projects/linux·blob v7.3-rc2 · refs

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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 */
21static 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 : &param_lock)
26#else
27#define KPARAM_MUTEX(mod) (&param_lock)
28#endif
29
30static inline void check_kparam_locked(struct module *mod)
31{
32 BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod)));
33}
34#else
35static 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. */
41struct kmalloced_param {
42 struct list_head list;
43 char val[];
44};
45static LIST_HEAD(kmalloced_params);
46static DEFINE_SPINLOCK(kmalloced_params_lock);
47
48static 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(&kmalloced_params_lock);
57 list_add(&p->list, &kmalloced_params);
58 spin_unlock(&kmalloced_params_lock);
59
60 return p->val;
61}
62
63/* Does nothing if parameter wasn't kmalloced above. */
64static void maybe_kfree_parameter(void *param)
65{
66 struct kmalloced_param *p;
67
68 spin_lock(&kmalloced_params_lock);
69 list_for_each_entry(p, &kmalloced_params, list) {
70 if (p->val == param) {
71 list_del(&p->list);
72 kfree(p);
73 break;
74 }
75 }
76 spin_unlock(&kmalloced_params_lock);
77}
78
79static char dash2underscore(char c)
80{
81 if (c == '-')
82 return '_';
83 return c;
84}
85
86bool 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(a[i]) != dash2underscore(b[i]))
92 return false;
93 }
94 return true;
95}
96
97bool parameq(const char *a, const char *b)
98{
99 return parameqn(a, b, strlen(a)+1);
100}
101
102static bool param_check_unsafe(const struct kernel_param *kp)
103{
104 if (kp->flags & KERNEL_PARAM_FL_HWPARAM &&
105 security_locked_down(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
117static 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(param, 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 value '%s'\n", param,
140 val ? val : "no-arg");
141 kernel_param_lock(params[i].mod);
142 if (param_check_unsafe(&params[i]))
143 err = params[i].ops->set(val, &params[i]);
144 else
145 err = -EPERM;
146 kernel_param_unlock(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". */
161char *parse_args(const char *doing,
162 char *args,
163 const struct kernel_param *params,
164 unsigned int 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, &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,
187 min_level, max_level, arg, 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(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
234STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
235STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
236STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
237STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
238STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
239STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
240STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
241STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull);
242STANDARD_PARAM_DEF(hexint, unsigned int, "%#08x", kstrtouint);
243
244int 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(val, 0, &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}
260EXPORT_SYMBOL_GPL(param_set_uint_minmax);
261
262int param_set_charp(const char *val, const struct kernel_param *kp)
263{
264 char *tmp;
265 size_t len, maxlen = 1024;
266
267 len = strnlen(val, maxlen + 1);
268 if (len == maxlen + 1) {
269 pr_err("%s: string parameter too long\n", kp->name);
270 return -ENOSPC;
271 }
272
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 */
277 if (slab_is_available()) {
278 tmp = kmalloc_parameter(len + 1);
279 if (!tmp)
280 return -ENOMEM;
281 memcpy(tmp, val, len + 1);
282 } else
283 tmp = (char *)val;
284
285 maybe_kfree_parameter(*(char **)kp->arg);
286 *(char **)kp->arg = tmp;
287
288 return 0;
289}
290EXPORT_SYMBOL(param_set_charp);
291
292int param_get_charp(char *buffer, const struct kernel_param *kp)
293{
294 return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg));
295}
296EXPORT_SYMBOL(param_get_charp);
297
298void param_free_charp(void *arg)
299{
300 maybe_kfree_parameter(*((char **)arg));
301}
302EXPORT_SYMBOL(param_free_charp);
303
304const struct kernel_param_ops param_ops_charp = {
305 .set = param_set_charp,
306 .get = param_get_charp,
307 .free = param_free_charp,
308};
309EXPORT_SYMBOL(param_ops_charp);
310
311/* Actually could be a bool or an int, for historical reasons. */
312int param_set_bool(const char *val, const struct kernel_param *kp)
313{
314 /* No equals means "set"... */
315 if (!val) val = "1";
316
317 /* One of =[yYnN01] */
318 return kstrtobool(val, kp->arg);
319}
320EXPORT_SYMBOL(param_set_bool);
321
322int param_get_bool(char *buffer, const struct kernel_param *kp)
323{
324 /* Y and N chosen as being relatively non-coder friendly */
325 return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N');
326}
327EXPORT_SYMBOL(param_get_bool);
328
329const struct kernel_param_ops param_ops_bool = {
330 .flags = KERNEL_PARAM_OPS_FL_NOARG,
331 .set = param_set_bool,
332 .get = param_get_bool,
333};
334EXPORT_SYMBOL(param_ops_bool);
335
336int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
337{
338 int err;
339 bool new_value;
340 bool orig_value = *(bool *)kp->arg;
341 struct kernel_param dummy_kp = *kp;
342
343 dummy_kp.arg = &new_value;
344
345 err = param_set_bool(val, &dummy_kp);
346 if (err)
347 return err;
348
349 /* Don't let them unset it once it's set! */
350 if (!new_value && orig_value)
351 return -EROFS;
352
353 if (new_value)
354 err = param_set_bool(val, kp);
355
356 return err;
357}
358EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
359
360const struct kernel_param_ops param_ops_bool_enable_only = {
361 .flags = KERNEL_PARAM_OPS_FL_NOARG,
362 .set = param_set_bool_enable_only,
363 .get = param_get_bool,
364};
365EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
366
367/* This one must be bool. */
368int param_set_invbool(const char *val, const struct kernel_param *kp)
369{
370 int ret;
371 bool boolval;
372 struct kernel_param dummy;
373
374 dummy.arg = &boolval;
375 ret = param_set_bool(val, &dummy);
376 if (ret == 0)
377 *(bool *)kp->arg = !boolval;
378 return ret;
379}
380EXPORT_SYMBOL(param_set_invbool);
381
382int param_get_invbool(char *buffer, const struct kernel_param *kp)
383{
384 return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y');
385}
386EXPORT_SYMBOL(param_get_invbool);
387
388const struct kernel_param_ops param_ops_invbool = {
389 .set = param_set_invbool,
390 .get = param_get_invbool,
391};
392EXPORT_SYMBOL(param_ops_invbool);
393
394int param_set_bint(const char *val, const struct kernel_param *kp)
395{
396 /* Match bool exactly, by re-using it. */
397 struct kernel_param boolkp = *kp;
398 bool v;
399 int ret;
400
401 boolkp.arg = &v;
402
403 ret = param_set_bool(val, &boolkp);
404 if (ret == 0)
405 *(int *)kp->arg = v;
406 return ret;
407}
408EXPORT_SYMBOL(param_set_bint);
409
410const struct kernel_param_ops param_ops_bint = {
411 .flags = KERNEL_PARAM_OPS_FL_NOARG,
412 .set = param_set_bint,
413 .get = param_get_int,
414};
415EXPORT_SYMBOL(param_ops_bint);
416
417/* We break the rule and mangle the string. */
418static int param_array(struct module *mod,
419 const char *name,
420 const char *val,
421 unsigned int min, unsigned int max,
422 void *elem, int elemsize,
423 int (*set)(const char *, const struct kernel_param *kp),
424 s16 level,
425 unsigned int *num)
426{
427 int ret;
428 struct kernel_param kp;
429 char save;
430
431 /* Get the name right for errors. */
432 kp.name = name;
433 kp.arg = elem;
434 kp.level = level;
435
436 *num = 0;
437 /* We expect a comma-separated list of values. */
438 do {
439 int len;
440
441 if (*num == max) {
442 pr_err("%s: can only take %i arguments\n", name, max);
443 return -EINVAL;
444 }
445 len = strcspn(val, ",");
446
447 /* nul-terminate and parse */
448 save = val[len];
449 ((char *)val)[len] = '\0';
450 check_kparam_locked(mod);
451 ret = set(val, &kp);
452
453 if (ret != 0)
454 return ret;
455 kp.arg += elemsize;
456 val += len+1;
457 (*num)++;
458 } while (save == ',');
459
460 if (*num < min) {
461 pr_err("%s: needs at least %i arguments\n", name, min);
462 return -EINVAL;
463 }
464 return 0;
465}
466
467static int param_array_set(const char *val, const struct kernel_param *kp)
468{
469 const struct kparam_array *arr = kp->arr;
470 unsigned int temp_num;
471
472 return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem,
473 arr->elemsize, arr->ops->set, kp->level,
474 arr->num ?: &temp_num);
475}
476
477static int param_array_get(char *buffer, const struct kernel_param *kp)
478{
479 int i, off, ret;
480 const struct kparam_array *arr = kp->arr;
481 struct kernel_param p = *kp;
482
483 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
484 /* Replace \n with comma */
485 if (i)
486 buffer[off - 1] = ',';
487 p.arg = arr->elem + arr->elemsize * i;
488 check_kparam_locked(p.mod);
489 ret = arr->ops->get(buffer + off, &p);
490 if (ret < 0)
491 return ret;
492 off += ret;
493 }
494 buffer[off] = '\0';
495 return off;
496}
497
498static void param_array_free(void *arg)
499{
500 unsigned int i;
501 const struct kparam_array *arr = arg;
502
503 if (arr->ops->free)
504 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
505 arr->ops->free(arr->elem + arr->elemsize * i);
506}
507
508const struct kernel_param_ops param_array_ops = {
509 .set = param_array_set,
510 .get = param_array_get,
511 .free = param_array_free,
512};
513EXPORT_SYMBOL(param_array_ops);
514
515int param_set_copystring(const char *val, const struct kernel_param *kp)
516{
517 const struct kparam_string *kps = kp->str;
518 const size_t len = strnlen(val, kps->maxlen);
519
520 if (len == kps->maxlen) {
521 pr_err("%s: string doesn't fit in %u chars.\n",
522 kp->name, kps->maxlen-1);
523 return -ENOSPC;
524 }
525 memcpy(kps->string, val, len + 1);
526 return 0;
527}
528EXPORT_SYMBOL(param_set_copystring);
529
530int param_get_string(char *buffer, const struct kernel_param *kp)
531{
532 const struct kparam_string *kps = kp->str;
533 return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string);
534}
535EXPORT_SYMBOL(param_get_string);
536
537const struct kernel_param_ops param_ops_string = {
538 .set = param_set_copystring,
539 .get = param_get_string,
540};
541EXPORT_SYMBOL(param_ops_string);
542
543/* sysfs output in /sys/module/XYZ/parameters/ */
544#define to_module_attr(n) container_of_const(n, struct module_attribute, attr)
545#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
546
547struct param_attribute
548{
549 struct module_attribute mattr;
550 const struct kernel_param *param;
551};
552
553struct module_param_attrs
554{
555 unsigned int num;
556 struct attribute_group grp;
557 struct param_attribute attrs[] __counted_by(num);
558};
559
560#ifdef CONFIG_SYSFS
561#define to_param_attr(n) container_of_const(n, struct param_attribute, mattr)
562
563static ssize_t param_attr_show(const struct module_attribute *mattr,
564 struct module_kobject *mk, char *buf)
565{
566 int count;
567 const struct param_attribute *attribute = to_param_attr(mattr);
568
569 if (!attribute->param->ops->get)
570 return -EPERM;
571
572 kernel_param_lock(mk->mod);
573 count = attribute->param->ops->get(buf, attribute->param);
574 kernel_param_unlock(mk->mod);
575 return count;
576}
577
578/* sysfs always hands a nul-terminated string in buf. We rely on that. */
579static ssize_t param_attr_store(const struct module_attribute *mattr,
580 struct module_kobject *mk,
581 const char *buf, size_t len)
582{
583 int err;
584 const struct param_attribute *attribute = to_param_attr(mattr);
585
586 if (!attribute->param->ops->set)
587 return -EPERM;
588
589 kernel_param_lock(mk->mod);
590 if (param_check_unsafe(attribute->param))
591 err = attribute->param->ops->set(buf, attribute->param);
592 else
593 err = -EPERM;
594 kernel_param_unlock(mk->mod);
595 if (!err)
596 return len;
597 return err;
598}
599#endif
600
601#ifdef CONFIG_SYSFS
602void kernel_param_lock(struct module *mod)
603{
604 mutex_lock(KPARAM_MUTEX(mod));
605}
606
607void kernel_param_unlock(struct module *mod)
608{
609 mutex_unlock(KPARAM_MUTEX(mod));
610}
611
612EXPORT_SYMBOL(kernel_param_lock);
613EXPORT_SYMBOL(kernel_param_unlock);
614
615/*
616 * add_sysfs_param - add a parameter to sysfs
617 * @mk: struct module_kobject
618 * @kp: the actual parameter definition to add to sysfs
619 * @name: name of parameter
620 *
621 * Create a kobject if for a (per-module) parameter if mp NULL, and
622 * create file in sysfs. Returns an error on out of memory. Always cleans up
623 * if there's an error.
624 */
625static __init_or_module int add_sysfs_param(struct module_kobject *mk,
626 const struct kernel_param *kp,
627 const char *name)
628{
629 struct module_param_attrs *new_mp;
630 struct attribute **new_attrs;
631 unsigned int i;
632
633 /* We don't bother calling this with invisible parameters. */
634 BUG_ON(!kp->perm);
635
636 if (!mk->mp) {
637 /* First allocation. */
638 mk->mp = kzalloc_obj(*mk->mp);
639 if (!mk->mp)
640 return -ENOMEM;
641 mk->mp->grp.name = "parameters";
642 /* NULL-terminated attribute array. */
643 mk->mp->grp.attrs = kzalloc_obj(mk->mp->grp.attrs[0]);
644 /* Caller will cleanup via free_module_param_attrs */
645 if (!mk->mp->grp.attrs)
646 return -ENOMEM;
647 }
648
649 /* Enlarge allocations. */
650 new_mp = krealloc(mk->mp, struct_size(mk->mp, attrs, mk->mp->num + 1),
651 GFP_KERNEL);
652 if (!new_mp)
653 return -ENOMEM;
654 mk->mp = new_mp;
655 mk->mp->num++;
656
657 /* Extra pointer for NULL terminator */
658 new_attrs = krealloc_array(mk->mp->grp.attrs, mk->mp->num + 1,
659 sizeof(mk->mp->grp.attrs[0]), GFP_KERNEL);
660 if (!new_attrs)
661 return -ENOMEM;
662 mk->mp->grp.attrs = new_attrs;
663
664 /* Tack new one on the end. */
665 memset(&mk->mp->attrs[mk->mp->num - 1], 0, sizeof(mk->mp->attrs[0]));
666 sysfs_attr_init(&mk->mp->attrs[mk->mp->num - 1].mattr.attr);
667 mk->mp->attrs[mk->mp->num - 1].param = kp;
668 mk->mp->attrs[mk->mp->num - 1].mattr.show = param_attr_show;
669 /* Do not allow runtime DAC changes to make param writable. */
670 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
671 mk->mp->attrs[mk->mp->num - 1].mattr.store = param_attr_store;
672 else
673 mk->mp->attrs[mk->mp->num - 1].mattr.store = NULL;
674 mk->mp->attrs[mk->mp->num - 1].mattr.attr.name = (char *)name;
675 mk->mp->attrs[mk->mp->num - 1].mattr.attr.mode = kp->perm;
676
677 /* Fix up all the pointers, since krealloc can move us */
678 for (i = 0; i < mk->mp->num; i++)
679 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
680 mk->mp->grp.attrs[mk->mp->num] = NULL;
681 return 0;
682}
683
684#ifdef CONFIG_MODULES
685static void free_module_param_attrs(struct module_kobject *mk)
686{
687 if (mk->mp)
688 kfree(mk->mp->grp.attrs);
689 kfree(mk->mp);
690 mk->mp = NULL;
691}
692
693/*
694 * module_param_sysfs_setup - setup sysfs support for one module
695 * @mod: module
696 * @kparam: module parameters (array)
697 * @num_params: number of module parameters
698 *
699 * Adds sysfs entries for module parameters under
700 * /sys/module/[mod->name]/parameters/
701 */
702int module_param_sysfs_setup(struct module *mod,
703 const struct kernel_param *kparam,
704 unsigned int num_params)
705{
706 int i, err;
707 bool params = false;
708
709 for (i = 0; i < num_params; i++) {
710 if (kparam[i].perm == 0)
711 continue;
712 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
713 if (err) {
714 free_module_param_attrs(&mod->mkobj);
715 return err;
716 }
717 params = true;
718 }
719
720 if (!params)
721 return 0;
722
723 /* Create the param group. */
724 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
725 if (err)
726 free_module_param_attrs(&mod->mkobj);
727 return err;
728}
729
730/*
731 * module_param_sysfs_remove - remove sysfs support for one module
732 * @mod: module
733 *
734 * Remove sysfs entries for module parameters and the corresponding
735 * kobject.
736 */
737void module_param_sysfs_remove(struct module *mod)
738{
739 if (mod->mkobj.mp) {
740 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
741 /*
742 * We are positive that no one is using any param
743 * attrs at this point. Deallocate immediately.
744 */
745 free_module_param_attrs(&mod->mkobj);
746 }
747}
748#endif
749
750struct module_kobject * __init_or_module
751lookup_or_create_module_kobject(const char *name)
752{
753 struct module_kobject *mk;
754 struct kobject *kobj;
755 int err;
756
757 kobj = kset_find_obj(module_kset, name);
758 if (kobj)
759 return to_module_kobject(kobj);
760
761 mk = kzalloc_obj(struct module_kobject);
762 if (!mk)
763 return NULL;
764
765 mk->mod = THIS_MODULE;
766 mk->kobj.kset = module_kset;
767 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, "%s", name);
768 if (IS_ENABLED(CONFIG_MODULES) && !err)
769 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
770 if (err) {
771 kobject_put(&mk->kobj);
772 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
773 name, err);
774 return NULL;
775 }
776
777 /* So that we hold reference in both cases. */
778 kobject_get(&mk->kobj);
779
780 return mk;
781}
782
783static void __init kernel_add_sysfs_param(const char *name,
784 const struct kernel_param *kparam,
785 unsigned int name_skip)
786{
787 struct module_kobject *mk;
788 int err;
789
790 mk = lookup_or_create_module_kobject(name);
791 if (!mk)
792 return;
793
794 /* We need to remove old parameters before adding more. */
795 if (mk->mp)
796 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
797
798 /* These should not fail at boot. */
799 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
800 BUG_ON(err);
801 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
802 BUG_ON(err);
803 kobject_uevent(&mk->kobj, KOBJ_ADD);
804 kobject_put(&mk->kobj);
805}
806
807/*
808 * param_sysfs_builtin - add sysfs parameters for built-in modules
809 *
810 * Add module_parameters to sysfs for "modules" built into the kernel.
811 *
812 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
813 * "parameter" name is stored behind a dot in kernel_param->name. So,
814 * extract the "module" name for all built-in kernel_param-eters,
815 * and for all who have the same, call kernel_add_sysfs_param.
816 */
817static void __init param_sysfs_builtin(void)
818{
819 const struct kernel_param *kp;
820 unsigned int name_len;
821 char modname[MODULE_NAME_LEN];
822
823 for (kp = __start___param; kp < __stop___param; kp++) {
824 char *dot;
825
826 if (kp->perm == 0)
827 continue;
828
829 dot = strchr(kp->name, '.');
830 if (!dot) {
831 /* This happens for core_param() */
832 strscpy(modname, "kernel");
833 name_len = 0;
834 } else {
835 name_len = dot - kp->name + 1;
836 strscpy(modname, kp->name, name_len);
837 }
838 kernel_add_sysfs_param(modname, kp, name_len);
839 }
840}
841
842ssize_t __modver_version_show(const struct module_attribute *mattr,
843 struct module_kobject *mk, char *buf)
844{
845 const struct module_version_attribute *vattr =
846 container_of_const(mattr, struct module_version_attribute, mattr);
847
848 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
849}
850
851extern const struct module_version_attribute __start___modver[];
852extern const struct module_version_attribute __stop___modver[];
853
854static void __init version_sysfs_builtin(void)
855{
856 const struct module_version_attribute *vattr;
857 struct module_kobject *mk;
858 int err;
859
860 for (vattr = __start___modver; vattr < __stop___modver; vattr++) {
861 mk = lookup_or_create_module_kobject(vattr->module_name);
862 if (mk) {
863 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
864 WARN_ON_ONCE(err);
865 kobject_uevent(&mk->kobj, KOBJ_ADD);
866 kobject_put(&mk->kobj);
867 }
868 }
869}
870
871/* module-related sysfs stuff */
872
873static ssize_t module_attr_show(struct kobject *kobj,
874 struct attribute *attr,
875 char *buf)
876{
877 const struct module_attribute *attribute;
878 struct module_kobject *mk;
879 int ret;
880
881 attribute = to_module_attr(attr);
882 mk = to_module_kobject(kobj);
883
884 if (!attribute->show)
885 return -EIO;
886
887 ret = attribute->show(attribute, mk, buf);
888
889 return ret;
890}
891
892static ssize_t module_attr_store(struct kobject *kobj,
893 struct attribute *attr,
894 const char *buf, size_t len)
895{
896 const struct module_attribute *attribute;
897 struct module_kobject *mk;
898 int ret;
899
900 attribute = to_module_attr(attr);
901 mk = to_module_kobject(kobj);
902
903 if (!attribute->store)
904 return -EIO;
905
906 ret = attribute->store(attribute, mk, buf, len);
907
908 return ret;
909}
910
911static const struct sysfs_ops module_sysfs_ops = {
912 .show = module_attr_show,
913 .store = module_attr_store,
914};
915
916static int uevent_filter(const struct kobject *kobj)
917{
918 const struct kobj_type *ktype = get_ktype(kobj);
919
920 if (ktype == &module_ktype)
921 return 1;
922 return 0;
923}
924
925static const struct kset_uevent_ops module_uevent_ops = {
926 .filter = uevent_filter,
927};
928
929struct kset *module_kset;
930
931static void module_kobj_release(struct kobject *kobj)
932{
933 struct module_kobject *mk = to_module_kobject(kobj);
934
935 if (mk->kobj_completion)
936 complete(mk->kobj_completion);
937}
938
939const struct kobj_type module_ktype = {
940 .release = module_kobj_release,
941 .sysfs_ops = &module_sysfs_ops,
942};
943
944/*
945 * param_sysfs_init - create "module" kset
946 *
947 * This must be done before any driver registration so that when a driver comes
948 * from a built-in module, the driver core can add the module under /sys/module
949 * and create the associated driver symlinks.
950 */
951static int __init param_sysfs_init(void)
952{
953 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
954 if (!module_kset) {
955 printk(KERN_WARNING "%s (%d): error creating kset\n",
956 __FILE__, __LINE__);
957 return -ENOMEM;
958 }
959
960 return 0;
961}
962pure_initcall(param_sysfs_init);
963
964/*
965 * param_sysfs_builtin_init - add sysfs version and parameter
966 * attributes for built-in modules
967 */
968static int __init param_sysfs_builtin_init(void)
969{
970 if (!module_kset)
971 return -ENOMEM;
972
973 version_sysfs_builtin();
974 param_sysfs_builtin();
975
976 return 0;
977}
978late_initcall(param_sysfs_builtin_init);
979
980#endif /* CONFIG_SYSFS */
981
982#ifdef CONFIG_MODULES
983
984/*
985 * module_destroy_params - free all parameters for one module
986 * @params: module parameters (array)
987 * @num: number of module parameters
988 */
989void module_destroy_params(const struct kernel_param *params, unsigned int num)
990{
991 unsigned int i;
992
993 for (i = 0; i < num; i++)
994 if (params[i].ops->free)
995 params[i].ops->free(params[i].arg);
996}
997
998#endif /* CONFIG_MODULES */