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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 &&
107 !(params[i].ops->flags & KERNEL_PARAM_FL_NOARG))
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, strtolfn) \
231 int param_set_##name(const char *val, const struct kernel_param *kp) \
232 { \
233 return strtolfn(val, 0, (type *)kp->arg); \
234 } \
235 int param_get_##name(char *buffer, const struct kernel_param *kp) \
236 { \
237 return scnprintf(buffer, PAGE_SIZE, format, \
238 *((type *)kp->arg)); \
239 } \
240 struct kernel_param_ops param_ops_##name = { \
241 .set = param_set_##name, \
242 .get = param_get_##name, \
243 }; \
244 EXPORT_SYMBOL(param_set_##name); \
245 EXPORT_SYMBOL(param_get_##name); \
246 EXPORT_SYMBOL(param_ops_##name)
247
248
249STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
250STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
251STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
252STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
253STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
254STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
255STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
256
257int param_set_charp(const char *val, const struct kernel_param *kp)
258{
259 if (strlen(val) > 1024) {
260 pr_err("%s: string parameter too long\n", kp->name);
261 return -ENOSPC;
262 }
263
264 maybe_kfree_parameter(*(char **)kp->arg);
265
266 /* This is a hack. We can't kmalloc in early boot, and we
267 * don't need to; this mangled commandline is preserved. */
268 if (slab_is_available()) {
269 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
270 if (!*(char **)kp->arg)
271 return -ENOMEM;
272 strcpy(*(char **)kp->arg, val);
273 } else
274 *(const char **)kp->arg = val;
275
276 return 0;
277}
278EXPORT_SYMBOL(param_set_charp);
279
280int param_get_charp(char *buffer, const struct kernel_param *kp)
281{
282 return scnprintf(buffer, PAGE_SIZE, "%s", *((char **)kp->arg));
283}
284EXPORT_SYMBOL(param_get_charp);
285
286static void param_free_charp(void *arg)
287{
288 maybe_kfree_parameter(*((char **)arg));
289}
290
291struct kernel_param_ops param_ops_charp = {
292 .set = param_set_charp,
293 .get = param_get_charp,
294 .free = param_free_charp,
295};
296EXPORT_SYMBOL(param_ops_charp);
297
298/* Actually could be a bool or an int, for historical reasons. */
299int param_set_bool(const char *val, const struct kernel_param *kp)
300{
301 /* No equals means "set"... */
302 if (!val) val = "1";
303
304 /* One of =[yYnN01] */
305 return strtobool(val, kp->arg);
306}
307EXPORT_SYMBOL(param_set_bool);
308
309int param_get_bool(char *buffer, const struct kernel_param *kp)
310{
311 /* Y and N chosen as being relatively non-coder friendly */
312 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
313}
314EXPORT_SYMBOL(param_get_bool);
315
316struct kernel_param_ops param_ops_bool = {
317 .flags = KERNEL_PARAM_FL_NOARG,
318 .set = param_set_bool,
319 .get = param_get_bool,
320};
321EXPORT_SYMBOL(param_ops_bool);
322
323/* This one must be bool. */
324int param_set_invbool(const char *val, const struct kernel_param *kp)
325{
326 int ret;
327 bool boolval;
328 struct kernel_param dummy;
329
330 dummy.arg = &boolval;
331 ret = param_set_bool(val, &dummy);
332 if (ret == 0)
333 *(bool *)kp->arg = !boolval;
334 return ret;
335}
336EXPORT_SYMBOL(param_set_invbool);
337
338int param_get_invbool(char *buffer, const struct kernel_param *kp)
339{
340 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
341}
342EXPORT_SYMBOL(param_get_invbool);
343
344struct kernel_param_ops param_ops_invbool = {
345 .set = param_set_invbool,
346 .get = param_get_invbool,
347};
348EXPORT_SYMBOL(param_ops_invbool);
349
350int param_set_bint(const char *val, const struct kernel_param *kp)
351{
352 struct kernel_param boolkp;
353 bool v;
354 int ret;
355
356 /* Match bool exactly, by re-using it. */
357 boolkp = *kp;
358 boolkp.arg = &v;
359
360 ret = param_set_bool(val, &boolkp);
361 if (ret == 0)
362 *(int *)kp->arg = v;
363 return ret;
364}
365EXPORT_SYMBOL(param_set_bint);
366
367struct kernel_param_ops param_ops_bint = {
368 .flags = KERNEL_PARAM_FL_NOARG,
369 .set = param_set_bint,
370 .get = param_get_int,
371};
372EXPORT_SYMBOL(param_ops_bint);
373
374/* We break the rule and mangle the string. */
375static int param_array(const char *name,
376 const char *val,
377 unsigned int min, unsigned int max,
378 void *elem, int elemsize,
379 int (*set)(const char *, const struct kernel_param *kp),
380 s16 level,
381 unsigned int *num)
382{
383 int ret;
384 struct kernel_param kp;
385 char save;
386
387 /* Get the name right for errors. */
388 kp.name = name;
389 kp.arg = elem;
390 kp.level = level;
391
392 *num = 0;
393 /* We expect a comma-separated list of values. */
394 do {
395 int len;
396
397 if (*num == max) {
398 pr_err("%s: can only take %i arguments\n", name, max);
399 return -EINVAL;
400 }
401 len = strcspn(val, ",");
402
403 /* nul-terminate and parse */
404 save = val[len];
405 ((char *)val)[len] = '\0';
406 BUG_ON(!mutex_is_locked(¶m_lock));
407 ret = set(val, &kp);
408
409 if (ret != 0)
410 return ret;
411 kp.arg += elemsize;
412 val += len+1;
413 (*num)++;
414 } while (save == ',');
415
416 if (*num < min) {
417 pr_err("%s: needs at least %i arguments\n", name, min);
418 return -EINVAL;
419 }
420 return 0;
421}
422
423static int param_array_set(const char *val, const struct kernel_param *kp)
424{
425 const struct kparam_array *arr = kp->arr;
426 unsigned int temp_num;
427
428 return param_array(kp->name, val, 1, arr->max, arr->elem,
429 arr->elemsize, arr->ops->set, kp->level,
430 arr->num ?: &temp_num);
431}
432
433static int param_array_get(char *buffer, const struct kernel_param *kp)
434{
435 int i, off, ret;
436 const struct kparam_array *arr = kp->arr;
437 struct kernel_param p;
438
439 p = *kp;
440 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
441 if (i)
442 buffer[off++] = ',';
443 p.arg = arr->elem + arr->elemsize * i;
444 BUG_ON(!mutex_is_locked(¶m_lock));
445 ret = arr->ops->get(buffer + off, &p);
446 if (ret < 0)
447 return ret;
448 off += ret;
449 }
450 buffer[off] = '\0';
451 return off;
452}
453
454static void param_array_free(void *arg)
455{
456 unsigned int i;
457 const struct kparam_array *arr = arg;
458
459 if (arr->ops->free)
460 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
461 arr->ops->free(arr->elem + arr->elemsize * i);
462}
463
464struct kernel_param_ops param_array_ops = {
465 .set = param_array_set,
466 .get = param_array_get,
467 .free = param_array_free,
468};
469EXPORT_SYMBOL(param_array_ops);
470
471int param_set_copystring(const char *val, const struct kernel_param *kp)
472{
473 const struct kparam_string *kps = kp->str;
474
475 if (strlen(val)+1 > kps->maxlen) {
476 pr_err("%s: string doesn't fit in %u chars.\n",
477 kp->name, kps->maxlen-1);
478 return -ENOSPC;
479 }
480 strcpy(kps->string, val);
481 return 0;
482}
483EXPORT_SYMBOL(param_set_copystring);
484
485int param_get_string(char *buffer, const struct kernel_param *kp)
486{
487 const struct kparam_string *kps = kp->str;
488 return strlcpy(buffer, kps->string, kps->maxlen);
489}
490EXPORT_SYMBOL(param_get_string);
491
492struct kernel_param_ops param_ops_string = {
493 .set = param_set_copystring,
494 .get = param_get_string,
495};
496EXPORT_SYMBOL(param_ops_string);
497
498/* sysfs output in /sys/modules/XYZ/parameters/ */
499#define to_module_attr(n) container_of(n, struct module_attribute, attr)
500#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
501
502extern struct kernel_param __start___param[], __stop___param[];
503
504struct param_attribute
505{
506 struct module_attribute mattr;
507 const struct kernel_param *param;
508};
509
510struct module_param_attrs
511{
512 unsigned int num;
513 struct attribute_group grp;
514 struct param_attribute attrs[0];
515};
516
517#ifdef CONFIG_SYSFS
518#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
519
520static ssize_t param_attr_show(struct module_attribute *mattr,
521 struct module_kobject *mk, char *buf)
522{
523 int count;
524 struct param_attribute *attribute = to_param_attr(mattr);
525
526 if (!attribute->param->ops->get)
527 return -EPERM;
528
529 mutex_lock(¶m_lock);
530 count = attribute->param->ops->get(buf, attribute->param);
531 mutex_unlock(¶m_lock);
532 if (count > 0) {
533 strcat(buf, "\n");
534 ++count;
535 }
536 return count;
537}
538
539/* sysfs always hands a nul-terminated string in buf. We rely on that. */
540static ssize_t param_attr_store(struct module_attribute *mattr,
541 struct module_kobject *km,
542 const char *buf, size_t len)
543{
544 int err;
545 struct param_attribute *attribute = to_param_attr(mattr);
546
547 if (!attribute->param->ops->set)
548 return -EPERM;
549
550 mutex_lock(¶m_lock);
551 err = attribute->param->ops->set(buf, attribute->param);
552 mutex_unlock(¶m_lock);
553 if (!err)
554 return len;
555 return err;
556}
557#endif
558
559#ifdef CONFIG_MODULES
560#define __modinit
561#else
562#define __modinit __init
563#endif
564
565#ifdef CONFIG_SYSFS
566void __kernel_param_lock(void)
567{
568 mutex_lock(¶m_lock);
569}
570EXPORT_SYMBOL(__kernel_param_lock);
571
572void __kernel_param_unlock(void)
573{
574 mutex_unlock(¶m_lock);
575}
576EXPORT_SYMBOL(__kernel_param_unlock);
577
578/*
579 * add_sysfs_param - add a parameter to sysfs
580 * @mk: struct module_kobject
581 * @kparam: the actual parameter definition to add to sysfs
582 * @name: name of parameter
583 *
584 * Create a kobject if for a (per-module) parameter if mp NULL, and
585 * create file in sysfs. Returns an error on out of memory. Always cleans up
586 * if there's an error.
587 */
588static __modinit int add_sysfs_param(struct module_kobject *mk,
589 const struct kernel_param *kp,
590 const char *name)
591{
592 struct module_param_attrs *new;
593 struct attribute **attrs;
594 int err, num;
595
596 /* We don't bother calling this with invisible parameters. */
597 BUG_ON(!kp->perm);
598
599 if (!mk->mp) {
600 num = 0;
601 attrs = NULL;
602 } else {
603 num = mk->mp->num;
604 attrs = mk->mp->grp.attrs;
605 }
606
607 /* Enlarge. */
608 new = krealloc(mk->mp,
609 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
610 GFP_KERNEL);
611 if (!new) {
612 kfree(attrs);
613 err = -ENOMEM;
614 goto fail;
615 }
616 /* Despite looking like the typical realloc() bug, this is safe.
617 * We *want* the old 'attrs' to be freed either way, and we'll store
618 * the new one in the success case. */
619 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
620 if (!attrs) {
621 err = -ENOMEM;
622 goto fail_free_new;
623 }
624
625 /* Sysfs wants everything zeroed. */
626 memset(new, 0, sizeof(*new));
627 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
628 memset(&attrs[num], 0, sizeof(attrs[num]));
629 new->grp.name = "parameters";
630 new->grp.attrs = attrs;
631
632 /* Tack new one on the end. */
633 sysfs_attr_init(&new->attrs[num].mattr.attr);
634 new->attrs[num].param = kp;
635 new->attrs[num].mattr.show = param_attr_show;
636 new->attrs[num].mattr.store = param_attr_store;
637 new->attrs[num].mattr.attr.name = (char *)name;
638 new->attrs[num].mattr.attr.mode = kp->perm;
639 new->num = num+1;
640
641 /* Fix up all the pointers, since krealloc can move us */
642 for (num = 0; num < new->num; num++)
643 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
644 new->grp.attrs[num] = NULL;
645
646 mk->mp = new;
647 return 0;
648
649fail_free_new:
650 kfree(new);
651fail:
652 mk->mp = NULL;
653 return err;
654}
655
656#ifdef CONFIG_MODULES
657static void free_module_param_attrs(struct module_kobject *mk)
658{
659 kfree(mk->mp->grp.attrs);
660 kfree(mk->mp);
661 mk->mp = NULL;
662}
663
664/*
665 * module_param_sysfs_setup - setup sysfs support for one module
666 * @mod: module
667 * @kparam: module parameters (array)
668 * @num_params: number of module parameters
669 *
670 * Adds sysfs entries for module parameters under
671 * /sys/module/[mod->name]/parameters/
672 */
673int module_param_sysfs_setup(struct module *mod,
674 const struct kernel_param *kparam,
675 unsigned int num_params)
676{
677 int i, err;
678 bool params = false;
679
680 for (i = 0; i < num_params; i++) {
681 if (kparam[i].perm == 0)
682 continue;
683 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
684 if (err)
685 return err;
686 params = true;
687 }
688
689 if (!params)
690 return 0;
691
692 /* Create the param group. */
693 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
694 if (err)
695 free_module_param_attrs(&mod->mkobj);
696 return err;
697}
698
699/*
700 * module_param_sysfs_remove - remove sysfs support for one module
701 * @mod: module
702 *
703 * Remove sysfs entries for module parameters and the corresponding
704 * kobject.
705 */
706void module_param_sysfs_remove(struct module *mod)
707{
708 if (mod->mkobj.mp) {
709 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
710 /* We are positive that no one is using any param
711 * attrs at this point. Deallocate immediately. */
712 free_module_param_attrs(&mod->mkobj);
713 }
714}
715#endif
716
717void destroy_params(const struct kernel_param *params, unsigned num)
718{
719 unsigned int i;
720
721 for (i = 0; i < num; i++)
722 if (params[i].ops->free)
723 params[i].ops->free(params[i].arg);
724}
725
726static struct module_kobject * __init locate_module_kobject(const char *name)
727{
728 struct module_kobject *mk;
729 struct kobject *kobj;
730 int err;
731
732 kobj = kset_find_obj(module_kset, name);
733 if (kobj) {
734 mk = to_module_kobject(kobj);
735 } else {
736 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
737 BUG_ON(!mk);
738
739 mk->mod = THIS_MODULE;
740 mk->kobj.kset = module_kset;
741 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
742 "%s", name);
743#ifdef CONFIG_MODULES
744 if (!err)
745 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
746#endif
747 if (err) {
748 kobject_put(&mk->kobj);
749 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
750 name, err);
751 return NULL;
752 }
753
754 /* So that we hold reference in both cases. */
755 kobject_get(&mk->kobj);
756 }
757
758 return mk;
759}
760
761static void __init kernel_add_sysfs_param(const char *name,
762 struct kernel_param *kparam,
763 unsigned int name_skip)
764{
765 struct module_kobject *mk;
766 int err;
767
768 mk = locate_module_kobject(name);
769 if (!mk)
770 return;
771
772 /* We need to remove old parameters before adding more. */
773 if (mk->mp)
774 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
775
776 /* These should not fail at boot. */
777 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
778 BUG_ON(err);
779 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
780 BUG_ON(err);
781 kobject_uevent(&mk->kobj, KOBJ_ADD);
782 kobject_put(&mk->kobj);
783}
784
785/*
786 * param_sysfs_builtin - add sysfs parameters for built-in modules
787 *
788 * Add module_parameters to sysfs for "modules" built into the kernel.
789 *
790 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
791 * "parameter" name is stored behind a dot in kernel_param->name. So,
792 * extract the "module" name for all built-in kernel_param-eters,
793 * and for all who have the same, call kernel_add_sysfs_param.
794 */
795static void __init param_sysfs_builtin(void)
796{
797 struct kernel_param *kp;
798 unsigned int name_len;
799 char modname[MODULE_NAME_LEN];
800
801 for (kp = __start___param; kp < __stop___param; kp++) {
802 char *dot;
803
804 if (kp->perm == 0)
805 continue;
806
807 dot = strchr(kp->name, '.');
808 if (!dot) {
809 /* This happens for core_param() */
810 strcpy(modname, "kernel");
811 name_len = 0;
812 } else {
813 name_len = dot - kp->name + 1;
814 strlcpy(modname, kp->name, name_len);
815 }
816 kernel_add_sysfs_param(modname, kp, name_len);
817 }
818}
819
820ssize_t __modver_version_show(struct module_attribute *mattr,
821 struct module_kobject *mk, char *buf)
822{
823 struct module_version_attribute *vattr =
824 container_of(mattr, struct module_version_attribute, mattr);
825
826 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
827}
828
829extern const struct module_version_attribute *__start___modver[];
830extern const struct module_version_attribute *__stop___modver[];
831
832static void __init version_sysfs_builtin(void)
833{
834 const struct module_version_attribute **p;
835 struct module_kobject *mk;
836 int err;
837
838 for (p = __start___modver; p < __stop___modver; p++) {
839 const struct module_version_attribute *vattr = *p;
840
841 mk = locate_module_kobject(vattr->module_name);
842 if (mk) {
843 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
844 kobject_uevent(&mk->kobj, KOBJ_ADD);
845 kobject_put(&mk->kobj);
846 }
847 }
848}
849
850/* module-related sysfs stuff */
851
852static ssize_t module_attr_show(struct kobject *kobj,
853 struct attribute *attr,
854 char *buf)
855{
856 struct module_attribute *attribute;
857 struct module_kobject *mk;
858 int ret;
859
860 attribute = to_module_attr(attr);
861 mk = to_module_kobject(kobj);
862
863 if (!attribute->show)
864 return -EIO;
865
866 ret = attribute->show(attribute, mk, buf);
867
868 return ret;
869}
870
871static ssize_t module_attr_store(struct kobject *kobj,
872 struct attribute *attr,
873 const char *buf, size_t len)
874{
875 struct module_attribute *attribute;
876 struct module_kobject *mk;
877 int ret;
878
879 attribute = to_module_attr(attr);
880 mk = to_module_kobject(kobj);
881
882 if (!attribute->store)
883 return -EIO;
884
885 ret = attribute->store(attribute, mk, buf, len);
886
887 return ret;
888}
889
890static const struct sysfs_ops module_sysfs_ops = {
891 .show = module_attr_show,
892 .store = module_attr_store,
893};
894
895static int uevent_filter(struct kset *kset, struct kobject *kobj)
896{
897 struct kobj_type *ktype = get_ktype(kobj);
898
899 if (ktype == &module_ktype)
900 return 1;
901 return 0;
902}
903
904static const struct kset_uevent_ops module_uevent_ops = {
905 .filter = uevent_filter,
906};
907
908struct kset *module_kset;
909int module_sysfs_initialized;
910
911static void module_kobj_release(struct kobject *kobj)
912{
913 struct module_kobject *mk = to_module_kobject(kobj);
914 complete(mk->kobj_completion);
915}
916
917struct kobj_type module_ktype = {
918 .release = module_kobj_release,
919 .sysfs_ops = &module_sysfs_ops,
920};
921
922/*
923 * param_sysfs_init - wrapper for built-in params support
924 */
925static int __init param_sysfs_init(void)
926{
927 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
928 if (!module_kset) {
929 printk(KERN_WARNING "%s (%d): error creating kset\n",
930 __FILE__, __LINE__);
931 return -ENOMEM;
932 }
933 module_sysfs_initialized = 1;
934
935 version_sysfs_builtin();
936 param_sysfs_builtin();
937
938 return 0;
939}
940subsys_initcall(param_sysfs_init);
941
942#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 */