Greg Kroah-Hartman | 3bce94fd | 2017-11-07 16:59:23 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
Harry Wei | bd33d12 | 2011-07-16 16:45:13 +0800 | [diff] [blame] | 3 | * inode.c - part of debugfs, a tiny little debug file system |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 5 | * Copyright (C) 2004,2019 Greg Kroah-Hartman <greg@kroah.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * Copyright (C) 2004 IBM Inc. |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 7 | * Copyright (C) 2019 Linux Foundation <gregkh@linuxfoundation.org> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | * debugfs is for people to use instead of /proc or /sys. |
Mauro Carvalho Chehab | e1511a8 | 2017-05-14 12:09:53 -0300 | [diff] [blame] | 10 | * See ./Documentation/core-api/kernel-api.rst for more details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | */ |
| 12 | |
Greg Kroah-Hartman | d03ae47 | 2019-07-03 09:16:52 +0200 | [diff] [blame] | 13 | #define pr_fmt(fmt) "debugfs: " fmt |
| 14 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/module.h> |
| 16 | #include <linux/fs.h> |
| 17 | #include <linux/mount.h> |
| 18 | #include <linux/pagemap.h> |
| 19 | #include <linux/init.h> |
Randy Dunlap | 4d8ebdd | 2006-11-25 11:09:26 -0800 | [diff] [blame] | 20 | #include <linux/kobject.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/namei.h> |
| 22 | #include <linux/debugfs.h> |
Mathieu Desnoyers | 4f36557 | 2006-11-24 13:45:37 -0500 | [diff] [blame] | 23 | #include <linux/fsnotify.h> |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 24 | #include <linux/string.h> |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 25 | #include <linux/seq_file.h> |
| 26 | #include <linux/parser.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 27 | #include <linux/magic.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 28 | #include <linux/slab.h> |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 29 | #include <linux/security.h> |
Nicolai Stange | 9fd4dce | 2016-03-22 14:11:13 +0100 | [diff] [blame] | 30 | |
| 31 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Kees Cook | 82aceae4 | 2012-08-27 13:32:15 -0700 | [diff] [blame] | 33 | #define DEBUGFS_DEFAULT_MODE 0700 |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 34 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | static struct vfsmount *debugfs_mount; |
| 36 | static int debugfs_mount_count; |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 37 | static bool debugfs_registered; |
Kees Cook | 312723a | 2021-04-05 14:39:59 -0700 | [diff] [blame] | 38 | static unsigned int debugfs_allow __ro_after_init = DEFAULT_DEBUGFS_ALLOW_BITS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 40 | /* |
| 41 | * Don't allow access attributes to be changed whilst the kernel is locked down |
| 42 | * so that we can use the file mode as part of a heuristic to determine whether |
| 43 | * to lock down individual files. |
| 44 | */ |
Christian Brauner | c1632a0 | 2023-01-13 12:49:11 +0100 | [diff] [blame] | 45 | static int debugfs_setattr(struct mnt_idmap *idmap, |
Christian Brauner | 549c729 | 2021-01-21 14:19:43 +0100 | [diff] [blame] | 46 | struct dentry *dentry, struct iattr *ia) |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 47 | { |
Ondrej Mosnacek | 5881fa8 | 2021-05-07 14:53:04 +0200 | [diff] [blame] | 48 | int ret; |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 49 | |
Ondrej Mosnacek | 5881fa8 | 2021-05-07 14:53:04 +0200 | [diff] [blame] | 50 | if (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) { |
| 51 | ret = security_locked_down(LOCKDOWN_DEBUGFS); |
| 52 | if (ret) |
| 53 | return ret; |
| 54 | } |
Christian Brauner | c1632a0 | 2023-01-13 12:49:11 +0100 | [diff] [blame] | 55 | return simple_setattr(&nop_mnt_idmap, dentry, ia); |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 56 | } |
| 57 | |
| 58 | static const struct inode_operations debugfs_file_inode_operations = { |
| 59 | .setattr = debugfs_setattr, |
| 60 | }; |
| 61 | static const struct inode_operations debugfs_dir_inode_operations = { |
| 62 | .lookup = simple_lookup, |
| 63 | .setattr = debugfs_setattr, |
| 64 | }; |
| 65 | static const struct inode_operations debugfs_symlink_inode_operations = { |
| 66 | .get_link = simple_get_link, |
| 67 | .setattr = debugfs_setattr, |
| 68 | }; |
| 69 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 70 | static struct inode *debugfs_get_inode(struct super_block *sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | { |
| 72 | struct inode *inode = new_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 74 | inode->i_ino = get_next_ino(); |
Deepa Dinamani | 1b48b53 | 2016-02-22 07:17:47 -0800 | [diff] [blame] | 75 | inode->i_atime = inode->i_mtime = |
Deepa Dinamani | c2050a4 | 2016-09-14 07:48:06 -0700 | [diff] [blame] | 76 | inode->i_ctime = current_time(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | } |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 78 | return inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | } |
| 80 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 81 | struct debugfs_mount_opts { |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 82 | kuid_t uid; |
| 83 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 84 | umode_t mode; |
Brian Norris | b8de524c | 2022-09-12 16:31:42 -0700 | [diff] [blame] | 85 | /* Opt_* bitfield. */ |
| 86 | unsigned int opts; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 87 | }; |
| 88 | |
| 89 | enum { |
| 90 | Opt_uid, |
| 91 | Opt_gid, |
| 92 | Opt_mode, |
| 93 | Opt_err |
| 94 | }; |
| 95 | |
| 96 | static const match_table_t tokens = { |
| 97 | {Opt_uid, "uid=%u"}, |
| 98 | {Opt_gid, "gid=%u"}, |
| 99 | {Opt_mode, "mode=%o"}, |
| 100 | {Opt_err, NULL} |
| 101 | }; |
| 102 | |
| 103 | struct debugfs_fs_info { |
| 104 | struct debugfs_mount_opts mount_opts; |
| 105 | }; |
| 106 | |
| 107 | static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts) |
| 108 | { |
| 109 | substring_t args[MAX_OPT_ARGS]; |
| 110 | int option; |
| 111 | int token; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 112 | kuid_t uid; |
| 113 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 114 | char *p; |
| 115 | |
Brian Norris | b8de524c | 2022-09-12 16:31:42 -0700 | [diff] [blame] | 116 | opts->opts = 0; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 117 | opts->mode = DEBUGFS_DEFAULT_MODE; |
| 118 | |
| 119 | while ((p = strsep(&data, ",")) != NULL) { |
| 120 | if (!*p) |
| 121 | continue; |
| 122 | |
| 123 | token = match_token(p, tokens, args); |
| 124 | switch (token) { |
| 125 | case Opt_uid: |
| 126 | if (match_int(&args[0], &option)) |
| 127 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 128 | uid = make_kuid(current_user_ns(), option); |
| 129 | if (!uid_valid(uid)) |
| 130 | return -EINVAL; |
| 131 | opts->uid = uid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 132 | break; |
| 133 | case Opt_gid: |
Dave Reisner | f1688e0 | 2013-01-02 08:54:37 -0500 | [diff] [blame] | 134 | if (match_int(&args[0], &option)) |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 135 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 136 | gid = make_kgid(current_user_ns(), option); |
| 137 | if (!gid_valid(gid)) |
| 138 | return -EINVAL; |
| 139 | opts->gid = gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 140 | break; |
| 141 | case Opt_mode: |
| 142 | if (match_octal(&args[0], &option)) |
| 143 | return -EINVAL; |
| 144 | opts->mode = option & S_IALLUGO; |
| 145 | break; |
| 146 | /* |
| 147 | * We might like to report bad mount options here; |
| 148 | * but traditionally debugfs has ignored all mount options |
| 149 | */ |
| 150 | } |
Brian Norris | b8de524c | 2022-09-12 16:31:42 -0700 | [diff] [blame] | 151 | |
| 152 | opts->opts |= BIT(token); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 153 | } |
| 154 | |
| 155 | return 0; |
| 156 | } |
| 157 | |
Brian Norris | b8de524c | 2022-09-12 16:31:42 -0700 | [diff] [blame] | 158 | static void _debugfs_apply_options(struct super_block *sb, bool remount) |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 159 | { |
| 160 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 161 | struct inode *inode = d_inode(sb->s_root); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 162 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 163 | |
Brian Norris | b8de524c | 2022-09-12 16:31:42 -0700 | [diff] [blame] | 164 | /* |
| 165 | * On remount, only reset mode/uid/gid if they were provided as mount |
| 166 | * options. |
| 167 | */ |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 168 | |
Brian Norris | b8de524c | 2022-09-12 16:31:42 -0700 | [diff] [blame] | 169 | if (!remount || opts->opts & BIT(Opt_mode)) { |
| 170 | inode->i_mode &= ~S_IALLUGO; |
| 171 | inode->i_mode |= opts->mode; |
| 172 | } |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 173 | |
Brian Norris | b8de524c | 2022-09-12 16:31:42 -0700 | [diff] [blame] | 174 | if (!remount || opts->opts & BIT(Opt_uid)) |
| 175 | inode->i_uid = opts->uid; |
| 176 | |
| 177 | if (!remount || opts->opts & BIT(Opt_gid)) |
| 178 | inode->i_gid = opts->gid; |
| 179 | } |
| 180 | |
| 181 | static void debugfs_apply_options(struct super_block *sb) |
| 182 | { |
| 183 | _debugfs_apply_options(sb, false); |
| 184 | } |
| 185 | |
| 186 | static void debugfs_apply_options_remount(struct super_block *sb) |
| 187 | { |
| 188 | _debugfs_apply_options(sb, true); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 189 | } |
| 190 | |
| 191 | static int debugfs_remount(struct super_block *sb, int *flags, char *data) |
| 192 | { |
| 193 | int err; |
| 194 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
| 195 | |
Theodore Ts'o | 02b9984 | 2014-03-13 10:14:33 -0400 | [diff] [blame] | 196 | sync_filesystem(sb); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 197 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 198 | if (err) |
| 199 | goto fail; |
| 200 | |
Brian Norris | b8de524c | 2022-09-12 16:31:42 -0700 | [diff] [blame] | 201 | debugfs_apply_options_remount(sb); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 202 | |
| 203 | fail: |
| 204 | return err; |
| 205 | } |
| 206 | |
| 207 | static int debugfs_show_options(struct seq_file *m, struct dentry *root) |
| 208 | { |
| 209 | struct debugfs_fs_info *fsi = root->d_sb->s_fs_info; |
| 210 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 211 | |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 212 | if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) |
| 213 | seq_printf(m, ",uid=%u", |
| 214 | from_kuid_munged(&init_user_ns, opts->uid)); |
| 215 | if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) |
| 216 | seq_printf(m, ",gid=%u", |
| 217 | from_kgid_munged(&init_user_ns, opts->gid)); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 218 | if (opts->mode != DEBUGFS_DEFAULT_MODE) |
| 219 | seq_printf(m, ",mode=%o", opts->mode); |
| 220 | |
| 221 | return 0; |
| 222 | } |
| 223 | |
Al Viro | 6234ddf | 2019-04-14 23:19:45 -0400 | [diff] [blame] | 224 | static void debugfs_free_inode(struct inode *inode) |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 225 | { |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 226 | if (S_ISLNK(inode->i_mode)) |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame] | 227 | kfree(inode->i_link); |
Al Viro | 93b919d | 2019-03-26 01:43:37 +0000 | [diff] [blame] | 228 | free_inode_nonrcu(inode); |
| 229 | } |
| 230 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 231 | static const struct super_operations debugfs_super_operations = { |
| 232 | .statfs = simple_statfs, |
| 233 | .remount_fs = debugfs_remount, |
| 234 | .show_options = debugfs_show_options, |
Al Viro | 6234ddf | 2019-04-14 23:19:45 -0400 | [diff] [blame] | 235 | .free_inode = debugfs_free_inode, |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 236 | }; |
| 237 | |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 238 | static void debugfs_release_dentry(struct dentry *dentry) |
| 239 | { |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame] | 240 | void *fsd = dentry->d_fsdata; |
| 241 | |
| 242 | if (!((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) |
| 243 | kfree(dentry->d_fsdata); |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 244 | } |
| 245 | |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 246 | static struct vfsmount *debugfs_automount(struct path *path) |
| 247 | { |
Eric W. Biederman | 93faccbb | 2017-02-01 06:06:16 +1300 | [diff] [blame] | 248 | debugfs_automount_t f; |
| 249 | f = (debugfs_automount_t)path->dentry->d_fsdata; |
| 250 | return f(path->dentry, d_inode(path->dentry)->i_private); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 251 | } |
| 252 | |
| 253 | static const struct dentry_operations debugfs_dops = { |
| 254 | .d_delete = always_delete_dentry, |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 255 | .d_release = debugfs_release_dentry, |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 256 | .d_automount = debugfs_automount, |
| 257 | }; |
| 258 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | static int debug_fill_super(struct super_block *sb, void *data, int silent) |
| 260 | { |
Eric Biggers | cda3712 | 2017-03-25 21:15:37 -0700 | [diff] [blame] | 261 | static const struct tree_descr debug_files[] = {{""}}; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 262 | struct debugfs_fs_info *fsi; |
| 263 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 265 | fsi = kzalloc(sizeof(struct debugfs_fs_info), GFP_KERNEL); |
| 266 | sb->s_fs_info = fsi; |
| 267 | if (!fsi) { |
| 268 | err = -ENOMEM; |
| 269 | goto fail; |
| 270 | } |
| 271 | |
| 272 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 273 | if (err) |
| 274 | goto fail; |
| 275 | |
| 276 | err = simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); |
| 277 | if (err) |
| 278 | goto fail; |
| 279 | |
| 280 | sb->s_op = &debugfs_super_operations; |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 281 | sb->s_d_op = &debugfs_dops; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 282 | |
| 283 | debugfs_apply_options(sb); |
| 284 | |
| 285 | return 0; |
| 286 | |
| 287 | fail: |
| 288 | kfree(fsi); |
| 289 | sb->s_fs_info = NULL; |
| 290 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | } |
| 292 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 293 | static struct dentry *debug_mount(struct file_system_type *fs_type, |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 294 | int flags, const char *dev_name, |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 295 | void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | { |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 297 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) |
| 298 | return ERR_PTR(-EPERM); |
| 299 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 300 | return mount_single(fs_type, flags, data, debug_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | } |
| 302 | |
| 303 | static struct file_system_type debug_fs_type = { |
| 304 | .owner = THIS_MODULE, |
| 305 | .name = "debugfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 306 | .mount = debug_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | .kill_sb = kill_litter_super, |
| 308 | }; |
Eric W. Biederman | 7f78e03 | 2013-03-02 19:39:14 -0800 | [diff] [blame] | 309 | MODULE_ALIAS_FS("debugfs"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | |
Omar Sandoval | a7c5437 | 2017-01-31 14:53:17 -0800 | [diff] [blame] | 311 | /** |
| 312 | * debugfs_lookup() - look up an existing debugfs file |
| 313 | * @name: a pointer to a string containing the name of the file to look up. |
| 314 | * @parent: a pointer to the parent dentry of the file. |
| 315 | * |
| 316 | * This function will return a pointer to a dentry if it succeeds. If the file |
| 317 | * doesn't exist or an error occurs, %NULL will be returned. The returned |
| 318 | * dentry must be passed to dput() when it is no longer needed. |
| 319 | * |
| 320 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 321 | * returned. |
| 322 | */ |
| 323 | struct dentry *debugfs_lookup(const char *name, struct dentry *parent) |
| 324 | { |
| 325 | struct dentry *dentry; |
| 326 | |
Greg Kroah-Hartman | bc6de80 | 2021-02-18 11:08:17 +0100 | [diff] [blame] | 327 | if (!debugfs_initialized() || IS_ERR_OR_NULL(name) || IS_ERR(parent)) |
Omar Sandoval | a7c5437 | 2017-01-31 14:53:17 -0800 | [diff] [blame] | 328 | return NULL; |
| 329 | |
| 330 | if (!parent) |
| 331 | parent = debugfs_mount->mnt_root; |
| 332 | |
Al Viro | 6c2d4798 | 2019-10-31 01:21:58 -0400 | [diff] [blame] | 333 | dentry = lookup_positive_unlocked(name, parent, strlen(name)); |
Omar Sandoval | a7c5437 | 2017-01-31 14:53:17 -0800 | [diff] [blame] | 334 | if (IS_ERR(dentry)) |
| 335 | return NULL; |
Omar Sandoval | a7c5437 | 2017-01-31 14:53:17 -0800 | [diff] [blame] | 336 | return dentry; |
| 337 | } |
| 338 | EXPORT_SYMBOL_GPL(debugfs_lookup); |
| 339 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 340 | static struct dentry *start_creating(const char *name, struct dentry *parent) |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 341 | { |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 342 | struct dentry *dentry; |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 343 | int error; |
| 344 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 345 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) |
| 346 | return ERR_PTR(-EPERM); |
| 347 | |
Greg Kroah-Hartman | 5634856 | 2021-02-18 11:08:18 +0100 | [diff] [blame] | 348 | if (!debugfs_initialized()) |
| 349 | return ERR_PTR(-ENOENT); |
| 350 | |
Greg Kroah-Hartman | d03ae47 | 2019-07-03 09:16:52 +0200 | [diff] [blame] | 351 | pr_debug("creating file '%s'\n", name); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 352 | |
Greg KH | c9e15f2 | 2015-03-30 14:59:15 +0200 | [diff] [blame] | 353 | if (IS_ERR(parent)) |
| 354 | return parent; |
| 355 | |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 356 | error = simple_pin_fs(&debug_fs_type, &debugfs_mount, |
| 357 | &debugfs_mount_count); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 358 | if (error) { |
| 359 | pr_err("Unable to pin filesystem for file '%s'\n", name); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 360 | return ERR_PTR(error); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 361 | } |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 362 | |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 363 | /* If the parent is not specified, we create it in the root. |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 364 | * We need the root dentry to do this, which is in the super |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 365 | * block. A pointer to that is in the struct vfsmount that we |
| 366 | * have around. |
| 367 | */ |
| 368 | if (!parent) |
| 369 | parent = debugfs_mount->mnt_root; |
| 370 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 371 | inode_lock(d_inode(parent)); |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 372 | if (unlikely(IS_DEADDIR(d_inode(parent)))) |
| 373 | dentry = ERR_PTR(-ENOENT); |
| 374 | else |
| 375 | dentry = lookup_one_len(name, parent, strlen(name)); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 376 | if (!IS_ERR(dentry) && d_really_is_positive(dentry)) { |
Greg Kroah-Hartman | c33d442 | 2019-07-06 17:42:56 +0200 | [diff] [blame] | 377 | if (d_is_dir(dentry)) |
| 378 | pr_err("Directory '%s' with parent '%s' already present!\n", |
| 379 | name, parent->d_name.name); |
| 380 | else |
| 381 | pr_err("File '%s' in directory '%s' already present!\n", |
| 382 | name, parent->d_name.name); |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 383 | dput(dentry); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 384 | dentry = ERR_PTR(-EEXIST); |
| 385 | } |
Daniel Borkmann | 0ee9608 | 2015-11-05 00:01:51 +0100 | [diff] [blame] | 386 | |
| 387 | if (IS_ERR(dentry)) { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 388 | inode_unlock(d_inode(parent)); |
Daniel Borkmann | 0ee9608 | 2015-11-05 00:01:51 +0100 | [diff] [blame] | 389 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 390 | } |
| 391 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 392 | return dentry; |
| 393 | } |
| 394 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 395 | static struct dentry *failed_creating(struct dentry *dentry) |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 396 | { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 397 | inode_unlock(d_inode(dentry->d_parent)); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 398 | dput(dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 399 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 400 | return ERR_PTR(-ENOMEM); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 401 | } |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 402 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 403 | static struct dentry *end_creating(struct dentry *dentry) |
| 404 | { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 405 | inode_unlock(d_inode(dentry->d_parent)); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 406 | return dentry; |
| 407 | } |
| 408 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 409 | static struct dentry *__debugfs_create_file(const char *name, umode_t mode, |
| 410 | struct dentry *parent, void *data, |
| 411 | const struct file_operations *proxy_fops, |
| 412 | const struct file_operations *real_fops) |
| 413 | { |
| 414 | struct dentry *dentry; |
| 415 | struct inode *inode; |
| 416 | |
| 417 | if (!(mode & S_IFMT)) |
| 418 | mode |= S_IFREG; |
| 419 | BUG_ON(!S_ISREG(mode)); |
| 420 | dentry = start_creating(name, parent); |
| 421 | |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame] | 422 | if (IS_ERR(dentry)) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 423 | return dentry; |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 424 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 425 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) { |
| 426 | failed_creating(dentry); |
| 427 | return ERR_PTR(-EPERM); |
| 428 | } |
| 429 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 430 | inode = debugfs_get_inode(dentry->d_sb); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 431 | if (unlikely(!inode)) { |
| 432 | pr_err("out of free dentries, can not create file '%s'\n", |
| 433 | name); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 434 | return failed_creating(dentry); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 435 | } |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 436 | |
| 437 | inode->i_mode = mode; |
| 438 | inode->i_private = data; |
| 439 | |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 440 | inode->i_op = &debugfs_file_inode_operations; |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 441 | inode->i_fop = proxy_fops; |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame] | 442 | dentry->d_fsdata = (void *)((unsigned long)real_fops | |
| 443 | DEBUGFS_FSDATA_IS_REAL_FOPS_BIT); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 444 | |
| 445 | d_instantiate(dentry, inode); |
| 446 | fsnotify_create(d_inode(dentry->d_parent), dentry); |
| 447 | return end_creating(dentry); |
| 448 | } |
| 449 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | /** |
| 451 | * debugfs_create_file - create a file in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | * @name: a pointer to a string containing the name of the file to create. |
Alberto Bertogli | be030e6 | 2009-10-31 18:26:52 -0300 | [diff] [blame] | 453 | * @mode: the permission that the file should have. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | * @parent: a pointer to the parent dentry for this file. This should be a |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 455 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | * file will be created in the root of the debugfs filesystem. |
| 457 | * @data: a pointer to something that the caller will want to get to later |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 458 | * on. The inode.i_private pointer will point to this value on |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | * the open() call. |
| 460 | * @fops: a pointer to a struct file_operations that should be used for |
| 461 | * this file. |
| 462 | * |
| 463 | * This is the basic "create a file" function for debugfs. It allows for a |
Alberto Bertogli | be030e6 | 2009-10-31 18:26:52 -0300 | [diff] [blame] | 464 | * wide range of flexibility in creating a file, or a directory (if you want |
| 465 | * to create a directory, the debugfs_create_dir() function is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | * recommended to be used instead.) |
| 467 | * |
| 468 | * This function will return a pointer to a dentry if it succeeds. This |
| 469 | * pointer must be passed to the debugfs_remove() function when the file is |
| 470 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Daniel W. S. Almeida | adc92dd | 2019-12-26 22:00:33 -0300 | [diff] [blame] | 471 | * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 472 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 474 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
Cornelia Huck | 873760f | 2007-02-14 07:57:47 +0100 | [diff] [blame] | 475 | * returned. |
Douglas Anderson | 8bcbde2 | 2022-02-22 15:46:00 -0800 | [diff] [blame] | 476 | * |
| 477 | * NOTE: it's expected that most callers should _ignore_ the errors returned |
| 478 | * by this function. Other debugfs functions handle the fact that the "dentry" |
| 479 | * passed to them could be an error and they don't crash in that case. |
| 480 | * Drivers should generally work fine even if debugfs fails to init anyway. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | */ |
Al Viro | f4ae40a6 | 2011-07-24 04:33:43 -0400 | [diff] [blame] | 482 | struct dentry *debugfs_create_file(const char *name, umode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | struct dentry *parent, void *data, |
Arjan van de Ven | 99ac48f | 2006-03-28 01:56:41 -0800 | [diff] [blame] | 484 | const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | { |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 486 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 487 | return __debugfs_create_file(name, mode, parent, data, |
| 488 | fops ? &debugfs_full_proxy_file_operations : |
| 489 | &debugfs_noop_file_operations, |
| 490 | fops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | } |
| 492 | EXPORT_SYMBOL_GPL(debugfs_create_file); |
| 493 | |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 494 | /** |
| 495 | * debugfs_create_file_unsafe - create a file in the debugfs filesystem |
| 496 | * @name: a pointer to a string containing the name of the file to create. |
| 497 | * @mode: the permission that the file should have. |
| 498 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 499 | * directory dentry if set. If this parameter is NULL, then the |
| 500 | * file will be created in the root of the debugfs filesystem. |
| 501 | * @data: a pointer to something that the caller will want to get to later |
| 502 | * on. The inode.i_private pointer will point to this value on |
| 503 | * the open() call. |
| 504 | * @fops: a pointer to a struct file_operations that should be used for |
| 505 | * this file. |
| 506 | * |
| 507 | * debugfs_create_file_unsafe() is completely analogous to |
| 508 | * debugfs_create_file(), the only difference being that the fops |
| 509 | * handed it will not get protected against file removals by the |
| 510 | * debugfs core. |
| 511 | * |
| 512 | * It is your responsibility to protect your struct file_operation |
Sergey Senozhatsky | 0eeb273 | 2018-12-30 12:46:52 +0900 | [diff] [blame] | 513 | * methods against file removals by means of debugfs_file_get() |
| 514 | * and debugfs_file_put(). ->open() is still protected by |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 515 | * debugfs though. |
| 516 | * |
| 517 | * Any struct file_operations defined by means of |
| 518 | * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and |
| 519 | * thus, may be used here. |
| 520 | */ |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 521 | struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, |
| 522 | struct dentry *parent, void *data, |
| 523 | const struct file_operations *fops) |
| 524 | { |
| 525 | |
| 526 | return __debugfs_create_file(name, mode, parent, data, |
| 527 | fops ? &debugfs_open_proxy_file_operations : |
| 528 | &debugfs_noop_file_operations, |
| 529 | fops); |
| 530 | } |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 531 | EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 532 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | /** |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 534 | * debugfs_create_file_size - create a file in the debugfs filesystem |
| 535 | * @name: a pointer to a string containing the name of the file to create. |
| 536 | * @mode: the permission that the file should have. |
| 537 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 538 | * directory dentry if set. If this parameter is NULL, then the |
| 539 | * file will be created in the root of the debugfs filesystem. |
| 540 | * @data: a pointer to something that the caller will want to get to later |
| 541 | * on. The inode.i_private pointer will point to this value on |
| 542 | * the open() call. |
| 543 | * @fops: a pointer to a struct file_operations that should be used for |
| 544 | * this file. |
| 545 | * @file_size: initial file size |
| 546 | * |
| 547 | * This is the basic "create a file" function for debugfs. It allows for a |
| 548 | * wide range of flexibility in creating a file, or a directory (if you want |
| 549 | * to create a directory, the debugfs_create_dir() function is |
| 550 | * recommended to be used instead.) |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 551 | */ |
Greg Kroah-Hartman | 526ee72 | 2020-03-09 17:36:40 +0100 | [diff] [blame] | 552 | void debugfs_create_file_size(const char *name, umode_t mode, |
| 553 | struct dentry *parent, void *data, |
| 554 | const struct file_operations *fops, |
| 555 | loff_t file_size) |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 556 | { |
| 557 | struct dentry *de = debugfs_create_file(name, mode, parent, data, fops); |
| 558 | |
Nirmoy Das | af505ca | 2021-09-02 12:29:17 +0200 | [diff] [blame] | 559 | if (!IS_ERR(de)) |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 560 | d_inode(de)->i_size = file_size; |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 561 | } |
| 562 | EXPORT_SYMBOL_GPL(debugfs_create_file_size); |
| 563 | |
| 564 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | * debugfs_create_dir - create a directory in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | * @name: a pointer to a string containing the name of the directory to |
| 567 | * create. |
| 568 | * @parent: a pointer to the parent dentry for this file. This should be a |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 569 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | * directory will be created in the root of the debugfs filesystem. |
| 571 | * |
| 572 | * This function creates a directory in debugfs with the given name. |
| 573 | * |
| 574 | * This function will return a pointer to a dentry if it succeeds. This |
| 575 | * pointer must be passed to the debugfs_remove() function when the file is |
| 576 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Daniel W. S. Almeida | adc92dd | 2019-12-26 22:00:33 -0300 | [diff] [blame] | 577 | * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 578 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 580 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
Cornelia Huck | 873760f | 2007-02-14 07:57:47 +0100 | [diff] [blame] | 581 | * returned. |
Douglas Anderson | 8bcbde2 | 2022-02-22 15:46:00 -0800 | [diff] [blame] | 582 | * |
| 583 | * NOTE: it's expected that most callers should _ignore_ the errors returned |
| 584 | * by this function. Other debugfs functions handle the fact that the "dentry" |
| 585 | * passed to them could be an error and they don't crash in that case. |
| 586 | * Drivers should generally work fine even if debugfs fails to init anyway. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | */ |
| 588 | struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) |
| 589 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 590 | struct dentry *dentry = start_creating(name, parent); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 591 | struct inode *inode; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 592 | |
| 593 | if (IS_ERR(dentry)) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 594 | return dentry; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 595 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 596 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) { |
| 597 | failed_creating(dentry); |
| 598 | return ERR_PTR(-EPERM); |
| 599 | } |
| 600 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 601 | inode = debugfs_get_inode(dentry->d_sb); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 602 | if (unlikely(!inode)) { |
| 603 | pr_err("out of free dentries, can not create directory '%s'\n", |
| 604 | name); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 605 | return failed_creating(dentry); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 606 | } |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 607 | |
Linus Torvalds | f5b7769e | 2018-06-12 20:52:16 -0700 | [diff] [blame] | 608 | inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 609 | inode->i_op = &debugfs_dir_inode_operations; |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 610 | inode->i_fop = &simple_dir_operations; |
| 611 | |
| 612 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 613 | inc_nlink(inode); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 614 | d_instantiate(dentry, inode); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 615 | inc_nlink(d_inode(dentry->d_parent)); |
| 616 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 617 | return end_creating(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 618 | } |
| 619 | EXPORT_SYMBOL_GPL(debugfs_create_dir); |
| 620 | |
| 621 | /** |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 622 | * debugfs_create_automount - create automount point in the debugfs filesystem |
| 623 | * @name: a pointer to a string containing the name of the file to create. |
| 624 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 625 | * directory dentry if set. If this parameter is NULL, then the |
| 626 | * file will be created in the root of the debugfs filesystem. |
| 627 | * @f: function to be called when pathname resolution steps on that one. |
| 628 | * @data: opaque argument to pass to f(). |
| 629 | * |
| 630 | * @f should return what ->d_automount() would. |
| 631 | */ |
| 632 | struct dentry *debugfs_create_automount(const char *name, |
| 633 | struct dentry *parent, |
Eric W. Biederman | 93faccbb | 2017-02-01 06:06:16 +1300 | [diff] [blame] | 634 | debugfs_automount_t f, |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 635 | void *data) |
| 636 | { |
| 637 | struct dentry *dentry = start_creating(name, parent); |
| 638 | struct inode *inode; |
| 639 | |
| 640 | if (IS_ERR(dentry)) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 641 | return dentry; |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 642 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 643 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) { |
| 644 | failed_creating(dentry); |
| 645 | return ERR_PTR(-EPERM); |
| 646 | } |
| 647 | |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 648 | inode = debugfs_get_inode(dentry->d_sb); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 649 | if (unlikely(!inode)) { |
| 650 | pr_err("out of free dentries, can not create automount '%s'\n", |
| 651 | name); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 652 | return failed_creating(dentry); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 653 | } |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 654 | |
Seth Forshee | 87243de | 2016-03-09 09:18:07 -0600 | [diff] [blame] | 655 | make_empty_dir_inode(inode); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 656 | inode->i_flags |= S_AUTOMOUNT; |
| 657 | inode->i_private = data; |
| 658 | dentry->d_fsdata = (void *)f; |
Roman Pen | a8f324a | 2016-02-09 11:30:29 +0100 | [diff] [blame] | 659 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 660 | inc_nlink(inode); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 661 | d_instantiate(dentry, inode); |
Roman Pen | a8f324a | 2016-02-09 11:30:29 +0100 | [diff] [blame] | 662 | inc_nlink(d_inode(dentry->d_parent)); |
| 663 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 664 | return end_creating(dentry); |
| 665 | } |
| 666 | EXPORT_SYMBOL(debugfs_create_automount); |
| 667 | |
| 668 | /** |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 669 | * debugfs_create_symlink- create a symbolic link in the debugfs filesystem |
| 670 | * @name: a pointer to a string containing the name of the symbolic link to |
| 671 | * create. |
| 672 | * @parent: a pointer to the parent dentry for this symbolic link. This |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 673 | * should be a directory dentry if set. If this parameter is NULL, |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 674 | * then the symbolic link will be created in the root of the debugfs |
| 675 | * filesystem. |
| 676 | * @target: a pointer to a string containing the path to the target of the |
| 677 | * symbolic link. |
| 678 | * |
| 679 | * This function creates a symbolic link with the given name in debugfs that |
| 680 | * links to the given target path. |
| 681 | * |
| 682 | * This function will return a pointer to a dentry if it succeeds. This |
| 683 | * pointer must be passed to the debugfs_remove() function when the symbolic |
| 684 | * link is to be removed (no automatic cleanup happens if your module is |
Daniel W. S. Almeida | adc92dd | 2019-12-26 22:00:33 -0300 | [diff] [blame] | 685 | * unloaded, you are responsible here.) If an error occurs, ERR_PTR(-ERROR) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 686 | * will be returned. |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 687 | * |
| 688 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
Cornelia Huck | 873760f | 2007-02-14 07:57:47 +0100 | [diff] [blame] | 689 | * returned. |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 690 | */ |
| 691 | struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, |
| 692 | const char *target) |
| 693 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 694 | struct dentry *dentry; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 695 | struct inode *inode; |
| 696 | char *link = kstrdup(target, GFP_KERNEL); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 697 | if (!link) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 698 | return ERR_PTR(-ENOMEM); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 699 | |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 700 | dentry = start_creating(name, parent); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 701 | if (IS_ERR(dentry)) { |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 702 | kfree(link); |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 703 | return dentry; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 704 | } |
| 705 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 706 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 707 | if (unlikely(!inode)) { |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 708 | pr_err("out of free dentries, can not create symlink '%s'\n", |
| 709 | name); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 710 | kfree(link); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 711 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 712 | } |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 713 | inode->i_mode = S_IFLNK | S_IRWXUGO; |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 714 | inode->i_op = &debugfs_symlink_inode_operations; |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame] | 715 | inode->i_link = link; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 716 | d_instantiate(dentry, inode); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 717 | return end_creating(dentry); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 718 | } |
| 719 | EXPORT_SYMBOL_GPL(debugfs_create_symlink); |
| 720 | |
Amir Goldstein | 823e545 | 2019-05-26 17:34:07 +0300 | [diff] [blame] | 721 | static void __debugfs_file_removed(struct dentry *dentry) |
Nicolai Stange | e9117a5 | 2017-10-31 00:15:48 +0100 | [diff] [blame] | 722 | { |
| 723 | struct debugfs_fsdata *fsd; |
| 724 | |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame] | 725 | /* |
| 726 | * Paired with the closing smp_mb() implied by a successful |
| 727 | * cmpxchg() in debugfs_file_get(): either |
| 728 | * debugfs_file_get() must see a dead dentry or we must see a |
| 729 | * debugfs_fsdata instance at ->d_fsdata here (or both). |
| 730 | */ |
| 731 | smp_mb(); |
| 732 | fsd = READ_ONCE(dentry->d_fsdata); |
| 733 | if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) |
| 734 | return; |
Nicolai Stange | e9117a5 | 2017-10-31 00:15:48 +0100 | [diff] [blame] | 735 | if (!refcount_dec_and_test(&fsd->active_users)) |
| 736 | wait_for_completion(&fsd->active_users_drained); |
| 737 | } |
| 738 | |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 739 | static void remove_one(struct dentry *victim) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | { |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 741 | if (d_is_reg(victim)) |
| 742 | __debugfs_file_removed(victim); |
| 743 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 744 | } |
| 745 | |
| 746 | /** |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 747 | * debugfs_remove - recursively removes a directory |
Ulf Magnusson | 398dc4a | 2015-09-07 19:03:15 +0200 | [diff] [blame] | 748 | * @dentry: a pointer to a the dentry of the directory to be removed. If this |
| 749 | * parameter is NULL or an error value, nothing will be done. |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 750 | * |
| 751 | * This function recursively removes a directory tree in debugfs that |
| 752 | * was previously created with a call to another debugfs function |
| 753 | * (like debugfs_create_file() or variants thereof.) |
| 754 | * |
| 755 | * This function is required to be called in order for the file to be |
| 756 | * removed, no automatic cleanup of files will happen when a module is |
| 757 | * removed, you are responsible here. |
| 758 | */ |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 759 | void debugfs_remove(struct dentry *dentry) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 760 | { |
Arend van Spriel | a59d629 | 2012-05-23 15:13:07 +0200 | [diff] [blame] | 761 | if (IS_ERR_OR_NULL(dentry)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 762 | return; |
| 763 | |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 764 | simple_pin_fs(&debug_fs_type, &debugfs_mount, &debugfs_mount_count); |
| 765 | simple_recursive_removal(dentry, remove_one); |
| 766 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 767 | } |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 768 | EXPORT_SYMBOL_GPL(debugfs_remove); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 769 | |
| 770 | /** |
Greg Kroah-Hartman | dec9b2f | 2022-09-02 16:59:15 +0200 | [diff] [blame] | 771 | * debugfs_lookup_and_remove - lookup a directory or file and recursively remove it |
| 772 | * @name: a pointer to a string containing the name of the item to look up. |
| 773 | * @parent: a pointer to the parent dentry of the item. |
| 774 | * |
| 775 | * This is the equlivant of doing something like |
| 776 | * debugfs_remove(debugfs_lookup(..)) but with the proper reference counting |
| 777 | * handled for the directory being looked up. |
| 778 | */ |
| 779 | void debugfs_lookup_and_remove(const char *name, struct dentry *parent) |
| 780 | { |
| 781 | struct dentry *dentry; |
| 782 | |
| 783 | dentry = debugfs_lookup(name, parent); |
| 784 | if (!dentry) |
| 785 | return; |
| 786 | |
| 787 | debugfs_remove(dentry); |
| 788 | dput(dentry); |
| 789 | } |
| 790 | EXPORT_SYMBOL_GPL(debugfs_lookup_and_remove); |
| 791 | |
| 792 | /** |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 793 | * debugfs_rename - rename a file/directory in the debugfs filesystem |
| 794 | * @old_dir: a pointer to the parent dentry for the renamed object. This |
| 795 | * should be a directory dentry. |
| 796 | * @old_dentry: dentry of an object to be renamed. |
| 797 | * @new_dir: a pointer to the parent dentry where the object should be |
| 798 | * moved. This should be a directory dentry. |
| 799 | * @new_name: a pointer to a string containing the target name. |
| 800 | * |
| 801 | * This function renames a file/directory in debugfs. The target must not |
| 802 | * exist for rename to succeed. |
| 803 | * |
| 804 | * This function will return a pointer to old_dentry (which is updated to |
Bagas Sanjaya | 88cd618 | 2023-02-20 19:47:21 +0700 | [diff] [blame] | 805 | * reflect renaming) if it succeeds. If an error occurs, ERR_PTR(-ERROR) |
Qi Zheng | d300246 | 2023-02-08 11:56:34 +0800 | [diff] [blame] | 806 | * will be returned. |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 807 | * |
| 808 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 809 | * returned. |
| 810 | */ |
| 811 | struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, |
| 812 | struct dentry *new_dir, const char *new_name) |
| 813 | { |
| 814 | int error; |
| 815 | struct dentry *dentry = NULL, *trap; |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 816 | struct name_snapshot old_name; |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 817 | |
Greg Kroah-Hartman | d88c93f | 2019-01-23 11:27:02 +0100 | [diff] [blame] | 818 | if (IS_ERR(old_dir)) |
| 819 | return old_dir; |
| 820 | if (IS_ERR(new_dir)) |
| 821 | return new_dir; |
| 822 | if (IS_ERR_OR_NULL(old_dentry)) |
| 823 | return old_dentry; |
| 824 | |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 825 | trap = lock_rename(new_dir, old_dir); |
| 826 | /* Source or destination directories don't exist? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 827 | if (d_really_is_negative(old_dir) || d_really_is_negative(new_dir)) |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 828 | goto exit; |
| 829 | /* Source does not exist, cyclic rename, or mountpoint? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 830 | if (d_really_is_negative(old_dentry) || old_dentry == trap || |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 831 | d_mountpoint(old_dentry)) |
| 832 | goto exit; |
| 833 | dentry = lookup_one_len(new_name, new_dir, strlen(new_name)); |
| 834 | /* Lookup failed, cyclic rename or target exists? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 835 | if (IS_ERR(dentry) || dentry == trap || d_really_is_positive(dentry)) |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 836 | goto exit; |
| 837 | |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 838 | take_dentry_name_snapshot(&old_name, old_dentry); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 839 | |
Christian Brauner | e18275a | 2023-01-13 12:49:17 +0100 | [diff] [blame] | 840 | error = simple_rename(&nop_mnt_idmap, d_inode(old_dir), old_dentry, |
Christian Brauner | 549c729 | 2021-01-21 14:19:43 +0100 | [diff] [blame] | 841 | d_inode(new_dir), dentry, 0); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 842 | if (error) { |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 843 | release_dentry_name_snapshot(&old_name); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 844 | goto exit; |
| 845 | } |
| 846 | d_move(old_dentry, dentry); |
Al Viro | f4ec3a3 | 2019-04-26 13:21:24 -0400 | [diff] [blame] | 847 | fsnotify_move(d_inode(old_dir), d_inode(new_dir), &old_name.name, |
David Howells | e36cb0b | 2015-01-29 12:02:35 +0000 | [diff] [blame] | 848 | d_is_dir(old_dentry), |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 849 | NULL, old_dentry); |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 850 | release_dentry_name_snapshot(&old_name); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 851 | unlock_rename(new_dir, old_dir); |
| 852 | dput(dentry); |
| 853 | return old_dentry; |
| 854 | exit: |
| 855 | if (dentry && !IS_ERR(dentry)) |
| 856 | dput(dentry); |
| 857 | unlock_rename(new_dir, old_dir); |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 858 | if (IS_ERR(dentry)) |
| 859 | return dentry; |
| 860 | return ERR_PTR(-EINVAL); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 861 | } |
| 862 | EXPORT_SYMBOL_GPL(debugfs_rename); |
| 863 | |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 864 | /** |
| 865 | * debugfs_initialized - Tells whether debugfs has been registered |
| 866 | */ |
| 867 | bool debugfs_initialized(void) |
| 868 | { |
| 869 | return debugfs_registered; |
| 870 | } |
| 871 | EXPORT_SYMBOL_GPL(debugfs_initialized); |
| 872 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 873 | static int __init debugfs_kernel(char *str) |
| 874 | { |
| 875 | if (str) { |
| 876 | if (!strcmp(str, "on")) |
| 877 | debugfs_allow = DEBUGFS_ALLOW_API | DEBUGFS_ALLOW_MOUNT; |
| 878 | else if (!strcmp(str, "no-mount")) |
| 879 | debugfs_allow = DEBUGFS_ALLOW_API; |
| 880 | else if (!strcmp(str, "off")) |
| 881 | debugfs_allow = 0; |
| 882 | } |
| 883 | |
| 884 | return 0; |
| 885 | } |
| 886 | early_param("debugfs", debugfs_kernel); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | static int __init debugfs_init(void) |
| 888 | { |
| 889 | int retval; |
| 890 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 891 | if (!(debugfs_allow & DEBUGFS_ALLOW_MOUNT)) |
| 892 | return -EPERM; |
| 893 | |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 894 | retval = sysfs_create_mount_point(kernel_kobj, "debug"); |
| 895 | if (retval) |
| 896 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | |
| 898 | retval = register_filesystem(&debug_fs_type); |
| 899 | if (retval) |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 900 | sysfs_remove_mount_point(kernel_kobj, "debug"); |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 901 | else |
| 902 | debugfs_registered = true; |
| 903 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 904 | return retval; |
| 905 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 906 | core_initcall(debugfs_init); |