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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 | |
f0083451 | 54 | * @stats_mode: enable binder stats in binderfs. |
849d540d CB |
55 | */ |
56 | struct binderfs_mount_opts { | |
57 | int max; | |
f0083451 | 58 | int stats_mode; |
849d540d CB |
59 | }; |
60 | ||
61 | enum { | |
62 | Opt_max, | |
f0083451 | 63 | Opt_stats_mode, |
849d540d CB |
64 | Opt_err |
65 | }; | |
66 | ||
f0083451 HV |
67 | enum binderfs_stats_mode { |
68 | STATS_NONE, | |
69 | STATS_GLOBAL, | |
70 | }; | |
71 | ||
849d540d CB |
72 | static const match_table_t tokens = { |
73 | { Opt_max, "max=%d" }, | |
f0083451 | 74 | { Opt_stats_mode, "stats=%s" }, |
849d540d CB |
75 | { Opt_err, NULL } |
76 | }; | |
77 | ||
3ad20fe3 CB |
78 | /** |
79 | * binderfs_info - information about a binderfs mount | |
80 | * @ipc_ns: The ipc namespace the binderfs mount belongs to. | |
81 | * @control_dentry: This records the dentry of this binderfs mount | |
82 | * binder-control device. | |
83 | * @root_uid: uid that needs to be used when a new binder device is | |
84 | * created. | |
85 | * @root_gid: gid that needs to be used when a new binder device is | |
86 | * created. | |
849d540d CB |
87 | * @mount_opts: The mount options in use. |
88 | * @device_count: The current number of allocated binder devices. | |
3ad20fe3 CB |
89 | */ |
90 | struct binderfs_info { | |
91 | struct ipc_namespace *ipc_ns; | |
92 | struct dentry *control_dentry; | |
93 | kuid_t root_uid; | |
94 | kgid_t root_gid; | |
849d540d CB |
95 | struct binderfs_mount_opts mount_opts; |
96 | int device_count; | |
3ad20fe3 CB |
97 | }; |
98 | ||
99 | static inline struct binderfs_info *BINDERFS_I(const struct inode *inode) | |
100 | { | |
101 | return inode->i_sb->s_fs_info; | |
102 | } | |
103 | ||
104 | bool is_binderfs_device(const struct inode *inode) | |
105 | { | |
106 | if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC) | |
107 | return true; | |
108 | ||
109 | return false; | |
110 | } | |
111 | ||
112 | /** | |
113 | * binderfs_binder_device_create - allocate inode from super block of a | |
114 | * binderfs mount | |
115 | * @ref_inode: inode from wich the super block will be taken | |
116 | * @userp: buffer to copy information about new device for userspace to | |
117 | * @req: struct binderfs_device as copied from userspace | |
118 | * | |
01b3f1fc | 119 | * This function allocates a new binder_device and reserves a new minor |
3ad20fe3 CB |
120 | * number for it. |
121 | * Minor numbers are limited and tracked globally in binderfs_minors. The | |
122 | * function will stash a struct binder_device for the specific binder | |
123 | * device in i_private of the inode. | |
124 | * It will go on to allocate a new inode from the super block of the | |
125 | * filesystem mount, stash a struct binder_device in its i_private field | |
126 | * and attach a dentry to that inode. | |
127 | * | |
128 | * Return: 0 on success, negative errno on failure | |
129 | */ | |
130 | static int binderfs_binder_device_create(struct inode *ref_inode, | |
131 | struct binderfs_device __user *userp, | |
132 | struct binderfs_device *req) | |
133 | { | |
134 | int minor, ret; | |
01b3f1fc | 135 | struct dentry *dentry, *root; |
3ad20fe3 | 136 | struct binder_device *device; |
3ad20fe3 | 137 | char *name = NULL; |
01b3f1fc | 138 | size_t name_len; |
3ad20fe3 CB |
139 | struct inode *inode = NULL; |
140 | struct super_block *sb = ref_inode->i_sb; | |
141 | struct binderfs_info *info = sb->s_fs_info; | |
7fefaadd | 142 | #if defined(CONFIG_IPC_NS) |
36bdf3ca | 143 | bool use_reserve = (info->ipc_ns == &init_ipc_ns); |
7fefaadd CB |
144 | #else |
145 | bool use_reserve = true; | |
146 | #endif | |
3ad20fe3 CB |
147 | |
148 | /* Reserve new minor number for the new device. */ | |
149 | mutex_lock(&binderfs_minors_mutex); | |
849d540d | 150 | if (++info->device_count <= info->mount_opts.max) |
36bdf3ca CB |
151 | minor = ida_alloc_max(&binderfs_minors, |
152 | use_reserve ? BINDERFS_MAX_MINOR : | |
153 | BINDERFS_MAX_MINOR_CAPPED, | |
849d540d CB |
154 | GFP_KERNEL); |
155 | else | |
156 | minor = -ENOSPC; | |
157 | if (minor < 0) { | |
158 | --info->device_count; | |
159 | mutex_unlock(&binderfs_minors_mutex); | |
3ad20fe3 | 160 | return minor; |
849d540d CB |
161 | } |
162 | mutex_unlock(&binderfs_minors_mutex); | |
3ad20fe3 CB |
163 | |
164 | ret = -ENOMEM; | |
165 | device = kzalloc(sizeof(*device), GFP_KERNEL); | |
166 | if (!device) | |
167 | goto err; | |
168 | ||
169 | inode = new_inode(sb); | |
170 | if (!inode) | |
171 | goto err; | |
172 | ||
173 | inode->i_ino = minor + INODE_OFFSET; | |
174 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); | |
175 | init_special_inode(inode, S_IFCHR | 0600, | |
176 | MKDEV(MAJOR(binderfs_dev), minor)); | |
177 | inode->i_fop = &binder_fops; | |
178 | inode->i_uid = info->root_uid; | |
179 | inode->i_gid = info->root_gid; | |
180 | ||
01b3f1fc CB |
181 | req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */ |
182 | name_len = strlen(req->name); | |
183 | /* Make sure to include terminating NUL byte */ | |
184 | name = kmemdup(req->name, name_len + 1, GFP_KERNEL); | |
3ad20fe3 CB |
185 | if (!name) |
186 | goto err; | |
187 | ||
3ad20fe3 CB |
188 | device->binderfs_inode = inode; |
189 | device->context.binder_context_mgr_uid = INVALID_UID; | |
190 | device->context.name = name; | |
191 | device->miscdev.name = name; | |
192 | device->miscdev.minor = minor; | |
193 | mutex_init(&device->context.context_mgr_node_lock); | |
194 | ||
195 | req->major = MAJOR(binderfs_dev); | |
196 | req->minor = minor; | |
197 | ||
ca2864c6 | 198 | if (userp && copy_to_user(userp, req, sizeof(*req))) { |
3ad20fe3 CB |
199 | ret = -EFAULT; |
200 | goto err; | |
201 | } | |
202 | ||
203 | root = sb->s_root; | |
204 | inode_lock(d_inode(root)); | |
01b3f1fc CB |
205 | |
206 | /* look it up */ | |
207 | dentry = lookup_one_len(name, root, name_len); | |
208 | if (IS_ERR(dentry)) { | |
3ad20fe3 | 209 | inode_unlock(d_inode(root)); |
01b3f1fc | 210 | ret = PTR_ERR(dentry); |
3ad20fe3 CB |
211 | goto err; |
212 | } | |
213 | ||
01b3f1fc CB |
214 | if (d_really_is_positive(dentry)) { |
215 | /* already exists */ | |
216 | dput(dentry); | |
217 | inode_unlock(d_inode(root)); | |
218 | ret = -EEXIST; | |
219 | goto err; | |
3ad20fe3 CB |
220 | } |
221 | ||
222 | inode->i_private = device; | |
01684db9 | 223 | d_instantiate(dentry, inode); |
3ad20fe3 CB |
224 | fsnotify_create(root->d_inode, dentry); |
225 | inode_unlock(d_inode(root)); | |
226 | ||
227 | return 0; | |
228 | ||
229 | err: | |
230 | kfree(name); | |
231 | kfree(device); | |
232 | mutex_lock(&binderfs_minors_mutex); | |
849d540d | 233 | --info->device_count; |
3ad20fe3 CB |
234 | ida_free(&binderfs_minors, minor); |
235 | mutex_unlock(&binderfs_minors_mutex); | |
236 | iput(inode); | |
237 | ||
238 | return ret; | |
239 | } | |
240 | ||
241 | /** | |
242 | * binderfs_ctl_ioctl - handle binder device node allocation requests | |
243 | * | |
244 | * The request handler for the binder-control device. All requests operate on | |
245 | * the binderfs mount the binder-control device resides in: | |
246 | * - BINDER_CTL_ADD | |
247 | * Allocate a new binder device. | |
248 | * | |
249 | * Return: 0 on success, negative errno on failure | |
250 | */ | |
251 | static long binder_ctl_ioctl(struct file *file, unsigned int cmd, | |
252 | unsigned long arg) | |
253 | { | |
254 | int ret = -EINVAL; | |
255 | struct inode *inode = file_inode(file); | |
256 | struct binderfs_device __user *device = (struct binderfs_device __user *)arg; | |
257 | struct binderfs_device device_req; | |
258 | ||
259 | switch (cmd) { | |
260 | case BINDER_CTL_ADD: | |
261 | ret = copy_from_user(&device_req, device, sizeof(device_req)); | |
262 | if (ret) { | |
263 | ret = -EFAULT; | |
264 | break; | |
265 | } | |
266 | ||
267 | ret = binderfs_binder_device_create(inode, device, &device_req); | |
268 | break; | |
269 | default: | |
270 | break; | |
271 | } | |
272 | ||
273 | return ret; | |
274 | } | |
275 | ||
276 | static void binderfs_evict_inode(struct inode *inode) | |
277 | { | |
278 | struct binder_device *device = inode->i_private; | |
849d540d | 279 | struct binderfs_info *info = BINDERFS_I(inode); |
3ad20fe3 CB |
280 | |
281 | clear_inode(inode); | |
282 | ||
283 | if (!device) | |
284 | return; | |
285 | ||
286 | mutex_lock(&binderfs_minors_mutex); | |
849d540d | 287 | --info->device_count; |
3ad20fe3 CB |
288 | ida_free(&binderfs_minors, device->miscdev.minor); |
289 | mutex_unlock(&binderfs_minors_mutex); | |
290 | ||
291 | kfree(device->context.name); | |
292 | kfree(device); | |
293 | } | |
294 | ||
849d540d CB |
295 | /** |
296 | * binderfs_parse_mount_opts - parse binderfs mount options | |
297 | * @data: options to set (can be NULL in which case defaults are used) | |
298 | */ | |
299 | static int binderfs_parse_mount_opts(char *data, | |
300 | struct binderfs_mount_opts *opts) | |
301 | { | |
f0083451 | 302 | char *p, *stats; |
849d540d | 303 | opts->max = BINDERFS_MAX_MINOR; |
f0083451 | 304 | opts->stats_mode = STATS_NONE; |
849d540d CB |
305 | |
306 | while ((p = strsep(&data, ",")) != NULL) { | |
307 | substring_t args[MAX_OPT_ARGS]; | |
308 | int token; | |
309 | int max_devices; | |
310 | ||
311 | if (!*p) | |
312 | continue; | |
313 | ||
314 | token = match_token(p, tokens, args); | |
315 | switch (token) { | |
316 | case Opt_max: | |
317 | if (match_int(&args[0], &max_devices) || | |
318 | (max_devices < 0 || | |
319 | (max_devices > BINDERFS_MAX_MINOR))) | |
320 | return -EINVAL; | |
321 | ||
322 | opts->max = max_devices; | |
323 | break; | |
f0083451 HV |
324 | case Opt_stats_mode: |
325 | if (!capable(CAP_SYS_ADMIN)) | |
326 | return -EINVAL; | |
327 | ||
328 | stats = match_strdup(&args[0]); | |
329 | if (!stats) | |
330 | return -ENOMEM; | |
331 | ||
332 | if (strcmp(stats, "global") != 0) { | |
333 | kfree(stats); | |
334 | return -EINVAL; | |
335 | } | |
336 | ||
337 | opts->stats_mode = STATS_GLOBAL; | |
338 | kfree(stats); | |
339 | break; | |
849d540d CB |
340 | default: |
341 | pr_err("Invalid mount options\n"); | |
342 | return -EINVAL; | |
343 | } | |
344 | } | |
345 | ||
346 | return 0; | |
347 | } | |
348 | ||
349 | static int binderfs_remount(struct super_block *sb, int *flags, char *data) | |
350 | { | |
f0083451 | 351 | int prev_stats_mode, ret; |
849d540d | 352 | struct binderfs_info *info = sb->s_fs_info; |
f0083451 HV |
353 | |
354 | prev_stats_mode = info->mount_opts.stats_mode; | |
355 | ret = binderfs_parse_mount_opts(data, &info->mount_opts); | |
356 | if (ret) | |
357 | return ret; | |
358 | ||
359 | if (prev_stats_mode != info->mount_opts.stats_mode) { | |
360 | pr_err("Binderfs stats mode cannot be changed during a remount\n"); | |
361 | info->mount_opts.stats_mode = prev_stats_mode; | |
362 | return -EINVAL; | |
363 | } | |
364 | ||
365 | return 0; | |
849d540d CB |
366 | } |
367 | ||
368 | static int binderfs_show_mount_opts(struct seq_file *seq, struct dentry *root) | |
369 | { | |
370 | struct binderfs_info *info; | |
371 | ||
372 | info = root->d_sb->s_fs_info; | |
373 | if (info->mount_opts.max <= BINDERFS_MAX_MINOR) | |
374 | seq_printf(seq, ",max=%d", info->mount_opts.max); | |
f0083451 HV |
375 | if (info->mount_opts.stats_mode == STATS_GLOBAL) |
376 | seq_printf(seq, ",stats=global"); | |
849d540d CB |
377 | |
378 | return 0; | |
379 | } | |
380 | ||
3ad20fe3 | 381 | static const struct super_operations binderfs_super_ops = { |
849d540d CB |
382 | .evict_inode = binderfs_evict_inode, |
383 | .remount_fs = binderfs_remount, | |
384 | .show_options = binderfs_show_mount_opts, | |
385 | .statfs = simple_statfs, | |
3ad20fe3 CB |
386 | }; |
387 | ||
e98e6fa1 CB |
388 | static inline bool is_binderfs_control_device(const struct dentry *dentry) |
389 | { | |
390 | struct binderfs_info *info = dentry->d_sb->s_fs_info; | |
391 | return info->control_dentry == dentry; | |
392 | } | |
393 | ||
3ad20fe3 CB |
394 | static int binderfs_rename(struct inode *old_dir, struct dentry *old_dentry, |
395 | struct inode *new_dir, struct dentry *new_dentry, | |
396 | unsigned int flags) | |
397 | { | |
e98e6fa1 CB |
398 | if (is_binderfs_control_device(old_dentry) || |
399 | is_binderfs_control_device(new_dentry)) | |
3ad20fe3 CB |
400 | return -EPERM; |
401 | ||
e98e6fa1 | 402 | return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); |
3ad20fe3 CB |
403 | } |
404 | ||
405 | static int binderfs_unlink(struct inode *dir, struct dentry *dentry) | |
406 | { | |
e98e6fa1 | 407 | if (is_binderfs_control_device(dentry)) |
3ad20fe3 CB |
408 | return -EPERM; |
409 | ||
410 | return simple_unlink(dir, dentry); | |
411 | } | |
412 | ||
413 | static const struct file_operations binder_ctl_fops = { | |
414 | .owner = THIS_MODULE, | |
415 | .open = nonseekable_open, | |
416 | .unlocked_ioctl = binder_ctl_ioctl, | |
417 | .compat_ioctl = binder_ctl_ioctl, | |
418 | .llseek = noop_llseek, | |
419 | }; | |
420 | ||
421 | /** | |
422 | * binderfs_binder_ctl_create - create a new binder-control device | |
423 | * @sb: super block of the binderfs mount | |
424 | * | |
425 | * This function creates a new binder-control device node in the binderfs mount | |
426 | * referred to by @sb. | |
427 | * | |
428 | * Return: 0 on success, negative errno on failure | |
429 | */ | |
430 | static int binderfs_binder_ctl_create(struct super_block *sb) | |
431 | { | |
432 | int minor, ret; | |
433 | struct dentry *dentry; | |
434 | struct binder_device *device; | |
435 | struct inode *inode = NULL; | |
436 | struct dentry *root = sb->s_root; | |
437 | struct binderfs_info *info = sb->s_fs_info; | |
da8ddba5 CB |
438 | #if defined(CONFIG_IPC_NS) |
439 | bool use_reserve = (info->ipc_ns == &init_ipc_ns); | |
440 | #else | |
441 | bool use_reserve = true; | |
442 | #endif | |
3ad20fe3 CB |
443 | |
444 | device = kzalloc(sizeof(*device), GFP_KERNEL); | |
445 | if (!device) | |
446 | return -ENOMEM; | |
447 | ||
3ad20fe3 CB |
448 | /* If we have already created a binder-control node, return. */ |
449 | if (info->control_dentry) { | |
450 | ret = 0; | |
451 | goto out; | |
452 | } | |
453 | ||
454 | ret = -ENOMEM; | |
455 | inode = new_inode(sb); | |
456 | if (!inode) | |
457 | goto out; | |
458 | ||
459 | /* Reserve a new minor number for the new device. */ | |
460 | mutex_lock(&binderfs_minors_mutex); | |
da8ddba5 CB |
461 | minor = ida_alloc_max(&binderfs_minors, |
462 | use_reserve ? BINDERFS_MAX_MINOR : | |
463 | BINDERFS_MAX_MINOR_CAPPED, | |
464 | GFP_KERNEL); | |
3ad20fe3 CB |
465 | mutex_unlock(&binderfs_minors_mutex); |
466 | if (minor < 0) { | |
467 | ret = minor; | |
468 | goto out; | |
469 | } | |
470 | ||
471 | inode->i_ino = SECOND_INODE; | |
472 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); | |
473 | init_special_inode(inode, S_IFCHR | 0600, | |
474 | MKDEV(MAJOR(binderfs_dev), minor)); | |
475 | inode->i_fop = &binder_ctl_fops; | |
476 | inode->i_uid = info->root_uid; | |
477 | inode->i_gid = info->root_gid; | |
478 | ||
479 | device->binderfs_inode = inode; | |
480 | device->miscdev.minor = minor; | |
481 | ||
482 | dentry = d_alloc_name(root, "binder-control"); | |
483 | if (!dentry) | |
484 | goto out; | |
485 | ||
486 | inode->i_private = device; | |
487 | info->control_dentry = dentry; | |
488 | d_add(dentry, inode); | |
3ad20fe3 CB |
489 | |
490 | return 0; | |
491 | ||
492 | out: | |
3ad20fe3 CB |
493 | kfree(device); |
494 | iput(inode); | |
495 | ||
496 | return ret; | |
497 | } | |
498 | ||
499 | static const struct inode_operations binderfs_dir_inode_operations = { | |
500 | .lookup = simple_lookup, | |
501 | .rename = binderfs_rename, | |
502 | .unlink = binderfs_unlink, | |
503 | }; | |
504 | ||
505 | static int binderfs_fill_super(struct super_block *sb, void *data, int silent) | |
506 | { | |
36975fc3 | 507 | int ret; |
3ad20fe3 | 508 | struct binderfs_info *info; |
3ad20fe3 | 509 | struct inode *inode = NULL; |
ca2864c6 HV |
510 | struct binderfs_device device_info = { 0 }; |
511 | const char *name; | |
512 | size_t len; | |
3ad20fe3 CB |
513 | |
514 | sb->s_blocksize = PAGE_SIZE; | |
515 | sb->s_blocksize_bits = PAGE_SHIFT; | |
516 | ||
517 | /* | |
518 | * The binderfs filesystem can be mounted by userns root in a | |
519 | * non-initial userns. By default such mounts have the SB_I_NODEV flag | |
520 | * set in s_iflags to prevent security issues where userns root can | |
521 | * just create random device nodes via mknod() since it owns the | |
522 | * filesystem mount. But binderfs does not allow to create any files | |
523 | * including devices nodes. The only way to create binder devices nodes | |
524 | * is through the binder-control device which userns root is explicitly | |
525 | * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both | |
526 | * necessary and safe. | |
527 | */ | |
528 | sb->s_iflags &= ~SB_I_NODEV; | |
529 | sb->s_iflags |= SB_I_NOEXEC; | |
530 | sb->s_magic = BINDERFS_SUPER_MAGIC; | |
531 | sb->s_op = &binderfs_super_ops; | |
532 | sb->s_time_gran = 1; | |
533 | ||
36975fc3 CB |
534 | sb->s_fs_info = kzalloc(sizeof(struct binderfs_info), GFP_KERNEL); |
535 | if (!sb->s_fs_info) | |
536 | return -ENOMEM; | |
537 | info = sb->s_fs_info; | |
538 | ||
539 | info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); | |
3ad20fe3 | 540 | |
849d540d CB |
541 | ret = binderfs_parse_mount_opts(data, &info->mount_opts); |
542 | if (ret) | |
36975fc3 | 543 | return ret; |
849d540d | 544 | |
3ad20fe3 CB |
545 | info->root_gid = make_kgid(sb->s_user_ns, 0); |
546 | if (!gid_valid(info->root_gid)) | |
547 | info->root_gid = GLOBAL_ROOT_GID; | |
548 | info->root_uid = make_kuid(sb->s_user_ns, 0); | |
549 | if (!uid_valid(info->root_uid)) | |
550 | info->root_uid = GLOBAL_ROOT_UID; | |
551 | ||
3ad20fe3 CB |
552 | inode = new_inode(sb); |
553 | if (!inode) | |
36975fc3 | 554 | return -ENOMEM; |
3ad20fe3 CB |
555 | |
556 | inode->i_ino = FIRST_INODE; | |
557 | inode->i_fop = &simple_dir_operations; | |
558 | inode->i_mode = S_IFDIR | 0755; | |
559 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); | |
560 | inode->i_op = &binderfs_dir_inode_operations; | |
561 | set_nlink(inode, 2); | |
562 | ||
563 | sb->s_root = d_make_root(inode); | |
564 | if (!sb->s_root) | |
36975fc3 | 565 | return -ENOMEM; |
3ad20fe3 | 566 | |
ca2864c6 HV |
567 | ret = binderfs_binder_ctl_create(sb); |
568 | if (ret) | |
569 | return ret; | |
570 | ||
571 | name = binder_devices_param; | |
572 | for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { | |
573 | strscpy(device_info.name, name, len + 1); | |
574 | ret = binderfs_binder_device_create(inode, NULL, &device_info); | |
575 | if (ret) | |
576 | return ret; | |
577 | name += len; | |
578 | if (*name == ',') | |
579 | name++; | |
580 | } | |
581 | ||
582 | return 0; | |
3ad20fe3 CB |
583 | } |
584 | ||
3ad20fe3 CB |
585 | static struct dentry *binderfs_mount(struct file_system_type *fs_type, |
586 | int flags, const char *dev_name, | |
587 | void *data) | |
588 | { | |
b6c770d7 | 589 | return mount_nodev(fs_type, flags, data, binderfs_fill_super); |
3ad20fe3 CB |
590 | } |
591 | ||
592 | static void binderfs_kill_super(struct super_block *sb) | |
593 | { | |
594 | struct binderfs_info *info = sb->s_fs_info; | |
595 | ||
41984795 CB |
596 | kill_litter_super(sb); |
597 | ||
3ad20fe3 CB |
598 | if (info && info->ipc_ns) |
599 | put_ipc_ns(info->ipc_ns); | |
600 | ||
601 | kfree(info); | |
3ad20fe3 CB |
602 | } |
603 | ||
604 | static struct file_system_type binder_fs_type = { | |
605 | .name = "binder", | |
606 | .mount = binderfs_mount, | |
607 | .kill_sb = binderfs_kill_super, | |
608 | .fs_flags = FS_USERNS_MOUNT, | |
609 | }; | |
610 | ||
5b9633af | 611 | int __init init_binderfs(void) |
3ad20fe3 CB |
612 | { |
613 | int ret; | |
028fb582 HV |
614 | const char *name; |
615 | size_t len; | |
616 | ||
617 | /* Verify that the default binderfs device names are valid. */ | |
618 | name = binder_devices_param; | |
619 | for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { | |
620 | if (len > BINDERFS_MAX_NAME) | |
621 | return -E2BIG; | |
622 | name += len; | |
623 | if (*name == ',') | |
624 | name++; | |
625 | } | |
3ad20fe3 CB |
626 | |
627 | /* Allocate new major number for binderfs. */ | |
628 | ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR, | |
629 | "binder"); | |
630 | if (ret) | |
631 | return ret; | |
632 | ||
633 | ret = register_filesystem(&binder_fs_type); | |
634 | if (ret) { | |
635 | unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR); | |
636 | return ret; | |
637 | } | |
638 | ||
3ad20fe3 CB |
639 | return ret; |
640 | } |