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; |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 38 | static unsigned int debugfs_allow = 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 | */ |
| 45 | static int debugfs_setattr(struct dentry *dentry, struct iattr *ia) |
| 46 | { |
| 47 | int ret = security_locked_down(LOCKDOWN_DEBUGFS); |
| 48 | |
| 49 | if (ret && (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))) |
| 50 | return ret; |
| 51 | return simple_setattr(dentry, ia); |
| 52 | } |
| 53 | |
| 54 | static const struct inode_operations debugfs_file_inode_operations = { |
| 55 | .setattr = debugfs_setattr, |
| 56 | }; |
| 57 | static const struct inode_operations debugfs_dir_inode_operations = { |
| 58 | .lookup = simple_lookup, |
| 59 | .setattr = debugfs_setattr, |
| 60 | }; |
| 61 | static const struct inode_operations debugfs_symlink_inode_operations = { |
| 62 | .get_link = simple_get_link, |
| 63 | .setattr = debugfs_setattr, |
| 64 | }; |
| 65 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 66 | static struct inode *debugfs_get_inode(struct super_block *sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | { |
| 68 | struct inode *inode = new_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 70 | inode->i_ino = get_next_ino(); |
Deepa Dinamani | 1b48b53 | 2016-02-22 07:17:47 -0800 | [diff] [blame] | 71 | inode->i_atime = inode->i_mtime = |
Deepa Dinamani | c2050a4 | 2016-09-14 07:48:06 -0700 | [diff] [blame] | 72 | inode->i_ctime = current_time(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | } |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 74 | return inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | } |
| 76 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 77 | struct debugfs_mount_opts { |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 78 | kuid_t uid; |
| 79 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 80 | umode_t mode; |
| 81 | }; |
| 82 | |
| 83 | enum { |
| 84 | Opt_uid, |
| 85 | Opt_gid, |
| 86 | Opt_mode, |
| 87 | Opt_err |
| 88 | }; |
| 89 | |
| 90 | static const match_table_t tokens = { |
| 91 | {Opt_uid, "uid=%u"}, |
| 92 | {Opt_gid, "gid=%u"}, |
| 93 | {Opt_mode, "mode=%o"}, |
| 94 | {Opt_err, NULL} |
| 95 | }; |
| 96 | |
| 97 | struct debugfs_fs_info { |
| 98 | struct debugfs_mount_opts mount_opts; |
| 99 | }; |
| 100 | |
| 101 | static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts) |
| 102 | { |
| 103 | substring_t args[MAX_OPT_ARGS]; |
| 104 | int option; |
| 105 | int token; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 106 | kuid_t uid; |
| 107 | kgid_t gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 108 | char *p; |
| 109 | |
| 110 | opts->mode = DEBUGFS_DEFAULT_MODE; |
| 111 | |
| 112 | while ((p = strsep(&data, ",")) != NULL) { |
| 113 | if (!*p) |
| 114 | continue; |
| 115 | |
| 116 | token = match_token(p, tokens, args); |
| 117 | switch (token) { |
| 118 | case Opt_uid: |
| 119 | if (match_int(&args[0], &option)) |
| 120 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 121 | uid = make_kuid(current_user_ns(), option); |
| 122 | if (!uid_valid(uid)) |
| 123 | return -EINVAL; |
| 124 | opts->uid = uid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 125 | break; |
| 126 | case Opt_gid: |
Dave Reisner | f1688e0 | 2013-01-02 08:54:37 -0500 | [diff] [blame] | 127 | if (match_int(&args[0], &option)) |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 128 | return -EINVAL; |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 129 | gid = make_kgid(current_user_ns(), option); |
| 130 | if (!gid_valid(gid)) |
| 131 | return -EINVAL; |
| 132 | opts->gid = gid; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 133 | break; |
| 134 | case Opt_mode: |
| 135 | if (match_octal(&args[0], &option)) |
| 136 | return -EINVAL; |
| 137 | opts->mode = option & S_IALLUGO; |
| 138 | break; |
| 139 | /* |
| 140 | * We might like to report bad mount options here; |
| 141 | * but traditionally debugfs has ignored all mount options |
| 142 | */ |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | return 0; |
| 147 | } |
| 148 | |
| 149 | static int debugfs_apply_options(struct super_block *sb) |
| 150 | { |
| 151 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 152 | struct inode *inode = d_inode(sb->s_root); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 153 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 154 | |
| 155 | inode->i_mode &= ~S_IALLUGO; |
| 156 | inode->i_mode |= opts->mode; |
| 157 | |
| 158 | inode->i_uid = opts->uid; |
| 159 | inode->i_gid = opts->gid; |
| 160 | |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | static int debugfs_remount(struct super_block *sb, int *flags, char *data) |
| 165 | { |
| 166 | int err; |
| 167 | struct debugfs_fs_info *fsi = sb->s_fs_info; |
| 168 | |
Theodore Ts'o | 02b9984 | 2014-03-13 10:14:33 -0400 | [diff] [blame] | 169 | sync_filesystem(sb); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 170 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 171 | if (err) |
| 172 | goto fail; |
| 173 | |
| 174 | debugfs_apply_options(sb); |
| 175 | |
| 176 | fail: |
| 177 | return err; |
| 178 | } |
| 179 | |
| 180 | static int debugfs_show_options(struct seq_file *m, struct dentry *root) |
| 181 | { |
| 182 | struct debugfs_fs_info *fsi = root->d_sb->s_fs_info; |
| 183 | struct debugfs_mount_opts *opts = &fsi->mount_opts; |
| 184 | |
Eric W. Biederman | 7dc0588 | 2012-04-03 14:01:31 -0700 | [diff] [blame] | 185 | if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) |
| 186 | seq_printf(m, ",uid=%u", |
| 187 | from_kuid_munged(&init_user_ns, opts->uid)); |
| 188 | if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) |
| 189 | seq_printf(m, ",gid=%u", |
| 190 | from_kgid_munged(&init_user_ns, opts->gid)); |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 191 | if (opts->mode != DEBUGFS_DEFAULT_MODE) |
| 192 | seq_printf(m, ",mode=%o", opts->mode); |
| 193 | |
| 194 | return 0; |
| 195 | } |
| 196 | |
Al Viro | 6234ddf | 2019-04-14 23:19:45 -0400 | [diff] [blame] | 197 | static void debugfs_free_inode(struct inode *inode) |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 198 | { |
Al Viro | 0db59e5 | 2015-02-21 22:05:11 -0500 | [diff] [blame] | 199 | if (S_ISLNK(inode->i_mode)) |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame] | 200 | kfree(inode->i_link); |
Al Viro | 93b919d | 2019-03-26 01:43:37 +0000 | [diff] [blame] | 201 | free_inode_nonrcu(inode); |
| 202 | } |
| 203 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 204 | static const struct super_operations debugfs_super_operations = { |
| 205 | .statfs = simple_statfs, |
| 206 | .remount_fs = debugfs_remount, |
| 207 | .show_options = debugfs_show_options, |
Al Viro | 6234ddf | 2019-04-14 23:19:45 -0400 | [diff] [blame] | 208 | .free_inode = debugfs_free_inode, |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 209 | }; |
| 210 | |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 211 | static void debugfs_release_dentry(struct dentry *dentry) |
| 212 | { |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame] | 213 | void *fsd = dentry->d_fsdata; |
| 214 | |
| 215 | if (!((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) |
| 216 | kfree(dentry->d_fsdata); |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 217 | } |
| 218 | |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 219 | static struct vfsmount *debugfs_automount(struct path *path) |
| 220 | { |
Eric W. Biederman | 93faccbb | 2017-02-01 06:06:16 +1300 | [diff] [blame] | 221 | debugfs_automount_t f; |
| 222 | f = (debugfs_automount_t)path->dentry->d_fsdata; |
| 223 | return f(path->dentry, d_inode(path->dentry)->i_private); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 224 | } |
| 225 | |
| 226 | static const struct dentry_operations debugfs_dops = { |
| 227 | .d_delete = always_delete_dentry, |
Nicolai Stange | 7c8d469 | 2017-10-31 00:15:47 +0100 | [diff] [blame] | 228 | .d_release = debugfs_release_dentry, |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 229 | .d_automount = debugfs_automount, |
| 230 | }; |
| 231 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | static int debug_fill_super(struct super_block *sb, void *data, int silent) |
| 233 | { |
Eric Biggers | cda3712 | 2017-03-25 21:15:37 -0700 | [diff] [blame] | 234 | static const struct tree_descr debug_files[] = {{""}}; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 235 | struct debugfs_fs_info *fsi; |
| 236 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 238 | fsi = kzalloc(sizeof(struct debugfs_fs_info), GFP_KERNEL); |
| 239 | sb->s_fs_info = fsi; |
| 240 | if (!fsi) { |
| 241 | err = -ENOMEM; |
| 242 | goto fail; |
| 243 | } |
| 244 | |
| 245 | err = debugfs_parse_options(data, &fsi->mount_opts); |
| 246 | if (err) |
| 247 | goto fail; |
| 248 | |
| 249 | err = simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); |
| 250 | if (err) |
| 251 | goto fail; |
| 252 | |
| 253 | sb->s_op = &debugfs_super_operations; |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 254 | sb->s_d_op = &debugfs_dops; |
Ludwig Nussel | d6e4868 | 2012-01-25 11:52:28 +0100 | [diff] [blame] | 255 | |
| 256 | debugfs_apply_options(sb); |
| 257 | |
| 258 | return 0; |
| 259 | |
| 260 | fail: |
| 261 | kfree(fsi); |
| 262 | sb->s_fs_info = NULL; |
| 263 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | } |
| 265 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 266 | static struct dentry *debug_mount(struct file_system_type *fs_type, |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 267 | int flags, const char *dev_name, |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 268 | void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | { |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 270 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) |
| 271 | return ERR_PTR(-EPERM); |
| 272 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 273 | return mount_single(fs_type, flags, data, debug_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | } |
| 275 | |
| 276 | static struct file_system_type debug_fs_type = { |
| 277 | .owner = THIS_MODULE, |
| 278 | .name = "debugfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 279 | .mount = debug_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | .kill_sb = kill_litter_super, |
| 281 | }; |
Eric W. Biederman | 7f78e03 | 2013-03-02 19:39:14 -0800 | [diff] [blame] | 282 | MODULE_ALIAS_FS("debugfs"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | |
Omar Sandoval | a7c5437 | 2017-01-31 14:53:17 -0800 | [diff] [blame] | 284 | /** |
| 285 | * debugfs_lookup() - look up an existing debugfs file |
| 286 | * @name: a pointer to a string containing the name of the file to look up. |
| 287 | * @parent: a pointer to the parent dentry of the file. |
| 288 | * |
| 289 | * This function will return a pointer to a dentry if it succeeds. If the file |
| 290 | * doesn't exist or an error occurs, %NULL will be returned. The returned |
| 291 | * dentry must be passed to dput() when it is no longer needed. |
| 292 | * |
| 293 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 294 | * returned. |
| 295 | */ |
| 296 | struct dentry *debugfs_lookup(const char *name, struct dentry *parent) |
| 297 | { |
| 298 | struct dentry *dentry; |
| 299 | |
| 300 | if (IS_ERR(parent)) |
| 301 | return NULL; |
| 302 | |
| 303 | if (!parent) |
| 304 | parent = debugfs_mount->mnt_root; |
| 305 | |
Al Viro | 6c2d4798 | 2019-10-31 01:21:58 -0400 | [diff] [blame] | 306 | dentry = lookup_positive_unlocked(name, parent, strlen(name)); |
Omar Sandoval | a7c5437 | 2017-01-31 14:53:17 -0800 | [diff] [blame] | 307 | if (IS_ERR(dentry)) |
| 308 | return NULL; |
Omar Sandoval | a7c5437 | 2017-01-31 14:53:17 -0800 | [diff] [blame] | 309 | return dentry; |
| 310 | } |
| 311 | EXPORT_SYMBOL_GPL(debugfs_lookup); |
| 312 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 313 | static struct dentry *start_creating(const char *name, struct dentry *parent) |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 314 | { |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 315 | struct dentry *dentry; |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 316 | int error; |
| 317 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 318 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) |
| 319 | return ERR_PTR(-EPERM); |
| 320 | |
Greg Kroah-Hartman | d03ae47 | 2019-07-03 09:16:52 +0200 | [diff] [blame] | 321 | pr_debug("creating file '%s'\n", name); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 322 | |
Greg KH | c9e15f2 | 2015-03-30 14:59:15 +0200 | [diff] [blame] | 323 | if (IS_ERR(parent)) |
| 324 | return parent; |
| 325 | |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 326 | error = simple_pin_fs(&debug_fs_type, &debugfs_mount, |
| 327 | &debugfs_mount_count); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 328 | if (error) { |
| 329 | pr_err("Unable to pin filesystem for file '%s'\n", name); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 330 | return ERR_PTR(error); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 331 | } |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 332 | |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 333 | /* If the parent is not specified, we create it in the root. |
Rahul Bedarkar | 88e412e | 2014-06-06 23:12:04 +0530 | [diff] [blame] | 334 | * 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] | 335 | * block. A pointer to that is in the struct vfsmount that we |
| 336 | * have around. |
| 337 | */ |
| 338 | if (!parent) |
| 339 | parent = debugfs_mount->mnt_root; |
| 340 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 341 | inode_lock(d_inode(parent)); |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 342 | if (unlikely(IS_DEADDIR(d_inode(parent)))) |
| 343 | dentry = ERR_PTR(-ENOENT); |
| 344 | else |
| 345 | dentry = lookup_one_len(name, parent, strlen(name)); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 346 | if (!IS_ERR(dentry) && d_really_is_positive(dentry)) { |
Greg Kroah-Hartman | c33d442 | 2019-07-06 17:42:56 +0200 | [diff] [blame] | 347 | if (d_is_dir(dentry)) |
| 348 | pr_err("Directory '%s' with parent '%s' already present!\n", |
| 349 | name, parent->d_name.name); |
| 350 | else |
| 351 | pr_err("File '%s' in directory '%s' already present!\n", |
| 352 | name, parent->d_name.name); |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 353 | dput(dentry); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 354 | dentry = ERR_PTR(-EEXIST); |
| 355 | } |
Daniel Borkmann | 0ee9608 | 2015-11-05 00:01:51 +0100 | [diff] [blame] | 356 | |
| 357 | if (IS_ERR(dentry)) { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 358 | inode_unlock(d_inode(parent)); |
Daniel Borkmann | 0ee9608 | 2015-11-05 00:01:51 +0100 | [diff] [blame] | 359 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
| 360 | } |
| 361 | |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 362 | return dentry; |
| 363 | } |
| 364 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 365 | static struct dentry *failed_creating(struct dentry *dentry) |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 366 | { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 367 | inode_unlock(d_inode(dentry->d_parent)); |
Al Viro | 190afd8 | 2015-01-25 13:55:55 -0500 | [diff] [blame] | 368 | dput(dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 369 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 370 | return ERR_PTR(-ENOMEM); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 371 | } |
Al Viro | cfa57c1 | 2012-06-09 20:33:28 -0400 | [diff] [blame] | 372 | |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 373 | static struct dentry *end_creating(struct dentry *dentry) |
| 374 | { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 375 | inode_unlock(d_inode(dentry->d_parent)); |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 376 | return dentry; |
| 377 | } |
| 378 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 379 | static struct dentry *__debugfs_create_file(const char *name, umode_t mode, |
| 380 | struct dentry *parent, void *data, |
| 381 | const struct file_operations *proxy_fops, |
| 382 | const struct file_operations *real_fops) |
| 383 | { |
| 384 | struct dentry *dentry; |
| 385 | struct inode *inode; |
| 386 | |
| 387 | if (!(mode & S_IFMT)) |
| 388 | mode |= S_IFREG; |
| 389 | BUG_ON(!S_ISREG(mode)); |
| 390 | dentry = start_creating(name, parent); |
| 391 | |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame] | 392 | if (IS_ERR(dentry)) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 393 | return dentry; |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 394 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 395 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) { |
| 396 | failed_creating(dentry); |
| 397 | return ERR_PTR(-EPERM); |
| 398 | } |
| 399 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 400 | inode = debugfs_get_inode(dentry->d_sb); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 401 | if (unlikely(!inode)) { |
| 402 | pr_err("out of free dentries, can not create file '%s'\n", |
| 403 | name); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 404 | return failed_creating(dentry); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 405 | } |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 406 | |
| 407 | inode->i_mode = mode; |
| 408 | inode->i_private = data; |
| 409 | |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 410 | inode->i_op = &debugfs_file_inode_operations; |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 411 | inode->i_fop = proxy_fops; |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame] | 412 | dentry->d_fsdata = (void *)((unsigned long)real_fops | |
| 413 | DEBUGFS_FSDATA_IS_REAL_FOPS_BIT); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 414 | |
| 415 | d_instantiate(dentry, inode); |
| 416 | fsnotify_create(d_inode(dentry->d_parent), dentry); |
| 417 | return end_creating(dentry); |
| 418 | } |
| 419 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | /** |
| 421 | * debugfs_create_file - create a file in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | * @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] | 423 | * @mode: the permission that the file should have. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | * @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] | 425 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | * file will be created in the root of the debugfs filesystem. |
| 427 | * @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] | 428 | * on. The inode.i_private pointer will point to this value on |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | * the open() call. |
| 430 | * @fops: a pointer to a struct file_operations that should be used for |
| 431 | * this file. |
| 432 | * |
| 433 | * 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] | 434 | * wide range of flexibility in creating a file, or a directory (if you want |
| 435 | * to create a directory, the debugfs_create_dir() function is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | * recommended to be used instead.) |
| 437 | * |
| 438 | * This function will return a pointer to a dentry if it succeeds. This |
| 439 | * pointer must be passed to the debugfs_remove() function when the file is |
| 440 | * 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] | 441 | * 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] | 442 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 444 | * 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] | 445 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | */ |
Al Viro | f4ae40a6 | 2011-07-24 04:33:43 -0400 | [diff] [blame] | 447 | struct dentry *debugfs_create_file(const char *name, umode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | struct dentry *parent, void *data, |
Arjan van de Ven | 99ac48f | 2006-03-28 01:56:41 -0800 | [diff] [blame] | 449 | const struct file_operations *fops) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | { |
Al Viro | c3b1a35 | 2012-06-09 20:28:22 -0400 | [diff] [blame] | 451 | |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 452 | return __debugfs_create_file(name, mode, parent, data, |
| 453 | fops ? &debugfs_full_proxy_file_operations : |
| 454 | &debugfs_noop_file_operations, |
| 455 | fops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | } |
| 457 | EXPORT_SYMBOL_GPL(debugfs_create_file); |
| 458 | |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 459 | /** |
| 460 | * debugfs_create_file_unsafe - create a file in the debugfs filesystem |
| 461 | * @name: a pointer to a string containing the name of the file to create. |
| 462 | * @mode: the permission that the file should have. |
| 463 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 464 | * directory dentry if set. If this parameter is NULL, then the |
| 465 | * file will be created in the root of the debugfs filesystem. |
| 466 | * @data: a pointer to something that the caller will want to get to later |
| 467 | * on. The inode.i_private pointer will point to this value on |
| 468 | * the open() call. |
| 469 | * @fops: a pointer to a struct file_operations that should be used for |
| 470 | * this file. |
| 471 | * |
| 472 | * debugfs_create_file_unsafe() is completely analogous to |
| 473 | * debugfs_create_file(), the only difference being that the fops |
| 474 | * handed it will not get protected against file removals by the |
| 475 | * debugfs core. |
| 476 | * |
| 477 | * It is your responsibility to protect your struct file_operation |
Sergey Senozhatsky | 0eeb273 | 2018-12-30 12:46:52 +0900 | [diff] [blame] | 478 | * methods against file removals by means of debugfs_file_get() |
| 479 | * and debugfs_file_put(). ->open() is still protected by |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 480 | * debugfs though. |
| 481 | * |
| 482 | * Any struct file_operations defined by means of |
| 483 | * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and |
| 484 | * thus, may be used here. |
| 485 | */ |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 486 | struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, |
| 487 | struct dentry *parent, void *data, |
| 488 | const struct file_operations *fops) |
| 489 | { |
| 490 | |
| 491 | return __debugfs_create_file(name, mode, parent, data, |
| 492 | fops ? &debugfs_open_proxy_file_operations : |
| 493 | &debugfs_noop_file_operations, |
| 494 | fops); |
| 495 | } |
Nicolai Stange | c646880 | 2016-03-22 14:11:15 +0100 | [diff] [blame] | 496 | EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe); |
Nicolai Stange | 49d200d | 2016-03-22 14:11:14 +0100 | [diff] [blame] | 497 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | /** |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 499 | * debugfs_create_file_size - create a file in the debugfs filesystem |
| 500 | * @name: a pointer to a string containing the name of the file to create. |
| 501 | * @mode: the permission that the file should have. |
| 502 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 503 | * directory dentry if set. If this parameter is NULL, then the |
| 504 | * file will be created in the root of the debugfs filesystem. |
| 505 | * @data: a pointer to something that the caller will want to get to later |
| 506 | * on. The inode.i_private pointer will point to this value on |
| 507 | * the open() call. |
| 508 | * @fops: a pointer to a struct file_operations that should be used for |
| 509 | * this file. |
| 510 | * @file_size: initial file size |
| 511 | * |
| 512 | * This is the basic "create a file" function for debugfs. It allows for a |
| 513 | * wide range of flexibility in creating a file, or a directory (if you want |
| 514 | * to create a directory, the debugfs_create_dir() function is |
| 515 | * recommended to be used instead.) |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 516 | */ |
Greg Kroah-Hartman | 526ee72 | 2020-03-09 17:36:40 +0100 | [diff] [blame] | 517 | void debugfs_create_file_size(const char *name, umode_t mode, |
| 518 | struct dentry *parent, void *data, |
| 519 | const struct file_operations *fops, |
| 520 | loff_t file_size) |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 521 | { |
| 522 | struct dentry *de = debugfs_create_file(name, mode, parent, data, fops); |
| 523 | |
| 524 | if (de) |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 525 | d_inode(de)->i_size = file_size; |
David Howells | e59b4e9 | 2015-01-21 20:03:40 +0000 | [diff] [blame] | 526 | } |
| 527 | EXPORT_SYMBOL_GPL(debugfs_create_file_size); |
| 528 | |
| 529 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | * debugfs_create_dir - create a directory in the debugfs filesystem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | * @name: a pointer to a string containing the name of the directory to |
| 532 | * create. |
| 533 | * @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] | 534 | * directory dentry if set. If this parameter is NULL, then the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | * directory will be created in the root of the debugfs filesystem. |
| 536 | * |
| 537 | * This function creates a directory in debugfs with the given name. |
| 538 | * |
| 539 | * This function will return a pointer to a dentry if it succeeds. This |
| 540 | * pointer must be passed to the debugfs_remove() function when the file is |
| 541 | * 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] | 542 | * 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] | 543 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | * |
Randy Dunlap | 6468b3a | 2006-07-20 08:16:42 -0700 | [diff] [blame] | 545 | * 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] | 546 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | */ |
| 548 | struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) |
| 549 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 550 | struct dentry *dentry = start_creating(name, parent); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 551 | struct inode *inode; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 552 | |
| 553 | if (IS_ERR(dentry)) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 554 | return dentry; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 555 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 556 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) { |
| 557 | failed_creating(dentry); |
| 558 | return ERR_PTR(-EPERM); |
| 559 | } |
| 560 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 561 | inode = debugfs_get_inode(dentry->d_sb); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 562 | if (unlikely(!inode)) { |
| 563 | pr_err("out of free dentries, can not create directory '%s'\n", |
| 564 | name); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 565 | return failed_creating(dentry); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 566 | } |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 567 | |
Linus Torvalds | f5b7769e | 2018-06-12 20:52:16 -0700 | [diff] [blame] | 568 | inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 569 | inode->i_op = &debugfs_dir_inode_operations; |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 570 | inode->i_fop = &simple_dir_operations; |
| 571 | |
| 572 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 573 | inc_nlink(inode); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 574 | d_instantiate(dentry, inode); |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 575 | inc_nlink(d_inode(dentry->d_parent)); |
| 576 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 577 | return end_creating(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | } |
| 579 | EXPORT_SYMBOL_GPL(debugfs_create_dir); |
| 580 | |
| 581 | /** |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 582 | * debugfs_create_automount - create automount point in the debugfs filesystem |
| 583 | * @name: a pointer to a string containing the name of the file to create. |
| 584 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 585 | * directory dentry if set. If this parameter is NULL, then the |
| 586 | * file will be created in the root of the debugfs filesystem. |
| 587 | * @f: function to be called when pathname resolution steps on that one. |
| 588 | * @data: opaque argument to pass to f(). |
| 589 | * |
| 590 | * @f should return what ->d_automount() would. |
| 591 | */ |
| 592 | struct dentry *debugfs_create_automount(const char *name, |
| 593 | struct dentry *parent, |
Eric W. Biederman | 93faccbb | 2017-02-01 06:06:16 +1300 | [diff] [blame] | 594 | debugfs_automount_t f, |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 595 | void *data) |
| 596 | { |
| 597 | struct dentry *dentry = start_creating(name, parent); |
| 598 | struct inode *inode; |
| 599 | |
| 600 | if (IS_ERR(dentry)) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 601 | return dentry; |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 602 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 603 | if (!(debugfs_allow & DEBUGFS_ALLOW_API)) { |
| 604 | failed_creating(dentry); |
| 605 | return ERR_PTR(-EPERM); |
| 606 | } |
| 607 | |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 608 | inode = debugfs_get_inode(dentry->d_sb); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 609 | if (unlikely(!inode)) { |
| 610 | pr_err("out of free dentries, can not create automount '%s'\n", |
| 611 | name); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 612 | return failed_creating(dentry); |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 613 | } |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 614 | |
Seth Forshee | 87243de | 2016-03-09 09:18:07 -0600 | [diff] [blame] | 615 | make_empty_dir_inode(inode); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 616 | inode->i_flags |= S_AUTOMOUNT; |
| 617 | inode->i_private = data; |
| 618 | dentry->d_fsdata = (void *)f; |
Roman Pen | a8f324a | 2016-02-09 11:30:29 +0100 | [diff] [blame] | 619 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
| 620 | inc_nlink(inode); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 621 | d_instantiate(dentry, inode); |
Roman Pen | a8f324a | 2016-02-09 11:30:29 +0100 | [diff] [blame] | 622 | inc_nlink(d_inode(dentry->d_parent)); |
| 623 | fsnotify_mkdir(d_inode(dentry->d_parent), dentry); |
Al Viro | 77b3da6 | 2015-01-25 15:10:32 -0500 | [diff] [blame] | 624 | return end_creating(dentry); |
| 625 | } |
| 626 | EXPORT_SYMBOL(debugfs_create_automount); |
| 627 | |
| 628 | /** |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 629 | * debugfs_create_symlink- create a symbolic link in the debugfs filesystem |
| 630 | * @name: a pointer to a string containing the name of the symbolic link to |
| 631 | * create. |
| 632 | * @parent: a pointer to the parent dentry for this symbolic link. This |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 633 | * should be a directory dentry if set. If this parameter is NULL, |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 634 | * then the symbolic link will be created in the root of the debugfs |
| 635 | * filesystem. |
| 636 | * @target: a pointer to a string containing the path to the target of the |
| 637 | * symbolic link. |
| 638 | * |
| 639 | * This function creates a symbolic link with the given name in debugfs that |
| 640 | * links to the given target path. |
| 641 | * |
| 642 | * This function will return a pointer to a dentry if it succeeds. This |
| 643 | * pointer must be passed to the debugfs_remove() function when the symbolic |
| 644 | * 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] | 645 | * 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] | 646 | * will be returned. |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 647 | * |
| 648 | * 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] | 649 | * returned. |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 650 | */ |
| 651 | struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, |
| 652 | const char *target) |
| 653 | { |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 654 | struct dentry *dentry; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 655 | struct inode *inode; |
| 656 | char *link = kstrdup(target, GFP_KERNEL); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 657 | if (!link) |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 658 | return ERR_PTR(-ENOMEM); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 659 | |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 660 | dentry = start_creating(name, parent); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 661 | if (IS_ERR(dentry)) { |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 662 | kfree(link); |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 663 | return dentry; |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 664 | } |
| 665 | |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 666 | inode = debugfs_get_inode(dentry->d_sb); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 667 | if (unlikely(!inode)) { |
Greg Kroah-Hartman | 43e23b6 | 2019-07-03 09:16:53 +0200 | [diff] [blame] | 668 | pr_err("out of free dentries, can not create symlink '%s'\n", |
| 669 | name); |
Al Viro | ad5abd5 | 2015-01-25 14:02:31 -0500 | [diff] [blame] | 670 | kfree(link); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 671 | return failed_creating(dentry); |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 672 | } |
Al Viro | edac65ea | 2015-01-25 14:36:18 -0500 | [diff] [blame] | 673 | inode->i_mode = S_IFLNK | S_IRWXUGO; |
David Howells | 5496197 | 2019-08-19 17:18:02 -0700 | [diff] [blame] | 674 | inode->i_op = &debugfs_symlink_inode_operations; |
Al Viro | 5723cb0 | 2015-05-02 10:27:18 -0400 | [diff] [blame] | 675 | inode->i_link = link; |
Al Viro | 680b302 | 2015-01-25 14:31:32 -0500 | [diff] [blame] | 676 | d_instantiate(dentry, inode); |
Al Viro | 5233e31 | 2015-01-25 14:39:49 -0500 | [diff] [blame] | 677 | return end_creating(dentry); |
Peter Oberparleiter | 66f5496 | 2007-02-13 12:13:54 +0100 | [diff] [blame] | 678 | } |
| 679 | EXPORT_SYMBOL_GPL(debugfs_create_symlink); |
| 680 | |
Amir Goldstein | 823e545 | 2019-05-26 17:34:07 +0300 | [diff] [blame] | 681 | static void __debugfs_file_removed(struct dentry *dentry) |
Nicolai Stange | e9117a5 | 2017-10-31 00:15:48 +0100 | [diff] [blame] | 682 | { |
| 683 | struct debugfs_fsdata *fsd; |
| 684 | |
Nicolai Stange | 7d39bc5 | 2017-10-31 00:15:54 +0100 | [diff] [blame] | 685 | /* |
| 686 | * Paired with the closing smp_mb() implied by a successful |
| 687 | * cmpxchg() in debugfs_file_get(): either |
| 688 | * debugfs_file_get() must see a dead dentry or we must see a |
| 689 | * debugfs_fsdata instance at ->d_fsdata here (or both). |
| 690 | */ |
| 691 | smp_mb(); |
| 692 | fsd = READ_ONCE(dentry->d_fsdata); |
| 693 | if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) |
| 694 | return; |
Nicolai Stange | e9117a5 | 2017-10-31 00:15:48 +0100 | [diff] [blame] | 695 | if (!refcount_dec_and_test(&fsd->active_users)) |
| 696 | wait_for_completion(&fsd->active_users_drained); |
| 697 | } |
| 698 | |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 699 | static void remove_one(struct dentry *victim) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | { |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 701 | if (d_is_reg(victim)) |
| 702 | __debugfs_file_removed(victim); |
| 703 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 704 | } |
| 705 | |
| 706 | /** |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 707 | * debugfs_remove - recursively removes a directory |
Ulf Magnusson | 398dc4a | 2015-09-07 19:03:15 +0200 | [diff] [blame] | 708 | * @dentry: a pointer to a the dentry of the directory to be removed. If this |
| 709 | * parameter is NULL or an error value, nothing will be done. |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 710 | * |
| 711 | * This function recursively removes a directory tree in debugfs that |
| 712 | * was previously created with a call to another debugfs function |
| 713 | * (like debugfs_create_file() or variants thereof.) |
| 714 | * |
| 715 | * This function is required to be called in order for the file to be |
| 716 | * removed, no automatic cleanup of files will happen when a module is |
| 717 | * removed, you are responsible here. |
| 718 | */ |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 719 | void debugfs_remove(struct dentry *dentry) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 720 | { |
Arend van Spriel | a59d629 | 2012-05-23 15:13:07 +0200 | [diff] [blame] | 721 | if (IS_ERR_OR_NULL(dentry)) |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 722 | return; |
| 723 | |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 724 | simple_pin_fs(&debug_fs_type, &debugfs_mount, &debugfs_mount_count); |
| 725 | simple_recursive_removal(dentry, remove_one); |
| 726 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 727 | } |
Al Viro | a3d1e7e | 2019-11-18 09:43:10 -0500 | [diff] [blame] | 728 | EXPORT_SYMBOL_GPL(debugfs_remove); |
Haavard Skinnemoen | 9505e63 | 2008-07-01 15:14:51 +0200 | [diff] [blame] | 729 | |
| 730 | /** |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 731 | * debugfs_rename - rename a file/directory in the debugfs filesystem |
| 732 | * @old_dir: a pointer to the parent dentry for the renamed object. This |
| 733 | * should be a directory dentry. |
| 734 | * @old_dentry: dentry of an object to be renamed. |
| 735 | * @new_dir: a pointer to the parent dentry where the object should be |
| 736 | * moved. This should be a directory dentry. |
| 737 | * @new_name: a pointer to a string containing the target name. |
| 738 | * |
| 739 | * This function renames a file/directory in debugfs. The target must not |
| 740 | * exist for rename to succeed. |
| 741 | * |
| 742 | * This function will return a pointer to old_dentry (which is updated to |
| 743 | * reflect renaming) if it succeeds. If an error occurs, %NULL will be |
| 744 | * returned. |
| 745 | * |
| 746 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 747 | * returned. |
| 748 | */ |
| 749 | struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, |
| 750 | struct dentry *new_dir, const char *new_name) |
| 751 | { |
| 752 | int error; |
| 753 | struct dentry *dentry = NULL, *trap; |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 754 | struct name_snapshot old_name; |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 755 | |
Greg Kroah-Hartman | d88c93f | 2019-01-23 11:27:02 +0100 | [diff] [blame] | 756 | if (IS_ERR(old_dir)) |
| 757 | return old_dir; |
| 758 | if (IS_ERR(new_dir)) |
| 759 | return new_dir; |
| 760 | if (IS_ERR_OR_NULL(old_dentry)) |
| 761 | return old_dentry; |
| 762 | |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 763 | trap = lock_rename(new_dir, old_dir); |
| 764 | /* Source or destination directories don't exist? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 765 | 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] | 766 | goto exit; |
| 767 | /* Source does not exist, cyclic rename, or mountpoint? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 768 | if (d_really_is_negative(old_dentry) || old_dentry == trap || |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 769 | d_mountpoint(old_dentry)) |
| 770 | goto exit; |
| 771 | dentry = lookup_one_len(new_name, new_dir, strlen(new_name)); |
| 772 | /* Lookup failed, cyclic rename or target exists? */ |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 773 | if (IS_ERR(dentry) || dentry == trap || d_really_is_positive(dentry)) |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 774 | goto exit; |
| 775 | |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 776 | take_dentry_name_snapshot(&old_name, old_dentry); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 777 | |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame] | 778 | error = simple_rename(d_inode(old_dir), old_dentry, d_inode(new_dir), |
Miklos Szeredi | e0e0be8 | 2016-09-27 11:03:57 +0200 | [diff] [blame] | 779 | dentry, 0); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 780 | if (error) { |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 781 | release_dentry_name_snapshot(&old_name); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 782 | goto exit; |
| 783 | } |
| 784 | d_move(old_dentry, dentry); |
Al Viro | f4ec3a3 | 2019-04-26 13:21:24 -0400 | [diff] [blame] | 785 | 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] | 786 | d_is_dir(old_dentry), |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 787 | NULL, old_dentry); |
Al Viro | 49d31c2 | 2017-07-07 14:51:19 -0400 | [diff] [blame] | 788 | release_dentry_name_snapshot(&old_name); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 789 | unlock_rename(new_dir, old_dir); |
| 790 | dput(dentry); |
| 791 | return old_dentry; |
| 792 | exit: |
| 793 | if (dentry && !IS_ERR(dentry)) |
| 794 | dput(dentry); |
| 795 | unlock_rename(new_dir, old_dir); |
Greg Kroah-Hartman | ff9fb72 | 2019-01-23 11:28:14 +0100 | [diff] [blame] | 796 | if (IS_ERR(dentry)) |
| 797 | return dentry; |
| 798 | return ERR_PTR(-EINVAL); |
Jan Kara | cfc94cd | 2007-05-09 13:19:52 +0200 | [diff] [blame] | 799 | } |
| 800 | EXPORT_SYMBOL_GPL(debugfs_rename); |
| 801 | |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 802 | /** |
| 803 | * debugfs_initialized - Tells whether debugfs has been registered |
| 804 | */ |
| 805 | bool debugfs_initialized(void) |
| 806 | { |
| 807 | return debugfs_registered; |
| 808 | } |
| 809 | EXPORT_SYMBOL_GPL(debugfs_initialized); |
| 810 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 811 | static int __init debugfs_kernel(char *str) |
| 812 | { |
| 813 | if (str) { |
| 814 | if (!strcmp(str, "on")) |
| 815 | debugfs_allow = DEBUGFS_ALLOW_API | DEBUGFS_ALLOW_MOUNT; |
| 816 | else if (!strcmp(str, "no-mount")) |
| 817 | debugfs_allow = DEBUGFS_ALLOW_API; |
| 818 | else if (!strcmp(str, "off")) |
| 819 | debugfs_allow = 0; |
| 820 | } |
| 821 | |
| 822 | return 0; |
| 823 | } |
| 824 | early_param("debugfs", debugfs_kernel); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | static int __init debugfs_init(void) |
| 826 | { |
| 827 | int retval; |
| 828 | |
Peter Enderborg | a24c6f7 | 2020-07-16 09:15:11 +0200 | [diff] [blame] | 829 | if (!(debugfs_allow & DEBUGFS_ALLOW_MOUNT)) |
| 830 | return -EPERM; |
| 831 | |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 832 | retval = sysfs_create_mount_point(kernel_kobj, "debug"); |
| 833 | if (retval) |
| 834 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | |
| 836 | retval = register_filesystem(&debug_fs_type); |
| 837 | if (retval) |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 838 | sysfs_remove_mount_point(kernel_kobj, "debug"); |
Frederic Weisbecker | c0f92ba | 2009-03-22 23:10:44 +0100 | [diff] [blame] | 839 | else |
| 840 | debugfs_registered = true; |
| 841 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | return retval; |
| 843 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | core_initcall(debugfs_init); |