11da177e4SLinus Torvalds /* -*- linux-c -*- --------------------------------------------------------- * 21da177e4SLinus Torvalds * 31da177e4SLinus Torvalds * linux/fs/devpts/inode.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * Copyright 1998-2004 H. Peter Anvin -- All Rights Reserved 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * This file is part of the Linux kernel and is made available under 81da177e4SLinus Torvalds * the terms of the GNU General Public License, version 2, or at your 91da177e4SLinus Torvalds * option, any later version, incorporated herein by reference. 101da177e4SLinus Torvalds * 111da177e4SLinus Torvalds * ------------------------------------------------------------------------- */ 121da177e4SLinus Torvalds 1304541a2fSFabian Frederick #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 1404541a2fSFabian Frederick 151da177e4SLinus Torvalds #include <linux/module.h> 161da177e4SLinus Torvalds #include <linux/init.h> 171da177e4SLinus Torvalds #include <linux/fs.h> 181da177e4SLinus Torvalds #include <linux/sched.h> 191da177e4SLinus Torvalds #include <linux/namei.h> 205a0e3ad6STejun Heo #include <linux/slab.h> 211da177e4SLinus Torvalds #include <linux/mount.h> 221da177e4SLinus Torvalds #include <linux/tty.h> 23718a9163SSukadev Bhattiprolu #include <linux/mutex.h> 241fd7317dSNick Black #include <linux/magic.h> 25718a9163SSukadev Bhattiprolu #include <linux/idr.h> 261da177e4SLinus Torvalds #include <linux/devpts_fs.h> 277a673c6bSDomen Puncer #include <linux/parser.h> 283972b7f6SFlorin Malita #include <linux/fsnotify.h> 29b87a267eSMiklos Szeredi #include <linux/seq_file.h> 301da177e4SLinus Torvalds 31b87a267eSMiklos Szeredi #define DEVPTS_DEFAULT_MODE 0600 321f8f1e29SSukadev Bhattiprolu /* 331f8f1e29SSukadev Bhattiprolu * ptmx is a new node in /dev/pts and will be unused in legacy (single- 341f8f1e29SSukadev Bhattiprolu * instance) mode. To prevent surprises in user space, set permissions of 351f8f1e29SSukadev Bhattiprolu * ptmx to 0. Use 'chmod' or remount with '-o ptmxmode' to set meaningful 361f8f1e29SSukadev Bhattiprolu * permissions. 371f8f1e29SSukadev Bhattiprolu */ 381f8f1e29SSukadev Bhattiprolu #define DEVPTS_DEFAULT_PTMX_MODE 0000 39527b3e47SSukadev Bhattiprolu #define PTMX_MINOR 2 40b87a267eSMiklos Szeredi 41a4834c10SKonstantin Khlebnikov /* 42a4834c10SKonstantin Khlebnikov * sysctl support for setting limits on the number of Unix98 ptys allocated. 43a4834c10SKonstantin Khlebnikov * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. 44a4834c10SKonstantin Khlebnikov */ 45a4834c10SKonstantin Khlebnikov static int pty_limit = NR_UNIX98_PTY_DEFAULT; 46e9aba515SKonstantin Khlebnikov static int pty_reserve = NR_UNIX98_PTY_RESERVE; 47a4834c10SKonstantin Khlebnikov static int pty_limit_min; 48e9aba515SKonstantin Khlebnikov static int pty_limit_max = INT_MAX; 49a4834c10SKonstantin Khlebnikov static int pty_count; 50a4834c10SKonstantin Khlebnikov 51a4834c10SKonstantin Khlebnikov static struct ctl_table pty_table[] = { 52a4834c10SKonstantin Khlebnikov { 53a4834c10SKonstantin Khlebnikov .procname = "max", 54a4834c10SKonstantin Khlebnikov .maxlen = sizeof(int), 55a4834c10SKonstantin Khlebnikov .mode = 0644, 56a4834c10SKonstantin Khlebnikov .data = &pty_limit, 57a4834c10SKonstantin Khlebnikov .proc_handler = proc_dointvec_minmax, 58a4834c10SKonstantin Khlebnikov .extra1 = &pty_limit_min, 59a4834c10SKonstantin Khlebnikov .extra2 = &pty_limit_max, 60a4834c10SKonstantin Khlebnikov }, { 61e9aba515SKonstantin Khlebnikov .procname = "reserve", 62e9aba515SKonstantin Khlebnikov .maxlen = sizeof(int), 63e9aba515SKonstantin Khlebnikov .mode = 0644, 64e9aba515SKonstantin Khlebnikov .data = &pty_reserve, 65e9aba515SKonstantin Khlebnikov .proc_handler = proc_dointvec_minmax, 66e9aba515SKonstantin Khlebnikov .extra1 = &pty_limit_min, 67e9aba515SKonstantin Khlebnikov .extra2 = &pty_limit_max, 68e9aba515SKonstantin Khlebnikov }, { 69a4834c10SKonstantin Khlebnikov .procname = "nr", 70a4834c10SKonstantin Khlebnikov .maxlen = sizeof(int), 71a4834c10SKonstantin Khlebnikov .mode = 0444, 72a4834c10SKonstantin Khlebnikov .data = &pty_count, 73a4834c10SKonstantin Khlebnikov .proc_handler = proc_dointvec, 74a4834c10SKonstantin Khlebnikov }, 75a4834c10SKonstantin Khlebnikov {} 76a4834c10SKonstantin Khlebnikov }; 77a4834c10SKonstantin Khlebnikov 78a4834c10SKonstantin Khlebnikov static struct ctl_table pty_kern_table[] = { 79a4834c10SKonstantin Khlebnikov { 80a4834c10SKonstantin Khlebnikov .procname = "pty", 81a4834c10SKonstantin Khlebnikov .mode = 0555, 82a4834c10SKonstantin Khlebnikov .child = pty_table, 83a4834c10SKonstantin Khlebnikov }, 84a4834c10SKonstantin Khlebnikov {} 85a4834c10SKonstantin Khlebnikov }; 86a4834c10SKonstantin Khlebnikov 87a4834c10SKonstantin Khlebnikov static struct ctl_table pty_root_table[] = { 88a4834c10SKonstantin Khlebnikov { 89a4834c10SKonstantin Khlebnikov .procname = "kernel", 90a4834c10SKonstantin Khlebnikov .mode = 0555, 91a4834c10SKonstantin Khlebnikov .child = pty_kern_table, 92a4834c10SKonstantin Khlebnikov }, 93a4834c10SKonstantin Khlebnikov {} 94a4834c10SKonstantin Khlebnikov }; 95a4834c10SKonstantin Khlebnikov 96718a9163SSukadev Bhattiprolu static DEFINE_MUTEX(allocated_ptys_lock); 97718a9163SSukadev Bhattiprolu 981da177e4SLinus Torvalds static struct vfsmount *devpts_mnt; 991da177e4SLinus Torvalds 10031af0abbSSukadev Bhattiprolu struct pts_mount_opts { 1011da177e4SLinus Torvalds int setuid; 1021da177e4SLinus Torvalds int setgid; 103f04c6ce2SEric W. Biederman kuid_t uid; 104f04c6ce2SEric W. Biederman kgid_t gid; 1051da177e4SLinus Torvalds umode_t mode; 1061f8f1e29SSukadev Bhattiprolu umode_t ptmxmode; 1072a1b2dc0SSukadev Bhattiprolu int newinstance; 108e9aba515SKonstantin Khlebnikov int max; 10931af0abbSSukadev Bhattiprolu }; 1101da177e4SLinus Torvalds 1117a673c6bSDomen Puncer enum { 112e9aba515SKonstantin Khlebnikov Opt_uid, Opt_gid, Opt_mode, Opt_ptmxmode, Opt_newinstance, Opt_max, 1137a673c6bSDomen Puncer Opt_err 1147a673c6bSDomen Puncer }; 1157a673c6bSDomen Puncer 116a447c093SSteven Whitehouse static const match_table_t tokens = { 1177a673c6bSDomen Puncer {Opt_uid, "uid=%u"}, 1187a673c6bSDomen Puncer {Opt_gid, "gid=%u"}, 1197a673c6bSDomen Puncer {Opt_mode, "mode=%o"}, 1201f8f1e29SSukadev Bhattiprolu #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES 1211f8f1e29SSukadev Bhattiprolu {Opt_ptmxmode, "ptmxmode=%o"}, 1222a1b2dc0SSukadev Bhattiprolu {Opt_newinstance, "newinstance"}, 123e9aba515SKonstantin Khlebnikov {Opt_max, "max=%d"}, 1241f8f1e29SSukadev Bhattiprolu #endif 1257a673c6bSDomen Puncer {Opt_err, NULL} 1267a673c6bSDomen Puncer }; 1277a673c6bSDomen Puncer 128e76b7c01SSukadev Bhattiprolu struct pts_fs_info { 129e76b7c01SSukadev Bhattiprolu struct ida allocated_ptys; 13031af0abbSSukadev Bhattiprolu struct pts_mount_opts mount_opts; 1311f8f1e29SSukadev Bhattiprolu struct dentry *ptmx_dentry; 132e76b7c01SSukadev Bhattiprolu }; 133e76b7c01SSukadev Bhattiprolu 134e76b7c01SSukadev Bhattiprolu static inline struct pts_fs_info *DEVPTS_SB(struct super_block *sb) 135e76b7c01SSukadev Bhattiprolu { 136e76b7c01SSukadev Bhattiprolu return sb->s_fs_info; 137e76b7c01SSukadev Bhattiprolu } 138e76b7c01SSukadev Bhattiprolu 13959e55e6cSSukadev Bhattiprolu static inline struct super_block *pts_sb_from_inode(struct inode *inode) 14059e55e6cSSukadev Bhattiprolu { 1412a1b2dc0SSukadev Bhattiprolu #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES 14259e55e6cSSukadev Bhattiprolu if (inode->i_sb->s_magic == DEVPTS_SUPER_MAGIC) 14359e55e6cSSukadev Bhattiprolu return inode->i_sb; 1442a1b2dc0SSukadev Bhattiprolu #endif 14559e55e6cSSukadev Bhattiprolu return devpts_mnt->mnt_sb; 14659e55e6cSSukadev Bhattiprolu } 14759e55e6cSSukadev Bhattiprolu 1482a1b2dc0SSukadev Bhattiprolu #define PARSE_MOUNT 0 1492a1b2dc0SSukadev Bhattiprolu #define PARSE_REMOUNT 1 1502a1b2dc0SSukadev Bhattiprolu 1511f71ebedSSukadev Bhattiprolu /* 1521f71ebedSSukadev Bhattiprolu * parse_mount_options(): 1531f71ebedSSukadev Bhattiprolu * Set @opts to mount options specified in @data. If an option is not 1541f71ebedSSukadev Bhattiprolu * specified in @data, set it to its default value. The exception is 1551f71ebedSSukadev Bhattiprolu * 'newinstance' option which can only be set/cleared on a mount (i.e. 1561f71ebedSSukadev Bhattiprolu * cannot be changed during remount). 1571f71ebedSSukadev Bhattiprolu * 1581f71ebedSSukadev Bhattiprolu * Note: @data may be NULL (in which case all options are set to default). 1591f71ebedSSukadev Bhattiprolu */ 1602a1b2dc0SSukadev Bhattiprolu static int parse_mount_options(char *data, int op, struct pts_mount_opts *opts) 1611da177e4SLinus Torvalds { 1627a673c6bSDomen Puncer char *p; 163f04c6ce2SEric W. Biederman kuid_t uid; 164f04c6ce2SEric W. Biederman kgid_t gid; 1651da177e4SLinus Torvalds 16631af0abbSSukadev Bhattiprolu opts->setuid = 0; 16731af0abbSSukadev Bhattiprolu opts->setgid = 0; 168f04c6ce2SEric W. Biederman opts->uid = GLOBAL_ROOT_UID; 169f04c6ce2SEric W. Biederman opts->gid = GLOBAL_ROOT_GID; 17031af0abbSSukadev Bhattiprolu opts->mode = DEVPTS_DEFAULT_MODE; 1711f8f1e29SSukadev Bhattiprolu opts->ptmxmode = DEVPTS_DEFAULT_PTMX_MODE; 172e9aba515SKonstantin Khlebnikov opts->max = NR_UNIX98_PTY_MAX; 1737a673c6bSDomen Puncer 1742a1b2dc0SSukadev Bhattiprolu /* newinstance makes sense only on initial mount */ 1752a1b2dc0SSukadev Bhattiprolu if (op == PARSE_MOUNT) 1762a1b2dc0SSukadev Bhattiprolu opts->newinstance = 0; 1772a1b2dc0SSukadev Bhattiprolu 1787a673c6bSDomen Puncer while ((p = strsep(&data, ",")) != NULL) { 1797a673c6bSDomen Puncer substring_t args[MAX_OPT_ARGS]; 1807a673c6bSDomen Puncer int token; 1817a673c6bSDomen Puncer int option; 1827a673c6bSDomen Puncer 1837a673c6bSDomen Puncer if (!*p) 1841da177e4SLinus Torvalds continue; 1857a673c6bSDomen Puncer 1867a673c6bSDomen Puncer token = match_token(p, tokens, args); 1877a673c6bSDomen Puncer switch (token) { 1887a673c6bSDomen Puncer case Opt_uid: 1897a673c6bSDomen Puncer if (match_int(&args[0], &option)) 1907a673c6bSDomen Puncer return -EINVAL; 191f04c6ce2SEric W. Biederman uid = make_kuid(current_user_ns(), option); 192f04c6ce2SEric W. Biederman if (!uid_valid(uid)) 193f04c6ce2SEric W. Biederman return -EINVAL; 194f04c6ce2SEric W. Biederman opts->uid = uid; 19531af0abbSSukadev Bhattiprolu opts->setuid = 1; 1967a673c6bSDomen Puncer break; 1977a673c6bSDomen Puncer case Opt_gid: 1987a673c6bSDomen Puncer if (match_int(&args[0], &option)) 1997a673c6bSDomen Puncer return -EINVAL; 200f04c6ce2SEric W. Biederman gid = make_kgid(current_user_ns(), option); 201f04c6ce2SEric W. Biederman if (!gid_valid(gid)) 202f04c6ce2SEric W. Biederman return -EINVAL; 203f04c6ce2SEric W. Biederman opts->gid = gid; 20431af0abbSSukadev Bhattiprolu opts->setgid = 1; 2057a673c6bSDomen Puncer break; 2067a673c6bSDomen Puncer case Opt_mode: 2077a673c6bSDomen Puncer if (match_octal(&args[0], &option)) 2087a673c6bSDomen Puncer return -EINVAL; 20931af0abbSSukadev Bhattiprolu opts->mode = option & S_IALLUGO; 2107a673c6bSDomen Puncer break; 2111f8f1e29SSukadev Bhattiprolu #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES 2121f8f1e29SSukadev Bhattiprolu case Opt_ptmxmode: 2131f8f1e29SSukadev Bhattiprolu if (match_octal(&args[0], &option)) 2141f8f1e29SSukadev Bhattiprolu return -EINVAL; 2151f8f1e29SSukadev Bhattiprolu opts->ptmxmode = option & S_IALLUGO; 2161f8f1e29SSukadev Bhattiprolu break; 2172a1b2dc0SSukadev Bhattiprolu case Opt_newinstance: 2182a1b2dc0SSukadev Bhattiprolu /* newinstance makes sense only on initial mount */ 2192a1b2dc0SSukadev Bhattiprolu if (op == PARSE_MOUNT) 2202a1b2dc0SSukadev Bhattiprolu opts->newinstance = 1; 2212a1b2dc0SSukadev Bhattiprolu break; 222e9aba515SKonstantin Khlebnikov case Opt_max: 223e9aba515SKonstantin Khlebnikov if (match_int(&args[0], &option) || 224e9aba515SKonstantin Khlebnikov option < 0 || option > NR_UNIX98_PTY_MAX) 225e9aba515SKonstantin Khlebnikov return -EINVAL; 226e9aba515SKonstantin Khlebnikov opts->max = option; 227e9aba515SKonstantin Khlebnikov break; 2281f8f1e29SSukadev Bhattiprolu #endif 2297a673c6bSDomen Puncer default: 23004541a2fSFabian Frederick pr_err("called with bogus options\n"); 2311da177e4SLinus Torvalds return -EINVAL; 2321da177e4SLinus Torvalds } 2331da177e4SLinus Torvalds } 2341da177e4SLinus Torvalds 2351da177e4SLinus Torvalds return 0; 2361da177e4SLinus Torvalds } 2371da177e4SLinus Torvalds 2381f8f1e29SSukadev Bhattiprolu #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES 2391f8f1e29SSukadev Bhattiprolu static int mknod_ptmx(struct super_block *sb) 24053af8ee4SSukadev Bhattiprolu { 2411f8f1e29SSukadev Bhattiprolu int mode; 2421f8f1e29SSukadev Bhattiprolu int rc = -ENOMEM; 2431f8f1e29SSukadev Bhattiprolu struct dentry *dentry; 2441f8f1e29SSukadev Bhattiprolu struct inode *inode; 2451f8f1e29SSukadev Bhattiprolu struct dentry *root = sb->s_root; 24653af8ee4SSukadev Bhattiprolu struct pts_fs_info *fsi = DEVPTS_SB(sb); 24753af8ee4SSukadev Bhattiprolu struct pts_mount_opts *opts = &fsi->mount_opts; 248ec2aa8e8SEric W. Biederman kuid_t root_uid; 249ec2aa8e8SEric W. Biederman kgid_t root_gid; 250ec2aa8e8SEric W. Biederman 251ec2aa8e8SEric W. Biederman root_uid = make_kuid(current_user_ns(), 0); 252ec2aa8e8SEric W. Biederman root_gid = make_kgid(current_user_ns(), 0); 253ec2aa8e8SEric W. Biederman if (!uid_valid(root_uid) || !gid_valid(root_gid)) 254ec2aa8e8SEric W. Biederman return -EINVAL; 25553af8ee4SSukadev Bhattiprolu 2562b0143b5SDavid Howells mutex_lock(&d_inode(root)->i_mutex); 2571f8f1e29SSukadev Bhattiprolu 2581f8f1e29SSukadev Bhattiprolu /* If we have already created ptmx node, return */ 2591f8f1e29SSukadev Bhattiprolu if (fsi->ptmx_dentry) { 2601f8f1e29SSukadev Bhattiprolu rc = 0; 2611f8f1e29SSukadev Bhattiprolu goto out; 2621f8f1e29SSukadev Bhattiprolu } 2631f8f1e29SSukadev Bhattiprolu 2641f8f1e29SSukadev Bhattiprolu dentry = d_alloc_name(root, "ptmx"); 2651f8f1e29SSukadev Bhattiprolu if (!dentry) { 26604541a2fSFabian Frederick pr_err("Unable to alloc dentry for ptmx node\n"); 2671f8f1e29SSukadev Bhattiprolu goto out; 2681f8f1e29SSukadev Bhattiprolu } 2691f8f1e29SSukadev Bhattiprolu 2701f8f1e29SSukadev Bhattiprolu /* 2711f8f1e29SSukadev Bhattiprolu * Create a new 'ptmx' node in this mount of devpts. 2721f8f1e29SSukadev Bhattiprolu */ 2731f8f1e29SSukadev Bhattiprolu inode = new_inode(sb); 2741f8f1e29SSukadev Bhattiprolu if (!inode) { 27504541a2fSFabian Frederick pr_err("Unable to alloc inode for ptmx node\n"); 2761f8f1e29SSukadev Bhattiprolu dput(dentry); 2771f8f1e29SSukadev Bhattiprolu goto out; 2781f8f1e29SSukadev Bhattiprolu } 2791f8f1e29SSukadev Bhattiprolu 2801f8f1e29SSukadev Bhattiprolu inode->i_ino = 2; 2811f8f1e29SSukadev Bhattiprolu inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2821f8f1e29SSukadev Bhattiprolu 2831f8f1e29SSukadev Bhattiprolu mode = S_IFCHR|opts->ptmxmode; 2841f8f1e29SSukadev Bhattiprolu init_special_inode(inode, mode, MKDEV(TTYAUX_MAJOR, 2)); 285ec2aa8e8SEric W. Biederman inode->i_uid = root_uid; 286ec2aa8e8SEric W. Biederman inode->i_gid = root_gid; 2871f8f1e29SSukadev Bhattiprolu 2881f8f1e29SSukadev Bhattiprolu d_add(dentry, inode); 2891f8f1e29SSukadev Bhattiprolu 2901f8f1e29SSukadev Bhattiprolu fsi->ptmx_dentry = dentry; 2911f8f1e29SSukadev Bhattiprolu rc = 0; 2921f8f1e29SSukadev Bhattiprolu out: 2932b0143b5SDavid Howells mutex_unlock(&d_inode(root)->i_mutex); 2941f8f1e29SSukadev Bhattiprolu return rc; 2951f8f1e29SSukadev Bhattiprolu } 2961f8f1e29SSukadev Bhattiprolu 2971f8f1e29SSukadev Bhattiprolu static void update_ptmx_mode(struct pts_fs_info *fsi) 2981f8f1e29SSukadev Bhattiprolu { 2991f8f1e29SSukadev Bhattiprolu struct inode *inode; 3001f8f1e29SSukadev Bhattiprolu if (fsi->ptmx_dentry) { 3012b0143b5SDavid Howells inode = d_inode(fsi->ptmx_dentry); 3021f8f1e29SSukadev Bhattiprolu inode->i_mode = S_IFCHR|fsi->mount_opts.ptmxmode; 3031f8f1e29SSukadev Bhattiprolu } 3041f8f1e29SSukadev Bhattiprolu } 3051f8f1e29SSukadev Bhattiprolu #else 3061f8f1e29SSukadev Bhattiprolu static inline void update_ptmx_mode(struct pts_fs_info *fsi) 3071f8f1e29SSukadev Bhattiprolu { 3081f8f1e29SSukadev Bhattiprolu return; 3091f8f1e29SSukadev Bhattiprolu } 3101f8f1e29SSukadev Bhattiprolu #endif 3111f8f1e29SSukadev Bhattiprolu 3121f8f1e29SSukadev Bhattiprolu static int devpts_remount(struct super_block *sb, int *flags, char *data) 3131f8f1e29SSukadev Bhattiprolu { 3141f8f1e29SSukadev Bhattiprolu int err; 3151f8f1e29SSukadev Bhattiprolu struct pts_fs_info *fsi = DEVPTS_SB(sb); 3161f8f1e29SSukadev Bhattiprolu struct pts_mount_opts *opts = &fsi->mount_opts; 3171f8f1e29SSukadev Bhattiprolu 31802b9984dSTheodore Ts'o sync_filesystem(sb); 3192a1b2dc0SSukadev Bhattiprolu err = parse_mount_options(data, PARSE_REMOUNT, opts); 3201f8f1e29SSukadev Bhattiprolu 3211f8f1e29SSukadev Bhattiprolu /* 3221f8f1e29SSukadev Bhattiprolu * parse_mount_options() restores options to default values 3231f8f1e29SSukadev Bhattiprolu * before parsing and may have changed ptmxmode. So, update the 3241f8f1e29SSukadev Bhattiprolu * mode in the inode too. Bogus options don't fail the remount, 3251f8f1e29SSukadev Bhattiprolu * so do this even on error return. 3261f8f1e29SSukadev Bhattiprolu */ 3271f8f1e29SSukadev Bhattiprolu update_ptmx_mode(fsi); 3281f8f1e29SSukadev Bhattiprolu 3291f8f1e29SSukadev Bhattiprolu return err; 33053af8ee4SSukadev Bhattiprolu } 33153af8ee4SSukadev Bhattiprolu 33234c80b1dSAl Viro static int devpts_show_options(struct seq_file *seq, struct dentry *root) 333b87a267eSMiklos Szeredi { 33434c80b1dSAl Viro struct pts_fs_info *fsi = DEVPTS_SB(root->d_sb); 33531af0abbSSukadev Bhattiprolu struct pts_mount_opts *opts = &fsi->mount_opts; 33631af0abbSSukadev Bhattiprolu 33731af0abbSSukadev Bhattiprolu if (opts->setuid) 33804541a2fSFabian Frederick seq_printf(seq, ",uid=%u", 33904541a2fSFabian Frederick from_kuid_munged(&init_user_ns, opts->uid)); 34031af0abbSSukadev Bhattiprolu if (opts->setgid) 34104541a2fSFabian Frederick seq_printf(seq, ",gid=%u", 34204541a2fSFabian Frederick from_kgid_munged(&init_user_ns, opts->gid)); 34331af0abbSSukadev Bhattiprolu seq_printf(seq, ",mode=%03o", opts->mode); 3441f8f1e29SSukadev Bhattiprolu #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES 3451f8f1e29SSukadev Bhattiprolu seq_printf(seq, ",ptmxmode=%03o", opts->ptmxmode); 346e9aba515SKonstantin Khlebnikov if (opts->max < NR_UNIX98_PTY_MAX) 347e9aba515SKonstantin Khlebnikov seq_printf(seq, ",max=%d", opts->max); 3481f8f1e29SSukadev Bhattiprolu #endif 349b87a267eSMiklos Szeredi 350b87a267eSMiklos Szeredi return 0; 351b87a267eSMiklos Szeredi } 352b87a267eSMiklos Szeredi 353ee9b6d61SJosef 'Jeff' Sipek static const struct super_operations devpts_sops = { 3541da177e4SLinus Torvalds .statfs = simple_statfs, 3551da177e4SLinus Torvalds .remount_fs = devpts_remount, 356b87a267eSMiklos Szeredi .show_options = devpts_show_options, 3571da177e4SLinus Torvalds }; 3581da177e4SLinus Torvalds 359e76b7c01SSukadev Bhattiprolu static void *new_pts_fs_info(void) 360e76b7c01SSukadev Bhattiprolu { 361e76b7c01SSukadev Bhattiprolu struct pts_fs_info *fsi; 362e76b7c01SSukadev Bhattiprolu 363e76b7c01SSukadev Bhattiprolu fsi = kzalloc(sizeof(struct pts_fs_info), GFP_KERNEL); 364e76b7c01SSukadev Bhattiprolu if (!fsi) 365e76b7c01SSukadev Bhattiprolu return NULL; 366e76b7c01SSukadev Bhattiprolu 367e76b7c01SSukadev Bhattiprolu ida_init(&fsi->allocated_ptys); 36831af0abbSSukadev Bhattiprolu fsi->mount_opts.mode = DEVPTS_DEFAULT_MODE; 3691f8f1e29SSukadev Bhattiprolu fsi->mount_opts.ptmxmode = DEVPTS_DEFAULT_PTMX_MODE; 370e76b7c01SSukadev Bhattiprolu 371e76b7c01SSukadev Bhattiprolu return fsi; 372e76b7c01SSukadev Bhattiprolu } 373e76b7c01SSukadev Bhattiprolu 3741da177e4SLinus Torvalds static int 3751da177e4SLinus Torvalds devpts_fill_super(struct super_block *s, void *data, int silent) 3761da177e4SLinus Torvalds { 3771da177e4SLinus Torvalds struct inode *inode; 3781da177e4SLinus Torvalds 3791da177e4SLinus Torvalds s->s_blocksize = 1024; 3801da177e4SLinus Torvalds s->s_blocksize_bits = 10; 3811da177e4SLinus Torvalds s->s_magic = DEVPTS_SUPER_MAGIC; 3821da177e4SLinus Torvalds s->s_op = &devpts_sops; 3831da177e4SLinus Torvalds s->s_time_gran = 1; 3841da177e4SLinus Torvalds 385e76b7c01SSukadev Bhattiprolu s->s_fs_info = new_pts_fs_info(); 386e76b7c01SSukadev Bhattiprolu if (!s->s_fs_info) 387e76b7c01SSukadev Bhattiprolu goto fail; 388e76b7c01SSukadev Bhattiprolu 3891da177e4SLinus Torvalds inode = new_inode(s); 3901da177e4SLinus Torvalds if (!inode) 3913850aba7SAl Viro goto fail; 3921da177e4SLinus Torvalds inode->i_ino = 1; 3931da177e4SLinus Torvalds inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 3941da177e4SLinus Torvalds inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR; 3951da177e4SLinus Torvalds inode->i_op = &simple_dir_inode_operations; 3961da177e4SLinus Torvalds inode->i_fop = &simple_dir_operations; 397bfe86848SMiklos Szeredi set_nlink(inode, 2); 3981da177e4SLinus Torvalds 39948fde701SAl Viro s->s_root = d_make_root(inode); 4001da177e4SLinus Torvalds if (s->s_root) 4011da177e4SLinus Torvalds return 0; 4021da177e4SLinus Torvalds 40304541a2fSFabian Frederick pr_err("get root dentry failed\n"); 404e76b7c01SSukadev Bhattiprolu 4051da177e4SLinus Torvalds fail: 4061da177e4SLinus Torvalds return -ENOMEM; 4071da177e4SLinus Torvalds } 4081da177e4SLinus Torvalds 4098c056e5bSAndrew Morton #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES 410d4076ac5SSukadev Bhattiprolu static int compare_init_pts_sb(struct super_block *s, void *p) 411d4076ac5SSukadev Bhattiprolu { 412d4076ac5SSukadev Bhattiprolu if (devpts_mnt) 413d4076ac5SSukadev Bhattiprolu return devpts_mnt->mnt_sb == s; 4142a1b2dc0SSukadev Bhattiprolu return 0; 4152a1b2dc0SSukadev Bhattiprolu } 4162a1b2dc0SSukadev Bhattiprolu 4172a1b2dc0SSukadev Bhattiprolu /* 418fc14f2feSAl Viro * devpts_mount() 419289f00e2SSukadev Bhattiprolu * 4201bd79035SSukadev Bhattiprolu * If the '-o newinstance' mount option was specified, mount a new 4211bd79035SSukadev Bhattiprolu * (private) instance of devpts. PTYs created in this instance are 4221bd79035SSukadev Bhattiprolu * independent of the PTYs in other devpts instances. 423d4076ac5SSukadev Bhattiprolu * 4241bd79035SSukadev Bhattiprolu * If the '-o newinstance' option was not specified, mount/remount the 4251bd79035SSukadev Bhattiprolu * initial kernel mount of devpts. This type of mount gives the 4261bd79035SSukadev Bhattiprolu * legacy, single-instance semantics. 427d4076ac5SSukadev Bhattiprolu * 4281bd79035SSukadev Bhattiprolu * The 'newinstance' option is needed to support multiple namespace 4291bd79035SSukadev Bhattiprolu * semantics in devpts while preserving backward compatibility of the 4301bd79035SSukadev Bhattiprolu * current 'single-namespace' semantics. i.e all mounts of devpts 4311bd79035SSukadev Bhattiprolu * without the 'newinstance' mount option should bind to the initial 432fc14f2feSAl Viro * kernel mount, like mount_single(). 433d4076ac5SSukadev Bhattiprolu * 4341bd79035SSukadev Bhattiprolu * Mounts with 'newinstance' option create a new, private namespace. 4351bd79035SSukadev Bhattiprolu * 4361bd79035SSukadev Bhattiprolu * NOTE: 4371bd79035SSukadev Bhattiprolu * 438fc14f2feSAl Viro * For single-mount semantics, devpts cannot use mount_single(), 439fc14f2feSAl Viro * because mount_single()/sget() find and use the super-block from 440d4076ac5SSukadev Bhattiprolu * the most recent mount of devpts. But that recent mount may be a 441fc14f2feSAl Viro * 'newinstance' mount and mount_single() would pick the newinstance 442d4076ac5SSukadev Bhattiprolu * super-block instead of the initial super-block. 443d4076ac5SSukadev Bhattiprolu */ 444fc14f2feSAl Viro static struct dentry *devpts_mount(struct file_system_type *fs_type, 445fc14f2feSAl Viro int flags, const char *dev_name, void *data) 4461da177e4SLinus Torvalds { 447482984f0SSukadev Bhattiprolu int error; 448482984f0SSukadev Bhattiprolu struct pts_mount_opts opts; 4491bd79035SSukadev Bhattiprolu struct super_block *s; 4502a1b2dc0SSukadev Bhattiprolu 451482984f0SSukadev Bhattiprolu error = parse_mount_options(data, PARSE_MOUNT, &opts); 452482984f0SSukadev Bhattiprolu if (error) 453fc14f2feSAl Viro return ERR_PTR(error); 454482984f0SSukadev Bhattiprolu 455ec2aa8e8SEric W. Biederman /* Require newinstance for all user namespace mounts to ensure 456ec2aa8e8SEric W. Biederman * the mount options are not changed. 457ec2aa8e8SEric W. Biederman */ 458ec2aa8e8SEric W. Biederman if ((current_user_ns() != &init_user_ns) && !opts.newinstance) 459ec2aa8e8SEric W. Biederman return ERR_PTR(-EINVAL); 460ec2aa8e8SEric W. Biederman 461482984f0SSukadev Bhattiprolu if (opts.newinstance) 4629249e17fSDavid Howells s = sget(fs_type, NULL, set_anon_super, flags, NULL); 463482984f0SSukadev Bhattiprolu else 4649249e17fSDavid Howells s = sget(fs_type, compare_init_pts_sb, set_anon_super, flags, 4659249e17fSDavid Howells NULL); 466945cf2c7SSukadev Bhattiprolu 4671bd79035SSukadev Bhattiprolu if (IS_ERR(s)) 468fc14f2feSAl Viro return ERR_CAST(s); 4691bd79035SSukadev Bhattiprolu 4701bd79035SSukadev Bhattiprolu if (!s->s_root) { 4711bd79035SSukadev Bhattiprolu error = devpts_fill_super(s, data, flags & MS_SILENT ? 1 : 0); 472945cf2c7SSukadev Bhattiprolu if (error) 4731bd79035SSukadev Bhattiprolu goto out_undo_sget; 4741bd79035SSukadev Bhattiprolu s->s_flags |= MS_ACTIVE; 4751bd79035SSukadev Bhattiprolu } 476945cf2c7SSukadev Bhattiprolu 4771bd79035SSukadev Bhattiprolu memcpy(&(DEVPTS_SB(s))->mount_opts, &opts, sizeof(opts)); 4781bd79035SSukadev Bhattiprolu 4791bd79035SSukadev Bhattiprolu error = mknod_ptmx(s); 480945cf2c7SSukadev Bhattiprolu if (error) 48189468071SAl Viro goto out_undo_sget; 48289468071SAl Viro 483fc14f2feSAl Viro return dget(s->s_root); 484945cf2c7SSukadev Bhattiprolu 4851bd79035SSukadev Bhattiprolu out_undo_sget: 4866f5bbff9SAl Viro deactivate_locked_super(s); 487fc14f2feSAl Viro return ERR_PTR(error); 488482984f0SSukadev Bhattiprolu } 489482984f0SSukadev Bhattiprolu 4902a1b2dc0SSukadev Bhattiprolu #else 4912a1b2dc0SSukadev Bhattiprolu /* 4922a1b2dc0SSukadev Bhattiprolu * This supports only the legacy single-instance semantics (no 4932a1b2dc0SSukadev Bhattiprolu * multiple-instance semantics) 4942a1b2dc0SSukadev Bhattiprolu */ 495fc14f2feSAl Viro static struct dentry *devpts_mount(struct file_system_type *fs_type, int flags, 496fc14f2feSAl Viro const char *dev_name, void *data) 4972a1b2dc0SSukadev Bhattiprolu { 498fc14f2feSAl Viro return mount_single(fs_type, flags, data, devpts_fill_super); 4992a1b2dc0SSukadev Bhattiprolu } 5002a1b2dc0SSukadev Bhattiprolu #endif 5011da177e4SLinus Torvalds 502e76b7c01SSukadev Bhattiprolu static void devpts_kill_sb(struct super_block *sb) 503e76b7c01SSukadev Bhattiprolu { 504e76b7c01SSukadev Bhattiprolu struct pts_fs_info *fsi = DEVPTS_SB(sb); 505e76b7c01SSukadev Bhattiprolu 50666da0e1fSIlija Hadzic ida_destroy(&fsi->allocated_ptys); 507e76b7c01SSukadev Bhattiprolu kfree(fsi); 5081f8f1e29SSukadev Bhattiprolu kill_litter_super(sb); 509e76b7c01SSukadev Bhattiprolu } 510e76b7c01SSukadev Bhattiprolu 5111da177e4SLinus Torvalds static struct file_system_type devpts_fs_type = { 5121da177e4SLinus Torvalds .name = "devpts", 513fc14f2feSAl Viro .mount = devpts_mount, 514e76b7c01SSukadev Bhattiprolu .kill_sb = devpts_kill_sb, 515ec2aa8e8SEric W. Biederman #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES 516ec2aa8e8SEric W. Biederman .fs_flags = FS_USERNS_MOUNT | FS_USERNS_DEV_MOUNT, 517ec2aa8e8SEric W. Biederman #endif 5181da177e4SLinus Torvalds }; 5191da177e4SLinus Torvalds 5201da177e4SLinus Torvalds /* 5211da177e4SLinus Torvalds * The normal naming convention is simply /dev/pts/<number>; this conforms 5221da177e4SLinus Torvalds * to the System V naming convention 5231da177e4SLinus Torvalds */ 5241da177e4SLinus Torvalds 52515f1a633SSukadev Bhattiprolu int devpts_new_index(struct inode *ptmx_inode) 526718a9163SSukadev Bhattiprolu { 527e76b7c01SSukadev Bhattiprolu struct super_block *sb = pts_sb_from_inode(ptmx_inode); 528e76b7c01SSukadev Bhattiprolu struct pts_fs_info *fsi = DEVPTS_SB(sb); 529718a9163SSukadev Bhattiprolu int index; 5307ee7c12bSAlexey Dobriyan int ida_ret; 531718a9163SSukadev Bhattiprolu 532718a9163SSukadev Bhattiprolu retry: 533835aa440SAlan Cox if (!ida_pre_get(&fsi->allocated_ptys, GFP_KERNEL)) 534718a9163SSukadev Bhattiprolu return -ENOMEM; 535718a9163SSukadev Bhattiprolu 536718a9163SSukadev Bhattiprolu mutex_lock(&allocated_ptys_lock); 537e9aba515SKonstantin Khlebnikov if (pty_count >= pty_limit - 538e9aba515SKonstantin Khlebnikov (fsi->mount_opts.newinstance ? pty_reserve : 0)) { 539e9aba515SKonstantin Khlebnikov mutex_unlock(&allocated_ptys_lock); 540e9aba515SKonstantin Khlebnikov return -ENOSPC; 541e9aba515SKonstantin Khlebnikov } 542e9aba515SKonstantin Khlebnikov 543e76b7c01SSukadev Bhattiprolu ida_ret = ida_get_new(&fsi->allocated_ptys, &index); 5447ee7c12bSAlexey Dobriyan if (ida_ret < 0) { 545718a9163SSukadev Bhattiprolu mutex_unlock(&allocated_ptys_lock); 5467ee7c12bSAlexey Dobriyan if (ida_ret == -EAGAIN) 547718a9163SSukadev Bhattiprolu goto retry; 548718a9163SSukadev Bhattiprolu return -EIO; 549718a9163SSukadev Bhattiprolu } 550718a9163SSukadev Bhattiprolu 551e9aba515SKonstantin Khlebnikov if (index >= fsi->mount_opts.max) { 552e76b7c01SSukadev Bhattiprolu ida_remove(&fsi->allocated_ptys, index); 553718a9163SSukadev Bhattiprolu mutex_unlock(&allocated_ptys_lock); 554e9aba515SKonstantin Khlebnikov return -ENOSPC; 555718a9163SSukadev Bhattiprolu } 556a4834c10SKonstantin Khlebnikov pty_count++; 557718a9163SSukadev Bhattiprolu mutex_unlock(&allocated_ptys_lock); 558718a9163SSukadev Bhattiprolu return index; 559718a9163SSukadev Bhattiprolu } 560718a9163SSukadev Bhattiprolu 56115f1a633SSukadev Bhattiprolu void devpts_kill_index(struct inode *ptmx_inode, int idx) 562718a9163SSukadev Bhattiprolu { 563e76b7c01SSukadev Bhattiprolu struct super_block *sb = pts_sb_from_inode(ptmx_inode); 564e76b7c01SSukadev Bhattiprolu struct pts_fs_info *fsi = DEVPTS_SB(sb); 565e76b7c01SSukadev Bhattiprolu 566718a9163SSukadev Bhattiprolu mutex_lock(&allocated_ptys_lock); 567e76b7c01SSukadev Bhattiprolu ida_remove(&fsi->allocated_ptys, idx); 568a4834c10SKonstantin Khlebnikov pty_count--; 569718a9163SSukadev Bhattiprolu mutex_unlock(&allocated_ptys_lock); 570718a9163SSukadev Bhattiprolu } 571718a9163SSukadev Bhattiprolu 5721dcb8e6dSJiri Slaby /** 5731dcb8e6dSJiri Slaby * devpts_pty_new -- create a new inode in /dev/pts/ 5741dcb8e6dSJiri Slaby * @ptmx_inode: inode of the master 5751dcb8e6dSJiri Slaby * @device: major+minor of the node to be created 5761dcb8e6dSJiri Slaby * @index: used as a name of the node 5771dcb8e6dSJiri Slaby * @priv: what's given back by devpts_get_priv 5781dcb8e6dSJiri Slaby * 5791dcb8e6dSJiri Slaby * The created inode is returned. Remove it from /dev/pts/ by devpts_pty_kill. 5801dcb8e6dSJiri Slaby */ 581f11afb61SJiri Slaby struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index, 582f11afb61SJiri Slaby void *priv) 5831da177e4SLinus Torvalds { 5841da177e4SLinus Torvalds struct dentry *dentry; 58559e55e6cSSukadev Bhattiprolu struct super_block *sb = pts_sb_from_inode(ptmx_inode); 586162b97cfSJiri Slaby struct inode *inode; 58759e55e6cSSukadev Bhattiprolu struct dentry *root = sb->s_root; 58831af0abbSSukadev Bhattiprolu struct pts_fs_info *fsi = DEVPTS_SB(sb); 58931af0abbSSukadev Bhattiprolu struct pts_mount_opts *opts = &fsi->mount_opts; 59089a52e10SSukadev Bhattiprolu char s[12]; 5911da177e4SLinus Torvalds 592162b97cfSJiri Slaby inode = new_inode(sb); 5931da177e4SLinus Torvalds if (!inode) 594162b97cfSJiri Slaby return ERR_PTR(-ENOMEM); 5951da177e4SLinus Torvalds 596f11afb61SJiri Slaby inode->i_ino = index + 3; 597d0eafc7dSDavid Howells inode->i_uid = opts->setuid ? opts->uid : current_fsuid(); 598d0eafc7dSDavid Howells inode->i_gid = opts->setgid ? opts->gid : current_fsgid(); 5991da177e4SLinus Torvalds inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 60031af0abbSSukadev Bhattiprolu init_special_inode(inode, S_IFCHR|opts->mode, device); 601f11afb61SJiri Slaby inode->i_private = priv; 6021da177e4SLinus Torvalds 603f11afb61SJiri Slaby sprintf(s, "%d", index); 60489a52e10SSukadev Bhattiprolu 6052b0143b5SDavid Howells mutex_lock(&d_inode(root)->i_mutex); 60689a52e10SSukadev Bhattiprolu 60759e55e6cSSukadev Bhattiprolu dentry = d_alloc_name(root, s); 608b12d1259SAndrey Vagin if (dentry) { 60989a52e10SSukadev Bhattiprolu d_add(dentry, inode); 6102b0143b5SDavid Howells fsnotify_create(d_inode(root), dentry); 611aa597bc1SAndrey Vagin } else { 612aa597bc1SAndrey Vagin iput(inode); 613162b97cfSJiri Slaby inode = ERR_PTR(-ENOMEM); 6143972b7f6SFlorin Malita } 6151da177e4SLinus Torvalds 6162b0143b5SDavid Howells mutex_unlock(&d_inode(root)->i_mutex); 6171da177e4SLinus Torvalds 618162b97cfSJiri Slaby return inode; 6191da177e4SLinus Torvalds } 6201da177e4SLinus Torvalds 6211dcb8e6dSJiri Slaby /** 6221dcb8e6dSJiri Slaby * devpts_get_priv -- get private data for a slave 6231dcb8e6dSJiri Slaby * @pts_inode: inode of the slave 6241dcb8e6dSJiri Slaby * 6251dcb8e6dSJiri Slaby * Returns whatever was passed as priv in devpts_pty_new for a given inode. 6261dcb8e6dSJiri Slaby */ 6278fcbaa2bSJiri Slaby void *devpts_get_priv(struct inode *pts_inode) 6281da177e4SLinus Torvalds { 629edfacdd6SSukadev Bhattiprolu struct dentry *dentry; 6308fcbaa2bSJiri Slaby void *priv = NULL; 631edfacdd6SSukadev Bhattiprolu 632527b3e47SSukadev Bhattiprolu BUG_ON(pts_inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR)); 6331da177e4SLinus Torvalds 634edfacdd6SSukadev Bhattiprolu /* Ensure dentry has not been deleted by devpts_pty_kill() */ 635edfacdd6SSukadev Bhattiprolu dentry = d_find_alias(pts_inode); 636edfacdd6SSukadev Bhattiprolu if (!dentry) 637527b3e47SSukadev Bhattiprolu return NULL; 638edfacdd6SSukadev Bhattiprolu 639edfacdd6SSukadev Bhattiprolu if (pts_inode->i_sb->s_magic == DEVPTS_SUPER_MAGIC) 6408fcbaa2bSJiri Slaby priv = pts_inode->i_private; 641edfacdd6SSukadev Bhattiprolu 642edfacdd6SSukadev Bhattiprolu dput(dentry); 643edfacdd6SSukadev Bhattiprolu 6448fcbaa2bSJiri Slaby return priv; 6451da177e4SLinus Torvalds } 6461da177e4SLinus Torvalds 6471dcb8e6dSJiri Slaby /** 6481dcb8e6dSJiri Slaby * devpts_pty_kill -- remove inode form /dev/pts/ 6491dcb8e6dSJiri Slaby * @inode: inode of the slave to be removed 6501dcb8e6dSJiri Slaby * 6511dcb8e6dSJiri Slaby * This is an inverse operation of devpts_pty_new. 6521dcb8e6dSJiri Slaby */ 653f11afb61SJiri Slaby void devpts_pty_kill(struct inode *inode) 6541da177e4SLinus Torvalds { 65559e55e6cSSukadev Bhattiprolu struct super_block *sb = pts_sb_from_inode(inode); 65659e55e6cSSukadev Bhattiprolu struct dentry *root = sb->s_root; 657a6f37daaSSukadev Bhattiprolu struct dentry *dentry; 6581da177e4SLinus Torvalds 659a6f37daaSSukadev Bhattiprolu BUG_ON(inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR)); 660a6f37daaSSukadev Bhattiprolu 6612b0143b5SDavid Howells mutex_lock(&d_inode(root)->i_mutex); 662a6f37daaSSukadev Bhattiprolu 663a6f37daaSSukadev Bhattiprolu dentry = d_find_alias(inode); 6642a1b2dc0SSukadev Bhattiprolu 6656d6b77f1SMiklos Szeredi drop_nlink(inode); 6661da177e4SLinus Torvalds d_delete(dentry); 667835aa440SAlan Cox dput(dentry); /* d_alloc_name() in devpts_pty_new() */ 668835aa440SAlan Cox dput(dentry); /* d_find_alias above */ 669aa597bc1SAndrey Vagin 6702b0143b5SDavid Howells mutex_unlock(&d_inode(root)->i_mutex); 6711da177e4SLinus Torvalds } 6721da177e4SLinus Torvalds 6731da177e4SLinus Torvalds static int __init init_devpts_fs(void) 6741da177e4SLinus Torvalds { 6751da177e4SLinus Torvalds int err = register_filesystem(&devpts_fs_type); 676a4834c10SKonstantin Khlebnikov struct ctl_table_header *table; 677a4834c10SKonstantin Khlebnikov 6781da177e4SLinus Torvalds if (!err) { 679a4834c10SKonstantin Khlebnikov table = register_sysctl_table(pty_root_table); 6801da177e4SLinus Torvalds devpts_mnt = kern_mount(&devpts_fs_type); 68193d5581eSAlan Cox if (IS_ERR(devpts_mnt)) { 6821da177e4SLinus Torvalds err = PTR_ERR(devpts_mnt); 68393d5581eSAlan Cox unregister_filesystem(&devpts_fs_type); 684a4834c10SKonstantin Khlebnikov unregister_sysctl_table(table); 68593d5581eSAlan Cox } 6861da177e4SLinus Torvalds } 6871da177e4SLinus Torvalds return err; 6881da177e4SLinus Torvalds } 6891da177e4SLinus Torvalds module_init(init_devpts_fs) 690