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d73f821c LR |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
3 | #include <linux/types.h> | |
4 | #include <linux/kconfig.h> | |
5 | #include <linux/list.h> | |
6 | #include <linux/slab.h> | |
7 | #include <linux/security.h> | |
8 | #include <linux/highmem.h> | |
9 | #include <linux/umh.h> | |
ceb18132 | 10 | #include <linux/sysctl.h> |
ccce305b | 11 | #include <linux/vmalloc.h> |
d73f821c | 12 | |
5d6d1ddd LR |
13 | #include "fallback.h" |
14 | #include "firmware.h" | |
d73f821c LR |
15 | |
16 | /* | |
17 | * firmware fallback mechanism | |
18 | */ | |
19 | ||
20 | extern struct firmware_fallback_config fw_fallback_config; | |
21 | ||
22 | /* These getters are vetted to use int properly */ | |
23 | static inline int __firmware_loading_timeout(void) | |
24 | { | |
25 | return fw_fallback_config.loading_timeout; | |
26 | } | |
27 | ||
28 | /* These setters are vetted to use int properly */ | |
29 | static void __fw_fallback_set_timeout(int timeout) | |
30 | { | |
31 | fw_fallback_config.loading_timeout = timeout; | |
32 | } | |
33 | ||
34 | /* | |
35 | * use small loading timeout for caching devices' firmware because all these | |
36 | * firmware images have been loaded successfully at lease once, also system is | |
37 | * ready for completing firmware loading now. The maximum size of firmware in | |
38 | * current distributions is about 2M bytes, so 10 secs should be enough. | |
39 | */ | |
40 | void fw_fallback_set_cache_timeout(void) | |
41 | { | |
42 | fw_fallback_config.old_timeout = __firmware_loading_timeout(); | |
43 | __fw_fallback_set_timeout(10); | |
44 | } | |
45 | ||
46 | /* Restores the timeout to the value last configured during normal operation */ | |
47 | void fw_fallback_set_default_timeout(void) | |
48 | { | |
49 | __fw_fallback_set_timeout(fw_fallback_config.old_timeout); | |
50 | } | |
51 | ||
52 | static long firmware_loading_timeout(void) | |
53 | { | |
54 | return __firmware_loading_timeout() > 0 ? | |
55 | __firmware_loading_timeout() * HZ : MAX_JIFFY_OFFSET; | |
56 | } | |
57 | ||
58 | static inline bool fw_sysfs_done(struct fw_priv *fw_priv) | |
59 | { | |
60 | return __fw_state_check(fw_priv, FW_STATUS_DONE); | |
61 | } | |
62 | ||
63 | static inline bool fw_sysfs_loading(struct fw_priv *fw_priv) | |
64 | { | |
65 | return __fw_state_check(fw_priv, FW_STATUS_LOADING); | |
66 | } | |
67 | ||
68 | static inline int fw_sysfs_wait_timeout(struct fw_priv *fw_priv, long timeout) | |
69 | { | |
70 | return __fw_state_wait_common(fw_priv, timeout); | |
71 | } | |
72 | ||
73 | struct fw_sysfs { | |
74 | bool nowait; | |
75 | struct device dev; | |
76 | struct fw_priv *fw_priv; | |
77 | struct firmware *fw; | |
78 | }; | |
79 | ||
80 | static struct fw_sysfs *to_fw_sysfs(struct device *dev) | |
81 | { | |
82 | return container_of(dev, struct fw_sysfs, dev); | |
83 | } | |
84 | ||
85 | static void __fw_load_abort(struct fw_priv *fw_priv) | |
86 | { | |
87 | /* | |
88 | * There is a small window in which user can write to 'loading' | |
89 | * between loading done and disappearance of 'loading' | |
90 | */ | |
91 | if (fw_sysfs_done(fw_priv)) | |
92 | return; | |
93 | ||
94 | list_del_init(&fw_priv->pending_list); | |
95 | fw_state_aborted(fw_priv); | |
96 | } | |
97 | ||
98 | static void fw_load_abort(struct fw_sysfs *fw_sysfs) | |
99 | { | |
100 | struct fw_priv *fw_priv = fw_sysfs->fw_priv; | |
101 | ||
102 | __fw_load_abort(fw_priv); | |
103 | } | |
104 | ||
105 | static LIST_HEAD(pending_fw_head); | |
106 | ||
107 | void kill_pending_fw_fallback_reqs(bool only_kill_custom) | |
108 | { | |
109 | struct fw_priv *fw_priv; | |
110 | struct fw_priv *next; | |
111 | ||
112 | mutex_lock(&fw_lock); | |
113 | list_for_each_entry_safe(fw_priv, next, &pending_fw_head, | |
114 | pending_list) { | |
115 | if (!fw_priv->need_uevent || !only_kill_custom) | |
116 | __fw_load_abort(fw_priv); | |
117 | } | |
118 | mutex_unlock(&fw_lock); | |
119 | } | |
120 | ||
121 | static ssize_t timeout_show(struct class *class, struct class_attribute *attr, | |
122 | char *buf) | |
123 | { | |
124 | return sprintf(buf, "%d\n", __firmware_loading_timeout()); | |
125 | } | |
126 | ||
127 | /** | |
c35f9cbb | 128 | * firmware_timeout_store() - set number of seconds to wait for firmware |
d73f821c LR |
129 | * @class: device class pointer |
130 | * @attr: device attribute pointer | |
131 | * @buf: buffer to scan for timeout value | |
132 | * @count: number of bytes in @buf | |
133 | * | |
134 | * Sets the number of seconds to wait for the firmware. Once | |
135 | * this expires an error will be returned to the driver and no | |
136 | * firmware will be provided. | |
137 | * | |
138 | * Note: zero means 'wait forever'. | |
139 | **/ | |
140 | static ssize_t timeout_store(struct class *class, struct class_attribute *attr, | |
141 | const char *buf, size_t count) | |
142 | { | |
143 | int tmp_loading_timeout = simple_strtol(buf, NULL, 10); | |
144 | ||
145 | if (tmp_loading_timeout < 0) | |
146 | tmp_loading_timeout = 0; | |
147 | ||
148 | __fw_fallback_set_timeout(tmp_loading_timeout); | |
149 | ||
150 | return count; | |
151 | } | |
152 | static CLASS_ATTR_RW(timeout); | |
153 | ||
154 | static struct attribute *firmware_class_attrs[] = { | |
155 | &class_attr_timeout.attr, | |
156 | NULL, | |
157 | }; | |
158 | ATTRIBUTE_GROUPS(firmware_class); | |
159 | ||
160 | static void fw_dev_release(struct device *dev) | |
161 | { | |
162 | struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev); | |
163 | ||
164 | kfree(fw_sysfs); | |
165 | } | |
166 | ||
167 | static int do_firmware_uevent(struct fw_sysfs *fw_sysfs, struct kobj_uevent_env *env) | |
168 | { | |
169 | if (add_uevent_var(env, "FIRMWARE=%s", fw_sysfs->fw_priv->fw_name)) | |
170 | return -ENOMEM; | |
171 | if (add_uevent_var(env, "TIMEOUT=%i", __firmware_loading_timeout())) | |
172 | return -ENOMEM; | |
173 | if (add_uevent_var(env, "ASYNC=%d", fw_sysfs->nowait)) | |
174 | return -ENOMEM; | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
179 | static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env) | |
180 | { | |
181 | struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev); | |
182 | int err = 0; | |
183 | ||
184 | mutex_lock(&fw_lock); | |
185 | if (fw_sysfs->fw_priv) | |
186 | err = do_firmware_uevent(fw_sysfs, env); | |
187 | mutex_unlock(&fw_lock); | |
188 | return err; | |
189 | } | |
190 | ||
191 | static struct class firmware_class = { | |
192 | .name = "firmware", | |
193 | .class_groups = firmware_class_groups, | |
194 | .dev_uevent = firmware_uevent, | |
195 | .dev_release = fw_dev_release, | |
196 | }; | |
197 | ||
198 | int register_sysfs_loader(void) | |
199 | { | |
200 | return class_register(&firmware_class); | |
201 | } | |
202 | ||
203 | void unregister_sysfs_loader(void) | |
204 | { | |
205 | class_unregister(&firmware_class); | |
206 | } | |
207 | ||
208 | static ssize_t firmware_loading_show(struct device *dev, | |
209 | struct device_attribute *attr, char *buf) | |
210 | { | |
211 | struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev); | |
212 | int loading = 0; | |
213 | ||
214 | mutex_lock(&fw_lock); | |
215 | if (fw_sysfs->fw_priv) | |
216 | loading = fw_sysfs_loading(fw_sysfs->fw_priv); | |
217 | mutex_unlock(&fw_lock); | |
218 | ||
219 | return sprintf(buf, "%d\n", loading); | |
220 | } | |
221 | ||
d73f821c | 222 | /** |
c35f9cbb | 223 | * firmware_loading_store() - set value in the 'loading' control file |
d73f821c LR |
224 | * @dev: device pointer |
225 | * @attr: device attribute pointer | |
226 | * @buf: buffer to scan for loading control value | |
227 | * @count: number of bytes in @buf | |
228 | * | |
229 | * The relevant values are: | |
230 | * | |
231 | * 1: Start a load, discarding any previous partial load. | |
232 | * 0: Conclude the load and hand the data to the driver code. | |
233 | * -1: Conclude the load with an error and discard any written data. | |
234 | **/ | |
235 | static ssize_t firmware_loading_store(struct device *dev, | |
236 | struct device_attribute *attr, | |
237 | const char *buf, size_t count) | |
238 | { | |
239 | struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev); | |
240 | struct fw_priv *fw_priv; | |
241 | ssize_t written = count; | |
242 | int loading = simple_strtol(buf, NULL, 10); | |
d73f821c LR |
243 | |
244 | mutex_lock(&fw_lock); | |
245 | fw_priv = fw_sysfs->fw_priv; | |
246 | if (fw_state_is_aborted(fw_priv)) | |
247 | goto out; | |
248 | ||
249 | switch (loading) { | |
250 | case 1: | |
251 | /* discarding any previous partial load */ | |
252 | if (!fw_sysfs_done(fw_priv)) { | |
8f58570b | 253 | fw_free_paged_buf(fw_priv); |
d73f821c LR |
254 | fw_state_start(fw_priv); |
255 | } | |
256 | break; | |
257 | case 0: | |
258 | if (fw_sysfs_loading(fw_priv)) { | |
259 | int rc; | |
260 | ||
261 | /* | |
262 | * Several loading requests may be pending on | |
263 | * one same firmware buf, so let all requests | |
264 | * see the mapped 'buf->data' once the loading | |
265 | * is completed. | |
266 | * */ | |
5342e709 | 267 | rc = fw_map_paged_buf(fw_priv); |
d73f821c LR |
268 | if (rc) |
269 | dev_err(dev, "%s: map pages failed\n", | |
270 | __func__); | |
271 | else | |
272 | rc = security_kernel_post_read_file(NULL, | |
273 | fw_priv->data, fw_priv->size, | |
274 | READING_FIRMWARE); | |
275 | ||
276 | /* | |
277 | * Same logic as fw_load_abort, only the DONE bit | |
278 | * is ignored and we set ABORT only on failure. | |
279 | */ | |
280 | list_del_init(&fw_priv->pending_list); | |
281 | if (rc) { | |
282 | fw_state_aborted(fw_priv); | |
283 | written = rc; | |
284 | } else { | |
285 | fw_state_done(fw_priv); | |
286 | } | |
287 | break; | |
288 | } | |
289 | /* fallthrough */ | |
290 | default: | |
291 | dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading); | |
292 | /* fallthrough */ | |
293 | case -1: | |
294 | fw_load_abort(fw_sysfs); | |
295 | break; | |
296 | } | |
297 | out: | |
298 | mutex_unlock(&fw_lock); | |
299 | return written; | |
300 | } | |
301 | ||
302 | static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store); | |
303 | ||
304 | static void firmware_rw_data(struct fw_priv *fw_priv, char *buffer, | |
305 | loff_t offset, size_t count, bool read) | |
306 | { | |
307 | if (read) | |
308 | memcpy(buffer, fw_priv->data + offset, count); | |
309 | else | |
310 | memcpy(fw_priv->data + offset, buffer, count); | |
311 | } | |
312 | ||
313 | static void firmware_rw(struct fw_priv *fw_priv, char *buffer, | |
314 | loff_t offset, size_t count, bool read) | |
315 | { | |
316 | while (count) { | |
317 | void *page_data; | |
318 | int page_nr = offset >> PAGE_SHIFT; | |
319 | int page_ofs = offset & (PAGE_SIZE-1); | |
320 | int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count); | |
321 | ||
322 | page_data = kmap(fw_priv->pages[page_nr]); | |
323 | ||
324 | if (read) | |
325 | memcpy(buffer, page_data + page_ofs, page_cnt); | |
326 | else | |
327 | memcpy(page_data + page_ofs, buffer, page_cnt); | |
328 | ||
329 | kunmap(fw_priv->pages[page_nr]); | |
330 | buffer += page_cnt; | |
331 | offset += page_cnt; | |
332 | count -= page_cnt; | |
333 | } | |
334 | } | |
335 | ||
336 | static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj, | |
337 | struct bin_attribute *bin_attr, | |
338 | char *buffer, loff_t offset, size_t count) | |
339 | { | |
340 | struct device *dev = kobj_to_dev(kobj); | |
341 | struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev); | |
342 | struct fw_priv *fw_priv; | |
343 | ssize_t ret_count; | |
344 | ||
345 | mutex_lock(&fw_lock); | |
346 | fw_priv = fw_sysfs->fw_priv; | |
347 | if (!fw_priv || fw_sysfs_done(fw_priv)) { | |
348 | ret_count = -ENODEV; | |
349 | goto out; | |
350 | } | |
351 | if (offset > fw_priv->size) { | |
352 | ret_count = 0; | |
353 | goto out; | |
354 | } | |
355 | if (count > fw_priv->size - offset) | |
356 | count = fw_priv->size - offset; | |
357 | ||
358 | ret_count = count; | |
359 | ||
360 | if (fw_priv->data) | |
361 | firmware_rw_data(fw_priv, buffer, offset, count, true); | |
362 | else | |
363 | firmware_rw(fw_priv, buffer, offset, count, true); | |
364 | ||
365 | out: | |
366 | mutex_unlock(&fw_lock); | |
367 | return ret_count; | |
368 | } | |
369 | ||
370 | static int fw_realloc_pages(struct fw_sysfs *fw_sysfs, int min_size) | |
371 | { | |
5342e709 | 372 | int err; |
d73f821c | 373 | |
5342e709 TI |
374 | err = fw_grow_paged_buf(fw_sysfs->fw_priv, |
375 | PAGE_ALIGN(min_size) >> PAGE_SHIFT); | |
376 | if (err) | |
377 | fw_load_abort(fw_sysfs); | |
378 | return err; | |
d73f821c LR |
379 | } |
380 | ||
381 | /** | |
c35f9cbb | 382 | * firmware_data_write() - write method for firmware |
d73f821c LR |
383 | * @filp: open sysfs file |
384 | * @kobj: kobject for the device | |
385 | * @bin_attr: bin_attr structure | |
386 | * @buffer: buffer being written | |
387 | * @offset: buffer offset for write in total data store area | |
388 | * @count: buffer size | |
389 | * | |
390 | * Data written to the 'data' attribute will be later handed to | |
391 | * the driver as a firmware image. | |
392 | **/ | |
393 | static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj, | |
394 | struct bin_attribute *bin_attr, | |
395 | char *buffer, loff_t offset, size_t count) | |
396 | { | |
397 | struct device *dev = kobj_to_dev(kobj); | |
398 | struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev); | |
399 | struct fw_priv *fw_priv; | |
400 | ssize_t retval; | |
401 | ||
402 | if (!capable(CAP_SYS_RAWIO)) | |
403 | return -EPERM; | |
404 | ||
405 | mutex_lock(&fw_lock); | |
406 | fw_priv = fw_sysfs->fw_priv; | |
407 | if (!fw_priv || fw_sysfs_done(fw_priv)) { | |
408 | retval = -ENODEV; | |
409 | goto out; | |
410 | } | |
411 | ||
412 | if (fw_priv->data) { | |
413 | if (offset + count > fw_priv->allocated_size) { | |
414 | retval = -ENOMEM; | |
415 | goto out; | |
416 | } | |
417 | firmware_rw_data(fw_priv, buffer, offset, count, false); | |
418 | retval = count; | |
419 | } else { | |
420 | retval = fw_realloc_pages(fw_sysfs, offset + count); | |
421 | if (retval) | |
422 | goto out; | |
423 | ||
424 | retval = count; | |
425 | firmware_rw(fw_priv, buffer, offset, count, false); | |
426 | } | |
427 | ||
428 | fw_priv->size = max_t(size_t, offset + count, fw_priv->size); | |
429 | out: | |
430 | mutex_unlock(&fw_lock); | |
431 | return retval; | |
432 | } | |
433 | ||
434 | static struct bin_attribute firmware_attr_data = { | |
435 | .attr = { .name = "data", .mode = 0644 }, | |
436 | .size = 0, | |
437 | .read = firmware_data_read, | |
438 | .write = firmware_data_write, | |
439 | }; | |
440 | ||
441 | static struct attribute *fw_dev_attrs[] = { | |
442 | &dev_attr_loading.attr, | |
443 | NULL | |
444 | }; | |
445 | ||
446 | static struct bin_attribute *fw_dev_bin_attrs[] = { | |
447 | &firmware_attr_data, | |
448 | NULL | |
449 | }; | |
450 | ||
451 | static const struct attribute_group fw_dev_attr_group = { | |
452 | .attrs = fw_dev_attrs, | |
453 | .bin_attrs = fw_dev_bin_attrs, | |
454 | }; | |
455 | ||
456 | static const struct attribute_group *fw_dev_attr_groups[] = { | |
457 | &fw_dev_attr_group, | |
458 | NULL | |
459 | }; | |
460 | ||
461 | static struct fw_sysfs * | |
462 | fw_create_instance(struct firmware *firmware, const char *fw_name, | |
eb33eb04 | 463 | struct device *device, enum fw_opt opt_flags) |
d73f821c LR |
464 | { |
465 | struct fw_sysfs *fw_sysfs; | |
466 | struct device *f_dev; | |
467 | ||
468 | fw_sysfs = kzalloc(sizeof(*fw_sysfs), GFP_KERNEL); | |
469 | if (!fw_sysfs) { | |
470 | fw_sysfs = ERR_PTR(-ENOMEM); | |
471 | goto exit; | |
472 | } | |
473 | ||
474 | fw_sysfs->nowait = !!(opt_flags & FW_OPT_NOWAIT); | |
475 | fw_sysfs->fw = firmware; | |
476 | f_dev = &fw_sysfs->dev; | |
477 | ||
478 | device_initialize(f_dev); | |
479 | dev_set_name(f_dev, "%s", fw_name); | |
480 | f_dev->parent = device; | |
481 | f_dev->class = &firmware_class; | |
482 | f_dev->groups = fw_dev_attr_groups; | |
483 | exit: | |
484 | return fw_sysfs; | |
485 | } | |
486 | ||
60fa7426 | 487 | /** |
c35f9cbb | 488 | * fw_load_sysfs_fallback() - load a firmware via the sysfs fallback mechanism |
b93815d0 | 489 | * @fw_sysfs: firmware sysfs information for the firmware to load |
60fa7426 LR |
490 | * @opt_flags: flags of options, FW_OPT_* |
491 | * @timeout: timeout to wait for the load | |
492 | * | |
493 | * In charge of constructing a sysfs fallback interface for firmware loading. | |
494 | **/ | |
495 | static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs, | |
eb33eb04 | 496 | enum fw_opt opt_flags, long timeout) |
d73f821c LR |
497 | { |
498 | int retval = 0; | |
499 | struct device *f_dev = &fw_sysfs->dev; | |
500 | struct fw_priv *fw_priv = fw_sysfs->fw_priv; | |
501 | ||
502 | /* fall back on userspace loading */ | |
503 | if (!fw_priv->data) | |
504 | fw_priv->is_paged_buf = true; | |
505 | ||
506 | dev_set_uevent_suppress(f_dev, true); | |
507 | ||
508 | retval = device_add(f_dev); | |
509 | if (retval) { | |
510 | dev_err(f_dev, "%s: device_register failed\n", __func__); | |
511 | goto err_put_dev; | |
512 | } | |
513 | ||
514 | mutex_lock(&fw_lock); | |
515 | list_add(&fw_priv->pending_list, &pending_fw_head); | |
516 | mutex_unlock(&fw_lock); | |
517 | ||
518 | if (opt_flags & FW_OPT_UEVENT) { | |
519 | fw_priv->need_uevent = true; | |
520 | dev_set_uevent_suppress(f_dev, false); | |
521 | dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_name); | |
522 | kobject_uevent(&fw_sysfs->dev.kobj, KOBJ_ADD); | |
523 | } else { | |
524 | timeout = MAX_JIFFY_OFFSET; | |
525 | } | |
526 | ||
527 | retval = fw_sysfs_wait_timeout(fw_priv, timeout); | |
528 | if (retval < 0) { | |
529 | mutex_lock(&fw_lock); | |
530 | fw_load_abort(fw_sysfs); | |
531 | mutex_unlock(&fw_lock); | |
532 | } | |
533 | ||
534 | if (fw_state_is_aborted(fw_priv)) { | |
535 | if (retval == -ERESTARTSYS) | |
536 | retval = -EINTR; | |
537 | else | |
538 | retval = -EAGAIN; | |
539 | } else if (fw_priv->is_paged_buf && !fw_priv->data) | |
540 | retval = -ENOMEM; | |
541 | ||
542 | device_del(f_dev); | |
543 | err_put_dev: | |
544 | put_device(f_dev); | |
545 | return retval; | |
546 | } | |
547 | ||
548 | static int fw_load_from_user_helper(struct firmware *firmware, | |
549 | const char *name, struct device *device, | |
eb33eb04 | 550 | enum fw_opt opt_flags) |
d73f821c LR |
551 | { |
552 | struct fw_sysfs *fw_sysfs; | |
553 | long timeout; | |
554 | int ret; | |
555 | ||
556 | timeout = firmware_loading_timeout(); | |
557 | if (opt_flags & FW_OPT_NOWAIT) { | |
558 | timeout = usermodehelper_read_lock_wait(timeout); | |
559 | if (!timeout) { | |
560 | dev_dbg(device, "firmware: %s loading timed out\n", | |
561 | name); | |
562 | return -EBUSY; | |
563 | } | |
564 | } else { | |
565 | ret = usermodehelper_read_trylock(); | |
566 | if (WARN_ON(ret)) { | |
567 | dev_err(device, "firmware: %s will not be loaded\n", | |
568 | name); | |
569 | return ret; | |
570 | } | |
571 | } | |
572 | ||
573 | fw_sysfs = fw_create_instance(firmware, name, device, opt_flags); | |
574 | if (IS_ERR(fw_sysfs)) { | |
575 | ret = PTR_ERR(fw_sysfs); | |
576 | goto out_unlock; | |
577 | } | |
578 | ||
579 | fw_sysfs->fw_priv = firmware->priv; | |
60fa7426 | 580 | ret = fw_load_sysfs_fallback(fw_sysfs, opt_flags, timeout); |
d73f821c LR |
581 | |
582 | if (!ret) | |
583 | ret = assign_fw(firmware, device, opt_flags); | |
584 | ||
585 | out_unlock: | |
586 | usermodehelper_read_unlock(); | |
587 | ||
588 | return ret; | |
589 | } | |
590 | ||
eb33eb04 | 591 | static bool fw_force_sysfs_fallback(enum fw_opt opt_flags) |
d73f821c LR |
592 | { |
593 | if (fw_fallback_config.force_sysfs_fallback) | |
594 | return true; | |
595 | if (!(opt_flags & FW_OPT_USERHELPER)) | |
596 | return false; | |
597 | return true; | |
598 | } | |
599 | ||
eb33eb04 | 600 | static bool fw_run_sysfs_fallback(enum fw_opt opt_flags) |
d73f821c | 601 | { |
6e852651 MZ |
602 | int ret; |
603 | ||
2cd7a1c6 | 604 | if (fw_fallback_config.ignore_sysfs_fallback) { |
c6263a48 | 605 | pr_info_once("Ignoring firmware sysfs fallback due to sysctl knob\n"); |
2cd7a1c6 LR |
606 | return false; |
607 | } | |
608 | ||
d73f821c LR |
609 | if ((opt_flags & FW_OPT_NOFALLBACK)) |
610 | return false; | |
611 | ||
6e852651 MZ |
612 | /* Also permit LSMs and IMA to fail firmware sysfs fallback */ |
613 | ret = security_kernel_load_data(LOADING_FIRMWARE); | |
614 | if (ret < 0) | |
2472d64a | 615 | return false; |
6e852651 | 616 | |
d73f821c LR |
617 | return fw_force_sysfs_fallback(opt_flags); |
618 | } | |
619 | ||
84b5c4fe LR |
620 | /** |
621 | * firmware_fallback_sysfs() - use the fallback mechanism to find firmware | |
622 | * @fw: pointer to firmware image | |
623 | * @name: name of firmware file to look for | |
624 | * @device: device for which firmware is being loaded | |
625 | * @opt_flags: options to control firmware loading behaviour | |
626 | * @ret: return value from direct lookup which triggered the fallback mechanism | |
627 | * | |
628 | * This function is called if direct lookup for the firmware failed, it enables | |
629 | * a fallback mechanism through userspace by exposing a sysfs loading | |
bbabc3fb JN |
630 | * interface. Userspace is in charge of loading the firmware through the sysfs |
631 | * loading interface. This sysfs fallback mechanism may be disabled completely | |
84b5c4fe LR |
632 | * on a system by setting the proc sysctl value ignore_sysfs_fallback to true. |
633 | * If this false we check if the internal API caller set the @FW_OPT_NOFALLBACK | |
634 | * flag, if so it would also disable the fallback mechanism. A system may want | |
635 | * to enfoce the sysfs fallback mechanism at all times, it can do this by | |
636 | * setting ignore_sysfs_fallback to false and force_sysfs_fallback to true. | |
637 | * Enabling force_sysfs_fallback is functionally equivalent to build a kernel | |
638 | * with CONFIG_FW_LOADER_USER_HELPER_FALLBACK. | |
639 | **/ | |
cf1cde7c AR |
640 | int firmware_fallback_sysfs(struct firmware *fw, const char *name, |
641 | struct device *device, | |
642 | enum fw_opt opt_flags, | |
643 | int ret) | |
d73f821c LR |
644 | { |
645 | if (!fw_run_sysfs_fallback(opt_flags)) | |
646 | return ret; | |
647 | ||
27d5d7dc | 648 | if (!(opt_flags & FW_OPT_NO_WARN)) |
bbabc3fb | 649 | dev_warn(device, "Falling back to sysfs fallback for: %s\n", |
27d5d7dc LR |
650 | name); |
651 | else | |
652 | dev_dbg(device, "Falling back to sysfs fallback for: %s\n", | |
653 | name); | |
d73f821c LR |
654 | return fw_load_from_user_helper(fw, name, device, opt_flags); |
655 | } |