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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/user_namespace.h>
20#include <linux/mount.h>
21#include <linux/pid_namespace.h>
22#include <linux/parser.h>
23
24#include "internal.h"
25
26static int proc_test_super(struct super_block *sb, void *data)
27{
28 return sb->s_fs_info == data;
29}
30
31static int proc_set_super(struct super_block *sb, void *data)
32{
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;
39}
40
41enum {
42 Opt_gid, Opt_hidepid, Opt_err,
43};
44
45static const match_table_t tokens = {
46 {Opt_hidepid, "hidepid=%u"},
47 {Opt_gid, "gid=%u"},
48 {Opt_err, NULL},
49};
50
51static int proc_parse_options(char *options, struct pid_namespace *pid)
52{
53 char *p;
54 substring_t args[MAX_OPT_ARGS];
55 int option;
56
57 if (!options)
58 return 1;
59
60 while ((p = strsep(&options, ",")) != NULL) {
61 int token;
62 if (!*p)
63 continue;
64
65 args[0].to = args[0].from = NULL;
66 token = match_token(p, tokens, args);
67 switch (token) {
68 case Opt_gid:
69 if (match_int(&args[0], &option))
70 return 0;
71 pid->pid_gid = make_kgid(current_user_ns(), option);
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;
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
92int 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
98static struct dentry *proc_mount(struct file_system_type *fs_type,
99 int flags, const char *dev_name, void *data)
100{
101 int err;
102 struct super_block *sb;
103 struct pid_namespace *ns;
104 char *options;
105
106 if (flags & MS_KERNMOUNT) {
107 ns = (struct pid_namespace *)data;
108 options = NULL;
109 } else {
110 ns = task_active_pid_ns(current);
111 options = data;
112
113 if (!current_user_ns()->may_mount_proc)
114 return ERR_PTR(-EPERM);
115 }
116
117 sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns);
118 if (IS_ERR(sb))
119 return ERR_CAST(sb);
120
121 if (!proc_parse_options(options, ns)) {
122 deactivate_locked_super(sb);
123 return ERR_PTR(-EINVAL);
124 }
125
126 if (!sb->s_root) {
127 err = proc_fill_super(sb);
128 if (err) {
129 deactivate_locked_super(sb);
130 return ERR_PTR(err);
131 }
132
133 sb->s_flags |= MS_ACTIVE;
134 }
135
136 return dget(sb->s_root);
137}
138
139static void proc_kill_sb(struct super_block *sb)
140{
141 struct pid_namespace *ns;
142
143 ns = (struct pid_namespace *)sb->s_fs_info;
144 if (ns->proc_self)
145 dput(ns->proc_self);
146 kill_anon_super(sb);
147 put_pid_ns(ns);
148}
149
150static struct file_system_type proc_fs_type = {
151 .name = "proc",
152 .mount = proc_mount,
153 .kill_sb = proc_kill_sb,
154 .fs_flags = FS_USERNS_MOUNT,
155};
156
157void __init proc_root_init(void)
158{
159 int err;
160
161 proc_init_inodecache();
162 err = register_filesystem(&proc_fs_type);
163 if (err)
164 return;
165
166 proc_self_init();
167 proc_symlink("mounts", NULL, "self/mounts");
168
169 proc_net_init();
170
171#ifdef CONFIG_SYSVIPC
172 proc_mkdir("sysvipc", NULL);
173#endif
174 proc_mkdir("fs", NULL);
175 proc_mkdir("driver", NULL);
176 proc_mkdir("fs/nfsd", NULL);
177#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
178
179 proc_mkdir("openprom", NULL);
180#endif
181 proc_tty_init();
182#ifdef CONFIG_PROC_DEVICETREE
183 proc_device_tree_init();
184#endif
185 proc_mkdir("bus", NULL);
186 proc_sys_init();
187}
188
189static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
190)
191{
192 generic_fillattr(dentry->d_inode, stat);
193 stat->nlink = proc_root.nlink + nr_processes();
194 return 0;
195}
196
197static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
198{
199 if (!proc_lookup(dir, dentry, flags))
200 return NULL;
201
202 return proc_pid_lookup(dir, dentry, flags);
203}
204
205static int proc_root_readdir(struct file *file, struct dir_context *ctx)
206{
207 if (ctx->pos < FIRST_PROCESS_ENTRY) {
208 int error = proc_readdir(file, ctx);
209 if (unlikely(error <= 0))
210 return error;
211 ctx->pos = FIRST_PROCESS_ENTRY;
212 }
213
214 return proc_pid_readdir(file, ctx);
215}
216
217
218
219
220
221
222static const struct file_operations proc_root_operations = {
223 .read = generic_read_dir,
224 .iterate = proc_root_readdir,
225 .llseek = default_llseek,
226};
227
228
229
230
231static const struct inode_operations proc_root_inode_operations = {
232 .lookup = proc_root_lookup,
233 .getattr = proc_root_getattr,
234};
235
236
237
238
239struct proc_dir_entry proc_root = {
240 .low_ino = PROC_ROOT_INO,
241 .namelen = 5,
242 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
243 .nlink = 2,
244 .count = ATOMIC_INIT(1),
245 .proc_iops = &proc_root_inode_operations,
246 .proc_fops = &proc_root_operations,
247 .parent = &proc_root,
248 .name = "/proc",
249};
250
251int pid_ns_prepare_proc(struct pid_namespace *ns)
252{
253 struct vfsmount *mnt;
254
255 mnt = kern_mount_data(&proc_fs_type, ns);
256 if (IS_ERR(mnt))
257 return PTR_ERR(mnt);
258
259 ns->proc_mnt = mnt;
260 return 0;
261}
262
263void pid_ns_release_proc(struct pid_namespace *ns)
264{
265 kern_unmount(ns->proc_mnt);
266}
267
