projects/linux·blob v6.7-rc5 · 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/kstrtox.h>
8#include <linux/string.h>
9#include <linux/errno.h>
10#include <linux/module.h>
11#include <linux/moduleparam.h>
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/slab.h>
15#include <linux/ctype.h>
16#include <linux/security.h>
17
18#ifdef CONFIG_SYSFS
19/* Protects all built-in parameters, modules use their own param_lock */
20static DEFINE_MUTEX(param_lock);
21
22/* Use the module's mutex, or if built-in use the built-in mutex */
23#ifdef CONFIG_MODULES
24#define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : &param_lock)
25#else
26#define KPARAM_MUTEX(mod) (&param_lock)
27#endif
28
29static inline void check_kparam_locked(struct module *mod)
30{
31 BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod)));
32}
33#else
34static inline void check_kparam_locked(struct module *mod)
35{
36}
37#endif /* !CONFIG_SYSFS */
38
39/* This just allows us to keep track of which parameters are kmalloced. */
40struct kmalloced_param {
41 struct list_head list;
42 char val[];
43};
44static LIST_HEAD(kmalloced_params);
45static DEFINE_SPINLOCK(kmalloced_params_lock);
46
47static void *kmalloc_parameter(unsigned int size)
48{
49 struct kmalloced_param *p;
50
51 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
52 if (!p)
53 return NULL;
54
55 spin_lock(&kmalloced_params_lock);
56 list_add(&p->list, &kmalloced_params);
57 spin_unlock(&kmalloced_params_lock);
58
59 return p->val;
60}
61
62/* Does nothing if parameter wasn't kmalloced above. */
63static void maybe_kfree_parameter(void *param)
64{
65 struct kmalloced_param *p;
66
67 spin_lock(&kmalloced_params_lock);
68 list_for_each_entry(p, &kmalloced_params, list) {
69 if (p->val == param) {
70 list_del(&p->list);
71 kfree(p);
72 break;
73 }
74 }
75 spin_unlock(&kmalloced_params_lock);
76}
77
78static char dash2underscore(char c)
79{
80 if (c == '-')
81 return '_';
82 return c;
83}
84
85bool parameqn(const char *a, const char *b, size_t n)
86{
87 size_t i;
88
89 for (i = 0; i < n; i++) {
90 if (dash2underscore(a[i]) != dash2underscore(b[i]))
91 return false;
92 }
93 return true;
94}
95
96bool parameq(const char *a, const char *b)
97{
98 return parameqn(a, b, strlen(a)+1);
99}
100
101static bool param_check_unsafe(const struct kernel_param *kp)
102{
103 if (kp->flags & KERNEL_PARAM_FL_HWPARAM &&
104 security_locked_down(LOCKDOWN_MODULE_PARAMETERS))
105 return false;
106
107 if (kp->flags & KERNEL_PARAM_FL_UNSAFE) {
108 pr_notice("Setting dangerous option %s - tainting kernel\n",
109 kp->name);
110 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
111 }
112
113 return true;
114}
115
116static int parse_one(char *param,
117 char *val,
118 const char *doing,
119 const struct kernel_param *params,
120 unsigned num_params,
121 s16 min_level,
122 s16 max_level,
123 void *arg,
124 int (*handle_unknown)(char *param, char *val,
125 const char *doing, void *arg))
126{
127 unsigned int i;
128 int err;
129
130 /* Find parameter */
131 for (i = 0; i < num_params; i++) {
132 if (parameq(param, params[i].name)) {
133 if (params[i].level < min_level
134 || params[i].level > max_level)
135 return 0;
136 /* No one handled NULL, so do it here. */
137 if (!val &&
138 !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG))
139 return -EINVAL;
140 pr_debug("handling %s with %p\n", param,
141 params[i].ops->set);
142 kernel_param_lock(params[i].mod);
143 if (param_check_unsafe(&params[i]))
144 err = params[i].ops->set(val, &params[i]);
145 else
146 err = -EPERM;
147 kernel_param_unlock(params[i].mod);
148 return err;
149 }
150 }
151
152 if (handle_unknown) {
153 pr_debug("doing %s: %s='%s'\n", doing, param, val);
154 return handle_unknown(param, val, doing, arg);
155 }
156
157 pr_debug("Unknown argument '%s'\n", param);
158 return -ENOENT;
159}
160
161/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
162char *parse_args(const char *doing,
163 char *args,
164 const struct kernel_param *params,
165 unsigned num,
166 s16 min_level,
167 s16 max_level,
168 void *arg,
169 int (*unknown)(char *param, char *val,
170 const char *doing, void *arg))
171{
172 char *param, *val, *err = NULL;
173
174 /* Chew leading spaces */
175 args = skip_spaces(args);
176
177 if (*args)
178 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
179
180 while (*args) {
181 int ret;
182 int irq_was_disabled;
183
184 args = next_arg(args, &param, &val);
185 /* Stop at -- */
186 if (!val && strcmp(param, "--") == 0)
187 return err ?: args;
188 irq_was_disabled = irqs_disabled();
189 ret = parse_one(param, val, doing, params, num,
190 min_level, max_level, arg, unknown);
191 if (irq_was_disabled && !irqs_disabled())
192 pr_warn("%s: option '%s' enabled irq's!\n",
193 doing, param);
194
195 switch (ret) {
196 case 0:
197 continue;
198 case -ENOENT:
199 pr_err("%s: Unknown parameter `%s'\n", doing, param);
200 break;
201 case -ENOSPC:
202 pr_err("%s: `%s' too large for parameter `%s'\n",
203 doing, val ?: "", param);
204 break;
205 default:
206 pr_err("%s: `%s' invalid for parameter `%s'\n",
207 doing, val ?: "", param);
208 break;
209 }
210
211 err = ERR_PTR(ret);
212 }
213
214 return err;
215}
216
217/* Lazy bastard, eh? */
218#define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
219 int param_set_##name(const char *val, const struct kernel_param *kp) \
220 { \
221 return strtolfn(val, 0, (type *)kp->arg); \
222 } \
223 int param_get_##name(char *buffer, const struct kernel_param *kp) \
224 { \
225 return scnprintf(buffer, PAGE_SIZE, format "\n", \
226 *((type *)kp->arg)); \
227 } \
228 const struct kernel_param_ops param_ops_##name = { \
229 .set = param_set_##name, \
230 .get = param_get_##name, \
231 }; \
232 EXPORT_SYMBOL(param_set_##name); \
233 EXPORT_SYMBOL(param_get_##name); \
234 EXPORT_SYMBOL(param_ops_##name)
235
236
237STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
238STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
239STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
240STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
241STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
242STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
243STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
244STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull);
245STANDARD_PARAM_DEF(hexint, unsigned int, "%#08x", kstrtouint);
246
247int param_set_uint_minmax(const char *val, const struct kernel_param *kp,
248 unsigned int min, unsigned int max)
249{
250 unsigned int num;
251 int ret;
252
253 if (!val)
254 return -EINVAL;
255 ret = kstrtouint(val, 0, &num);
256 if (ret)
257 return ret;
258 if (num < min || num > max)
259 return -EINVAL;
260 *((unsigned int *)kp->arg) = num;
261 return 0;
262}
263EXPORT_SYMBOL_GPL(param_set_uint_minmax);
264
265int param_set_charp(const char *val, const struct kernel_param *kp)
266{
267 if (strlen(val) > 1024) {
268 pr_err("%s: string parameter too long\n", kp->name);
269 return -ENOSPC;
270 }
271
272 maybe_kfree_parameter(*(char **)kp->arg);
273
274 /* This is a hack. We can't kmalloc in early boot, and we
275 * don't need to; this mangled commandline is preserved. */
276 if (slab_is_available()) {
277 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
278 if (!*(char **)kp->arg)
279 return -ENOMEM;
280 strcpy(*(char **)kp->arg, val);
281 } else
282 *(const char **)kp->arg = val;
283
284 return 0;
285}
286EXPORT_SYMBOL(param_set_charp);
287
288int param_get_charp(char *buffer, const struct kernel_param *kp)
289{
290 return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg));
291}
292EXPORT_SYMBOL(param_get_charp);
293
294void param_free_charp(void *arg)
295{
296 maybe_kfree_parameter(*((char **)arg));
297}
298EXPORT_SYMBOL(param_free_charp);
299
300const struct kernel_param_ops param_ops_charp = {
301 .set = param_set_charp,
302 .get = param_get_charp,
303 .free = param_free_charp,
304};
305EXPORT_SYMBOL(param_ops_charp);
306
307/* Actually could be a bool or an int, for historical reasons. */
308int param_set_bool(const char *val, const struct kernel_param *kp)
309{
310 /* No equals means "set"... */
311 if (!val) val = "1";
312
313 /* One of =[yYnN01] */
314 return kstrtobool(val, kp->arg);
315}
316EXPORT_SYMBOL(param_set_bool);
317
318int param_get_bool(char *buffer, const struct kernel_param *kp)
319{
320 /* Y and N chosen as being relatively non-coder friendly */
321 return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N');
322}
323EXPORT_SYMBOL(param_get_bool);
324
325const struct kernel_param_ops param_ops_bool = {
326 .flags = KERNEL_PARAM_OPS_FL_NOARG,
327 .set = param_set_bool,
328 .get = param_get_bool,
329};
330EXPORT_SYMBOL(param_ops_bool);
331
332int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
333{
334 int err;
335 bool new_value;
336 bool orig_value = *(bool *)kp->arg;
337 struct kernel_param dummy_kp = *kp;
338
339 dummy_kp.arg = &new_value;
340
341 err = param_set_bool(val, &dummy_kp);
342 if (err)
343 return err;
344
345 /* Don't let them unset it once it's set! */
346 if (!new_value && orig_value)
347 return -EROFS;
348
349 if (new_value)
350 err = param_set_bool(val, kp);
351
352 return err;
353}
354EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
355
356const struct kernel_param_ops param_ops_bool_enable_only = {
357 .flags = KERNEL_PARAM_OPS_FL_NOARG,
358 .set = param_set_bool_enable_only,
359 .get = param_get_bool,
360};
361EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
362
363/* This one must be bool. */
364int param_set_invbool(const char *val, const struct kernel_param *kp)
365{
366 int ret;
367 bool boolval;
368 struct kernel_param dummy;
369
370 dummy.arg = &boolval;
371 ret = param_set_bool(val, &dummy);
372 if (ret == 0)
373 *(bool *)kp->arg = !boolval;
374 return ret;
375}
376EXPORT_SYMBOL(param_set_invbool);
377
378int param_get_invbool(char *buffer, const struct kernel_param *kp)
379{
380 return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y');
381}
382EXPORT_SYMBOL(param_get_invbool);
383
384const struct kernel_param_ops param_ops_invbool = {
385 .set = param_set_invbool,
386 .get = param_get_invbool,
387};
388EXPORT_SYMBOL(param_ops_invbool);
389
390int param_set_bint(const char *val, const struct kernel_param *kp)
391{
392 /* Match bool exactly, by re-using it. */
393 struct kernel_param boolkp = *kp;
394 bool v;
395 int ret;
396
397 boolkp.arg = &v;
398
399 ret = param_set_bool(val, &boolkp);
400 if (ret == 0)
401 *(int *)kp->arg = v;
402 return ret;
403}
404EXPORT_SYMBOL(param_set_bint);
405
406const struct kernel_param_ops param_ops_bint = {
407 .flags = KERNEL_PARAM_OPS_FL_NOARG,
408 .set = param_set_bint,
409 .get = param_get_int,
410};
411EXPORT_SYMBOL(param_ops_bint);
412
413/* We break the rule and mangle the string. */
414static int param_array(struct module *mod,
415 const char *name,
416 const char *val,
417 unsigned int min, unsigned int max,
418 void *elem, int elemsize,
419 int (*set)(const char *, const struct kernel_param *kp),
420 s16 level,
421 unsigned int *num)
422{
423 int ret;
424 struct kernel_param kp;
425 char save;
426
427 /* Get the name right for errors. */
428 kp.name = name;
429 kp.arg = elem;
430 kp.level = level;
431
432 *num = 0;
433 /* We expect a comma-separated list of values. */
434 do {
435 int len;
436
437 if (*num == max) {
438 pr_err("%s: can only take %i arguments\n", name, max);
439 return -EINVAL;
440 }
441 len = strcspn(val, ",");
442
443 /* nul-terminate and parse */
444 save = val[len];
445 ((char *)val)[len] = '\0';
446 check_kparam_locked(mod);
447 ret = set(val, &kp);
448
449 if (ret != 0)
450 return ret;
451 kp.arg += elemsize;
452 val += len+1;
453 (*num)++;
454 } while (save == ',');
455
456 if (*num < min) {
457 pr_err("%s: needs at least %i arguments\n", name, min);
458 return -EINVAL;
459 }
460 return 0;
461}
462
463static int param_array_set(const char *val, const struct kernel_param *kp)
464{
465 const struct kparam_array *arr = kp->arr;
466 unsigned int temp_num;
467
468 return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem,
469 arr->elemsize, arr->ops->set, kp->level,
470 arr->num ?: &temp_num);
471}
472
473static int param_array_get(char *buffer, const struct kernel_param *kp)
474{
475 int i, off, ret;
476 const struct kparam_array *arr = kp->arr;
477 struct kernel_param p = *kp;
478
479 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
480 /* Replace \n with comma */
481 if (i)
482 buffer[off - 1] = ',';
483 p.arg = arr->elem + arr->elemsize * i;
484 check_kparam_locked(p.mod);
485 ret = arr->ops->get(buffer + off, &p);
486 if (ret < 0)
487 return ret;
488 off += ret;
489 }
490 buffer[off] = '\0';
491 return off;
492}
493
494static void param_array_free(void *arg)
495{
496 unsigned int i;
497 const struct kparam_array *arr = arg;
498
499 if (arr->ops->free)
500 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
501 arr->ops->free(arr->elem + arr->elemsize * i);
502}
503
504const struct kernel_param_ops param_array_ops = {
505 .set = param_array_set,
506 .get = param_array_get,
507 .free = param_array_free,
508};
509EXPORT_SYMBOL(param_array_ops);
510
511int param_set_copystring(const char *val, const struct kernel_param *kp)
512{
513 const struct kparam_string *kps = kp->str;
514
515 if (strlen(val)+1 > kps->maxlen) {
516 pr_err("%s: string doesn't fit in %u chars.\n",
517 kp->name, kps->maxlen-1);
518 return -ENOSPC;
519 }
520 strcpy(kps->string, val);
521 return 0;
522}
523EXPORT_SYMBOL(param_set_copystring);
524
525int param_get_string(char *buffer, const struct kernel_param *kp)
526{
527 const struct kparam_string *kps = kp->str;
528 return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string);
529}
530EXPORT_SYMBOL(param_get_string);
531
532const struct kernel_param_ops param_ops_string = {
533 .set = param_set_copystring,
534 .get = param_get_string,
535};
536EXPORT_SYMBOL(param_ops_string);
537
538/* sysfs output in /sys/modules/XYZ/parameters/ */
539#define to_module_attr(n) container_of(n, struct module_attribute, attr)
540#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
541
542struct param_attribute
543{
544 struct module_attribute mattr;
545 const struct kernel_param *param;
546};
547
548struct module_param_attrs
549{
550 unsigned int num;
551 struct attribute_group grp;
552 struct param_attribute attrs[];
553};
554
555#ifdef CONFIG_SYSFS
556#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
557
558static ssize_t param_attr_show(struct module_attribute *mattr,
559 struct module_kobject *mk, char *buf)
560{
561 int count;
562 struct param_attribute *attribute = to_param_attr(mattr);
563
564 if (!attribute->param->ops->get)
565 return -EPERM;
566
567 kernel_param_lock(mk->mod);
568 count = attribute->param->ops->get(buf, attribute->param);
569 kernel_param_unlock(mk->mod);
570 return count;
571}
572
573/* sysfs always hands a nul-terminated string in buf. We rely on that. */
574static ssize_t param_attr_store(struct module_attribute *mattr,
575 struct module_kobject *mk,
576 const char *buf, size_t len)
577{
578 int err;
579 struct param_attribute *attribute = to_param_attr(mattr);
580
581 if (!attribute->param->ops->set)
582 return -EPERM;
583
584 kernel_param_lock(mk->mod);
585 if (param_check_unsafe(attribute->param))
586 err = attribute->param->ops->set(buf, attribute->param);
587 else
588 err = -EPERM;
589 kernel_param_unlock(mk->mod);
590 if (!err)
591 return len;
592 return err;
593}
594#endif
595
596#ifdef CONFIG_MODULES
597#define __modinit
598#else
599#define __modinit __init
600#endif
601
602#ifdef CONFIG_SYSFS
603void kernel_param_lock(struct module *mod)
604{
605 mutex_lock(KPARAM_MUTEX(mod));
606}
607
608void kernel_param_unlock(struct module *mod)
609{
610 mutex_unlock(KPARAM_MUTEX(mod));
611}
612
613EXPORT_SYMBOL(kernel_param_lock);
614EXPORT_SYMBOL(kernel_param_unlock);
615
616/*
617 * add_sysfs_param - add a parameter to sysfs
618 * @mk: struct module_kobject
619 * @kp: the actual parameter definition to add to sysfs
620 * @name: name of parameter
621 *
622 * Create a kobject if for a (per-module) parameter if mp NULL, and
623 * create file in sysfs. Returns an error on out of memory. Always cleans up
624 * if there's an error.
625 */
626static __modinit int add_sysfs_param(struct module_kobject *mk,
627 const struct kernel_param *kp,
628 const char *name)
629{
630 struct module_param_attrs *new_mp;
631 struct attribute **new_attrs;
632 unsigned int i;
633
634 /* We don't bother calling this with invisible parameters. */
635 BUG_ON(!kp->perm);
636
637 if (!mk->mp) {
638 /* First allocation. */
639 mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
640 if (!mk->mp)
641 return -ENOMEM;
642 mk->mp->grp.name = "parameters";
643 /* NULL-terminated attribute array. */
644 mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
645 GFP_KERNEL);
646 /* Caller will cleanup via free_module_param_attrs */
647 if (!mk->mp->grp.attrs)
648 return -ENOMEM;
649 }
650
651 /* Enlarge allocations. */
652 new_mp = krealloc(mk->mp,
653 sizeof(*mk->mp) +
654 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
655 GFP_KERNEL);
656 if (!new_mp)
657 return -ENOMEM;
658 mk->mp = new_mp;
659
660 /* Extra pointer for NULL terminator */
661 new_attrs = krealloc(mk->mp->grp.attrs,
662 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
663 GFP_KERNEL);
664 if (!new_attrs)
665 return -ENOMEM;
666 mk->mp->grp.attrs = new_attrs;
667
668 /* Tack new one on the end. */
669 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
670 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
671 mk->mp->attrs[mk->mp->num].param = kp;
672 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
673 /* Do not allow runtime DAC changes to make param writable. */
674 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
675 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
676 else
677 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
678 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
679 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
680 mk->mp->num++;
681
682 /* Fix up all the pointers, since krealloc can move us */
683 for (i = 0; i < mk->mp->num; i++)
684 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
685 mk->mp->grp.attrs[mk->mp->num] = NULL;
686 return 0;
687}
688
689#ifdef CONFIG_MODULES
690static void free_module_param_attrs(struct module_kobject *mk)
691{
692 if (mk->mp)
693 kfree(mk->mp->grp.attrs);
694 kfree(mk->mp);
695 mk->mp = NULL;
696}
697
698/*
699 * module_param_sysfs_setup - setup sysfs support for one module
700 * @mod: module
701 * @kparam: module parameters (array)
702 * @num_params: number of module parameters
703 *
704 * Adds sysfs entries for module parameters under
705 * /sys/module/[mod->name]/parameters/
706 */
707int module_param_sysfs_setup(struct module *mod,
708 const struct kernel_param *kparam,
709 unsigned int num_params)
710{
711 int i, err;
712 bool params = false;
713
714 for (i = 0; i < num_params; i++) {
715 if (kparam[i].perm == 0)
716 continue;
717 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
718 if (err) {
719 free_module_param_attrs(&mod->mkobj);
720 return err;
721 }
722 params = true;
723 }
724
725 if (!params)
726 return 0;
727
728 /* Create the param group. */
729 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
730 if (err)
731 free_module_param_attrs(&mod->mkobj);
732 return err;
733}
734
735/*
736 * module_param_sysfs_remove - remove sysfs support for one module
737 * @mod: module
738 *
739 * Remove sysfs entries for module parameters and the corresponding
740 * kobject.
741 */
742void module_param_sysfs_remove(struct module *mod)
743{
744 if (mod->mkobj.mp) {
745 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
746 /* We are positive that no one is using any param
747 * attrs at this point. Deallocate immediately. */
748 free_module_param_attrs(&mod->mkobj);
749 }
750}
751#endif
752
753void destroy_params(const struct kernel_param *params, unsigned num)
754{
755 unsigned int i;
756
757 for (i = 0; i < num; i++)
758 if (params[i].ops->free)
759 params[i].ops->free(params[i].arg);
760}
761
762static struct module_kobject * __init locate_module_kobject(const char *name)
763{
764 struct module_kobject *mk;
765 struct kobject *kobj;
766 int err;
767
768 kobj = kset_find_obj(module_kset, name);
769 if (kobj) {
770 mk = to_module_kobject(kobj);
771 } else {
772 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
773 BUG_ON(!mk);
774
775 mk->mod = THIS_MODULE;
776 mk->kobj.kset = module_kset;
777 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
778 "%s", name);
779#ifdef CONFIG_MODULES
780 if (!err)
781 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
782#endif
783 if (err) {
784 kobject_put(&mk->kobj);
785 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
786 name, err);
787 return NULL;
788 }
789
790 /* So that we hold reference in both cases. */
791 kobject_get(&mk->kobj);
792 }
793
794 return mk;
795}
796
797static void __init kernel_add_sysfs_param(const char *name,
798 const struct kernel_param *kparam,
799 unsigned int name_skip)
800{
801 struct module_kobject *mk;
802 int err;
803
804 mk = locate_module_kobject(name);
805 if (!mk)
806 return;
807
808 /* We need to remove old parameters before adding more. */
809 if (mk->mp)
810 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
811
812 /* These should not fail at boot. */
813 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
814 BUG_ON(err);
815 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
816 BUG_ON(err);
817 kobject_uevent(&mk->kobj, KOBJ_ADD);
818 kobject_put(&mk->kobj);
819}
820
821/*
822 * param_sysfs_builtin - add sysfs parameters for built-in modules
823 *
824 * Add module_parameters to sysfs for "modules" built into the kernel.
825 *
826 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
827 * "parameter" name is stored behind a dot in kernel_param->name. So,
828 * extract the "module" name for all built-in kernel_param-eters,
829 * and for all who have the same, call kernel_add_sysfs_param.
830 */
831static void __init param_sysfs_builtin(void)
832{
833 const struct kernel_param *kp;
834 unsigned int name_len;
835 char modname[MODULE_NAME_LEN];
836
837 for (kp = __start___param; kp < __stop___param; kp++) {
838 char *dot;
839
840 if (kp->perm == 0)
841 continue;
842
843 dot = strchr(kp->name, '.');
844 if (!dot) {
845 /* This happens for core_param() */
846 strcpy(modname, "kernel");
847 name_len = 0;
848 } else {
849 name_len = dot - kp->name + 1;
850 strscpy(modname, kp->name, name_len);
851 }
852 kernel_add_sysfs_param(modname, kp, name_len);
853 }
854}
855
856ssize_t __modver_version_show(struct module_attribute *mattr,
857 struct module_kobject *mk, char *buf)
858{
859 struct module_version_attribute *vattr =
860 container_of(mattr, struct module_version_attribute, mattr);
861
862 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
863}
864
865extern const struct module_version_attribute __start___modver[];
866extern const struct module_version_attribute __stop___modver[];
867
868static void __init version_sysfs_builtin(void)
869{
870 const struct module_version_attribute *vattr;
871 struct module_kobject *mk;
872 int err;
873
874 for (vattr = __start___modver; vattr < __stop___modver; vattr++) {
875 mk = locate_module_kobject(vattr->module_name);
876 if (mk) {
877 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
878 WARN_ON_ONCE(err);
879 kobject_uevent(&mk->kobj, KOBJ_ADD);
880 kobject_put(&mk->kobj);
881 }
882 }
883}
884
885/* module-related sysfs stuff */
886
887static ssize_t module_attr_show(struct kobject *kobj,
888 struct attribute *attr,
889 char *buf)
890{
891 struct module_attribute *attribute;
892 struct module_kobject *mk;
893 int ret;
894
895 attribute = to_module_attr(attr);
896 mk = to_module_kobject(kobj);
897
898 if (!attribute->show)
899 return -EIO;
900
901 ret = attribute->show(attribute, mk, buf);
902
903 return ret;
904}
905
906static ssize_t module_attr_store(struct kobject *kobj,
907 struct attribute *attr,
908 const char *buf, size_t len)
909{
910 struct module_attribute *attribute;
911 struct module_kobject *mk;
912 int ret;
913
914 attribute = to_module_attr(attr);
915 mk = to_module_kobject(kobj);
916
917 if (!attribute->store)
918 return -EIO;
919
920 ret = attribute->store(attribute, mk, buf, len);
921
922 return ret;
923}
924
925static const struct sysfs_ops module_sysfs_ops = {
926 .show = module_attr_show,
927 .store = module_attr_store,
928};
929
930static int uevent_filter(const struct kobject *kobj)
931{
932 const struct kobj_type *ktype = get_ktype(kobj);
933
934 if (ktype == &module_ktype)
935 return 1;
936 return 0;
937}
938
939static const struct kset_uevent_ops module_uevent_ops = {
940 .filter = uevent_filter,
941};
942
943struct kset *module_kset;
944
945static void module_kobj_release(struct kobject *kobj)
946{
947 struct module_kobject *mk = to_module_kobject(kobj);
948 complete(mk->kobj_completion);
949}
950
951const 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 */
963static int __init param_sysfs_init(void)
964{
965 module_kset = kset_create_and_add("module", &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}
974subsys_initcall(param_sysfs_init);
975
976/*
977 * param_sysfs_builtin_init - add sysfs version and parameter
978 * attributes for built-in modules
979 */
980static 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}
990late_initcall(param_sysfs_builtin_init);
991
992#endif /* CONFIG_SYSFS */