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