Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/init.h> |
Al Viro | 914e263 | 2006-10-18 13:55:46 -0400 | [diff] [blame] | 16 | #include <linux/sched.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/module.h> |
| 18 | #include <linux/bitops.h> |
Eric W. Biederman | 87a8ebd | 2013-03-24 14:28:27 -0700 | [diff] [blame] | 19 | #include <linux/user_namespace.h> |
Eric W. Biederman | f6c7a1f | 2006-10-02 02:17:07 -0700 | [diff] [blame] | 20 | #include <linux/mount.h> |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 21 | #include <linux/pid_namespace.h> |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 22 | #include <linux/parser.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
Adrian Bunk | fee781e | 2006-01-08 01:04:16 -0800 | [diff] [blame] | 24 | #include "internal.h" |
| 25 | |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 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 | { |
Al Viro | ff78fca | 2011-06-12 09:42:17 -0400 | [diff] [blame] | 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; |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 39 | } |
| 40 | |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 41 | enum { |
Vasiliy Kulikov | 0499680 | 2012-01-10 15:11:31 -0800 | [diff] [blame] | 42 | Opt_gid, Opt_hidepid, Opt_err, |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 43 | }; |
| 44 | |
| 45 | static const match_table_t tokens = { |
Vasiliy Kulikov | 0499680 | 2012-01-10 15:11:31 -0800 | [diff] [blame] | 46 | {Opt_hidepid, "hidepid=%u"}, |
| 47 | {Opt_gid, "gid=%u"}, |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 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]; |
Vasiliy Kulikov | 0499680 | 2012-01-10 15:11:31 -0800 | [diff] [blame] | 55 | int option; |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 56 | |
| 57 | if (!options) |
| 58 | return 1; |
| 59 | |
| 60 | while ((p = strsep(&options, ",")) != NULL) { |
| 61 | int token; |
| 62 | if (!*p) |
| 63 | continue; |
| 64 | |
Sachin Kamat | 9fb8844 | 2012-10-04 17:15:46 -0700 | [diff] [blame] | 65 | args[0].to = args[0].from = NULL; |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 66 | token = match_token(p, tokens, args); |
| 67 | switch (token) { |
Vasiliy Kulikov | 0499680 | 2012-01-10 15:11:31 -0800 | [diff] [blame] | 68 | case Opt_gid: |
| 69 | if (match_int(&args[0], &option)) |
| 70 | return 0; |
Eric W. Biederman | dcb0f22 | 2012-02-09 08:48:21 -0800 | [diff] [blame] | 71 | pid->pid_gid = make_kgid(current_user_ns(), option); |
Vasiliy Kulikov | 0499680 | 2012-01-10 15:11:31 -0800 | [diff] [blame] | 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; |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 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 | |
Al Viro | aed1d84 | 2010-07-26 13:12:54 +0400 | [diff] [blame] | 98 | static struct dentry *proc_mount(struct file_system_type *fs_type, |
| 99 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | { |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 101 | int err; |
| 102 | struct super_block *sb; |
| 103 | struct pid_namespace *ns; |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 104 | char *options; |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 105 | |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 106 | if (flags & MS_KERNMOUNT) { |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 107 | ns = (struct pid_namespace *)data; |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 108 | options = NULL; |
| 109 | } else { |
Eric W. Biederman | 17cf22c | 2010-03-02 14:51:53 -0800 | [diff] [blame] | 110 | ns = task_active_pid_ns(current); |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 111 | options = data; |
Eric W. Biederman | 87a8ebd | 2013-03-24 14:28:27 -0700 | [diff] [blame] | 112 | |
| 113 | if (!current_user_ns()->may_mount_proc) |
| 114 | return ERR_PTR(-EPERM); |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 115 | } |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 116 | |
David Howells | 9249e17 | 2012-06-25 12:55:37 +0100 | [diff] [blame] | 117 | sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns); |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 118 | if (IS_ERR(sb)) |
Al Viro | aed1d84 | 2010-07-26 13:12:54 +0400 | [diff] [blame] | 119 | return ERR_CAST(sb); |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 120 | |
Vasiliy Kulikov | 99663be | 2012-04-05 14:25:04 -0700 | [diff] [blame] | 121 | if (!proc_parse_options(options, ns)) { |
| 122 | deactivate_locked_super(sb); |
| 123 | return ERR_PTR(-EINVAL); |
| 124 | } |
| 125 | |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 126 | if (!sb->s_root) { |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 127 | err = proc_fill_super(sb); |
| 128 | if (err) { |
Al Viro | 6f5bbff | 2009-05-06 01:34:22 -0400 | [diff] [blame] | 129 | deactivate_locked_super(sb); |
Al Viro | aed1d84 | 2010-07-26 13:12:54 +0400 | [diff] [blame] | 130 | return ERR_PTR(err); |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 131 | } |
| 132 | |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 133 | sb->s_flags |= MS_ACTIVE; |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 134 | } |
| 135 | |
Al Viro | aed1d84 | 2010-07-26 13:12:54 +0400 | [diff] [blame] | 136 | return dget(sb->s_root); |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 137 | } |
| 138 | |
| 139 | static 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 | kill_anon_super(sb); |
| 145 | put_pid_ns(ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | } |
| 147 | |
Alexey Dobriyan | c231954 | 2007-11-28 16:21:23 -0800 | [diff] [blame] | 148 | static struct file_system_type proc_fs_type = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | .name = "proc", |
Al Viro | aed1d84 | 2010-07-26 13:12:54 +0400 | [diff] [blame] | 150 | .mount = proc_mount, |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 151 | .kill_sb = proc_kill_sb, |
Eric W. Biederman | 4f326c0 | 2012-07-27 05:56:48 -0700 | [diff] [blame] | 152 | .fs_flags = FS_USERNS_MOUNT, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | }; |
| 154 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | void __init proc_root_init(void) |
| 156 | { |
Alexey Dobriyan | 5bcd7ff | 2008-10-17 03:43:55 +0400 | [diff] [blame] | 157 | int err; |
| 158 | |
| 159 | proc_init_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | err = register_filesystem(&proc_fs_type); |
| 161 | if (err) |
| 162 | return; |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 163 | |
Eric W. Biederman | e656d8a | 2010-07-10 14:52:49 -0700 | [diff] [blame] | 164 | proc_self_init(); |
Alexey Dobriyan | 59c7572 | 2008-10-06 14:49:39 +0400 | [diff] [blame] | 165 | proc_symlink("mounts", NULL, "self/mounts"); |
Eric W. Biederman | 457c4cb | 2007-09-12 12:01:34 +0200 | [diff] [blame] | 166 | |
| 167 | proc_net_init(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | |
| 169 | #ifdef CONFIG_SYSVIPC |
| 170 | proc_mkdir("sysvipc", NULL); |
| 171 | #endif |
Alexey Dobriyan | 36a5aeb | 2008-04-29 01:01:42 -0700 | [diff] [blame] | 172 | proc_mkdir("fs", NULL); |
Alexey Dobriyan | 928b4d8 | 2008-04-29 01:01:44 -0700 | [diff] [blame] | 173 | proc_mkdir("driver", NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */ |
| 175 | #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE) |
| 176 | /* just give it a mountpoint */ |
| 177 | proc_mkdir("openprom", NULL); |
| 178 | #endif |
| 179 | proc_tty_init(); |
| 180 | #ifdef CONFIG_PROC_DEVICETREE |
| 181 | proc_device_tree_init(); |
| 182 | #endif |
Alexey Dobriyan | 9c37066 | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 183 | proc_mkdir("bus", NULL); |
Eric W. Biederman | 77b14db | 2007-02-14 00:34:12 -0800 | [diff] [blame] | 184 | proc_sys_init(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | } |
| 186 | |
Al Viro | 76b6159 | 2006-02-08 14:37:40 -0500 | [diff] [blame] | 187 | static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat |
| 188 | ) |
| 189 | { |
| 190 | generic_fillattr(dentry->d_inode, stat); |
| 191 | stat->nlink = proc_root.nlink + nr_processes(); |
| 192 | return 0; |
| 193 | } |
| 194 | |
Al Viro | 00cd8dd | 2012-06-10 17:13:09 -0400 | [diff] [blame] | 195 | static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | { |
Al Viro | 00cd8dd | 2012-06-10 17:13:09 -0400 | [diff] [blame] | 197 | if (!proc_lookup(dir, dentry, flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | |
Al Viro | 00cd8dd | 2012-06-10 17:13:09 -0400 | [diff] [blame] | 200 | return proc_pid_lookup(dir, dentry, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | } |
| 202 | |
| 203 | static int proc_root_readdir(struct file * filp, |
| 204 | void * dirent, filldir_t filldir) |
| 205 | { |
| 206 | unsigned int nr = filp->f_pos; |
| 207 | int ret; |
| 208 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | if (nr < FIRST_PROCESS_ENTRY) { |
| 210 | int error = proc_readdir(filp, dirent, filldir); |
Alexey Dobriyan | b4df2b9 | 2008-10-27 22:48:36 +0300 | [diff] [blame] | 211 | if (error <= 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | filp->f_pos = FIRST_PROCESS_ENTRY; |
| 214 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
| 216 | ret = proc_pid_readdir(filp, dirent, filldir); |
| 217 | return ret; |
| 218 | } |
| 219 | |
| 220 | /* |
| 221 | * The root /proc directory is special, as it has the |
| 222 | * <pid> directories. Thus we don't use the generic |
| 223 | * directory handling functions for that.. |
| 224 | */ |
Arjan van de Ven | 00977a5 | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 225 | static const struct file_operations proc_root_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | .read = generic_read_dir, |
| 227 | .readdir = proc_root_readdir, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 228 | .llseek = default_llseek, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | }; |
| 230 | |
| 231 | /* |
| 232 | * proc root can do almost nothing.. |
| 233 | */ |
Arjan van de Ven | c5ef1c4 | 2007-02-12 00:55:40 -0800 | [diff] [blame] | 234 | static const struct inode_operations proc_root_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | .lookup = proc_root_lookup, |
Al Viro | 76b6159 | 2006-02-08 14:37:40 -0500 | [diff] [blame] | 236 | .getattr = proc_root_getattr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | }; |
| 238 | |
| 239 | /* |
| 240 | * This is the root "inode" in the /proc tree.. |
| 241 | */ |
| 242 | struct proc_dir_entry proc_root = { |
| 243 | .low_ino = PROC_ROOT_INO, |
| 244 | .namelen = 5, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
| 246 | .nlink = 2, |
Alexey Dobriyan | 5a622f2 | 2007-12-04 23:45:28 -0800 | [diff] [blame] | 247 | .count = ATOMIC_INIT(1), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | .proc_iops = &proc_root_inode_operations, |
| 249 | .proc_fops = &proc_root_operations, |
| 250 | .parent = &proc_root, |
David Howells | 09570f9 | 2011-07-27 21:47:03 +0300 | [diff] [blame] | 251 | .name = "/proc", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | }; |
| 253 | |
Pavel Emelyanov | 6f4e643 | 2007-10-18 23:40:11 -0700 | [diff] [blame] | 254 | int pid_ns_prepare_proc(struct pid_namespace *ns) |
| 255 | { |
| 256 | struct vfsmount *mnt; |
| 257 | |
| 258 | mnt = kern_mount_data(&proc_fs_type, ns); |
| 259 | if (IS_ERR(mnt)) |
| 260 | return PTR_ERR(mnt); |
| 261 | |
Al Viro | 579441a | 2010-07-26 13:09:36 +0400 | [diff] [blame] | 262 | ns->proc_mnt = mnt; |
Pavel Emelyanov | 6f4e643 | 2007-10-18 23:40:11 -0700 | [diff] [blame] | 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | void pid_ns_release_proc(struct pid_namespace *ns) |
| 267 | { |
Al Viro | 905ad26 | 2011-12-08 23:20:45 -0500 | [diff] [blame] | 268 | kern_unmount(ns->proc_mnt); |
Pavel Emelyanov | 6f4e643 | 2007-10-18 23:40:11 -0700 | [diff] [blame] | 269 | } |