_iops = &proc_root_inode_operations, |
252 | .proc_fops = &proc_root_operations, | |
253 | .parent = &proc_root, | |
09570f91 | 254 | .name = "/proc", |
1da177e4 LT |
255 | }; |
256 | ||
6f4e6433 PE |
257 | int pid_ns_prepare_proc(struct pid_namespace *ns) |
258 | { | |
259 | struct vfsmount *mnt; | |
260 | ||
261 | mnt = kern_mount_data(&proc_fs_type, ns); | |
262 | if (IS_ERR(mnt)) | |
263 | return PTR_ERR(mnt); | |
264 | ||
579441a3 | 265 | ns->proc_mnt = mnt; |
6f4e6433 PE |
266 | return 0; |
267 | } | |
268 | ||
269 | void pid_ns_release_proc(struct pid_namespace *ns) | |
270 | { | |
905ad269 | 271 | kern_unmount(ns->proc_mnt); |
6f4e6433 | 272 | } |