Loading...
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 : ¶m_lock)
26#else
27#define KPARAM_MUTEX(mod) (¶m_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(¶ms[i]))
143 err = params[i].ops->set(val, ¶ms[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, ¶m, &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(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[];
555};
556
557#ifdef CONFIG_SYSFS
558#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
559
560static ssize_t param_attr_show(struct module_attribute *mattr,
561 struct module_kobject *mk, char *buf)
562{
563 int count;
564 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(struct module_attribute *mattr,
577 struct module_kobject *mk,
578 const char *buf, size_t len)
579{
580 int err;
581 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,
655 sizeof(*mk->mp) +
656 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
657 GFP_KERNEL);
658 if (!new_mp)
659 return -ENOMEM;
660 mk->mp = new_mp;
661
662 /* Extra pointer for NULL terminator */
663 new_attrs = krealloc(mk->mp->grp.attrs,
664 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
665 GFP_KERNEL);
666 if (!new_attrs)
667 return -ENOMEM;
668 mk->mp->grp.attrs = new_attrs;
669
670 /* Tack new one on the end. */
671 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
672 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
673 mk->mp->attrs[mk->mp->num].param = kp;
674 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
675 /* Do not allow runtime DAC changes to make param writable. */
676 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
677 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
678 else
679 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
680 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
681 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
682 mk->mp->num++;
683
684 /* Fix up all the pointers, since krealloc can move us */
685 for (i = 0; i < mk->mp->num; i++)
686 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
687 mk->mp->grp.attrs[mk->mp->num] = NULL;
688 return 0;
689}
690
691#ifdef CONFIG_MODULES
692static void free_module_param_attrs(struct module_kobject *mk)
693{
694 if (mk->mp)
695 kfree(mk->mp->grp.attrs);
696 kfree(mk->mp);
697 mk->mp = NULL;
698}
699
700/*
701 * module_param_sysfs_setup - setup sysfs support for one module
702 * @mod: module
703 * @kparam: module parameters (array)
704 * @num_params: number of module parameters
705 *
706 * Adds sysfs entries for module parameters under
707 * /sys/module/[mod->name]/parameters/
708 */
709int module_param_sysfs_setup(struct module *mod,
710 const struct kernel_param *kparam,
711 unsigned int num_params)
712{
713 int i, err;
714 bool params = false;
715
716 for (i = 0; i < num_params; i++) {
717 if (kparam[i].perm == 0)
718 continue;
719 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
720 if (err) {
721 free_module_param_attrs(&mod->mkobj);
722 return err;
723 }
724 params = true;
725 }
726
727 if (!params)
728 return 0;
729
730 /* Create the param group. */
731 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
732 if (err)
733 free_module_param_attrs(&mod->mkobj);
734 return err;
735}
736
737/*
738 * module_param_sysfs_remove - remove sysfs support for one module
739 * @mod: module
740 *
741 * Remove sysfs entries for module parameters and the corresponding
742 * kobject.
743 */
744void module_param_sysfs_remove(struct module *mod)
745{
746 if (mod->mkobj.mp) {
747 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
748 /*
749 * We are positive that no one is using any param
750 * attrs at this point. Deallocate immediately.
751 */
752 free_module_param_attrs(&mod->mkobj);
753 }
754}
755#endif
756
757void destroy_params(const struct kernel_param *params, unsigned num)
758{
759 unsigned int i;
760
761 for (i = 0; i < num; i++)
762 if (params[i].ops->free)
763 params[i].ops->free(params[i].arg);
764}
765
766static struct module_kobject * __init locate_module_kobject(const char *name)
767{
768 struct module_kobject *mk;
769 struct kobject *kobj;
770 int err;
771
772 kobj = kset_find_obj(module_kset, name);
773 if (kobj) {
774 mk = to_module_kobject(kobj);
775 } else {
776 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
777 BUG_ON(!mk);
778
779 mk->mod = THIS_MODULE;
780 mk->kobj.kset = module_kset;
781 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
782 "%s", name);
783#ifdef CONFIG_MODULES
784 if (!err)
785 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
786#endif
787 if (err) {
788 kobject_put(&mk->kobj);
789 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
790 name, err);
791 return NULL;
792 }
793
794 /* So that we hold reference in both cases. */
795 kobject_get(&mk->kobj);
796 }
797
798 return mk;
799}
800
801static void __init kernel_add_sysfs_param(const char *name,
802 const struct kernel_param *kparam,
803 unsigned int name_skip)
804{
805 struct module_kobject *mk;
806 int err;
807
808 mk = locate_module_kobject(name);
809 if (!mk)
810 return;
811
812 /* We need to remove old parameters before adding more. */
813 if (mk->mp)
814 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
815
816 /* These should not fail at boot. */
817 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
818 BUG_ON(err);
819 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
820 BUG_ON(err);
821 kobject_uevent(&mk->kobj, KOBJ_ADD);
822 kobject_put(&mk->kobj);
823}
824
825/*
826 * param_sysfs_builtin - add sysfs parameters for built-in modules
827 *
828 * Add module_parameters to sysfs for "modules" built into the kernel.
829 *
830 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
831 * "parameter" name is stored behind a dot in kernel_param->name. So,
832 * extract the "module" name for all built-in kernel_param-eters,
833 * and for all who have the same, call kernel_add_sysfs_param.
834 */
835static void __init param_sysfs_builtin(void)
836{
837 const struct kernel_param *kp;
838 unsigned int name_len;
839 char modname[MODULE_NAME_LEN];
840
841 for (kp = __start___param; kp < __stop___param; kp++) {
842 char *dot;
843
844 if (kp->perm == 0)
845 continue;
846
847 dot = strchr(kp->name, '.');
848 if (!dot) {
849 /* This happens for core_param() */
850 strcpy(modname, "kernel");
851 name_len = 0;
852 } else {
853 name_len = dot - kp->name + 1;
854 strscpy(modname, kp->name, name_len);
855 }
856 kernel_add_sysfs_param(modname, kp, name_len);
857 }
858}
859
860ssize_t __modver_version_show(struct module_attribute *mattr,
861 struct module_kobject *mk, char *buf)
862{
863 struct module_version_attribute *vattr =
864 container_of(mattr, struct module_version_attribute, mattr);
865
866 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
867}
868
869extern const struct module_version_attribute __start___modver[];
870extern const struct module_version_attribute __stop___modver[];
871
872static void __init version_sysfs_builtin(void)
873{
874 const struct module_version_attribute *vattr;
875 struct module_kobject *mk;
876 int err;
877
878 for (vattr = __start___modver; vattr < __stop___modver; vattr++) {
879 mk = locate_module_kobject(vattr->module_name);
880 if (mk) {
881 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
882 WARN_ON_ONCE(err);
883 kobject_uevent(&mk->kobj, KOBJ_ADD);
884 kobject_put(&mk->kobj);
885 }
886 }
887}
888
889/* module-related sysfs stuff */
890
891static ssize_t module_attr_show(struct kobject *kobj,
892 struct attribute *attr,
893 char *buf)
894{
895 struct module_attribute *attribute;
896 struct module_kobject *mk;
897 int ret;
898
899 attribute = to_module_attr(attr);
900 mk = to_module_kobject(kobj);
901
902 if (!attribute->show)
903 return -EIO;
904
905 ret = attribute->show(attribute, mk, buf);
906
907 return ret;
908}
909
910static ssize_t module_attr_store(struct kobject *kobj,
911 struct attribute *attr,
912 const char *buf, size_t len)
913{
914 struct module_attribute *attribute;
915 struct module_kobject *mk;
916 int ret;
917
918 attribute = to_module_attr(attr);
919 mk = to_module_kobject(kobj);
920
921 if (!attribute->store)
922 return -EIO;
923
924 ret = attribute->store(attribute, mk, buf, len);
925
926 return ret;
927}
928
929static const struct sysfs_ops module_sysfs_ops = {
930 .show = module_attr_show,
931 .store = module_attr_store,
932};
933
934static int uevent_filter(const struct kobject *kobj)
935{
936 const struct kobj_type *ktype = get_ktype(kobj);
937
938 if (ktype == &module_ktype)
939 return 1;
940 return 0;
941}
942
943static const struct kset_uevent_ops module_uevent_ops = {
944 .filter = uevent_filter,
945};
946
947struct kset *module_kset;
948
949static void module_kobj_release(struct kobject *kobj)
950{
951 struct module_kobject *mk = to_module_kobject(kobj);
952 complete(mk->kobj_completion);
953}
954
955const struct kobj_type module_ktype = {
956 .release = module_kobj_release,
957 .sysfs_ops = &module_sysfs_ops,
958};
959
960/*
961 * param_sysfs_init - create "module" kset
962 *
963 * This must be done before the initramfs is unpacked and
964 * request_module() thus becomes possible, because otherwise the
965 * module load would fail in mod_sysfs_init.
966 */
967static int __init param_sysfs_init(void)
968{
969 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
970 if (!module_kset) {
971 printk(KERN_WARNING "%s (%d): error creating kset\n",
972 __FILE__, __LINE__);
973 return -ENOMEM;
974 }
975
976 return 0;
977}
978subsys_initcall(param_sysfs_init);
979
980/*
981 * param_sysfs_builtin_init - add sysfs version and parameter
982 * attributes for built-in modules
983 */
984static int __init param_sysfs_builtin_init(void)
985{
986 if (!module_kset)
987 return -ENOMEM;
988
989 version_sysfs_builtin();
990 param_sysfs_builtin();
991
992 return 0;
993}
994late_initcall(param_sysfs_builtin_init);
995
996#endif /* CONFIG_SYSFS */
1/* Helpers for initial module or kernel cmdline parsing
2 Copyright (C) 2001 Rusty Russell.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17*/
18#include <linux/moduleparam.h>
19#include <linux/kernel.h>
20#include <linux/string.h>
21#include <linux/errno.h>
22#include <linux/module.h>
23#include <linux/device.h>
24#include <linux/err.h>
25#include <linux/slab.h>
26#include <linux/ctype.h>
27
28#if 0
29#define DEBUGP printk
30#else
31#define DEBUGP(fmt, a...)
32#endif
33
34/* Protects all parameters, and incidentally kmalloced_param list. */
35static DEFINE_MUTEX(param_lock);
36
37/* This just allows us to keep track of which parameters are kmalloced. */
38struct kmalloced_param {
39 struct list_head list;
40 char val[];
41};
42static LIST_HEAD(kmalloced_params);
43
44static void *kmalloc_parameter(unsigned int size)
45{
46 struct kmalloced_param *p;
47
48 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
49 if (!p)
50 return NULL;
51
52 list_add(&p->list, &kmalloced_params);
53 return p->val;
54}
55
56/* Does nothing if parameter wasn't kmalloced above. */
57static void maybe_kfree_parameter(void *param)
58{
59 struct kmalloced_param *p;
60
61 list_for_each_entry(p, &kmalloced_params, list) {
62 if (p->val == param) {
63 list_del(&p->list);
64 kfree(p);
65 break;
66 }
67 }
68}
69
70static inline char dash2underscore(char c)
71{
72 if (c == '-')
73 return '_';
74 return c;
75}
76
77static inline int parameq(const char *input, const char *paramname)
78{
79 unsigned int i;
80 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
81 if (input[i] == '\0')
82 return 1;
83 return 0;
84}
85
86static int parse_one(char *param,
87 char *val,
88 const struct kernel_param *params,
89 unsigned num_params,
90 int (*handle_unknown)(char *param, char *val))
91{
92 unsigned int i;
93 int err;
94
95 /* Find parameter */
96 for (i = 0; i < num_params; i++) {
97 if (parameq(param, params[i].name)) {
98 /* No one handled NULL, so do it here. */
99 if (!val && params[i].ops->set != param_set_bool)
100 return -EINVAL;
101 DEBUGP("They are equal! Calling %p\n",
102 params[i].ops->set);
103 mutex_lock(¶m_lock);
104 err = params[i].ops->set(val, ¶ms[i]);
105 mutex_unlock(¶m_lock);
106 return err;
107 }
108 }
109
110 if (handle_unknown) {
111 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
112 return handle_unknown(param, val);
113 }
114
115 DEBUGP("Unknown argument `%s'\n", param);
116 return -ENOENT;
117}
118
119/* You can use " around spaces, but can't escape ". */
120/* Hyphens and underscores equivalent in parameter names. */
121static char *next_arg(char *args, char **param, char **val)
122{
123 unsigned int i, equals = 0;
124 int in_quote = 0, quoted = 0;
125 char *next;
126
127 if (*args == '"') {
128 args++;
129 in_quote = 1;
130 quoted = 1;
131 }
132
133 for (i = 0; args[i]; i++) {
134 if (isspace(args[i]) && !in_quote)
135 break;
136 if (equals == 0) {
137 if (args[i] == '=')
138 equals = i;
139 }
140 if (args[i] == '"')
141 in_quote = !in_quote;
142 }
143
144 *param = args;
145 if (!equals)
146 *val = NULL;
147 else {
148 args[equals] = '\0';
149 *val = args + equals + 1;
150
151 /* Don't include quotes in value. */
152 if (**val == '"') {
153 (*val)++;
154 if (args[i-1] == '"')
155 args[i-1] = '\0';
156 }
157 if (quoted && args[i-1] == '"')
158 args[i-1] = '\0';
159 }
160
161 if (args[i]) {
162 args[i] = '\0';
163 next = args + i + 1;
164 } else
165 next = args + i;
166
167 /* Chew up trailing spaces. */
168 return skip_spaces(next);
169}
170
171/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
172int parse_args(const char *name,
173 char *args,
174 const struct kernel_param *params,
175 unsigned num,
176 int (*unknown)(char *param, char *val))
177{
178 char *param, *val;
179
180 DEBUGP("Parsing ARGS: %s\n", args);
181
182 /* Chew leading spaces */
183 args = skip_spaces(args);
184
185 while (*args) {
186 int ret;
187 int irq_was_disabled;
188
189 args = next_arg(args, ¶m, &val);
190 irq_was_disabled = irqs_disabled();
191 ret = parse_one(param, val, params, num, unknown);
192 if (irq_was_disabled && !irqs_disabled()) {
193 printk(KERN_WARNING "parse_args(): option '%s' enabled "
194 "irq's!\n", param);
195 }
196 switch (ret) {
197 case -ENOENT:
198 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
199 name, param);
200 return ret;
201 case -ENOSPC:
202 printk(KERN_ERR
203 "%s: `%s' too large for parameter `%s'\n",
204 name, val ?: "", param);
205 return ret;
206 case 0:
207 break;
208 default:
209 printk(KERN_ERR
210 "%s: `%s' invalid for parameter `%s'\n",
211 name, val ?: "", param);
212 return ret;
213 }
214 }
215
216 /* All parsed OK. */
217 return 0;
218}
219
220/* Lazy bastard, eh? */
221#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
222 int param_set_##name(const char *val, const struct kernel_param *kp) \
223 { \
224 tmptype l; \
225 int ret; \
226 \
227 ret = strtolfn(val, 0, &l); \
228 if (ret < 0 || ((type)l != l)) \
229 return ret < 0 ? ret : -EINVAL; \
230 *((type *)kp->arg) = l; \
231 return 0; \
232 } \
233 int param_get_##name(char *buffer, const struct kernel_param *kp) \
234 { \
235 return sprintf(buffer, format, *((type *)kp->arg)); \
236 } \
237 struct kernel_param_ops param_ops_##name = { \
238 .set = param_set_##name, \
239 .get = param_get_##name, \
240 }; \
241 EXPORT_SYMBOL(param_set_##name); \
242 EXPORT_SYMBOL(param_get_##name); \
243 EXPORT_SYMBOL(param_ops_##name)
244
245
246STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
247STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
248STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
249STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
250STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
251STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
252STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
253
254int param_set_charp(const char *val, const struct kernel_param *kp)
255{
256 if (strlen(val) > 1024) {
257 printk(KERN_ERR "%s: string parameter too long\n",
258 kp->name);
259 return -ENOSPC;
260 }
261
262 maybe_kfree_parameter(*(char **)kp->arg);
263
264 /* This is a hack. We can't kmalloc in early boot, and we
265 * don't need to; this mangled commandline is preserved. */
266 if (slab_is_available()) {
267 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
268 if (!*(char **)kp->arg)
269 return -ENOMEM;
270 strcpy(*(char **)kp->arg, val);
271 } else
272 *(const char **)kp->arg = val;
273
274 return 0;
275}
276EXPORT_SYMBOL(param_set_charp);
277
278int param_get_charp(char *buffer, const struct kernel_param *kp)
279{
280 return sprintf(buffer, "%s", *((char **)kp->arg));
281}
282EXPORT_SYMBOL(param_get_charp);
283
284static void param_free_charp(void *arg)
285{
286 maybe_kfree_parameter(*((char **)arg));
287}
288
289struct kernel_param_ops param_ops_charp = {
290 .set = param_set_charp,
291 .get = param_get_charp,
292 .free = param_free_charp,
293};
294EXPORT_SYMBOL(param_ops_charp);
295
296/* Actually could be a bool or an int, for historical reasons. */
297int param_set_bool(const char *val, const struct kernel_param *kp)
298{
299 bool v;
300 int ret;
301
302 /* No equals means "set"... */
303 if (!val) val = "1";
304
305 /* One of =[yYnN01] */
306 ret = strtobool(val, &v);
307 if (ret)
308 return ret;
309
310 if (kp->flags & KPARAM_ISBOOL)
311 *(bool *)kp->arg = v;
312 else
313 *(int *)kp->arg = v;
314 return 0;
315}
316EXPORT_SYMBOL(param_set_bool);
317
318int param_get_bool(char *buffer, const struct kernel_param *kp)
319{
320 bool val;
321 if (kp->flags & KPARAM_ISBOOL)
322 val = *(bool *)kp->arg;
323 else
324 val = *(int *)kp->arg;
325
326 /* Y and N chosen as being relatively non-coder friendly */
327 return sprintf(buffer, "%c", val ? 'Y' : 'N');
328}
329EXPORT_SYMBOL(param_get_bool);
330
331struct kernel_param_ops param_ops_bool = {
332 .set = param_set_bool,
333 .get = param_get_bool,
334};
335EXPORT_SYMBOL(param_ops_bool);
336
337/* This one must be bool. */
338int param_set_invbool(const char *val, const struct kernel_param *kp)
339{
340 int ret;
341 bool boolval;
342 struct kernel_param dummy;
343
344 dummy.arg = &boolval;
345 dummy.flags = KPARAM_ISBOOL;
346 ret = param_set_bool(val, &dummy);
347 if (ret == 0)
348 *(bool *)kp->arg = !boolval;
349 return ret;
350}
351EXPORT_SYMBOL(param_set_invbool);
352
353int param_get_invbool(char *buffer, const struct kernel_param *kp)
354{
355 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
356}
357EXPORT_SYMBOL(param_get_invbool);
358
359struct kernel_param_ops param_ops_invbool = {
360 .set = param_set_invbool,
361 .get = param_get_invbool,
362};
363EXPORT_SYMBOL(param_ops_invbool);
364
365/* We break the rule and mangle the string. */
366static int param_array(const char *name,
367 const char *val,
368 unsigned int min, unsigned int max,
369 void *elem, int elemsize,
370 int (*set)(const char *, const struct kernel_param *kp),
371 u16 flags,
372 unsigned int *num)
373{
374 int ret;
375 struct kernel_param kp;
376 char save;
377
378 /* Get the name right for errors. */
379 kp.name = name;
380 kp.arg = elem;
381 kp.flags = flags;
382
383 *num = 0;
384 /* We expect a comma-separated list of values. */
385 do {
386 int len;
387
388 if (*num == max) {
389 printk(KERN_ERR "%s: can only take %i arguments\n",
390 name, max);
391 return -EINVAL;
392 }
393 len = strcspn(val, ",");
394
395 /* nul-terminate and parse */
396 save = val[len];
397 ((char *)val)[len] = '\0';
398 BUG_ON(!mutex_is_locked(¶m_lock));
399 ret = set(val, &kp);
400
401 if (ret != 0)
402 return ret;
403 kp.arg += elemsize;
404 val += len+1;
405 (*num)++;
406 } while (save == ',');
407
408 if (*num < min) {
409 printk(KERN_ERR "%s: needs at least %i arguments\n",
410 name, min);
411 return -EINVAL;
412 }
413 return 0;
414}
415
416static int param_array_set(const char *val, const struct kernel_param *kp)
417{
418 const struct kparam_array *arr = kp->arr;
419 unsigned int temp_num;
420
421 return param_array(kp->name, val, 1, arr->max, arr->elem,
422 arr->elemsize, arr->ops->set, kp->flags,
423 arr->num ?: &temp_num);
424}
425
426static int param_array_get(char *buffer, const struct kernel_param *kp)
427{
428 int i, off, ret;
429 const struct kparam_array *arr = kp->arr;
430 struct kernel_param p;
431
432 p = *kp;
433 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
434 if (i)
435 buffer[off++] = ',';
436 p.arg = arr->elem + arr->elemsize * i;
437 BUG_ON(!mutex_is_locked(¶m_lock));
438 ret = arr->ops->get(buffer + off, &p);
439 if (ret < 0)
440 return ret;
441 off += ret;
442 }
443 buffer[off] = '\0';
444 return off;
445}
446
447static void param_array_free(void *arg)
448{
449 unsigned int i;
450 const struct kparam_array *arr = arg;
451
452 if (arr->ops->free)
453 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
454 arr->ops->free(arr->elem + arr->elemsize * i);
455}
456
457struct kernel_param_ops param_array_ops = {
458 .set = param_array_set,
459 .get = param_array_get,
460 .free = param_array_free,
461};
462EXPORT_SYMBOL(param_array_ops);
463
464int param_set_copystring(const char *val, const struct kernel_param *kp)
465{
466 const struct kparam_string *kps = kp->str;
467
468 if (strlen(val)+1 > kps->maxlen) {
469 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
470 kp->name, kps->maxlen-1);
471 return -ENOSPC;
472 }
473 strcpy(kps->string, val);
474 return 0;
475}
476EXPORT_SYMBOL(param_set_copystring);
477
478int param_get_string(char *buffer, const struct kernel_param *kp)
479{
480 const struct kparam_string *kps = kp->str;
481 return strlcpy(buffer, kps->string, kps->maxlen);
482}
483EXPORT_SYMBOL(param_get_string);
484
485struct kernel_param_ops param_ops_string = {
486 .set = param_set_copystring,
487 .get = param_get_string,
488};
489EXPORT_SYMBOL(param_ops_string);
490
491/* sysfs output in /sys/modules/XYZ/parameters/ */
492#define to_module_attr(n) container_of(n, struct module_attribute, attr)
493#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
494
495extern struct kernel_param __start___param[], __stop___param[];
496
497struct param_attribute
498{
499 struct module_attribute mattr;
500 const struct kernel_param *param;
501};
502
503struct module_param_attrs
504{
505 unsigned int num;
506 struct attribute_group grp;
507 struct param_attribute attrs[0];
508};
509
510#ifdef CONFIG_SYSFS
511#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
512
513static ssize_t param_attr_show(struct module_attribute *mattr,
514 struct module_kobject *mk, char *buf)
515{
516 int count;
517 struct param_attribute *attribute = to_param_attr(mattr);
518
519 if (!attribute->param->ops->get)
520 return -EPERM;
521
522 mutex_lock(¶m_lock);
523 count = attribute->param->ops->get(buf, attribute->param);
524 mutex_unlock(¶m_lock);
525 if (count > 0) {
526 strcat(buf, "\n");
527 ++count;
528 }
529 return count;
530}
531
532/* sysfs always hands a nul-terminated string in buf. We rely on that. */
533static ssize_t param_attr_store(struct module_attribute *mattr,
534 struct module_kobject *km,
535 const char *buf, size_t len)
536{
537 int err;
538 struct param_attribute *attribute = to_param_attr(mattr);
539
540 if (!attribute->param->ops->set)
541 return -EPERM;
542
543 mutex_lock(¶m_lock);
544 err = attribute->param->ops->set(buf, attribute->param);
545 mutex_unlock(¶m_lock);
546 if (!err)
547 return len;
548 return err;
549}
550#endif
551
552#ifdef CONFIG_MODULES
553#define __modinit
554#else
555#define __modinit __init
556#endif
557
558#ifdef CONFIG_SYSFS
559void __kernel_param_lock(void)
560{
561 mutex_lock(¶m_lock);
562}
563EXPORT_SYMBOL(__kernel_param_lock);
564
565void __kernel_param_unlock(void)
566{
567 mutex_unlock(¶m_lock);
568}
569EXPORT_SYMBOL(__kernel_param_unlock);
570
571/*
572 * add_sysfs_param - add a parameter to sysfs
573 * @mk: struct module_kobject
574 * @kparam: the actual parameter definition to add to sysfs
575 * @name: name of parameter
576 *
577 * Create a kobject if for a (per-module) parameter if mp NULL, and
578 * create file in sysfs. Returns an error on out of memory. Always cleans up
579 * if there's an error.
580 */
581static __modinit int add_sysfs_param(struct module_kobject *mk,
582 const struct kernel_param *kp,
583 const char *name)
584{
585 struct module_param_attrs *new;
586 struct attribute **attrs;
587 int err, num;
588
589 /* We don't bother calling this with invisible parameters. */
590 BUG_ON(!kp->perm);
591
592 if (!mk->mp) {
593 num = 0;
594 attrs = NULL;
595 } else {
596 num = mk->mp->num;
597 attrs = mk->mp->grp.attrs;
598 }
599
600 /* Enlarge. */
601 new = krealloc(mk->mp,
602 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
603 GFP_KERNEL);
604 if (!new) {
605 kfree(mk->mp);
606 err = -ENOMEM;
607 goto fail;
608 }
609 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
610 if (!attrs) {
611 err = -ENOMEM;
612 goto fail_free_new;
613 }
614
615 /* Sysfs wants everything zeroed. */
616 memset(new, 0, sizeof(*new));
617 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
618 memset(&attrs[num], 0, sizeof(attrs[num]));
619 new->grp.name = "parameters";
620 new->grp.attrs = attrs;
621
622 /* Tack new one on the end. */
623 sysfs_attr_init(&new->attrs[num].mattr.attr);
624 new->attrs[num].param = kp;
625 new->attrs[num].mattr.show = param_attr_show;
626 new->attrs[num].mattr.store = param_attr_store;
627 new->attrs[num].mattr.attr.name = (char *)name;
628 new->attrs[num].mattr.attr.mode = kp->perm;
629 new->num = num+1;
630
631 /* Fix up all the pointers, since krealloc can move us */
632 for (num = 0; num < new->num; num++)
633 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
634 new->grp.attrs[num] = NULL;
635
636 mk->mp = new;
637 return 0;
638
639fail_free_new:
640 kfree(new);
641fail:
642 mk->mp = NULL;
643 return err;
644}
645
646#ifdef CONFIG_MODULES
647static void free_module_param_attrs(struct module_kobject *mk)
648{
649 kfree(mk->mp->grp.attrs);
650 kfree(mk->mp);
651 mk->mp = NULL;
652}
653
654/*
655 * module_param_sysfs_setup - setup sysfs support for one module
656 * @mod: module
657 * @kparam: module parameters (array)
658 * @num_params: number of module parameters
659 *
660 * Adds sysfs entries for module parameters under
661 * /sys/module/[mod->name]/parameters/
662 */
663int module_param_sysfs_setup(struct module *mod,
664 const struct kernel_param *kparam,
665 unsigned int num_params)
666{
667 int i, err;
668 bool params = false;
669
670 for (i = 0; i < num_params; i++) {
671 if (kparam[i].perm == 0)
672 continue;
673 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
674 if (err)
675 return err;
676 params = true;
677 }
678
679 if (!params)
680 return 0;
681
682 /* Create the param group. */
683 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
684 if (err)
685 free_module_param_attrs(&mod->mkobj);
686 return err;
687}
688
689/*
690 * module_param_sysfs_remove - remove sysfs support for one module
691 * @mod: module
692 *
693 * Remove sysfs entries for module parameters and the corresponding
694 * kobject.
695 */
696void module_param_sysfs_remove(struct module *mod)
697{
698 if (mod->mkobj.mp) {
699 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
700 /* We are positive that no one is using any param
701 * attrs at this point. Deallocate immediately. */
702 free_module_param_attrs(&mod->mkobj);
703 }
704}
705#endif
706
707void destroy_params(const struct kernel_param *params, unsigned num)
708{
709 unsigned int i;
710
711 for (i = 0; i < num; i++)
712 if (params[i].ops->free)
713 params[i].ops->free(params[i].arg);
714}
715
716static struct module_kobject * __init locate_module_kobject(const char *name)
717{
718 struct module_kobject *mk;
719 struct kobject *kobj;
720 int err;
721
722 kobj = kset_find_obj(module_kset, name);
723 if (kobj) {
724 mk = to_module_kobject(kobj);
725 } else {
726 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
727 BUG_ON(!mk);
728
729 mk->mod = THIS_MODULE;
730 mk->kobj.kset = module_kset;
731 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
732 "%s", name);
733#ifdef CONFIG_MODULES
734 if (!err)
735 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
736#endif
737 if (err) {
738 kobject_put(&mk->kobj);
739 printk(KERN_ERR
740 "Module '%s' failed add to sysfs, error number %d\n",
741 name, err);
742 printk(KERN_ERR
743 "The system will be unstable now.\n");
744 return NULL;
745 }
746
747 /* So that we hold reference in both cases. */
748 kobject_get(&mk->kobj);
749 }
750
751 return mk;
752}
753
754static void __init kernel_add_sysfs_param(const char *name,
755 struct kernel_param *kparam,
756 unsigned int name_skip)
757{
758 struct module_kobject *mk;
759 int err;
760
761 mk = locate_module_kobject(name);
762 if (!mk)
763 return;
764
765 /* We need to remove old parameters before adding more. */
766 if (mk->mp)
767 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
768
769 /* These should not fail at boot. */
770 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
771 BUG_ON(err);
772 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
773 BUG_ON(err);
774 kobject_uevent(&mk->kobj, KOBJ_ADD);
775 kobject_put(&mk->kobj);
776}
777
778/*
779 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
780 *
781 * Add module_parameters to sysfs for "modules" built into the kernel.
782 *
783 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
784 * "parameter" name is stored behind a dot in kernel_param->name. So,
785 * extract the "module" name for all built-in kernel_param-eters,
786 * and for all who have the same, call kernel_add_sysfs_param.
787 */
788static void __init param_sysfs_builtin(void)
789{
790 struct kernel_param *kp;
791 unsigned int name_len;
792 char modname[MODULE_NAME_LEN];
793
794 for (kp = __start___param; kp < __stop___param; kp++) {
795 char *dot;
796
797 if (kp->perm == 0)
798 continue;
799
800 dot = strchr(kp->name, '.');
801 if (!dot) {
802 /* This happens for core_param() */
803 strcpy(modname, "kernel");
804 name_len = 0;
805 } else {
806 name_len = dot - kp->name + 1;
807 strlcpy(modname, kp->name, name_len);
808 }
809 kernel_add_sysfs_param(modname, kp, name_len);
810 }
811}
812
813ssize_t __modver_version_show(struct module_attribute *mattr,
814 struct module_kobject *mk, char *buf)
815{
816 struct module_version_attribute *vattr =
817 container_of(mattr, struct module_version_attribute, mattr);
818
819 return sprintf(buf, "%s\n", vattr->version);
820}
821
822extern const struct module_version_attribute *__start___modver[];
823extern const struct module_version_attribute *__stop___modver[];
824
825static void __init version_sysfs_builtin(void)
826{
827 const struct module_version_attribute **p;
828 struct module_kobject *mk;
829 int err;
830
831 for (p = __start___modver; p < __stop___modver; p++) {
832 const struct module_version_attribute *vattr = *p;
833
834 mk = locate_module_kobject(vattr->module_name);
835 if (mk) {
836 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
837 kobject_uevent(&mk->kobj, KOBJ_ADD);
838 kobject_put(&mk->kobj);
839 }
840 }
841}
842
843/* module-related sysfs stuff */
844
845static ssize_t module_attr_show(struct kobject *kobj,
846 struct attribute *attr,
847 char *buf)
848{
849 struct module_attribute *attribute;
850 struct module_kobject *mk;
851 int ret;
852
853 attribute = to_module_attr(attr);
854 mk = to_module_kobject(kobj);
855
856 if (!attribute->show)
857 return -EIO;
858
859 ret = attribute->show(attribute, mk, buf);
860
861 return ret;
862}
863
864static ssize_t module_attr_store(struct kobject *kobj,
865 struct attribute *attr,
866 const char *buf, size_t len)
867{
868 struct module_attribute *attribute;
869 struct module_kobject *mk;
870 int ret;
871
872 attribute = to_module_attr(attr);
873 mk = to_module_kobject(kobj);
874
875 if (!attribute->store)
876 return -EIO;
877
878 ret = attribute->store(attribute, mk, buf, len);
879
880 return ret;
881}
882
883static const struct sysfs_ops module_sysfs_ops = {
884 .show = module_attr_show,
885 .store = module_attr_store,
886};
887
888static int uevent_filter(struct kset *kset, struct kobject *kobj)
889{
890 struct kobj_type *ktype = get_ktype(kobj);
891
892 if (ktype == &module_ktype)
893 return 1;
894 return 0;
895}
896
897static const struct kset_uevent_ops module_uevent_ops = {
898 .filter = uevent_filter,
899};
900
901struct kset *module_kset;
902int module_sysfs_initialized;
903
904struct kobj_type module_ktype = {
905 .sysfs_ops = &module_sysfs_ops,
906};
907
908/*
909 * param_sysfs_init - wrapper for built-in params support
910 */
911static int __init param_sysfs_init(void)
912{
913 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
914 if (!module_kset) {
915 printk(KERN_WARNING "%s (%d): error creating kset\n",
916 __FILE__, __LINE__);
917 return -ENOMEM;
918 }
919 module_sysfs_initialized = 1;
920
921 version_sysfs_builtin();
922 param_sysfs_builtin();
923
924 return 0;
925}
926subsys_initcall(param_sysfs_init);
927
928#endif /* CONFIG_SYSFS */