1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* Helpers for initial module or kernel cmdline parsing |
3 | Copyright (C) 2001 Rusty Russell. |
4 | |
5 | */ |
6 | #include <linux/kernel.h> |
7 | #include <linux/kstrtox.h> |
8 | #include <linux/string.h> |
9 | #include <linux/errno.h> |
10 | #include <linux/module.h> |
11 | #include <linux/moduleparam.h> |
12 | #include <linux/device.h> |
13 | #include <linux/err.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/ctype.h> |
16 | #include <linux/security.h> |
17 | |
18 | #ifdef CONFIG_SYSFS |
19 | /* Protects all built-in parameters, modules use their own param_lock */ |
20 | static DEFINE_MUTEX(param_lock); |
21 | |
22 | /* Use the module's mutex, or if built-in use the built-in mutex */ |
23 | #ifdef CONFIG_MODULES |
24 | #define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock) |
25 | #else |
26 | #define KPARAM_MUTEX(mod) (¶m_lock) |
27 | #endif |
28 | |
29 | static inline void check_kparam_locked(struct module *mod) |
30 | { |
31 | BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod))); |
32 | } |
33 | #else |
34 | static inline void check_kparam_locked(struct module *mod) |
35 | { |
36 | } |
37 | #endif /* !CONFIG_SYSFS */ |
38 | |
39 | /* This just allows us to keep track of which parameters are kmalloced. */ |
40 | struct kmalloced_param { |
41 | struct list_head list; |
42 | char val[]; |
43 | }; |
44 | static LIST_HEAD(kmalloced_params); |
45 | static DEFINE_SPINLOCK(kmalloced_params_lock); |
46 | |
47 | static void *kmalloc_parameter(unsigned int size) |
48 | { |
49 | struct kmalloced_param *p; |
50 | |
51 | p = kmalloc(size: sizeof(*p) + size, GFP_KERNEL); |
52 | if (!p) |
53 | return NULL; |
54 | |
55 | spin_lock(lock: &kmalloced_params_lock); |
56 | list_add(new: &p->list, head: &kmalloced_params); |
57 | spin_unlock(lock: &kmalloced_params_lock); |
58 | |
59 | return p->val; |
60 | } |
61 | |
62 | /* Does nothing if parameter wasn't kmalloced above. */ |
63 | static void maybe_kfree_parameter(void *param) |
64 | { |
65 | struct kmalloced_param *p; |
66 | |
67 | spin_lock(lock: &kmalloced_params_lock); |
68 | list_for_each_entry(p, &kmalloced_params, list) { |
69 | if (p->val == param) { |
70 | list_del(entry: &p->list); |
71 | kfree(objp: p); |
72 | break; |
73 | } |
74 | } |
75 | spin_unlock(lock: &kmalloced_params_lock); |
76 | } |
77 | |
78 | static char dash2underscore(char c) |
79 | { |
80 | if (c == '-') |
81 | return '_'; |
82 | return c; |
83 | } |
84 | |
85 | bool parameqn(const char *a, const char *b, size_t n) |
86 | { |
87 | size_t i; |
88 | |
89 | for (i = 0; i < n; i++) { |
90 | if (dash2underscore(c: a[i]) != dash2underscore(c: b[i])) |
91 | return false; |
92 | } |
93 | return true; |
94 | } |
95 | |
96 | bool parameq(const char *a, const char *b) |
97 | { |
98 | return parameqn(a, b, strlen(a)+1); |
99 | } |
100 | |
101 | static bool param_check_unsafe(const struct kernel_param *kp) |
102 | { |
103 | if (kp->flags & KERNEL_PARAM_FL_HWPARAM && |
104 | security_locked_down(what: LOCKDOWN_MODULE_PARAMETERS)) |
105 | return false; |
106 | |
107 | if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { |
108 | pr_notice("Setting dangerous option %s - tainting kernel\n" , |
109 | kp->name); |
110 | add_taint(TAINT_USER, LOCKDEP_STILL_OK); |
111 | } |
112 | |
113 | return true; |
114 | } |
115 | |
116 | static int parse_one(char *param, |
117 | char *val, |
118 | const char *doing, |
119 | const struct kernel_param *params, |
120 | unsigned num_params, |
121 | s16 min_level, |
122 | s16 max_level, |
123 | void *arg, |
124 | int (*handle_unknown)(char *param, char *val, |
125 | const char *doing, void *arg)) |
126 | { |
127 | unsigned int i; |
128 | int err; |
129 | |
130 | /* Find parameter */ |
131 | for (i = 0; i < num_params; i++) { |
132 | if (parameq(a: param, b: params[i].name)) { |
133 | if (params[i].level < min_level |
134 | || params[i].level > max_level) |
135 | return 0; |
136 | /* No one handled NULL, so do it here. */ |
137 | if (!val && |
138 | !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG)) |
139 | return -EINVAL; |
140 | pr_debug("handling %s with %p\n" , param, |
141 | params[i].ops->set); |
142 | kernel_param_lock(mod: params[i].mod); |
143 | if (param_check_unsafe(kp: ¶ms[i])) |
144 | err = params[i].ops->set(val, ¶ms[i]); |
145 | else |
146 | err = -EPERM; |
147 | kernel_param_unlock(mod: params[i].mod); |
148 | return err; |
149 | } |
150 | } |
151 | |
152 | if (handle_unknown) { |
153 | pr_debug("doing %s: %s='%s'\n" , doing, param, val); |
154 | return handle_unknown(param, val, doing, arg); |
155 | } |
156 | |
157 | pr_debug("Unknown argument '%s'\n" , param); |
158 | return -ENOENT; |
159 | } |
160 | |
161 | /* Args looks like "foo=bar,bar2 baz=fuz wiz". */ |
162 | char *parse_args(const char *doing, |
163 | char *args, |
164 | const struct kernel_param *params, |
165 | unsigned num, |
166 | s16 min_level, |
167 | s16 max_level, |
168 | void *arg, |
169 | int (*unknown)(char *param, char *val, |
170 | const char *doing, void *arg)) |
171 | { |
172 | char *param, *val, *err = NULL; |
173 | |
174 | /* Chew leading spaces */ |
175 | args = skip_spaces(args); |
176 | |
177 | if (*args) |
178 | pr_debug("doing %s, parsing ARGS: '%s'\n" , doing, args); |
179 | |
180 | while (*args) { |
181 | int ret; |
182 | int irq_was_disabled; |
183 | |
184 | args = next_arg(args, param: ¶m, val: &val); |
185 | /* Stop at -- */ |
186 | if (!val && strcmp(param, "--" ) == 0) |
187 | return err ?: args; |
188 | irq_was_disabled = irqs_disabled(); |
189 | ret = parse_one(param, val, doing, params, num_params: num, |
190 | min_level, max_level, arg, handle_unknown: unknown); |
191 | if (irq_was_disabled && !irqs_disabled()) |
192 | pr_warn("%s: option '%s' enabled irq's!\n" , |
193 | doing, param); |
194 | |
195 | switch (ret) { |
196 | case 0: |
197 | continue; |
198 | case -ENOENT: |
199 | pr_err("%s: Unknown parameter `%s'\n" , doing, param); |
200 | break; |
201 | case -ENOSPC: |
202 | pr_err("%s: `%s' too large for parameter `%s'\n" , |
203 | doing, val ?: "" , param); |
204 | break; |
205 | default: |
206 | pr_err("%s: `%s' invalid for parameter `%s'\n" , |
207 | doing, val ?: "" , param); |
208 | break; |
209 | } |
210 | |
211 | err = ERR_PTR(error: ret); |
212 | } |
213 | |
214 | return err; |
215 | } |
216 | |
217 | /* Lazy bastard, eh? */ |
218 | #define STANDARD_PARAM_DEF(name, type, format, strtolfn) \ |
219 | int param_set_##name(const char *val, const struct kernel_param *kp) \ |
220 | { \ |
221 | return strtolfn(val, 0, (type *)kp->arg); \ |
222 | } \ |
223 | int param_get_##name(char *buffer, const struct kernel_param *kp) \ |
224 | { \ |
225 | return scnprintf(buffer, PAGE_SIZE, format "\n", \ |
226 | *((type *)kp->arg)); \ |
227 | } \ |
228 | const struct kernel_param_ops param_ops_##name = { \ |
229 | .set = param_set_##name, \ |
230 | .get = param_get_##name, \ |
231 | }; \ |
232 | EXPORT_SYMBOL(param_set_##name); \ |
233 | EXPORT_SYMBOL(param_get_##name); \ |
234 | EXPORT_SYMBOL(param_ops_##name) |
235 | |
236 | |
237 | STANDARD_PARAM_DEF(byte, unsigned char, "%hhu" , kstrtou8); |
238 | STANDARD_PARAM_DEF(short, short, "%hi" , kstrtos16); |
239 | STANDARD_PARAM_DEF(ushort, unsigned short, "%hu" , kstrtou16); |
240 | STANDARD_PARAM_DEF(int, int, "%i" , kstrtoint); |
241 | STANDARD_PARAM_DEF(uint, unsigned int, "%u" , kstrtouint); |
242 | STANDARD_PARAM_DEF(long, long, "%li" , kstrtol); |
243 | STANDARD_PARAM_DEF(ulong, unsigned long, "%lu" , kstrtoul); |
244 | STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu" , kstrtoull); |
245 | STANDARD_PARAM_DEF(hexint, unsigned int, "%#08x" , kstrtouint); |
246 | |
247 | int param_set_uint_minmax(const char *val, const struct kernel_param *kp, |
248 | unsigned int min, unsigned int max) |
249 | { |
250 | unsigned int num; |
251 | int ret; |
252 | |
253 | if (!val) |
254 | return -EINVAL; |
255 | ret = kstrtouint(s: val, base: 0, res: &num); |
256 | if (ret) |
257 | return ret; |
258 | if (num < min || num > max) |
259 | return -EINVAL; |
260 | *((unsigned int *)kp->arg) = num; |
261 | return 0; |
262 | } |
263 | EXPORT_SYMBOL_GPL(param_set_uint_minmax); |
264 | |
265 | int param_set_charp(const char *val, const struct kernel_param *kp) |
266 | { |
267 | if (strlen(val) > 1024) { |
268 | pr_err("%s: string parameter too long\n" , kp->name); |
269 | return -ENOSPC; |
270 | } |
271 | |
272 | maybe_kfree_parameter(param: *(char **)kp->arg); |
273 | |
274 | /* This is a hack. We can't kmalloc in early boot, and we |
275 | * don't need to; this mangled commandline is preserved. */ |
276 | if (slab_is_available()) { |
277 | *(char **)kp->arg = kmalloc_parameter(strlen(val)+1); |
278 | if (!*(char **)kp->arg) |
279 | return -ENOMEM; |
280 | strcpy(p: *(char **)kp->arg, q: val); |
281 | } else |
282 | *(const char **)kp->arg = val; |
283 | |
284 | return 0; |
285 | } |
286 | EXPORT_SYMBOL(param_set_charp); |
287 | |
288 | int param_get_charp(char *buffer, const struct kernel_param *kp) |
289 | { |
290 | return scnprintf(buf: buffer, PAGE_SIZE, fmt: "%s\n" , *((char **)kp->arg)); |
291 | } |
292 | EXPORT_SYMBOL(param_get_charp); |
293 | |
294 | void param_free_charp(void *arg) |
295 | { |
296 | maybe_kfree_parameter(param: *((char **)arg)); |
297 | } |
298 | EXPORT_SYMBOL(param_free_charp); |
299 | |
300 | const struct kernel_param_ops param_ops_charp = { |
301 | .set = param_set_charp, |
302 | .get = param_get_charp, |
303 | .free = param_free_charp, |
304 | }; |
305 | EXPORT_SYMBOL(param_ops_charp); |
306 | |
307 | /* Actually could be a bool or an int, for historical reasons. */ |
308 | int param_set_bool(const char *val, const struct kernel_param *kp) |
309 | { |
310 | /* No equals means "set"... */ |
311 | if (!val) val = "1" ; |
312 | |
313 | /* One of =[yYnN01] */ |
314 | return kstrtobool(s: val, res: kp->arg); |
315 | } |
316 | EXPORT_SYMBOL(param_set_bool); |
317 | |
318 | int param_get_bool(char *buffer, const struct kernel_param *kp) |
319 | { |
320 | /* Y and N chosen as being relatively non-coder friendly */ |
321 | return sprintf(buf: buffer, fmt: "%c\n" , *(bool *)kp->arg ? 'Y' : 'N'); |
322 | } |
323 | EXPORT_SYMBOL(param_get_bool); |
324 | |
325 | const struct kernel_param_ops param_ops_bool = { |
326 | .flags = KERNEL_PARAM_OPS_FL_NOARG, |
327 | .set = param_set_bool, |
328 | .get = param_get_bool, |
329 | }; |
330 | EXPORT_SYMBOL(param_ops_bool); |
331 | |
332 | int param_set_bool_enable_only(const char *val, const struct kernel_param *kp) |
333 | { |
334 | int err; |
335 | bool new_value; |
336 | bool orig_value = *(bool *)kp->arg; |
337 | struct kernel_param dummy_kp = *kp; |
338 | |
339 | dummy_kp.arg = &new_value; |
340 | |
341 | err = param_set_bool(val, &dummy_kp); |
342 | if (err) |
343 | return err; |
344 | |
345 | /* Don't let them unset it once it's set! */ |
346 | if (!new_value && orig_value) |
347 | return -EROFS; |
348 | |
349 | if (new_value) |
350 | err = param_set_bool(val, kp); |
351 | |
352 | return err; |
353 | } |
354 | EXPORT_SYMBOL_GPL(param_set_bool_enable_only); |
355 | |
356 | const struct kernel_param_ops param_ops_bool_enable_only = { |
357 | .flags = KERNEL_PARAM_OPS_FL_NOARG, |
358 | .set = param_set_bool_enable_only, |
359 | .get = param_get_bool, |
360 | }; |
361 | EXPORT_SYMBOL_GPL(param_ops_bool_enable_only); |
362 | |
363 | /* This one must be bool. */ |
364 | int param_set_invbool(const char *val, const struct kernel_param *kp) |
365 | { |
366 | int ret; |
367 | bool boolval; |
368 | struct kernel_param dummy; |
369 | |
370 | dummy.arg = &boolval; |
371 | ret = param_set_bool(val, &dummy); |
372 | if (ret == 0) |
373 | *(bool *)kp->arg = !boolval; |
374 | return ret; |
375 | } |
376 | EXPORT_SYMBOL(param_set_invbool); |
377 | |
378 | int param_get_invbool(char *buffer, const struct kernel_param *kp) |
379 | { |
380 | return sprintf(buf: buffer, fmt: "%c\n" , (*(bool *)kp->arg) ? 'N' : 'Y'); |
381 | } |
382 | EXPORT_SYMBOL(param_get_invbool); |
383 | |
384 | const struct kernel_param_ops param_ops_invbool = { |
385 | .set = param_set_invbool, |
386 | .get = param_get_invbool, |
387 | }; |
388 | EXPORT_SYMBOL(param_ops_invbool); |
389 | |
390 | int param_set_bint(const char *val, const struct kernel_param *kp) |
391 | { |
392 | /* Match bool exactly, by re-using it. */ |
393 | struct kernel_param boolkp = *kp; |
394 | bool v; |
395 | int ret; |
396 | |
397 | boolkp.arg = &v; |
398 | |
399 | ret = param_set_bool(val, &boolkp); |
400 | if (ret == 0) |
401 | *(int *)kp->arg = v; |
402 | return ret; |
403 | } |
404 | EXPORT_SYMBOL(param_set_bint); |
405 | |
406 | const struct kernel_param_ops param_ops_bint = { |
407 | .flags = KERNEL_PARAM_OPS_FL_NOARG, |
408 | .set = param_set_bint, |
409 | .get = param_get_int, |
410 | }; |
411 | EXPORT_SYMBOL(param_ops_bint); |
412 | |
413 | /* We break the rule and mangle the string. */ |
414 | static int param_array(struct module *mod, |
415 | const char *name, |
416 | const char *val, |
417 | unsigned int min, unsigned int max, |
418 | void *elem, int elemsize, |
419 | int (*set)(const char *, const struct kernel_param *kp), |
420 | s16 level, |
421 | unsigned int *num) |
422 | { |
423 | int ret; |
424 | struct kernel_param kp; |
425 | char save; |
426 | |
427 | /* Get the name right for errors. */ |
428 | kp.name = name; |
429 | kp.arg = elem; |
430 | kp.level = level; |
431 | |
432 | *num = 0; |
433 | /* We expect a comma-separated list of values. */ |
434 | do { |
435 | int len; |
436 | |
437 | if (*num == max) { |
438 | pr_err("%s: can only take %i arguments\n" , name, max); |
439 | return -EINVAL; |
440 | } |
441 | len = strcspn(val, "," ); |
442 | |
443 | /* nul-terminate and parse */ |
444 | save = val[len]; |
445 | ((char *)val)[len] = '\0'; |
446 | check_kparam_locked(mod); |
447 | ret = set(val, &kp); |
448 | |
449 | if (ret != 0) |
450 | return ret; |
451 | kp.arg += elemsize; |
452 | val += len+1; |
453 | (*num)++; |
454 | } while (save == ','); |
455 | |
456 | if (*num < min) { |
457 | pr_err("%s: needs at least %i arguments\n" , name, min); |
458 | return -EINVAL; |
459 | } |
460 | return 0; |
461 | } |
462 | |
463 | static int param_array_set(const char *val, const struct kernel_param *kp) |
464 | { |
465 | const struct kparam_array *arr = kp->arr; |
466 | unsigned int temp_num; |
467 | |
468 | return param_array(mod: kp->mod, name: kp->name, val, min: 1, max: arr->max, elem: arr->elem, |
469 | elemsize: arr->elemsize, set: arr->ops->set, level: kp->level, |
470 | num: arr->num ?: &temp_num); |
471 | } |
472 | |
473 | static int param_array_get(char *buffer, const struct kernel_param *kp) |
474 | { |
475 | int i, off, ret; |
476 | const struct kparam_array *arr = kp->arr; |
477 | struct kernel_param p = *kp; |
478 | |
479 | for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { |
480 | /* Replace \n with comma */ |
481 | if (i) |
482 | buffer[off - 1] = ','; |
483 | p.arg = arr->elem + arr->elemsize * i; |
484 | check_kparam_locked(mod: p.mod); |
485 | ret = arr->ops->get(buffer + off, &p); |
486 | if (ret < 0) |
487 | return ret; |
488 | off += ret; |
489 | } |
490 | buffer[off] = '\0'; |
491 | return off; |
492 | } |
493 | |
494 | static void param_array_free(void *arg) |
495 | { |
496 | unsigned int i; |
497 | const struct kparam_array *arr = arg; |
498 | |
499 | if (arr->ops->free) |
500 | for (i = 0; i < (arr->num ? *arr->num : arr->max); i++) |
501 | arr->ops->free(arr->elem + arr->elemsize * i); |
502 | } |
503 | |
504 | const struct kernel_param_ops param_array_ops = { |
505 | .set = param_array_set, |
506 | .get = param_array_get, |
507 | .free = param_array_free, |
508 | }; |
509 | EXPORT_SYMBOL(param_array_ops); |
510 | |
511 | int param_set_copystring(const char *val, const struct kernel_param *kp) |
512 | { |
513 | const struct kparam_string *kps = kp->str; |
514 | |
515 | if (strlen(val)+1 > kps->maxlen) { |
516 | pr_err("%s: string doesn't fit in %u chars.\n" , |
517 | kp->name, kps->maxlen-1); |
518 | return -ENOSPC; |
519 | } |
520 | strcpy(p: kps->string, q: val); |
521 | return 0; |
522 | } |
523 | EXPORT_SYMBOL(param_set_copystring); |
524 | |
525 | int param_get_string(char *buffer, const struct kernel_param *kp) |
526 | { |
527 | const struct kparam_string *kps = kp->str; |
528 | return scnprintf(buf: buffer, PAGE_SIZE, fmt: "%s\n" , kps->string); |
529 | } |
530 | EXPORT_SYMBOL(param_get_string); |
531 | |
532 | const struct kernel_param_ops param_ops_string = { |
533 | .set = param_set_copystring, |
534 | .get = param_get_string, |
535 | }; |
536 | EXPORT_SYMBOL(param_ops_string); |
537 | |
538 | /* sysfs output in /sys/modules/XYZ/parameters/ */ |
539 | #define to_module_attr(n) container_of(n, struct module_attribute, attr) |
540 | #define to_module_kobject(n) container_of(n, struct module_kobject, kobj) |
541 | |
542 | struct param_attribute |
543 | { |
544 | struct module_attribute mattr; |
545 | const struct kernel_param *param; |
546 | }; |
547 | |
548 | struct module_param_attrs |
549 | { |
550 | unsigned int num; |
551 | struct attribute_group grp; |
552 | struct param_attribute attrs[]; |
553 | }; |
554 | |
555 | #ifdef CONFIG_SYSFS |
556 | #define to_param_attr(n) container_of(n, struct param_attribute, mattr) |
557 | |
558 | static ssize_t param_attr_show(struct module_attribute *mattr, |
559 | struct module_kobject *mk, char *buf) |
560 | { |
561 | int count; |
562 | struct param_attribute *attribute = to_param_attr(mattr); |
563 | |
564 | if (!attribute->param->ops->get) |
565 | return -EPERM; |
566 | |
567 | kernel_param_lock(mod: mk->mod); |
568 | count = attribute->param->ops->get(buf, attribute->param); |
569 | kernel_param_unlock(mod: mk->mod); |
570 | return count; |
571 | } |
572 | |
573 | /* sysfs always hands a nul-terminated string in buf. We rely on that. */ |
574 | static ssize_t param_attr_store(struct module_attribute *mattr, |
575 | struct module_kobject *mk, |
576 | const char *buf, size_t len) |
577 | { |
578 | int err; |
579 | struct param_attribute *attribute = to_param_attr(mattr); |
580 | |
581 | if (!attribute->param->ops->set) |
582 | return -EPERM; |
583 | |
584 | kernel_param_lock(mod: mk->mod); |
585 | if (param_check_unsafe(kp: attribute->param)) |
586 | err = attribute->param->ops->set(buf, attribute->param); |
587 | else |
588 | err = -EPERM; |
589 | kernel_param_unlock(mod: mk->mod); |
590 | if (!err) |
591 | return len; |
592 | return err; |
593 | } |
594 | #endif |
595 | |
596 | #ifdef CONFIG_MODULES |
597 | #define __modinit |
598 | #else |
599 | #define __modinit __init |
600 | #endif |
601 | |
602 | #ifdef CONFIG_SYSFS |
603 | void kernel_param_lock(struct module *mod) |
604 | { |
605 | mutex_lock(KPARAM_MUTEX(mod)); |
606 | } |
607 | |
608 | void kernel_param_unlock(struct module *mod) |
609 | { |
610 | mutex_unlock(KPARAM_MUTEX(mod)); |
611 | } |
612 | |
613 | EXPORT_SYMBOL(kernel_param_lock); |
614 | EXPORT_SYMBOL(kernel_param_unlock); |
615 | |
616 | /* |
617 | * add_sysfs_param - add a parameter to sysfs |
618 | * @mk: struct module_kobject |
619 | * @kp: the actual parameter definition to add to sysfs |
620 | * @name: name of parameter |
621 | * |
622 | * Create a kobject if for a (per-module) parameter if mp NULL, and |
623 | * create file in sysfs. Returns an error on out of memory. Always cleans up |
624 | * if there's an error. |
625 | */ |
626 | static __modinit int add_sysfs_param(struct module_kobject *mk, |
627 | const struct kernel_param *kp, |
628 | const char *name) |
629 | { |
630 | struct module_param_attrs *new_mp; |
631 | struct attribute **new_attrs; |
632 | unsigned int i; |
633 | |
634 | /* We don't bother calling this with invisible parameters. */ |
635 | BUG_ON(!kp->perm); |
636 | |
637 | if (!mk->mp) { |
638 | /* First allocation. */ |
639 | mk->mp = kzalloc(size: sizeof(*mk->mp), GFP_KERNEL); |
640 | if (!mk->mp) |
641 | return -ENOMEM; |
642 | mk->mp->grp.name = "parameters" ; |
643 | /* NULL-terminated attribute array. */ |
644 | mk->mp->grp.attrs = kzalloc(size: sizeof(mk->mp->grp.attrs[0]), |
645 | GFP_KERNEL); |
646 | /* Caller will cleanup via free_module_param_attrs */ |
647 | if (!mk->mp->grp.attrs) |
648 | return -ENOMEM; |
649 | } |
650 | |
651 | /* Enlarge allocations. */ |
652 | new_mp = krealloc(objp: mk->mp, |
653 | new_size: sizeof(*mk->mp) + |
654 | sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1), |
655 | GFP_KERNEL); |
656 | if (!new_mp) |
657 | return -ENOMEM; |
658 | mk->mp = new_mp; |
659 | |
660 | /* Extra pointer for NULL terminator */ |
661 | new_attrs = krealloc(objp: mk->mp->grp.attrs, |
662 | new_size: sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2), |
663 | GFP_KERNEL); |
664 | if (!new_attrs) |
665 | return -ENOMEM; |
666 | mk->mp->grp.attrs = new_attrs; |
667 | |
668 | /* Tack new one on the end. */ |
669 | memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0])); |
670 | sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr); |
671 | mk->mp->attrs[mk->mp->num].param = kp; |
672 | mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show; |
673 | /* Do not allow runtime DAC changes to make param writable. */ |
674 | if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0) |
675 | mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store; |
676 | else |
677 | mk->mp->attrs[mk->mp->num].mattr.store = NULL; |
678 | mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name; |
679 | mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm; |
680 | mk->mp->num++; |
681 | |
682 | /* Fix up all the pointers, since krealloc can move us */ |
683 | for (i = 0; i < mk->mp->num; i++) |
684 | mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr; |
685 | mk->mp->grp.attrs[mk->mp->num] = NULL; |
686 | return 0; |
687 | } |
688 | |
689 | #ifdef CONFIG_MODULES |
690 | static void free_module_param_attrs(struct module_kobject *mk) |
691 | { |
692 | if (mk->mp) |
693 | kfree(objp: mk->mp->grp.attrs); |
694 | kfree(objp: mk->mp); |
695 | mk->mp = NULL; |
696 | } |
697 | |
698 | /* |
699 | * module_param_sysfs_setup - setup sysfs support for one module |
700 | * @mod: module |
701 | * @kparam: module parameters (array) |
702 | * @num_params: number of module parameters |
703 | * |
704 | * Adds sysfs entries for module parameters under |
705 | * /sys/module/[mod->name]/parameters/ |
706 | */ |
707 | int module_param_sysfs_setup(struct module *mod, |
708 | const struct kernel_param *kparam, |
709 | unsigned int num_params) |
710 | { |
711 | int i, err; |
712 | bool params = false; |
713 | |
714 | for (i = 0; i < num_params; i++) { |
715 | if (kparam[i].perm == 0) |
716 | continue; |
717 | err = add_sysfs_param(mk: &mod->mkobj, kp: &kparam[i], name: kparam[i].name); |
718 | if (err) { |
719 | free_module_param_attrs(mk: &mod->mkobj); |
720 | return err; |
721 | } |
722 | params = true; |
723 | } |
724 | |
725 | if (!params) |
726 | return 0; |
727 | |
728 | /* Create the param group. */ |
729 | err = sysfs_create_group(kobj: &mod->mkobj.kobj, grp: &mod->mkobj.mp->grp); |
730 | if (err) |
731 | free_module_param_attrs(mk: &mod->mkobj); |
732 | return err; |
733 | } |
734 | |
735 | /* |
736 | * module_param_sysfs_remove - remove sysfs support for one module |
737 | * @mod: module |
738 | * |
739 | * Remove sysfs entries for module parameters and the corresponding |
740 | * kobject. |
741 | */ |
742 | void module_param_sysfs_remove(struct module *mod) |
743 | { |
744 | if (mod->mkobj.mp) { |
745 | sysfs_remove_group(kobj: &mod->mkobj.kobj, grp: &mod->mkobj.mp->grp); |
746 | /* We are positive that no one is using any param |
747 | * attrs at this point. Deallocate immediately. */ |
748 | free_module_param_attrs(mk: &mod->mkobj); |
749 | } |
750 | } |
751 | #endif |
752 | |
753 | void destroy_params(const struct kernel_param *params, unsigned num) |
754 | { |
755 | unsigned int i; |
756 | |
757 | for (i = 0; i < num; i++) |
758 | if (params[i].ops->free) |
759 | params[i].ops->free(params[i].arg); |
760 | } |
761 | |
762 | static struct module_kobject * __init locate_module_kobject(const char *name) |
763 | { |
764 | struct module_kobject *mk; |
765 | struct kobject *kobj; |
766 | int err; |
767 | |
768 | kobj = kset_find_obj(module_kset, name); |
769 | if (kobj) { |
770 | mk = to_module_kobject(kobj); |
771 | } else { |
772 | mk = kzalloc(size: sizeof(struct module_kobject), GFP_KERNEL); |
773 | BUG_ON(!mk); |
774 | |
775 | mk->mod = THIS_MODULE; |
776 | mk->kobj.kset = module_kset; |
777 | err = kobject_init_and_add(kobj: &mk->kobj, ktype: &module_ktype, NULL, |
778 | fmt: "%s" , name); |
779 | #ifdef CONFIG_MODULES |
780 | if (!err) |
781 | err = sysfs_create_file(kobj: &mk->kobj, attr: &module_uevent.attr); |
782 | #endif |
783 | if (err) { |
784 | kobject_put(kobj: &mk->kobj); |
785 | pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n" , |
786 | name, err); |
787 | return NULL; |
788 | } |
789 | |
790 | /* So that we hold reference in both cases. */ |
791 | kobject_get(kobj: &mk->kobj); |
792 | } |
793 | |
794 | return mk; |
795 | } |
796 | |
797 | static void __init kernel_add_sysfs_param(const char *name, |
798 | const struct kernel_param *kparam, |
799 | unsigned int name_skip) |
800 | { |
801 | struct module_kobject *mk; |
802 | int err; |
803 | |
804 | mk = locate_module_kobject(name); |
805 | if (!mk) |
806 | return; |
807 | |
808 | /* We need to remove old parameters before adding more. */ |
809 | if (mk->mp) |
810 | sysfs_remove_group(kobj: &mk->kobj, grp: &mk->mp->grp); |
811 | |
812 | /* These should not fail at boot. */ |
813 | err = add_sysfs_param(mk, kp: kparam, name: kparam->name + name_skip); |
814 | BUG_ON(err); |
815 | err = sysfs_create_group(kobj: &mk->kobj, grp: &mk->mp->grp); |
816 | BUG_ON(err); |
817 | kobject_uevent(kobj: &mk->kobj, action: KOBJ_ADD); |
818 | kobject_put(kobj: &mk->kobj); |
819 | } |
820 | |
821 | /* |
822 | * param_sysfs_builtin - add sysfs parameters for built-in modules |
823 | * |
824 | * Add module_parameters to sysfs for "modules" built into the kernel. |
825 | * |
826 | * The "module" name (KBUILD_MODNAME) is stored before a dot, the |
827 | * "parameter" name is stored behind a dot in kernel_param->name. So, |
828 | * extract the "module" name for all built-in kernel_param-eters, |
829 | * and for all who have the same, call kernel_add_sysfs_param. |
830 | */ |
831 | static void __init param_sysfs_builtin(void) |
832 | { |
833 | const struct kernel_param *kp; |
834 | unsigned int name_len; |
835 | char modname[MODULE_NAME_LEN]; |
836 | |
837 | for (kp = __start___param; kp < __stop___param; kp++) { |
838 | char *dot; |
839 | |
840 | if (kp->perm == 0) |
841 | continue; |
842 | |
843 | dot = strchr(kp->name, '.'); |
844 | if (!dot) { |
845 | /* This happens for core_param() */ |
846 | strcpy(p: modname, q: "kernel" ); |
847 | name_len = 0; |
848 | } else { |
849 | name_len = dot - kp->name + 1; |
850 | strscpy(p: modname, q: kp->name, size: name_len); |
851 | } |
852 | kernel_add_sysfs_param(name: modname, kparam: kp, name_skip: name_len); |
853 | } |
854 | } |
855 | |
856 | ssize_t __modver_version_show(struct module_attribute *mattr, |
857 | struct module_kobject *mk, char *buf) |
858 | { |
859 | struct module_version_attribute *vattr = |
860 | container_of(mattr, struct module_version_attribute, mattr); |
861 | |
862 | return scnprintf(buf, PAGE_SIZE, fmt: "%s\n" , vattr->version); |
863 | } |
864 | |
865 | extern const struct module_version_attribute __start___modver[]; |
866 | extern const struct module_version_attribute __stop___modver[]; |
867 | |
868 | static void __init version_sysfs_builtin(void) |
869 | { |
870 | const struct module_version_attribute *vattr; |
871 | struct module_kobject *mk; |
872 | int err; |
873 | |
874 | for (vattr = __start___modver; vattr < __stop___modver; vattr++) { |
875 | mk = locate_module_kobject(name: vattr->module_name); |
876 | if (mk) { |
877 | err = sysfs_create_file(kobj: &mk->kobj, attr: &vattr->mattr.attr); |
878 | WARN_ON_ONCE(err); |
879 | kobject_uevent(kobj: &mk->kobj, action: KOBJ_ADD); |
880 | kobject_put(kobj: &mk->kobj); |
881 | } |
882 | } |
883 | } |
884 | |
885 | /* module-related sysfs stuff */ |
886 | |
887 | static ssize_t module_attr_show(struct kobject *kobj, |
888 | struct attribute *attr, |
889 | char *buf) |
890 | { |
891 | struct module_attribute *attribute; |
892 | struct module_kobject *mk; |
893 | int ret; |
894 | |
895 | attribute = to_module_attr(attr); |
896 | mk = to_module_kobject(kobj); |
897 | |
898 | if (!attribute->show) |
899 | return -EIO; |
900 | |
901 | ret = attribute->show(attribute, mk, buf); |
902 | |
903 | return ret; |
904 | } |
905 | |
906 | static ssize_t module_attr_store(struct kobject *kobj, |
907 | struct attribute *attr, |
908 | const char *buf, size_t len) |
909 | { |
910 | struct module_attribute *attribute; |
911 | struct module_kobject *mk; |
912 | int ret; |
913 | |
914 | attribute = to_module_attr(attr); |
915 | mk = to_module_kobject(kobj); |
916 | |
917 | if (!attribute->store) |
918 | return -EIO; |
919 | |
920 | ret = attribute->store(attribute, mk, buf, len); |
921 | |
922 | return ret; |
923 | } |
924 | |
925 | static const struct sysfs_ops module_sysfs_ops = { |
926 | .show = module_attr_show, |
927 | .store = module_attr_store, |
928 | }; |
929 | |
930 | static int uevent_filter(const struct kobject *kobj) |
931 | { |
932 | const struct kobj_type *ktype = get_ktype(kobj); |
933 | |
934 | if (ktype == &module_ktype) |
935 | return 1; |
936 | return 0; |
937 | } |
938 | |
939 | static const struct kset_uevent_ops module_uevent_ops = { |
940 | .filter = uevent_filter, |
941 | }; |
942 | |
943 | struct kset *module_kset; |
944 | |
945 | static void module_kobj_release(struct kobject *kobj) |
946 | { |
947 | struct module_kobject *mk = to_module_kobject(kobj); |
948 | complete(mk->kobj_completion); |
949 | } |
950 | |
951 | const struct kobj_type module_ktype = { |
952 | .release = module_kobj_release, |
953 | .sysfs_ops = &module_sysfs_ops, |
954 | }; |
955 | |
956 | /* |
957 | * param_sysfs_init - create "module" kset |
958 | * |
959 | * This must be done before the initramfs is unpacked and |
960 | * request_module() thus becomes possible, because otherwise the |
961 | * module load would fail in mod_sysfs_init. |
962 | */ |
963 | static int __init param_sysfs_init(void) |
964 | { |
965 | module_kset = kset_create_and_add(name: "module" , u: &module_uevent_ops, NULL); |
966 | if (!module_kset) { |
967 | printk(KERN_WARNING "%s (%d): error creating kset\n" , |
968 | __FILE__, __LINE__); |
969 | return -ENOMEM; |
970 | } |
971 | |
972 | return 0; |
973 | } |
974 | subsys_initcall(param_sysfs_init); |
975 | |
976 | /* |
977 | * param_sysfs_builtin_init - add sysfs version and parameter |
978 | * attributes for built-in modules |
979 | */ |
980 | static int __init param_sysfs_builtin_init(void) |
981 | { |
982 | if (!module_kset) |
983 | return -ENOMEM; |
984 | |
985 | version_sysfs_builtin(); |
986 | param_sysfs_builtin(); |
987 | |
988 | return 0; |
989 | } |
990 | late_initcall(param_sysfs_builtin_init); |
991 | |
992 | #endif /* CONFIG_SYSFS */ |
993 | |