projects/linux·blob v5.13-rc1 · refs

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