projects/linux·blob v6.15-rc5 · 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 %p\n", param,
140 params[i].ops->set);
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 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 size_t len, maxlen = 1024;
265
266 len = strnlen(val, 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(*(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(len + 1);
280 if (!*(char **)kp->arg)
281 return -ENOMEM;
282 strcpy(*(char **)kp->arg, val);
283 } else
284 *(const char **)kp->arg = val;
285
286 return 0;
287}
288EXPORT_SYMBOL(param_set_charp);
289
290int param_get_charp(char *buffer, const struct kernel_param *kp)
291{
292 return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg));
293}
294EXPORT_SYMBOL(param_get_charp);
295
296void param_free_charp(void *arg)
297{
298 maybe_kfree_parameter(*((char **)arg));
299}
300EXPORT_SYMBOL(param_free_charp);
301
302const struct kernel_param_ops param_ops_charp = {
303 .set = param_set_charp,
304 .get = param_get_charp,
305 .free = param_free_charp,
306};
307EXPORT_SYMBOL(param_ops_charp);
308
309/* Actually could be a bool or an int, for historical reasons. */
310int 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(val, kp->arg);
317}
318EXPORT_SYMBOL(param_set_bool);
319
320int 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(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N');
324}
325EXPORT_SYMBOL(param_get_bool);
326
327const 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};
332EXPORT_SYMBOL(param_ops_bool);
333
334int 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}
356EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
357
358const 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};
363EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
364
365/* This one must be bool. */
366int 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}
378EXPORT_SYMBOL(param_set_invbool);
379
380int param_get_invbool(char *buffer, const struct kernel_param *kp)
381{
382 return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y');
383}
384EXPORT_SYMBOL(param_get_invbool);
385
386const struct kernel_param_ops param_ops_invbool = {
387 .set = param_set_invbool,
388 .get = param_get_invbool,
389};
390EXPORT_SYMBOL(param_ops_invbool);
391
392int 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}
406EXPORT_SYMBOL(param_set_bint);
407
408const 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};
413EXPORT_SYMBOL(param_ops_bint);
414
415/* We break the rule and mangle the string. */
416static 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
465static 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(kp->mod, kp->name, val, 1, arr->max, arr->elem,
471 arr->elemsize, arr->ops->set, kp->level,
472 arr->num ?: &temp_num);
473}
474
475static 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(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
496static 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
506const struct kernel_param_ops param_array_ops = {
507 .set = param_array_set,
508 .get = param_array_get,
509 .free = param_array_free,
510};
511EXPORT_SYMBOL(param_array_ops);
512
513int param_set_copystring(const char *val, const struct kernel_param *kp)
514{
515 const struct kparam_string *kps = kp->str;
516
517 if (strnlen(val, 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(kps->string, val);
523 return 0;
524}
525EXPORT_SYMBOL(param_set_copystring);
526
527int param_get_string(char *buffer, const struct kernel_param *kp)
528{
529 const struct kparam_string *kps = kp->str;
530 return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string);
531}
532EXPORT_SYMBOL(param_get_string);
533
534const struct kernel_param_ops param_ops_string = {
535 .set = param_set_copystring,
536 .get = param_get_string,
537};
538EXPORT_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
544struct param_attribute
545{
546 struct module_attribute mattr;
547 const struct kernel_param *param;
548};
549
550struct 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
560static 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(mk->mod);
570 count = attribute->param->ops->get(buf, attribute->param);
571 kernel_param_unlock(mk->mod);
572 return count;
573}
574
575/* sysfs always hands a nul-terminated string in buf. We rely on that. */
576static 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(mk->mod);
587 if (param_check_unsafe(attribute->param))
588 err = attribute->param->ops->set(buf, attribute->param);
589 else
590 err = -EPERM;
591 kernel_param_unlock(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
605void kernel_param_lock(struct module *mod)
606{
607 mutex_lock(KPARAM_MUTEX(mod));
608}
609
610void kernel_param_unlock(struct module *mod)
611{
612 mutex_unlock(KPARAM_MUTEX(mod));
613}
614
615EXPORT_SYMBOL(kernel_param_lock);
616EXPORT_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 */
628static __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
689static void free_module_param_attrs(struct module_kobject *mk)
690{
691 if (mk->mp)
692 kfree(mk->mp->grp.attrs);
693 kfree(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 */
706int 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(&mod->mkobj, &kparam[i], kparam[i].name);
717 if (err) {
718 free_module_param_attrs(&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(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
729 if (err)
730 free_module_param_attrs(&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 */
741void module_param_sysfs_remove(struct module *mod)
742{
743 if (mod->mkobj.mp) {
744 sysfs_remove_group(&mod->mkobj.kobj, &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(&mod->mkobj);
750 }
751}
752#endif
753
754void 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
763struct 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(&mk->kobj, &module_ktype, NULL, "%s", name);
780 if (IS_ENABLED(CONFIG_MODULES) && !err)
781 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
782 if (err) {
783 kobject_put(&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(&mk->kobj);
791
792 return mk;
793}
794
795static 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(&mk->kobj, &mk->mp->grp);
809
810 /* These should not fail at boot. */
811 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
812 BUG_ON(err);
813 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
814 BUG_ON(err);
815 kobject_uevent(&mk->kobj, KOBJ_ADD);
816 kobject_put(&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 */
829static 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(modname, "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(modname, kp, name_len);
851 }
852}
853
854ssize_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, "%s\n", vattr->version);
861}
862
863extern const struct module_version_attribute __start___modver[];
864extern const struct module_version_attribute __stop___modver[];
865
866static 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(vattr->module_name);
874 if (mk) {
875 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
876 WARN_ON_ONCE(err);
877 kobject_uevent(&mk->kobj, KOBJ_ADD);
878 kobject_put(&mk->kobj);
879 }
880 }
881}
882
883/* module-related sysfs stuff */
884
885static 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
904static 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
923static const struct sysfs_ops module_sysfs_ops = {
924 .show = module_attr_show,
925 .store = module_attr_store,
926};
927
928static 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
937static const struct kset_uevent_ops module_uevent_ops = {
938 .filter = uevent_filter,
939};
940
941struct kset *module_kset;
942
943static void module_kobj_release(struct kobject *kobj)
944{
945 struct module_kobject *mk = to_module_kobject(kobj);
946 complete(mk->kobj_completion);
947}
948
949const struct kobj_type module_ktype = {
950 .release = module_kobj_release,
951 .sysfs_ops = &module_sysfs_ops,
952};
953
954/*
955 * param_sysfs_init - create "module" kset
956 *
957 * This must be done before the initramfs is unpacked and
958 * request_module() thus becomes possible, because otherwise the
959 * module load would fail in mod_sysfs_init.
960 */
961static int __init param_sysfs_init(void)
962{
963 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
964 if (!module_kset) {
965 printk(KERN_WARNING "%s (%d): error creating kset\n",
966 __FILE__, __LINE__);
967 return -ENOMEM;
968 }
969
970 return 0;
971}
972subsys_initcall(param_sysfs_init);
973
974/*
975 * param_sysfs_builtin_init - add sysfs version and parameter
976 * attributes for built-in modules
977 */
978static int __init param_sysfs_builtin_init(void)
979{
980 if (!module_kset)
981 return -ENOMEM;
982
983 version_sysfs_builtin();
984 param_sysfs_builtin();
985
986 return 0;
987}
988late_initcall(param_sysfs_builtin_init);
989
990#endif /* CONFIG_SYSFS */