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/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
 96	sync_filesystem(sb);
 97	return !proc_parse_options(data, pid);
 98}
 99
100static struct dentry *proc_mount(struct file_system_type *fs_type,
101	int flags, const char *dev_name, void *data)
102{
103	int err;
104	struct super_block *sb;
105	struct pid_namespace *ns;
 
106	char *options;
107
108	if (flags & MS_KERNMOUNT) {
109		ns = (struct pid_namespace *)data;
110		options = NULL;
111	} else {
112		ns = task_active_pid_ns(current);
113		options = data;
114
115		/* Does the mounter have privilege over the pid namespace? */
116		if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN))
117			return ERR_PTR(-EPERM);
118	}
119
120	sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns);
121	if (IS_ERR(sb))
122		return ERR_CAST(sb);
123
124	if (!proc_parse_options(options, ns)) {
125		deactivate_locked_super(sb);
126		return ERR_PTR(-EINVAL);
127	}
128
129	if (!sb->s_root) {
 
130		err = proc_fill_super(sb);
131		if (err) {
132			deactivate_locked_super(sb);
133			return ERR_PTR(err);
134		}
135
136		sb->s_flags |= MS_ACTIVE;
137		/* User space would break if executables appear on proc */
138		sb->s_iflags |= SB_I_NOEXEC;
 
 
 
 
 
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	if (ns->proc_self)
150		dput(ns->proc_self);
151	if (ns->proc_thread_self)
152		dput(ns->proc_thread_self);
153	kill_anon_super(sb);
154	put_pid_ns(ns);
155}
156
157static struct file_system_type proc_fs_type = {
158	.name		= "proc",
159	.mount		= proc_mount,
160	.kill_sb	= proc_kill_sb,
161	.fs_flags	= FS_USERNS_VISIBLE | FS_USERNS_MOUNT,
162};
163
164void __init proc_root_init(void)
165{
166	int err;
167
168	proc_init_inodecache();
169	err = register_filesystem(&proc_fs_type);
170	if (err)
171		return;
 
 
 
 
 
172
173	proc_self_init();
174	proc_thread_self_init();
175	proc_symlink("mounts", NULL, "self/mounts");
176
177	proc_net_init();
178
179#ifdef CONFIG_SYSVIPC
180	proc_mkdir("sysvipc", NULL);
181#endif
182	proc_mkdir("fs", NULL);
183	proc_mkdir("driver", NULL);
184	proc_create_mount_point("fs/nfsd"); /* somewhere for the nfsd filesystem to be mounted */
185#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
186	/* just give it a mountpoint */
187	proc_create_mount_point("openprom");
188#endif
189	proc_tty_init();
 
 
 
190	proc_mkdir("bus", NULL);
191	proc_sys_init();
192}
193
194static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
195)
196{
197	generic_fillattr(d_inode(dentry), stat);
198	stat->nlink = proc_root.nlink + nr_processes();
199	return 0;
200}
201
202static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
203{
204	if (!proc_pid_lookup(dir, dentry, flags))
205		return NULL;
 
206	
207	return proc_lookup(dir, dentry, flags);
208}
209
210static int proc_root_readdir(struct file *file, struct dir_context *ctx)
 
211{
212	if (ctx->pos < FIRST_PROCESS_ENTRY) {
213		int error = proc_readdir(file, ctx);
214		if (unlikely(error <= 0))
 
 
 
215			return error;
216		ctx->pos = FIRST_PROCESS_ENTRY;
217	}
218
219	return proc_pid_readdir(file, ctx);
 
220}
221
222/*
223 * The root /proc directory is special, as it has the
224 * <pid> directories. Thus we don't use the generic
225 * directory handling functions for that..
226 */
227static const struct file_operations proc_root_operations = {
228	.read		 = generic_read_dir,
229	.iterate	 = proc_root_readdir,
230	.llseek		= default_llseek,
231};
232
233/*
234 * proc root can do almost nothing..
235 */
236static const struct inode_operations proc_root_inode_operations = {
237	.lookup		= proc_root_lookup,
238	.getattr	= proc_root_getattr,
239};
240
241/*
242 * This is the root "inode" in the /proc tree..
243 */
244struct proc_dir_entry proc_root = {
245	.low_ino	= PROC_ROOT_INO, 
246	.namelen	= 5, 
247	.mode		= S_IFDIR | S_IRUGO | S_IXUGO, 
248	.nlink		= 2, 
249	.count		= ATOMIC_INIT(1),
250	.proc_iops	= &proc_root_inode_operations, 
251	.proc_fops	= &proc_root_operations,
252	.parent		= &proc_root,
253	.subdir		= RB_ROOT,
254	.name		= "/proc",
255};
256
257int 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
265	ns->proc_mnt = mnt;
266	return 0;
267}
268
269void pid_ns_release_proc(struct pid_namespace *ns)
270{
271	kern_unmount(ns->proc_mnt);
272}

  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}