Loading...
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 : ¶m_lock)
24#else
25#define KPARAM_MUTEX(mod) (¶m_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(¶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,
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, ¶m, &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);
244
245int param_set_charp(const char *val, const struct kernel_param *kp)
246{
247 if (strlen(val) > 1024) {
248 pr_err("%s: string parameter too long\n", kp->name);
249 return -ENOSPC;
250 }
251
252 maybe_kfree_parameter(*(char **)kp->arg);
253
254 /* This is a hack. We can't kmalloc in early boot, and we
255 * don't need to; this mangled commandline is preserved. */
256 if (slab_is_available()) {
257 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
258 if (!*(char **)kp->arg)
259 return -ENOMEM;
260 strcpy(*(char **)kp->arg, val);
261 } else
262 *(const char **)kp->arg = val;
263
264 return 0;
265}
266EXPORT_SYMBOL(param_set_charp);
267
268int param_get_charp(char *buffer, const struct kernel_param *kp)
269{
270 return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg));
271}
272EXPORT_SYMBOL(param_get_charp);
273
274void param_free_charp(void *arg)
275{
276 maybe_kfree_parameter(*((char **)arg));
277}
278EXPORT_SYMBOL(param_free_charp);
279
280const struct kernel_param_ops param_ops_charp = {
281 .set = param_set_charp,
282 .get = param_get_charp,
283 .free = param_free_charp,
284};
285EXPORT_SYMBOL(param_ops_charp);
286
287/* Actually could be a bool or an int, for historical reasons. */
288int param_set_bool(const char *val, const struct kernel_param *kp)
289{
290 /* No equals means "set"... */
291 if (!val) val = "1";
292
293 /* One of =[yYnN01] */
294 return strtobool(val, kp->arg);
295}
296EXPORT_SYMBOL(param_set_bool);
297
298int param_get_bool(char *buffer, const struct kernel_param *kp)
299{
300 /* Y and N chosen as being relatively non-coder friendly */
301 return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N');
302}
303EXPORT_SYMBOL(param_get_bool);
304
305const struct kernel_param_ops param_ops_bool = {
306 .flags = KERNEL_PARAM_OPS_FL_NOARG,
307 .set = param_set_bool,
308 .get = param_get_bool,
309};
310EXPORT_SYMBOL(param_ops_bool);
311
312int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
313{
314 int err = 0;
315 bool new_value;
316 bool orig_value = *(bool *)kp->arg;
317 struct kernel_param dummy_kp = *kp;
318
319 dummy_kp.arg = &new_value;
320
321 err = param_set_bool(val, &dummy_kp);
322 if (err)
323 return err;
324
325 /* Don't let them unset it once it's set! */
326 if (!new_value && orig_value)
327 return -EROFS;
328
329 if (new_value)
330 err = param_set_bool(val, kp);
331
332 return err;
333}
334EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
335
336const struct kernel_param_ops param_ops_bool_enable_only = {
337 .flags = KERNEL_PARAM_OPS_FL_NOARG,
338 .set = param_set_bool_enable_only,
339 .get = param_get_bool,
340};
341EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
342
343/* This one must be bool. */
344int param_set_invbool(const char *val, const struct kernel_param *kp)
345{
346 int ret;
347 bool boolval;
348 struct kernel_param dummy;
349
350 dummy.arg = &boolval;
351 ret = param_set_bool(val, &dummy);
352 if (ret == 0)
353 *(bool *)kp->arg = !boolval;
354 return ret;
355}
356EXPORT_SYMBOL(param_set_invbool);
357
358int param_get_invbool(char *buffer, const struct kernel_param *kp)
359{
360 return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y');
361}
362EXPORT_SYMBOL(param_get_invbool);
363
364const struct kernel_param_ops param_ops_invbool = {
365 .set = param_set_invbool,
366 .get = param_get_invbool,
367};
368EXPORT_SYMBOL(param_ops_invbool);
369
370int param_set_bint(const char *val, const struct kernel_param *kp)
371{
372 /* Match bool exactly, by re-using it. */
373 struct kernel_param boolkp = *kp;
374 bool v;
375 int ret;
376
377 boolkp.arg = &v;
378
379 ret = param_set_bool(val, &boolkp);
380 if (ret == 0)
381 *(int *)kp->arg = v;
382 return ret;
383}
384EXPORT_SYMBOL(param_set_bint);
385
386const struct kernel_param_ops param_ops_bint = {
387 .flags = KERNEL_PARAM_OPS_FL_NOARG,
388 .set = param_set_bint,
389 .get = param_get_int,
390};
391EXPORT_SYMBOL(param_ops_bint);
392
393/* We break the rule and mangle the string. */
394static int param_array(struct module *mod,
395 const char *name,
396 const char *val,
397 unsigned int min, unsigned int max,
398 void *elem, int elemsize,
399 int (*set)(const char *, const struct kernel_param *kp),
400 s16 level,
401 unsigned int *num)
402{
403 int ret;
404 struct kernel_param kp;
405 char save;
406
407 /* Get the name right for errors. */
408 kp.name = name;
409 kp.arg = elem;
410 kp.level = level;
411
412 *num = 0;
413 /* We expect a comma-separated list of values. */
414 do {
415 int len;
416
417 if (*num == max) {
418 pr_err("%s: can only take %i arguments\n", name, max);
419 return -EINVAL;
420 }
421 len = strcspn(val, ",");
422
423 /* nul-terminate and parse */
424 save = val[len];
425 ((char *)val)[len] = '\0';
426 check_kparam_locked(mod);
427 ret = set(val, &kp);
428
429 if (ret != 0)
430 return ret;
431 kp.arg += elemsize;
432 val += len+1;
433 (*num)++;
434 } while (save == ',');
435
436 if (*num < min) {
437 pr_err("%s: needs at least %i arguments\n", name, min);
438 return -EINVAL;
439 }
440 return 0;
441}
442
443static int param_array_set(const char *val, const struct kernel_param *kp)
444{
445 const struct kparam_array *arr = kp->arr;
446 unsigned int temp_num;
447
448 return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem,
449 arr->elemsize, arr->ops->set, kp->level,
450 arr->num ?: &temp_num);
451}
452
453static int param_array_get(char *buffer, const struct kernel_param *kp)
454{
455 int i, off, ret;
456 const struct kparam_array *arr = kp->arr;
457 struct kernel_param p = *kp;
458
459 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
460 /* Replace \n with comma */
461 if (i)
462 buffer[off - 1] = ',';
463 p.arg = arr->elem + arr->elemsize * i;
464 check_kparam_locked(p.mod);
465 ret = arr->ops->get(buffer + off, &p);
466 if (ret < 0)
467 return ret;
468 off += ret;
469 }
470 buffer[off] = '\0';
471 return off;
472}
473
474static void param_array_free(void *arg)
475{
476 unsigned int i;
477 const struct kparam_array *arr = arg;
478
479 if (arr->ops->free)
480 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
481 arr->ops->free(arr->elem + arr->elemsize * i);
482}
483
484const struct kernel_param_ops param_array_ops = {
485 .set = param_array_set,
486 .get = param_array_get,
487 .free = param_array_free,
488};
489EXPORT_SYMBOL(param_array_ops);
490
491int param_set_copystring(const char *val, const struct kernel_param *kp)
492{
493 const struct kparam_string *kps = kp->str;
494
495 if (strlen(val)+1 > kps->maxlen) {
496 pr_err("%s: string doesn't fit in %u chars.\n",
497 kp->name, kps->maxlen-1);
498 return -ENOSPC;
499 }
500 strcpy(kps->string, val);
501 return 0;
502}
503EXPORT_SYMBOL(param_set_copystring);
504
505int param_get_string(char *buffer, const struct kernel_param *kp)
506{
507 const struct kparam_string *kps = kp->str;
508 return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string);
509}
510EXPORT_SYMBOL(param_get_string);
511
512const struct kernel_param_ops param_ops_string = {
513 .set = param_set_copystring,
514 .get = param_get_string,
515};
516EXPORT_SYMBOL(param_ops_string);
517
518/* sysfs output in /sys/modules/XYZ/parameters/ */
519#define to_module_attr(n) container_of(n, struct module_attribute, attr)
520#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
521
522struct param_attribute
523{
524 struct module_attribute mattr;
525 const struct kernel_param *param;
526};
527
528struct module_param_attrs
529{
530 unsigned int num;
531 struct attribute_group grp;
532 struct param_attribute attrs[0];
533};
534
535#ifdef CONFIG_SYSFS
536#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
537
538static ssize_t param_attr_show(struct module_attribute *mattr,
539 struct module_kobject *mk, char *buf)
540{
541 int count;
542 struct param_attribute *attribute = to_param_attr(mattr);
543
544 if (!attribute->param->ops->get)
545 return -EPERM;
546
547 kernel_param_lock(mk->mod);
548 count = attribute->param->ops->get(buf, attribute->param);
549 kernel_param_unlock(mk->mod);
550 return count;
551}
552
553/* sysfs always hands a nul-terminated string in buf. We rely on that. */
554static ssize_t param_attr_store(struct module_attribute *mattr,
555 struct module_kobject *mk,
556 const char *buf, size_t len)
557{
558 int err;
559 struct param_attribute *attribute = to_param_attr(mattr);
560
561 if (!attribute->param->ops->set)
562 return -EPERM;
563
564 kernel_param_lock(mk->mod);
565 if (param_check_unsafe(attribute->param))
566 err = attribute->param->ops->set(buf, attribute->param);
567 else
568 err = -EPERM;
569 kernel_param_unlock(mk->mod);
570 if (!err)
571 return len;
572 return err;
573}
574#endif
575
576#ifdef CONFIG_MODULES
577#define __modinit
578#else
579#define __modinit __init
580#endif
581
582#ifdef CONFIG_SYSFS
583void kernel_param_lock(struct module *mod)
584{
585 mutex_lock(KPARAM_MUTEX(mod));
586}
587
588void kernel_param_unlock(struct module *mod)
589{
590 mutex_unlock(KPARAM_MUTEX(mod));
591}
592
593EXPORT_SYMBOL(kernel_param_lock);
594EXPORT_SYMBOL(kernel_param_unlock);
595
596/*
597 * add_sysfs_param - add a parameter to sysfs
598 * @mk: struct module_kobject
599 * @kp: the actual parameter definition to add to sysfs
600 * @name: name of parameter
601 *
602 * Create a kobject if for a (per-module) parameter if mp NULL, and
603 * create file in sysfs. Returns an error on out of memory. Always cleans up
604 * if there's an error.
605 */
606static __modinit int add_sysfs_param(struct module_kobject *mk,
607 const struct kernel_param *kp,
608 const char *name)
609{
610 struct module_param_attrs *new_mp;
611 struct attribute **new_attrs;
612 unsigned int i;
613
614 /* We don't bother calling this with invisible parameters. */
615 BUG_ON(!kp->perm);
616
617 if (!mk->mp) {
618 /* First allocation. */
619 mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
620 if (!mk->mp)
621 return -ENOMEM;
622 mk->mp->grp.name = "parameters";
623 /* NULL-terminated attribute array. */
624 mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
625 GFP_KERNEL);
626 /* Caller will cleanup via free_module_param_attrs */
627 if (!mk->mp->grp.attrs)
628 return -ENOMEM;
629 }
630
631 /* Enlarge allocations. */
632 new_mp = krealloc(mk->mp,
633 sizeof(*mk->mp) +
634 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
635 GFP_KERNEL);
636 if (!new_mp)
637 return -ENOMEM;
638 mk->mp = new_mp;
639
640 /* Extra pointer for NULL terminator */
641 new_attrs = krealloc(mk->mp->grp.attrs,
642 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
643 GFP_KERNEL);
644 if (!new_attrs)
645 return -ENOMEM;
646 mk->mp->grp.attrs = new_attrs;
647
648 /* Tack new one on the end. */
649 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
650 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
651 mk->mp->attrs[mk->mp->num].param = kp;
652 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
653 /* Do not allow runtime DAC changes to make param writable. */
654 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
655 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
656 else
657 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
658 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
659 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
660 mk->mp->num++;
661
662 /* Fix up all the pointers, since krealloc can move us */
663 for (i = 0; i < mk->mp->num; i++)
664 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
665 mk->mp->grp.attrs[mk->mp->num] = NULL;
666 return 0;
667}
668
669#ifdef CONFIG_MODULES
670static void free_module_param_attrs(struct module_kobject *mk)
671{
672 if (mk->mp)
673 kfree(mk->mp->grp.attrs);
674 kfree(mk->mp);
675 mk->mp = NULL;
676}
677
678/*
679 * module_param_sysfs_setup - setup sysfs support for one module
680 * @mod: module
681 * @kparam: module parameters (array)
682 * @num_params: number of module parameters
683 *
684 * Adds sysfs entries for module parameters under
685 * /sys/module/[mod->name]/parameters/
686 */
687int module_param_sysfs_setup(struct module *mod,
688 const struct kernel_param *kparam,
689 unsigned int num_params)
690{
691 int i, err;
692 bool params = false;
693
694 for (i = 0; i < num_params; i++) {
695 if (kparam[i].perm == 0)
696 continue;
697 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
698 if (err) {
699 free_module_param_attrs(&mod->mkobj);
700 return err;
701 }
702 params = true;
703 }
704
705 if (!params)
706 return 0;
707
708 /* Create the param group. */
709 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
710 if (err)
711 free_module_param_attrs(&mod->mkobj);
712 return err;
713}
714
715/*
716 * module_param_sysfs_remove - remove sysfs support for one module
717 * @mod: module
718 *
719 * Remove sysfs entries for module parameters and the corresponding
720 * kobject.
721 */
722void module_param_sysfs_remove(struct module *mod)
723{
724 if (mod->mkobj.mp) {
725 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
726 /* We are positive that no one is using any param
727 * attrs at this point. Deallocate immediately. */
728 free_module_param_attrs(&mod->mkobj);
729 }
730}
731#endif
732
733void destroy_params(const struct kernel_param *params, unsigned num)
734{
735 unsigned int i;
736
737 for (i = 0; i < num; i++)
738 if (params[i].ops->free)
739 params[i].ops->free(params[i].arg);
740}
741
742static struct module_kobject * __init locate_module_kobject(const char *name)
743{
744 struct module_kobject *mk;
745 struct kobject *kobj;
746 int err;
747
748 kobj = kset_find_obj(module_kset, name);
749 if (kobj) {
750 mk = to_module_kobject(kobj);
751 } else {
752 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
753 BUG_ON(!mk);
754
755 mk->mod = THIS_MODULE;
756 mk->kobj.kset = module_kset;
757 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
758 "%s", name);
759#ifdef CONFIG_MODULES
760 if (!err)
761 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
762#endif
763 if (err) {
764 kobject_put(&mk->kobj);
765 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
766 name, err);
767 return NULL;
768 }
769
770 /* So that we hold reference in both cases. */
771 kobject_get(&mk->kobj);
772 }
773
774 return mk;
775}
776
777static void __init kernel_add_sysfs_param(const char *name,
778 const struct kernel_param *kparam,
779 unsigned int name_skip)
780{
781 struct module_kobject *mk;
782 int err;
783
784 mk = locate_module_kobject(name);
785 if (!mk)
786 return;
787
788 /* We need to remove old parameters before adding more. */
789 if (mk->mp)
790 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
791
792 /* These should not fail at boot. */
793 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
794 BUG_ON(err);
795 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
796 BUG_ON(err);
797 kobject_uevent(&mk->kobj, KOBJ_ADD);
798 kobject_put(&mk->kobj);
799}
800
801/*
802 * param_sysfs_builtin - add sysfs parameters for built-in modules
803 *
804 * Add module_parameters to sysfs for "modules" built into the kernel.
805 *
806 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
807 * "parameter" name is stored behind a dot in kernel_param->name. So,
808 * extract the "module" name for all built-in kernel_param-eters,
809 * and for all who have the same, call kernel_add_sysfs_param.
810 */
811static void __init param_sysfs_builtin(void)
812{
813 const struct kernel_param *kp;
814 unsigned int name_len;
815 char modname[MODULE_NAME_LEN];
816
817 for (kp = __start___param; kp < __stop___param; kp++) {
818 char *dot;
819
820 if (kp->perm == 0)
821 continue;
822
823 dot = strchr(kp->name, '.');
824 if (!dot) {
825 /* This happens for core_param() */
826 strcpy(modname, "kernel");
827 name_len = 0;
828 } else {
829 name_len = dot - kp->name + 1;
830 strlcpy(modname, kp->name, name_len);
831 }
832 kernel_add_sysfs_param(modname, kp, name_len);
833 }
834}
835
836ssize_t __modver_version_show(struct module_attribute *mattr,
837 struct module_kobject *mk, char *buf)
838{
839 struct module_version_attribute *vattr =
840 container_of(mattr, struct module_version_attribute, mattr);
841
842 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
843}
844
845extern const struct module_version_attribute *__start___modver[];
846extern const struct module_version_attribute *__stop___modver[];
847
848static void __init version_sysfs_builtin(void)
849{
850 const struct module_version_attribute **p;
851 struct module_kobject *mk;
852 int err;
853
854 for (p = __start___modver; p < __stop___modver; p++) {
855 const struct module_version_attribute *vattr = *p;
856
857 mk = locate_module_kobject(vattr->module_name);
858 if (mk) {
859 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
860 WARN_ON_ONCE(err);
861 kobject_uevent(&mk->kobj, KOBJ_ADD);
862 kobject_put(&mk->kobj);
863 }
864 }
865}
866
867/* module-related sysfs stuff */
868
869static ssize_t module_attr_show(struct kobject *kobj,
870 struct attribute *attr,
871 char *buf)
872{
873 struct module_attribute *attribute;
874 struct module_kobject *mk;
875 int ret;
876
877 attribute = to_module_attr(attr);
878 mk = to_module_kobject(kobj);
879
880 if (!attribute->show)
881 return -EIO;
882
883 ret = attribute->show(attribute, mk, buf);
884
885 return ret;
886}
887
888static ssize_t module_attr_store(struct kobject *kobj,
889 struct attribute *attr,
890 const char *buf, size_t len)
891{
892 struct module_attribute *attribute;
893 struct module_kobject *mk;
894 int ret;
895
896 attribute = to_module_attr(attr);
897 mk = to_module_kobject(kobj);
898
899 if (!attribute->store)
900 return -EIO;
901
902 ret = attribute->store(attribute, mk, buf, len);
903
904 return ret;
905}
906
907static const struct sysfs_ops module_sysfs_ops = {
908 .show = module_attr_show,
909 .store = module_attr_store,
910};
911
912static int uevent_filter(struct kset *kset, struct kobject *kobj)
913{
914 struct kobj_type *ktype = get_ktype(kobj);
915
916 if (ktype == &module_ktype)
917 return 1;
918 return 0;
919}
920
921static const struct kset_uevent_ops module_uevent_ops = {
922 .filter = uevent_filter,
923};
924
925struct kset *module_kset;
926int module_sysfs_initialized;
927
928static void module_kobj_release(struct kobject *kobj)
929{
930 struct module_kobject *mk = to_module_kobject(kobj);
931 complete(mk->kobj_completion);
932}
933
934struct kobj_type module_ktype = {
935 .release = module_kobj_release,
936 .sysfs_ops = &module_sysfs_ops,
937};
938
939/*
940 * param_sysfs_init - wrapper for built-in params support
941 */
942static int __init param_sysfs_init(void)
943{
944 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
945 if (!module_kset) {
946 printk(KERN_WARNING "%s (%d): error creating kset\n",
947 __FILE__, __LINE__);
948 return -ENOMEM;
949 }
950 module_sysfs_initialized = 1;
951
952 version_sysfs_builtin();
953 param_sysfs_builtin();
954
955 return 0;
956}
957subsys_initcall(param_sysfs_init);
958
959#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/kernel.h>
19#include <linux/string.h>
20#include <linux/errno.h>
21#include <linux/module.h>
22#include <linux/device.h>
23#include <linux/err.h>
24#include <linux/slab.h>
25#include <linux/ctype.h>
26
27/* Protects all parameters, and incidentally kmalloced_param list. */
28static DEFINE_MUTEX(param_lock);
29
30/* This just allows us to keep track of which parameters are kmalloced. */
31struct kmalloced_param {
32 struct list_head list;
33 char val[];
34};
35static LIST_HEAD(kmalloced_params);
36
37static void *kmalloc_parameter(unsigned int size)
38{
39 struct kmalloced_param *p;
40
41 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
42 if (!p)
43 return NULL;
44
45 list_add(&p->list, &kmalloced_params);
46 return p->val;
47}
48
49/* Does nothing if parameter wasn't kmalloced above. */
50static void maybe_kfree_parameter(void *param)
51{
52 struct kmalloced_param *p;
53
54 list_for_each_entry(p, &kmalloced_params, list) {
55 if (p->val == param) {
56 list_del(&p->list);
57 kfree(p);
58 break;
59 }
60 }
61}
62
63static char dash2underscore(char c)
64{
65 if (c == '-')
66 return '_';
67 return c;
68}
69
70bool parameqn(const char *a, const char *b, size_t n)
71{
72 size_t i;
73
74 for (i = 0; i < n; i++) {
75 if (dash2underscore(a[i]) != dash2underscore(b[i]))
76 return false;
77 }
78 return true;
79}
80
81bool parameq(const char *a, const char *b)
82{
83 return parameqn(a, b, strlen(a)+1);
84}
85
86static int parse_one(char *param,
87 char *val,
88 const char *doing,
89 const struct kernel_param *params,
90 unsigned num_params,
91 s16 min_level,
92 s16 max_level,
93 int (*handle_unknown)(char *param, char *val,
94 const char *doing))
95{
96 unsigned int i;
97 int err;
98
99 /* Find parameter */
100 for (i = 0; i < num_params; i++) {
101 if (parameq(param, params[i].name)) {
102 if (params[i].level < min_level
103 || params[i].level > max_level)
104 return 0;
105 /* No one handled NULL, so do it here. */
106 if (!val && params[i].ops->set != param_set_bool
107 && params[i].ops->set != param_set_bint)
108 return -EINVAL;
109 pr_debug("handling %s with %p\n", param,
110 params[i].ops->set);
111 mutex_lock(¶m_lock);
112 err = params[i].ops->set(val, ¶ms[i]);
113 mutex_unlock(¶m_lock);
114 return err;
115 }
116 }
117
118 if (handle_unknown) {
119 pr_debug("doing %s: %s='%s'\n", doing, param, val);
120 return handle_unknown(param, val, doing);
121 }
122
123 pr_debug("Unknown argument '%s'\n", param);
124 return -ENOENT;
125}
126
127/* You can use " around spaces, but can't escape ". */
128/* Hyphens and underscores equivalent in parameter names. */
129static char *next_arg(char *args, char **param, char **val)
130{
131 unsigned int i, equals = 0;
132 int in_quote = 0, quoted = 0;
133 char *next;
134
135 if (*args == '"') {
136 args++;
137 in_quote = 1;
138 quoted = 1;
139 }
140
141 for (i = 0; args[i]; i++) {
142 if (isspace(args[i]) && !in_quote)
143 break;
144 if (equals == 0) {
145 if (args[i] == '=')
146 equals = i;
147 }
148 if (args[i] == '"')
149 in_quote = !in_quote;
150 }
151
152 *param = args;
153 if (!equals)
154 *val = NULL;
155 else {
156 args[equals] = '\0';
157 *val = args + equals + 1;
158
159 /* Don't include quotes in value. */
160 if (**val == '"') {
161 (*val)++;
162 if (args[i-1] == '"')
163 args[i-1] = '\0';
164 }
165 if (quoted && args[i-1] == '"')
166 args[i-1] = '\0';
167 }
168
169 if (args[i]) {
170 args[i] = '\0';
171 next = args + i + 1;
172 } else
173 next = args + i;
174
175 /* Chew up trailing spaces. */
176 return skip_spaces(next);
177}
178
179/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
180int parse_args(const char *doing,
181 char *args,
182 const struct kernel_param *params,
183 unsigned num,
184 s16 min_level,
185 s16 max_level,
186 int (*unknown)(char *param, char *val, const char *doing))
187{
188 char *param, *val;
189
190 /* Chew leading spaces */
191 args = skip_spaces(args);
192
193 if (*args)
194 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
195
196 while (*args) {
197 int ret;
198 int irq_was_disabled;
199
200 args = next_arg(args, ¶m, &val);
201 irq_was_disabled = irqs_disabled();
202 ret = parse_one(param, val, doing, params, num,
203 min_level, max_level, unknown);
204 if (irq_was_disabled && !irqs_disabled())
205 pr_warn("%s: option '%s' enabled irq's!\n",
206 doing, param);
207
208 switch (ret) {
209 case -ENOENT:
210 pr_err("%s: Unknown parameter `%s'\n", doing, param);
211 return ret;
212 case -ENOSPC:
213 pr_err("%s: `%s' too large for parameter `%s'\n",
214 doing, val ?: "", param);
215 return ret;
216 case 0:
217 break;
218 default:
219 pr_err("%s: `%s' invalid for parameter `%s'\n",
220 doing, val ?: "", param);
221 return ret;
222 }
223 }
224
225 /* All parsed OK. */
226 return 0;
227}
228
229/* Lazy bastard, eh? */
230#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
231 int param_set_##name(const char *val, const struct kernel_param *kp) \
232 { \
233 tmptype l; \
234 int ret; \
235 \
236 ret = strtolfn(val, 0, &l); \
237 if (ret < 0 || ((type)l != l)) \
238 return ret < 0 ? ret : -EINVAL; \
239 *((type *)kp->arg) = l; \
240 return 0; \
241 } \
242 int param_get_##name(char *buffer, const struct kernel_param *kp) \
243 { \
244 return sprintf(buffer, format, *((type *)kp->arg)); \
245 } \
246 struct kernel_param_ops param_ops_##name = { \
247 .set = param_set_##name, \
248 .get = param_get_##name, \
249 }; \
250 EXPORT_SYMBOL(param_set_##name); \
251 EXPORT_SYMBOL(param_get_##name); \
252 EXPORT_SYMBOL(param_ops_##name)
253
254
255STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
256STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
257STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
258STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
259STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
260STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
261STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
262
263int param_set_charp(const char *val, const struct kernel_param *kp)
264{
265 if (strlen(val) > 1024) {
266 pr_err("%s: string parameter too long\n", kp->name);
267 return -ENOSPC;
268 }
269
270 maybe_kfree_parameter(*(char **)kp->arg);
271
272 /* This is a hack. We can't kmalloc in early boot, and we
273 * don't need to; this mangled commandline is preserved. */
274 if (slab_is_available()) {
275 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
276 if (!*(char **)kp->arg)
277 return -ENOMEM;
278 strcpy(*(char **)kp->arg, val);
279 } else
280 *(const char **)kp->arg = val;
281
282 return 0;
283}
284EXPORT_SYMBOL(param_set_charp);
285
286int param_get_charp(char *buffer, const struct kernel_param *kp)
287{
288 return sprintf(buffer, "%s", *((char **)kp->arg));
289}
290EXPORT_SYMBOL(param_get_charp);
291
292static void param_free_charp(void *arg)
293{
294 maybe_kfree_parameter(*((char **)arg));
295}
296
297struct kernel_param_ops param_ops_charp = {
298 .set = param_set_charp,
299 .get = param_get_charp,
300 .free = param_free_charp,
301};
302EXPORT_SYMBOL(param_ops_charp);
303
304/* Actually could be a bool or an int, for historical reasons. */
305int param_set_bool(const char *val, const struct kernel_param *kp)
306{
307 /* No equals means "set"... */
308 if (!val) val = "1";
309
310 /* One of =[yYnN01] */
311 return strtobool(val, kp->arg);
312}
313EXPORT_SYMBOL(param_set_bool);
314
315int param_get_bool(char *buffer, const struct kernel_param *kp)
316{
317 /* Y and N chosen as being relatively non-coder friendly */
318 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
319}
320EXPORT_SYMBOL(param_get_bool);
321
322struct kernel_param_ops param_ops_bool = {
323 .set = param_set_bool,
324 .get = param_get_bool,
325};
326EXPORT_SYMBOL(param_ops_bool);
327
328/* This one must be bool. */
329int param_set_invbool(const char *val, const struct kernel_param *kp)
330{
331 int ret;
332 bool boolval;
333 struct kernel_param dummy;
334
335 dummy.arg = &boolval;
336 ret = param_set_bool(val, &dummy);
337 if (ret == 0)
338 *(bool *)kp->arg = !boolval;
339 return ret;
340}
341EXPORT_SYMBOL(param_set_invbool);
342
343int param_get_invbool(char *buffer, const struct kernel_param *kp)
344{
345 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
346}
347EXPORT_SYMBOL(param_get_invbool);
348
349struct kernel_param_ops param_ops_invbool = {
350 .set = param_set_invbool,
351 .get = param_get_invbool,
352};
353EXPORT_SYMBOL(param_ops_invbool);
354
355int param_set_bint(const char *val, const struct kernel_param *kp)
356{
357 struct kernel_param boolkp;
358 bool v;
359 int ret;
360
361 /* Match bool exactly, by re-using it. */
362 boolkp = *kp;
363 boolkp.arg = &v;
364
365 ret = param_set_bool(val, &boolkp);
366 if (ret == 0)
367 *(int *)kp->arg = v;
368 return ret;
369}
370EXPORT_SYMBOL(param_set_bint);
371
372struct kernel_param_ops param_ops_bint = {
373 .set = param_set_bint,
374 .get = param_get_int,
375};
376EXPORT_SYMBOL(param_ops_bint);
377
378/* We break the rule and mangle the string. */
379static int param_array(const char *name,
380 const char *val,
381 unsigned int min, unsigned int max,
382 void *elem, int elemsize,
383 int (*set)(const char *, const struct kernel_param *kp),
384 s16 level,
385 unsigned int *num)
386{
387 int ret;
388 struct kernel_param kp;
389 char save;
390
391 /* Get the name right for errors. */
392 kp.name = name;
393 kp.arg = elem;
394 kp.level = level;
395
396 *num = 0;
397 /* We expect a comma-separated list of values. */
398 do {
399 int len;
400
401 if (*num == max) {
402 pr_err("%s: can only take %i arguments\n", name, max);
403 return -EINVAL;
404 }
405 len = strcspn(val, ",");
406
407 /* nul-terminate and parse */
408 save = val[len];
409 ((char *)val)[len] = '\0';
410 BUG_ON(!mutex_is_locked(¶m_lock));
411 ret = set(val, &kp);
412
413 if (ret != 0)
414 return ret;
415 kp.arg += elemsize;
416 val += len+1;
417 (*num)++;
418 } while (save == ',');
419
420 if (*num < min) {
421 pr_err("%s: needs at least %i arguments\n", name, min);
422 return -EINVAL;
423 }
424 return 0;
425}
426
427static int param_array_set(const char *val, const struct kernel_param *kp)
428{
429 const struct kparam_array *arr = kp->arr;
430 unsigned int temp_num;
431
432 return param_array(kp->name, val, 1, arr->max, arr->elem,
433 arr->elemsize, arr->ops->set, kp->level,
434 arr->num ?: &temp_num);
435}
436
437static int param_array_get(char *buffer, const struct kernel_param *kp)
438{
439 int i, off, ret;
440 const struct kparam_array *arr = kp->arr;
441 struct kernel_param p;
442
443 p = *kp;
444 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
445 if (i)
446 buffer[off++] = ',';
447 p.arg = arr->elem + arr->elemsize * i;
448 BUG_ON(!mutex_is_locked(¶m_lock));
449 ret = arr->ops->get(buffer + off, &p);
450 if (ret < 0)
451 return ret;
452 off += ret;
453 }
454 buffer[off] = '\0';
455 return off;
456}
457
458static void param_array_free(void *arg)
459{
460 unsigned int i;
461 const struct kparam_array *arr = arg;
462
463 if (arr->ops->free)
464 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
465 arr->ops->free(arr->elem + arr->elemsize * i);
466}
467
468struct kernel_param_ops param_array_ops = {
469 .set = param_array_set,
470 .get = param_array_get,
471 .free = param_array_free,
472};
473EXPORT_SYMBOL(param_array_ops);
474
475int param_set_copystring(const char *val, const struct kernel_param *kp)
476{
477 const struct kparam_string *kps = kp->str;
478
479 if (strlen(val)+1 > kps->maxlen) {
480 pr_err("%s: string doesn't fit in %u chars.\n",
481 kp->name, kps->maxlen-1);
482 return -ENOSPC;
483 }
484 strcpy(kps->string, val);
485 return 0;
486}
487EXPORT_SYMBOL(param_set_copystring);
488
489int param_get_string(char *buffer, const struct kernel_param *kp)
490{
491 const struct kparam_string *kps = kp->str;
492 return strlcpy(buffer, kps->string, kps->maxlen);
493}
494EXPORT_SYMBOL(param_get_string);
495
496struct kernel_param_ops param_ops_string = {
497 .set = param_set_copystring,
498 .get = param_get_string,
499};
500EXPORT_SYMBOL(param_ops_string);
501
502/* sysfs output in /sys/modules/XYZ/parameters/ */
503#define to_module_attr(n) container_of(n, struct module_attribute, attr)
504#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
505
506extern struct kernel_param __start___param[], __stop___param[];
507
508struct param_attribute
509{
510 struct module_attribute mattr;
511 const struct kernel_param *param;
512};
513
514struct module_param_attrs
515{
516 unsigned int num;
517 struct attribute_group grp;
518 struct param_attribute attrs[0];
519};
520
521#ifdef CONFIG_SYSFS
522#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
523
524static ssize_t param_attr_show(struct module_attribute *mattr,
525 struct module_kobject *mk, char *buf)
526{
527 int count;
528 struct param_attribute *attribute = to_param_attr(mattr);
529
530 if (!attribute->param->ops->get)
531 return -EPERM;
532
533 mutex_lock(¶m_lock);
534 count = attribute->param->ops->get(buf, attribute->param);
535 mutex_unlock(¶m_lock);
536 if (count > 0) {
537 strcat(buf, "\n");
538 ++count;
539 }
540 return count;
541}
542
543/* sysfs always hands a nul-terminated string in buf. We rely on that. */
544static ssize_t param_attr_store(struct module_attribute *mattr,
545 struct module_kobject *km,
546 const char *buf, size_t len)
547{
548 int err;
549 struct param_attribute *attribute = to_param_attr(mattr);
550
551 if (!attribute->param->ops->set)
552 return -EPERM;
553
554 mutex_lock(¶m_lock);
555 err = attribute->param->ops->set(buf, attribute->param);
556 mutex_unlock(¶m_lock);
557 if (!err)
558 return len;
559 return err;
560}
561#endif
562
563#ifdef CONFIG_MODULES
564#define __modinit
565#else
566#define __modinit __init
567#endif
568
569#ifdef CONFIG_SYSFS
570void __kernel_param_lock(void)
571{
572 mutex_lock(¶m_lock);
573}
574EXPORT_SYMBOL(__kernel_param_lock);
575
576void __kernel_param_unlock(void)
577{
578 mutex_unlock(¶m_lock);
579}
580EXPORT_SYMBOL(__kernel_param_unlock);
581
582/*
583 * add_sysfs_param - add a parameter to sysfs
584 * @mk: struct module_kobject
585 * @kparam: the actual parameter definition to add to sysfs
586 * @name: name of parameter
587 *
588 * Create a kobject if for a (per-module) parameter if mp NULL, and
589 * create file in sysfs. Returns an error on out of memory. Always cleans up
590 * if there's an error.
591 */
592static __modinit int add_sysfs_param(struct module_kobject *mk,
593 const struct kernel_param *kp,
594 const char *name)
595{
596 struct module_param_attrs *new;
597 struct attribute **attrs;
598 int err, num;
599
600 /* We don't bother calling this with invisible parameters. */
601 BUG_ON(!kp->perm);
602
603 if (!mk->mp) {
604 num = 0;
605 attrs = NULL;
606 } else {
607 num = mk->mp->num;
608 attrs = mk->mp->grp.attrs;
609 }
610
611 /* Enlarge. */
612 new = krealloc(mk->mp,
613 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
614 GFP_KERNEL);
615 if (!new) {
616 kfree(mk->mp);
617 err = -ENOMEM;
618 goto fail;
619 }
620 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
621 if (!attrs) {
622 err = -ENOMEM;
623 goto fail_free_new;
624 }
625
626 /* Sysfs wants everything zeroed. */
627 memset(new, 0, sizeof(*new));
628 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
629 memset(&attrs[num], 0, sizeof(attrs[num]));
630 new->grp.name = "parameters";
631 new->grp.attrs = attrs;
632
633 /* Tack new one on the end. */
634 sysfs_attr_init(&new->attrs[num].mattr.attr);
635 new->attrs[num].param = kp;
636 new->attrs[num].mattr.show = param_attr_show;
637 new->attrs[num].mattr.store = param_attr_store;
638 new->attrs[num].mattr.attr.name = (char *)name;
639 new->attrs[num].mattr.attr.mode = kp->perm;
640 new->num = num+1;
641
642 /* Fix up all the pointers, since krealloc can move us */
643 for (num = 0; num < new->num; num++)
644 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
645 new->grp.attrs[num] = NULL;
646
647 mk->mp = new;
648 return 0;
649
650fail_free_new:
651 kfree(new);
652fail:
653 mk->mp = NULL;
654 return err;
655}
656
657#ifdef CONFIG_MODULES
658static void free_module_param_attrs(struct module_kobject *mk)
659{
660 kfree(mk->mp->grp.attrs);
661 kfree(mk->mp);
662 mk->mp = NULL;
663}
664
665/*
666 * module_param_sysfs_setup - setup sysfs support for one module
667 * @mod: module
668 * @kparam: module parameters (array)
669 * @num_params: number of module parameters
670 *
671 * Adds sysfs entries for module parameters under
672 * /sys/module/[mod->name]/parameters/
673 */
674int module_param_sysfs_setup(struct module *mod,
675 const struct kernel_param *kparam,
676 unsigned int num_params)
677{
678 int i, err;
679 bool params = false;
680
681 for (i = 0; i < num_params; i++) {
682 if (kparam[i].perm == 0)
683 continue;
684 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
685 if (err)
686 return err;
687 params = true;
688 }
689
690 if (!params)
691 return 0;
692
693 /* Create the param group. */
694 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
695 if (err)
696 free_module_param_attrs(&mod->mkobj);
697 return err;
698}
699
700/*
701 * module_param_sysfs_remove - remove sysfs support for one module
702 * @mod: module
703 *
704 * Remove sysfs entries for module parameters and the corresponding
705 * kobject.
706 */
707void module_param_sysfs_remove(struct module *mod)
708{
709 if (mod->mkobj.mp) {
710 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
711 /* We are positive that no one is using any param
712 * attrs at this point. Deallocate immediately. */
713 free_module_param_attrs(&mod->mkobj);
714 }
715}
716#endif
717
718void destroy_params(const struct kernel_param *params, unsigned num)
719{
720 unsigned int i;
721
722 for (i = 0; i < num; i++)
723 if (params[i].ops->free)
724 params[i].ops->free(params[i].arg);
725}
726
727static struct module_kobject * __init locate_module_kobject(const char *name)
728{
729 struct module_kobject *mk;
730 struct kobject *kobj;
731 int err;
732
733 kobj = kset_find_obj(module_kset, name);
734 if (kobj) {
735 mk = to_module_kobject(kobj);
736 } else {
737 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
738 BUG_ON(!mk);
739
740 mk->mod = THIS_MODULE;
741 mk->kobj.kset = module_kset;
742 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
743 "%s", name);
744#ifdef CONFIG_MODULES
745 if (!err)
746 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
747#endif
748 if (err) {
749 kobject_put(&mk->kobj);
750 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
751 name, err);
752 return NULL;
753 }
754
755 /* So that we hold reference in both cases. */
756 kobject_get(&mk->kobj);
757 }
758
759 return mk;
760}
761
762static void __init kernel_add_sysfs_param(const char *name,
763 struct kernel_param *kparam,
764 unsigned int name_skip)
765{
766 struct module_kobject *mk;
767 int err;
768
769 mk = locate_module_kobject(name);
770 if (!mk)
771 return;
772
773 /* We need to remove old parameters before adding more. */
774 if (mk->mp)
775 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
776
777 /* These should not fail at boot. */
778 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
779 BUG_ON(err);
780 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
781 BUG_ON(err);
782 kobject_uevent(&mk->kobj, KOBJ_ADD);
783 kobject_put(&mk->kobj);
784}
785
786/*
787 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
788 *
789 * Add module_parameters to sysfs for "modules" built into the kernel.
790 *
791 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
792 * "parameter" name is stored behind a dot in kernel_param->name. So,
793 * extract the "module" name for all built-in kernel_param-eters,
794 * and for all who have the same, call kernel_add_sysfs_param.
795 */
796static void __init param_sysfs_builtin(void)
797{
798 struct kernel_param *kp;
799 unsigned int name_len;
800 char modname[MODULE_NAME_LEN];
801
802 for (kp = __start___param; kp < __stop___param; kp++) {
803 char *dot;
804
805 if (kp->perm == 0)
806 continue;
807
808 dot = strchr(kp->name, '.');
809 if (!dot) {
810 /* This happens for core_param() */
811 strcpy(modname, "kernel");
812 name_len = 0;
813 } else {
814 name_len = dot - kp->name + 1;
815 strlcpy(modname, kp->name, name_len);
816 }
817 kernel_add_sysfs_param(modname, kp, name_len);
818 }
819}
820
821ssize_t __modver_version_show(struct module_attribute *mattr,
822 struct module_kobject *mk, char *buf)
823{
824 struct module_version_attribute *vattr =
825 container_of(mattr, struct module_version_attribute, mattr);
826
827 return sprintf(buf, "%s\n", vattr->version);
828}
829
830extern const struct module_version_attribute *__start___modver[];
831extern const struct module_version_attribute *__stop___modver[];
832
833static void __init version_sysfs_builtin(void)
834{
835 const struct module_version_attribute **p;
836 struct module_kobject *mk;
837 int err;
838
839 for (p = __start___modver; p < __stop___modver; p++) {
840 const struct module_version_attribute *vattr = *p;
841
842 mk = locate_module_kobject(vattr->module_name);
843 if (mk) {
844 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
845 kobject_uevent(&mk->kobj, KOBJ_ADD);
846 kobject_put(&mk->kobj);
847 }
848 }
849}
850
851/* module-related sysfs stuff */
852
853static ssize_t module_attr_show(struct kobject *kobj,
854 struct attribute *attr,
855 char *buf)
856{
857 struct module_attribute *attribute;
858 struct module_kobject *mk;
859 int ret;
860
861 attribute = to_module_attr(attr);
862 mk = to_module_kobject(kobj);
863
864 if (!attribute->show)
865 return -EIO;
866
867 ret = attribute->show(attribute, mk, buf);
868
869 return ret;
870}
871
872static ssize_t module_attr_store(struct kobject *kobj,
873 struct attribute *attr,
874 const char *buf, size_t len)
875{
876 struct module_attribute *attribute;
877 struct module_kobject *mk;
878 int ret;
879
880 attribute = to_module_attr(attr);
881 mk = to_module_kobject(kobj);
882
883 if (!attribute->store)
884 return -EIO;
885
886 ret = attribute->store(attribute, mk, buf, len);
887
888 return ret;
889}
890
891static const struct sysfs_ops module_sysfs_ops = {
892 .show = module_attr_show,
893 .store = module_attr_store,
894};
895
896static int uevent_filter(struct kset *kset, struct kobject *kobj)
897{
898 struct kobj_type *ktype = get_ktype(kobj);
899
900 if (ktype == &module_ktype)
901 return 1;
902 return 0;
903}
904
905static const struct kset_uevent_ops module_uevent_ops = {
906 .filter = uevent_filter,
907};
908
909struct kset *module_kset;
910int module_sysfs_initialized;
911
912struct kobj_type module_ktype = {
913 .sysfs_ops = &module_sysfs_ops,
914};
915
916/*
917 * param_sysfs_init - wrapper for built-in params support
918 */
919static int __init param_sysfs_init(void)
920{
921 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
922 if (!module_kset) {
923 printk(KERN_WARNING "%s (%d): error creating kset\n",
924 __FILE__, __LINE__);
925 return -ENOMEM;
926 }
927 module_sysfs_initialized = 1;
928
929 version_sysfs_builtin();
930 param_sysfs_builtin();
931
932 return 0;
933}
934subsys_initcall(param_sysfs_init);
935
936#endif /* CONFIG_SYSFS */