]>
Commit | Line | Data |
---|---|---|
3ad20fe3 CB |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | ||
3 | #include <linux/compiler_types.h> | |
4 | #include <linux/errno.h> | |
5 | #include <linux/fs.h> | |
6 | #include <linux/fsnotify.h> | |
7 | #include <linux/gfp.h> | |
8 | #include <linux/idr.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/ipc_namespace.h> | |
11 | #include <linux/kdev_t.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/list.h> | |
01b3f1fc | 14 | #include <linux/namei.h> |
3ad20fe3 CB |
15 | #include <linux/magic.h> |
16 | #include <linux/major.h> | |
17 | #include <linux/miscdevice.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/mutex.h> | |
20 | #include <linux/mount.h> | |
21 | #include <linux/parser.h> | |
22 | #include <linux/radix-tree.h> | |
23 | #include <linux/sched.h> | |
849d540d | 24 | #include <linux/seq_file.h> |
3ad20fe3 CB |
25 | #include <linux/slab.h> |
26 | #include <linux/spinlock_types.h> | |
27 | #include <linux/stddef.h> | |
28 | #include <linux/string.h> | |
29 | #include <linux/types.h> | |
30 | #include <linux/uaccess.h> | |
31 | #include <linux/user_namespace.h> | |
32 | #include <linux/xarray.h> | |
33 | #include <uapi/asm-generic/errno-base.h> | |
34 | #include <uapi/linux/android/binder.h> | |
c13295ad | 35 | #include <uapi/linux/android/binderfs.h> |
3ad20fe3 CB |
36 | |
37 | #include "binder_internal.h" | |
38 | ||
39 | #define FIRST_INODE 1 | |
40 | #define SECOND_INODE 2 | |
41 | #define INODE_OFFSET 3 | |
42 | #define INTSTRLEN 21 | |
43 | #define BINDERFS_MAX_MINOR (1U << MINORBITS) | |
36bdf3ca CB |
44 | /* Ensure that the initial ipc namespace always has devices available. */ |
45 | #define BINDERFS_MAX_MINOR_CAPPED (BINDERFS_MAX_MINOR - 4) | |
3ad20fe3 | 46 | |
3ad20fe3 CB |
47 | static dev_t binderfs_dev; |
48 | static DEFINE_MUTEX(binderfs_minors_mutex); | |
49 | static DEFINE_IDA(binderfs_minors); | |
50 | ||
849d540d CB |
51 | /** |
52 | * binderfs_mount_opts - mount options for binderfs | |
53 | * @max: maximum number of allocatable binderfs binder devices | |
54 | */ | |
55 | struct binderfs_mount_opts { | |
56 | int max; | |
57 | }; | |
58 | ||
59 | enum { | |
60 | Opt_max, | |
61 | Opt_err | |
62 | }; | |
63 | ||
64 | static const match_table_t tokens = { | |
65 | { Opt_max, "max=%d" }, | |
66 | { Opt_err, NULL } | |
67 | }; | |
68 | ||
3ad20fe3 CB |
69 | /** |
70 | * binderfs_info - information about a binderfs mount | |
71 | * @ipc_ns: The ipc namespace the binderfs mount belongs to. | |
72 | * @control_dentry: This records the dentry of this binderfs mount | |
73 | * binder-control device. | |
74 | * @root_uid: uid that needs to be used when a new binder device is | |
75 | * created. | |
76 | * @root_gid: gid that needs to be used when a new binder device is | |
77 | * created. | |
849d540d CB |
78 | * @mount_opts: The mount options in use. |
79 | * @device_count: The current number of allocated binder devices. | |
3ad20fe3 CB |
80 | */ |
81 | struct binderfs_info { | |
82 | struct ipc_namespace *ipc_ns; | |
83 | struct dentry *control_dentry; | |
84 | kuid_t root_uid; | |
85 | kgid_t root_gid; | |
849d540d CB |
86 | struct binderfs_mount_opts mount_opts; |
87 | int device_count; | |
3ad20fe3 CB |
88 | }; |
89 | ||
90 | static inline struct binderfs_info *BINDERFS_I(const struct inode *inode) | |
91 | { | |
92 | return inode->i_sb->s_fs_info; | |
93 | } | |
94 | ||
95 | bool is_binderfs_device(const struct inode *inode) | |
96 | { | |
97 | if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC) | |
98 | return true; | |
99 | ||
100 | return false; | |
101 | } | |
102 | ||
103 | /** | |
104 | * binderfs_binder_device_create - allocate inode from super block of a | |
105 | * binderfs mount | |
106 | * @ref_inode: inode from wich the super block will be taken | |
107 | * @userp: buffer to copy information about new device for userspace to | |
108 | * @req: struct binderfs_device as copied from userspace | |
109 | * | |
01b3f1fc | 110 | * This function allocates a new binder_device and reserves a new minor |
3ad20fe3 CB |
111 | * number for it. |
112 | * Minor numbers are limited and tracked globally in binderfs_minors. The | |
113 | * function will stash a struct binder_device for the specific binder | |
114 | * device in i_private of the inode. | |
115 | * It will go on to allocate a new inode from the super block of the | |
116 | * filesystem mount, stash a struct binder_device in its i_private field | |
117 | * and attach a dentry to that inode. | |
118 | * | |
119 | * Return: 0 on success, negative errno on failure | |
120 | */ | |
121 | static int binderfs_binder_device_create(struct inode *ref_inode, | |
122 | struct binderfs_device __user *userp, | |
123 | struct binderfs_device *req) | |
124 | { | |
125 | int minor, ret; | |
01b3f1fc | 126 | struct dentry *dentry, *root; |
3ad20fe3 | 127 | struct binder_device *device; |
3ad20fe3 | 128 | char *name = NULL; |
01b3f1fc | 129 | size_t name_len; |
3ad20fe3 CB |
130 | struct inode *inode = NULL; |
131 | struct super_block *sb = ref_inode->i_sb; | |
132 | struct binderfs_info *info = sb->s_fs_info; | |
7fefaadd | 133 | #if defined(CONFIG_IPC_NS) |
36bdf3ca | 134 | bool use_reserve = (info->ipc_ns == &init_ipc_ns); |
7fefaadd CB |
135 | #else |
136 | bool use_reserve = true; | |
137 | #endif | |
3ad20fe3 CB |
138 | |
139 | /* Reserve new minor number for the new device. */ | |
140 | mutex_lock(&binderfs_minors_mutex); | |
849d540d | 141 | if (++info->device_count <= info->mount_opts.max) |
36bdf3ca CB |
142 | minor = ida_alloc_max(&binderfs_minors, |
143 | use_reserve ? BINDERFS_MAX_MINOR : | |
144 | BINDERFS_MAX_MINOR_CAPPED, | |
849d540d CB |
145 | GFP_KERNEL); |
146 | else | |
147 | minor = -ENOSPC; | |
148 | if (minor < 0) { | |
149 | --info->device_count; | |
150 | mutex_unlock(&binderfs_minors_mutex); | |
3ad20fe3 | 151 | return minor; |
849d540d CB |
152 | } |
153 | mutex_unlock(&binderfs_minors_mutex); | |
3ad20fe3 CB |
154 | |
155 | ret = -ENOMEM; | |
156 | device = kzalloc(sizeof(*device), GFP_KERNEL); | |
157 | if (!device) | |
158 | goto err; | |
159 | ||
160 | inode = new_inode(sb); | |
161 | if (!inode) | |
162 | goto err; | |
163 | ||
164 | inode->i_ino = minor + INODE_OFFSET; | |
165 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); | |
166 | init_special_inode(inode, S_IFCHR | 0600, | |
167 | MKDEV(MAJOR(binderfs_dev), minor)); | |
168 | inode->i_fop = &binder_fops; | |
169 | inode->i_uid = info->root_uid; | |
170 | inode->i_gid = info->root_gid; | |
171 | ||
01b3f1fc CB |
172 | req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */ |
173 | name_len = strlen(req->name); | |
174 | /* Make sure to include terminating NUL byte */ | |
175 | name = kmemdup(req->name, name_len + 1, GFP_KERNEL); | |
3ad20fe3 CB |
176 | if (!name) |
177 | goto err; | |
178 | ||
3ad20fe3 CB |
179 | device->binderfs_inode = inode; |
180 | device->context.binder_context_mgr_uid = INVALID_UID; | |
181 | device->context.name = name; | |
182 | device->miscdev.name = name; | |
183 | device->miscdev.minor = minor; | |
184 | mutex_init(&device->context.context_mgr_node_lock); | |
185 | ||
186 | req->major = MAJOR(binderfs_dev); | |
187 | req->minor = minor; | |
188 | ||
189 | ret = copy_to_user(userp, req, sizeof(*req)); | |
190 | if (ret) { | |
191 | ret = -EFAULT; | |
192 | goto err; | |
193 | } | |
194 | ||
195 | root = sb->s_root; | |
196 | inode_lock(d_inode(root)); | |
01b3f1fc CB |
197 | |
198 | /* look it up */ | |
199 | dentry = lookup_one_len(name, root, name_len); | |
200 | if (IS_ERR(dentry)) { | |
3ad20fe3 | 201 | inode_unlock(d_inode(root)); |
01b3f1fc | 202 | ret = PTR_ERR(dentry); |
3ad20fe3 CB |
203 | goto err; |
204 | } | |
205 | ||
01b3f1fc CB |
206 | if (d_really_is_positive(dentry)) { |
207 | /* already exists */ | |
208 | dput(dentry); | |
209 | inode_unlock(d_inode(root)); | |
210 | ret = -EEXIST; | |
211 | goto err; | |
3ad20fe3 CB |
212 | } |
213 | ||
214 | inode->i_private = device; | |
01684db9 | 215 | d_instantiate(dentry, inode); |
3ad20fe3 CB |
216 | fsnotify_create(root->d_inode, dentry); |
217 | inode_unlock(d_inode(root)); | |
218 | ||
219 | return 0; | |
220 | ||
221 | err: | |
222 | kfree(name); | |
223 | kfree(device); | |
224 | mutex_lock(&binderfs_minors_mutex); | |
849d540d | 225 | --info->device_count; |
3ad20fe3 CB |
226 | ida_free(&binderfs_minors, minor); |
227 | mutex_unlock(&binderfs_minors_mutex); | |
228 | iput(inode); | |
229 | ||
230 | return ret; | |
231 | } | |
232 | ||
233 | /** | |
234 | * binderfs_ctl_ioctl - handle binder device node allocation requests | |
235 | * | |
236 | * The request handler for the binder-control device. All requests operate on | |
237 | * the binderfs mount the binder-control device resides in: | |
238 | * - BINDER_CTL_ADD | |
239 | * Allocate a new binder device. | |
240 | * | |
241 | * Return: 0 on success, negative errno on failure | |
242 | */ | |
243 | static long binder_ctl_ioctl(struct file *file, unsigned int cmd, | |
244 | unsigned long arg) | |
245 | { | |
246 | int ret = -EINVAL; | |
247 | struct inode *inode = file_inode(file); | |
248 | struct binderfs_device __user *device = (struct binderfs_device __user *)arg; | |
249 | struct binderfs_device device_req; | |
250 | ||
251 | switch (cmd) { | |
252 | case BINDER_CTL_ADD: | |
253 | ret = copy_from_user(&device_req, device, sizeof(device_req)); | |
254 | if (ret) { | |
255 | ret = -EFAULT; | |
256 | break; | |
257 | } | |
258 | ||
259 | ret = binderfs_binder_device_create(inode, device, &device_req); | |
260 | break; | |
261 | default: | |
262 | break; | |
263 | } | |
264 | ||
265 | return ret; | |
266 | } | |
267 | ||
268 | static void binderfs_evict_inode(struct inode *inode) | |
269 | { | |
270 | struct binder_device *device = inode->i_private; | |
849d540d | 271 | struct binderfs_info *info = BINDERFS_I(inode); |
3ad20fe3 CB |
272 | |
273 | clear_inode(inode); | |
274 | ||
275 | if (!device) | |
276 | return; | |
277 | ||
278 | mutex_lock(&binderfs_minors_mutex); | |
849d540d | 279 | --info->device_count; |
3ad20fe3 CB |
280 | ida_free(&binderfs_minors, device->miscdev.minor); |
281 | mutex_unlock(&binderfs_minors_mutex); | |
282 | ||
283 | kfree(device->context.name); | |
284 | kfree(device); | |
285 | } | |
286 | ||
849d540d CB |
287 | /** |
288 | * binderfs_parse_mount_opts - parse binderfs mount options | |
289 | * @data: options to set (can be NULL in which case defaults are used) | |
290 | */ | |
291 | static int binderfs_parse_mount_opts(char *data, | |
292 | struct binderfs_mount_opts *opts) | |
293 | { | |
294 | char *p; | |
295 | opts->max = BINDERFS_MAX_MINOR; | |
296 | ||
297 | while ((p = strsep(&data, ",")) != NULL) { | |
298 | substring_t args[MAX_OPT_ARGS]; | |
299 | int token; | |
300 | int max_devices; | |
301 | ||
302 | if (!*p) | |
303 | continue; | |
304 | ||
305 | token = match_token(p, tokens, args); | |
306 | switch (token) { | |
307 | case Opt_max: | |
308 | if (match_int(&args[0], &max_devices) || | |
309 | (max_devices < 0 || | |
310 | (max_devices > BINDERFS_MAX_MINOR))) | |
311 | return -EINVAL; | |
312 | ||
313 | opts->max = max_devices; | |
314 | break; | |
315 | default: | |
316 | pr_err("Invalid mount options\n"); | |
317 | return -EINVAL; | |
318 | } | |
319 | } | |
320 | ||
321 | return 0; | |
322 | } | |
323 | ||
324 | static int binderfs_remount(struct super_block *sb, int *flags, char *data) | |
325 | { | |
326 | struct binderfs_info *info = sb->s_fs_info; | |
327 | return binderfs_parse_mount_opts(data, &info->mount_opts); | |
328 | } | |
329 | ||
330 | static int binderfs_show_mount_opts(struct seq_file *seq, struct dentry *root) | |
331 | { | |
332 | struct binderfs_info *info; | |
333 | ||
334 | info = root->d_sb->s_fs_info; | |
335 | if (info->mount_opts.max <= BINDERFS_MAX_MINOR) | |
336 | seq_printf(seq, ",max=%d", info->mount_opts.max); | |
337 | ||
338 | return 0; | |
339 | } | |
340 | ||
3ad20fe3 | 341 | static const struct super_operations binderfs_super_ops = { |
849d540d CB |
342 | .evict_inode = binderfs_evict_inode, |
343 | .remount_fs = binderfs_remount, | |
344 | .show_options = binderfs_show_mount_opts, | |
345 | .statfs = simple_statfs, | |
3ad20fe3 CB |
346 | }; |
347 | ||
e98e6fa1 CB |
348 | static inline bool is_binderfs_control_device(const struct dentry *dentry) |
349 | { | |
350 | struct binderfs_info *info = dentry->d_sb->s_fs_info; | |
351 | return info->control_dentry == dentry; | |
352 | } | |
353 | ||
3ad20fe3 CB |
354 | static int binderfs_rename(struct inode *old_dir, struct dentry *old_dentry, |
355 | struct inode *new_dir, struct dentry *new_dentry, | |
356 | unsigned int flags) | |
357 | { | |
e98e6fa1 CB |
358 | if (is_binderfs_control_device(old_dentry) || |
359 | is_binderfs_control_device(new_dentry)) | |
3ad20fe3 CB |
360 | return -EPERM; |
361 | ||
e98e6fa1 | 362 | return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); |
3ad20fe3 CB |
363 | } |
364 | ||
365 | static int binderfs_unlink(struct inode *dir, struct dentry *dentry) | |
366 | { | |
e98e6fa1 | 367 | if (is_binderfs_control_device(dentry)) |
3ad20fe3 CB |
368 | return -EPERM; |
369 | ||
370 | return simple_unlink(dir, dentry); | |
371 | } | |
372 | ||
373 | static const struct file_operations binder_ctl_fops = { | |
374 | .owner = THIS_MODULE, | |
375 | .open = nonseekable_open, | |
376 | .unlocked_ioctl = binder_ctl_ioctl, | |
377 | .compat_ioctl = binder_ctl_ioctl, | |
378 | .llseek = noop_llseek, | |
379 | }; | |
380 | ||
381 | /** | |
382 | * binderfs_binder_ctl_create - create a new binder-control device | |
383 | * @sb: super block of the binderfs mount | |
384 | * | |
385 | * This function creates a new binder-control device node in the binderfs mount | |
386 | * referred to by @sb. | |
387 | * | |
388 | * Return: 0 on success, negative errno on failure | |
389 | */ | |
390 | static int binderfs_binder_ctl_create(struct super_block *sb) | |
391 | { | |
392 | int minor, ret; | |
393 | struct dentry *dentry; | |
394 | struct binder_device *device; | |
395 | struct inode *inode = NULL; | |
396 | struct dentry *root = sb->s_root; | |
397 | struct binderfs_info *info = sb->s_fs_info; | |
da8ddba5 CB |
398 | #if defined(CONFIG_IPC_NS) |
399 | bool use_reserve = (info->ipc_ns == &init_ipc_ns); | |
400 | #else | |
401 | bool use_reserve = true; | |
402 | #endif | |
3ad20fe3 CB |
403 | |
404 | device = kzalloc(sizeof(*device), GFP_KERNEL); | |
405 | if (!device) | |
406 | return -ENOMEM; | |
407 | ||
3ad20fe3 CB |
408 | /* If we have already created a binder-control node, return. */ |
409 | if (info->control_dentry) { | |
410 | ret = 0; | |
411 | goto out; | |
412 | } | |
413 | ||
414 | ret = -ENOMEM; | |
415 | inode = new_inode(sb); | |
416 | if (!inode) | |
417 | goto out; | |
418 | ||
419 | /* Reserve a new minor number for the new device. */ | |
420 | mutex_lock(&binderfs_minors_mutex); | |
da8ddba5 CB |
421 | minor = ida_alloc_max(&binderfs_minors, |
422 | use_reserve ? BINDERFS_MAX_MINOR : | |
423 | BINDERFS_MAX_MINOR_CAPPED, | |
424 | GFP_KERNEL); | |
3ad20fe3 CB |
425 | mutex_unlock(&binderfs_minors_mutex); |
426 | if (minor < 0) { | |
427 | ret = minor; | |
428 | goto out; | |
429 | } | |
430 | ||
431 | inode->i_ino = SECOND_INODE; | |
432 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); | |
433 | init_special_inode(inode, S_IFCHR | 0600, | |
434 | MKDEV(MAJOR(binderfs_dev), minor)); | |
435 | inode->i_fop = &binder_ctl_fops; | |
436 | inode->i_uid = info->root_uid; | |
437 | inode->i_gid = info->root_gid; | |
438 | ||
439 | device->binderfs_inode = inode; | |
440 | device->miscdev.minor = minor; | |
441 | ||
442 | dentry = d_alloc_name(root, "binder-control"); | |
443 | if (!dentry) | |
444 | goto out; | |
445 | ||
446 | inode->i_private = device; | |
447 | info->control_dentry = dentry; | |
448 | d_add(dentry, inode); | |
3ad20fe3 CB |
449 | |
450 | return 0; | |
451 | ||
452 | out: | |
3ad20fe3 CB |
453 | kfree(device); |
454 | iput(inode); | |
455 | ||
456 | return ret; | |
457 | } | |
458 | ||
459 | static const struct inode_operations binderfs_dir_inode_operations = { | |
460 | .lookup = simple_lookup, | |
461 | .rename = binderfs_rename, | |
462 | .unlink = binderfs_unlink, | |
463 | }; | |
464 | ||
465 | static int binderfs_fill_super(struct super_block *sb, void *data, int silent) | |
466 | { | |
36975fc3 | 467 | int ret; |
3ad20fe3 | 468 | struct binderfs_info *info; |
3ad20fe3 | 469 | struct inode *inode = NULL; |
3ad20fe3 CB |
470 | |
471 | sb->s_blocksize = PAGE_SIZE; | |
472 | sb->s_blocksize_bits = PAGE_SHIFT; | |
473 | ||
474 | /* | |
475 | * The binderfs filesystem can be mounted by userns root in a | |
476 | * non-initial userns. By default such mounts have the SB_I_NODEV flag | |
477 | * set in s_iflags to prevent security issues where userns root can | |
478 | * just create random device nodes via mknod() since it owns the | |
479 | * filesystem mount. But binderfs does not allow to create any files | |
480 | * including devices nodes. The only way to create binder devices nodes | |
481 | * is through the binder-control device which userns root is explicitly | |
482 | * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both | |
483 | * necessary and safe. | |
484 | */ | |
485 | sb->s_iflags &= ~SB_I_NODEV; | |
486 | sb->s_iflags |= SB_I_NOEXEC; | |
487 | sb->s_magic = BINDERFS_SUPER_MAGIC; | |
488 | sb->s_op = &binderfs_super_ops; | |
489 | sb->s_time_gran = 1; | |
490 | ||
36975fc3 CB |
491 | sb->s_fs_info = kzalloc(sizeof(struct binderfs_info), GFP_KERNEL); |
492 | if (!sb->s_fs_info) | |
493 | return -ENOMEM; | |
494 | info = sb->s_fs_info; | |
495 | ||
496 | info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); | |
3ad20fe3 | 497 | |
849d540d CB |
498 | ret = binderfs_parse_mount_opts(data, &info->mount_opts); |
499 | if (ret) | |
36975fc3 | 500 | return ret; |
849d540d | 501 | |
3ad20fe3 CB |
502 | info->root_gid = make_kgid(sb->s_user_ns, 0); |
503 | if (!gid_valid(info->root_gid)) | |
504 | info->root_gid = GLOBAL_ROOT_GID; | |
505 | info->root_uid = make_kuid(sb->s_user_ns, 0); | |
506 | if (!uid_valid(info->root_uid)) | |
507 | info->root_uid = GLOBAL_ROOT_UID; | |
508 | ||
3ad20fe3 CB |
509 | inode = new_inode(sb); |
510 | if (!inode) | |
36975fc3 | 511 | return -ENOMEM; |
3ad20fe3 CB |
512 | |
513 | inode->i_ino = FIRST_INODE; | |
514 | inode->i_fop = &simple_dir_operations; | |
515 | inode->i_mode = S_IFDIR | 0755; | |
516 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); | |
517 | inode->i_op = &binderfs_dir_inode_operations; | |
518 | set_nlink(inode, 2); | |
519 | ||
520 | sb->s_root = d_make_root(inode); | |
521 | if (!sb->s_root) | |
36975fc3 | 522 | return -ENOMEM; |
3ad20fe3 | 523 | |
36975fc3 | 524 | return binderfs_binder_ctl_create(sb); |
3ad20fe3 CB |
525 | } |
526 | ||
3ad20fe3 CB |
527 | static struct dentry *binderfs_mount(struct file_system_type *fs_type, |
528 | int flags, const char *dev_name, | |
529 | void *data) | |
530 | { | |
b6c770d7 | 531 | return mount_nodev(fs_type, flags, data, binderfs_fill_super); |
3ad20fe3 CB |
532 | } |
533 | ||
534 | static void binderfs_kill_super(struct super_block *sb) | |
535 | { | |
536 | struct binderfs_info *info = sb->s_fs_info; | |
537 | ||
41984795 CB |
538 | kill_litter_super(sb); |
539 | ||
3ad20fe3 CB |
540 | if (info && info->ipc_ns) |
541 | put_ipc_ns(info->ipc_ns); | |
542 | ||
543 | kfree(info); | |
3ad20fe3 CB |
544 | } |
545 | ||
546 | static struct file_system_type binder_fs_type = { | |
547 | .name = "binder", | |
548 | .mount = binderfs_mount, | |
549 | .kill_sb = binderfs_kill_super, | |
550 | .fs_flags = FS_USERNS_MOUNT, | |
551 | }; | |
552 | ||
5b9633af | 553 | int __init init_binderfs(void) |
3ad20fe3 CB |
554 | { |
555 | int ret; | |
556 | ||
557 | /* Allocate new major number for binderfs. */ | |
558 | ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR, | |
559 | "binder"); | |
560 | if (ret) | |
561 | return ret; | |
562 | ||
563 | ret = register_filesystem(&binder_fs_type); | |
564 | if (ret) { | |
565 | unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR); | |
566 | return ret; | |
567 | } | |
568 | ||
3ad20fe3 CB |
569 | return ret; |
570 | } |