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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// 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);
244STANDARD_PARAM_DEF(hexint, unsigned int, "%#08x", kstrtouint);
245
246int param_set_uint_minmax(const char *val, const struct kernel_param *kp,
247 unsigned int min, unsigned int max)
248{
249 unsigned int num;
250 int ret;
251
252 if (!val)
253 return -EINVAL;
254 ret = kstrtouint(val, 0, &num);
255 if (ret)
256 return ret;
257 if (num < min || num > max)
258 return -EINVAL;
259 *((unsigned int *)kp->arg) = num;
260 return 0;
261}
262EXPORT_SYMBOL_GPL(param_set_uint_minmax);
263
264int param_set_charp(const char *val, const struct kernel_param *kp)
265{
266 if (strlen(val) > 1024) {
267 pr_err("%s: string parameter too long\n", kp->name);
268 return -ENOSPC;
269 }
270
271 maybe_kfree_parameter(*(char **)kp->arg);
272
273 /* This is a hack. We can't kmalloc in early boot, and we
274 * don't need to; this mangled commandline is preserved. */
275 if (slab_is_available()) {
276 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
277 if (!*(char **)kp->arg)
278 return -ENOMEM;
279 strcpy(*(char **)kp->arg, val);
280 } else
281 *(const char **)kp->arg = val;
282
283 return 0;
284}
285EXPORT_SYMBOL(param_set_charp);
286
287int param_get_charp(char *buffer, const struct kernel_param *kp)
288{
289 return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg));
290}
291EXPORT_SYMBOL(param_get_charp);
292
293void param_free_charp(void *arg)
294{
295 maybe_kfree_parameter(*((char **)arg));
296}
297EXPORT_SYMBOL(param_free_charp);
298
299const struct kernel_param_ops param_ops_charp = {
300 .set = param_set_charp,
301 .get = param_get_charp,
302 .free = param_free_charp,
303};
304EXPORT_SYMBOL(param_ops_charp);
305
306/* Actually could be a bool or an int, for historical reasons. */
307int param_set_bool(const char *val, const struct kernel_param *kp)
308{
309 /* No equals means "set"... */
310 if (!val) val = "1";
311
312 /* One of =[yYnN01] */
313 return strtobool(val, kp->arg);
314}
315EXPORT_SYMBOL(param_set_bool);
316
317int param_get_bool(char *buffer, const struct kernel_param *kp)
318{
319 /* Y and N chosen as being relatively non-coder friendly */
320 return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N');
321}
322EXPORT_SYMBOL(param_get_bool);
323
324const struct kernel_param_ops param_ops_bool = {
325 .flags = KERNEL_PARAM_OPS_FL_NOARG,
326 .set = param_set_bool,
327 .get = param_get_bool,
328};
329EXPORT_SYMBOL(param_ops_bool);
330
331int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
332{
333 int err = 0;
334 bool new_value;
335 bool orig_value = *(bool *)kp->arg;
336 struct kernel_param dummy_kp = *kp;
337
338 dummy_kp.arg = &new_value;
339
340 err = param_set_bool(val, &dummy_kp);
341 if (err)
342 return err;
343
344 /* Don't let them unset it once it's set! */
345 if (!new_value && orig_value)
346 return -EROFS;
347
348 if (new_value)
349 err = param_set_bool(val, kp);
350
351 return err;
352}
353EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
354
355const struct kernel_param_ops param_ops_bool_enable_only = {
356 .flags = KERNEL_PARAM_OPS_FL_NOARG,
357 .set = param_set_bool_enable_only,
358 .get = param_get_bool,
359};
360EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
361
362/* This one must be bool. */
363int param_set_invbool(const char *val, const struct kernel_param *kp)
364{
365 int ret;
366 bool boolval;
367 struct kernel_param dummy;
368
369 dummy.arg = &boolval;
370 ret = param_set_bool(val, &dummy);
371 if (ret == 0)
372 *(bool *)kp->arg = !boolval;
373 return ret;
374}
375EXPORT_SYMBOL(param_set_invbool);
376
377int param_get_invbool(char *buffer, const struct kernel_param *kp)
378{
379 return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y');
380}
381EXPORT_SYMBOL(param_get_invbool);
382
383const struct kernel_param_ops param_ops_invbool = {
384 .set = param_set_invbool,
385 .get = param_get_invbool,
386};
387EXPORT_SYMBOL(param_ops_invbool);
388
389int param_set_bint(const char *val, const struct kernel_param *kp)
390{
391 /* Match bool exactly, by re-using it. */
392 struct kernel_param boolkp = *kp;
393 bool v;
394 int ret;
395
396 boolkp.arg = &v;
397
398 ret = param_set_bool(val, &boolkp);
399 if (ret == 0)
400 *(int *)kp->arg = v;
401 return ret;
402}
403EXPORT_SYMBOL(param_set_bint);
404
405const struct kernel_param_ops param_ops_bint = {
406 .flags = KERNEL_PARAM_OPS_FL_NOARG,
407 .set = param_set_bint,
408 .get = param_get_int,
409};
410EXPORT_SYMBOL(param_ops_bint);
411
412/* We break the rule and mangle the string. */
413static int param_array(struct module *mod,
414 const char *name,
415 const char *val,
416 unsigned int min, unsigned int max,
417 void *elem, int elemsize,
418 int (*set)(const char *, const struct kernel_param *kp),
419 s16 level,
420 unsigned int *num)
421{
422 int ret;
423 struct kernel_param kp;
424 char save;
425
426 /* Get the name right for errors. */
427 kp.name = name;
428 kp.arg = elem;
429 kp.level = level;
430
431 *num = 0;
432 /* We expect a comma-separated list of values. */
433 do {
434 int len;
435
436 if (*num == max) {
437 pr_err("%s: can only take %i arguments\n", name, max);
438 return -EINVAL;
439 }
440 len = strcspn(val, ",");
441
442 /* nul-terminate and parse */
443 save = val[len];
444 ((char *)val)[len] = '\0';
445 check_kparam_locked(mod);
446 ret = set(val, &kp);
447
448 if (ret != 0)
449 return ret;
450 kp.arg += elemsize;
451 val += len+1;
452 (*num)++;
453 } while (save == ',');
454
455 if (*num < min) {
456 pr_err("%s: needs at least %i arguments\n", name, min);
457 return -EINVAL;
458 }
459 return 0;
460}
461
462static int param_array_set(const char *val, const struct kernel_param *kp)
463{
464 const struct kparam_array *arr = kp->arr;
465 unsigned int temp_num;
466
467 return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem,
468 arr->elemsize, arr->ops->set, kp->level,
469 arr->num ?: &temp_num);
470}
471
472static int param_array_get(char *buffer, const struct kernel_param *kp)
473{
474 int i, off, ret;
475 const struct kparam_array *arr = kp->arr;
476 struct kernel_param p = *kp;
477
478 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
479 /* Replace \n with comma */
480 if (i)
481 buffer[off - 1] = ',';
482 p.arg = arr->elem + arr->elemsize * i;
483 check_kparam_locked(p.mod);
484 ret = arr->ops->get(buffer + off, &p);
485 if (ret < 0)
486 return ret;
487 off += ret;
488 }
489 buffer[off] = '\0';
490 return off;
491}
492
493static void param_array_free(void *arg)
494{
495 unsigned int i;
496 const struct kparam_array *arr = arg;
497
498 if (arr->ops->free)
499 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
500 arr->ops->free(arr->elem + arr->elemsize * i);
501}
502
503const struct kernel_param_ops param_array_ops = {
504 .set = param_array_set,
505 .get = param_array_get,
506 .free = param_array_free,
507};
508EXPORT_SYMBOL(param_array_ops);
509
510int param_set_copystring(const char *val, const struct kernel_param *kp)
511{
512 const struct kparam_string *kps = kp->str;
513
514 if (strlen(val)+1 > kps->maxlen) {
515 pr_err("%s: string doesn't fit in %u chars.\n",
516 kp->name, kps->maxlen-1);
517 return -ENOSPC;
518 }
519 strcpy(kps->string, val);
520 return 0;
521}
522EXPORT_SYMBOL(param_set_copystring);
523
524int param_get_string(char *buffer, const struct kernel_param *kp)
525{
526 const struct kparam_string *kps = kp->str;
527 return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string);
528}
529EXPORT_SYMBOL(param_get_string);
530
531const struct kernel_param_ops param_ops_string = {
532 .set = param_set_copystring,
533 .get = param_get_string,
534};
535EXPORT_SYMBOL(param_ops_string);
536
537/* sysfs output in /sys/modules/XYZ/parameters/ */
538#define to_module_attr(n) container_of(n, struct module_attribute, attr)
539#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
540
541struct param_attribute
542{
543 struct module_attribute mattr;
544 const struct kernel_param *param;
545};
546
547struct module_param_attrs
548{
549 unsigned int num;
550 struct attribute_group grp;
551 struct param_attribute attrs[];
552};
553
554#ifdef CONFIG_SYSFS
555#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
556
557static ssize_t param_attr_show(struct module_attribute *mattr,
558 struct module_kobject *mk, char *buf)
559{
560 int count;
561 struct param_attribute *attribute = to_param_attr(mattr);
562
563 if (!attribute->param->ops->get)
564 return -EPERM;
565
566 kernel_param_lock(mk->mod);
567 count = attribute->param->ops->get(buf, attribute->param);
568 kernel_param_unlock(mk->mod);
569 return count;
570}
571
572/* sysfs always hands a nul-terminated string in buf. We rely on that. */
573static ssize_t param_attr_store(struct module_attribute *mattr,
574 struct module_kobject *mk,
575 const char *buf, size_t len)
576{
577 int err;
578 struct param_attribute *attribute = to_param_attr(mattr);
579
580 if (!attribute->param->ops->set)
581 return -EPERM;
582
583 kernel_param_lock(mk->mod);
584 if (param_check_unsafe(attribute->param))
585 err = attribute->param->ops->set(buf, attribute->param);
586 else
587 err = -EPERM;
588 kernel_param_unlock(mk->mod);
589 if (!err)
590 return len;
591 return err;
592}
593#endif
594
595#ifdef CONFIG_MODULES
596#define __modinit
597#else
598#define __modinit __init
599#endif
600
601#ifdef CONFIG_SYSFS
602void kernel_param_lock(struct module *mod)
603{
604 mutex_lock(KPARAM_MUTEX(mod));
605}
606
607void kernel_param_unlock(struct module *mod)
608{
609 mutex_unlock(KPARAM_MUTEX(mod));
610}
611
612EXPORT_SYMBOL(kernel_param_lock);
613EXPORT_SYMBOL(kernel_param_unlock);
614
615/*
616 * add_sysfs_param - add a parameter to sysfs
617 * @mk: struct module_kobject
618 * @kp: the actual parameter definition to add to sysfs
619 * @name: name of parameter
620 *
621 * Create a kobject if for a (per-module) parameter if mp NULL, and
622 * create file in sysfs. Returns an error on out of memory. Always cleans up
623 * if there's an error.
624 */
625static __modinit int add_sysfs_param(struct module_kobject *mk,
626 const struct kernel_param *kp,
627 const char *name)
628{
629 struct module_param_attrs *new_mp;
630 struct attribute **new_attrs;
631 unsigned int i;
632
633 /* We don't bother calling this with invisible parameters. */
634 BUG_ON(!kp->perm);
635
636 if (!mk->mp) {
637 /* First allocation. */
638 mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
639 if (!mk->mp)
640 return -ENOMEM;
641 mk->mp->grp.name = "parameters";
642 /* NULL-terminated attribute array. */
643 mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
644 GFP_KERNEL);
645 /* Caller will cleanup via free_module_param_attrs */
646 if (!mk->mp->grp.attrs)
647 return -ENOMEM;
648 }
649
650 /* Enlarge allocations. */
651 new_mp = krealloc(mk->mp,
652 sizeof(*mk->mp) +
653 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
654 GFP_KERNEL);
655 if (!new_mp)
656 return -ENOMEM;
657 mk->mp = new_mp;
658
659 /* Extra pointer for NULL terminator */
660 new_attrs = krealloc(mk->mp->grp.attrs,
661 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
662 GFP_KERNEL);
663 if (!new_attrs)
664 return -ENOMEM;
665 mk->mp->grp.attrs = new_attrs;
666
667 /* Tack new one on the end. */
668 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
669 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
670 mk->mp->attrs[mk->mp->num].param = kp;
671 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
672 /* Do not allow runtime DAC changes to make param writable. */
673 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
674 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
675 else
676 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
677 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
678 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
679 mk->mp->num++;
680
681 /* Fix up all the pointers, since krealloc can move us */
682 for (i = 0; i < mk->mp->num; i++)
683 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
684 mk->mp->grp.attrs[mk->mp->num] = NULL;
685 return 0;
686}
687
688#ifdef CONFIG_MODULES
689static void free_module_param_attrs(struct module_kobject *mk)
690{
691 if (mk->mp)
692 kfree(mk->mp->grp.attrs);
693 kfree(mk->mp);
694 mk->mp = NULL;
695}
696
697/*
698 * module_param_sysfs_setup - setup sysfs support for one module
699 * @mod: module
700 * @kparam: module parameters (array)
701 * @num_params: number of module parameters
702 *
703 * Adds sysfs entries for module parameters under
704 * /sys/module/[mod->name]/parameters/
705 */
706int module_param_sysfs_setup(struct module *mod,
707 const struct kernel_param *kparam,
708 unsigned int num_params)
709{
710 int i, err;
711 bool params = false;
712
713 for (i = 0; i < num_params; i++) {
714 if (kparam[i].perm == 0)
715 continue;
716 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
717 if (err) {
718 free_module_param_attrs(&mod->mkobj);
719 return err;
720 }
721 params = true;
722 }
723
724 if (!params)
725 return 0;
726
727 /* Create the param group. */
728 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
729 if (err)
730 free_module_param_attrs(&mod->mkobj);
731 return err;
732}
733
734/*
735 * module_param_sysfs_remove - remove sysfs support for one module
736 * @mod: module
737 *
738 * Remove sysfs entries for module parameters and the corresponding
739 * kobject.
740 */
741void module_param_sysfs_remove(struct module *mod)
742{
743 if (mod->mkobj.mp) {
744 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
745 /* We are positive that no one is using any param
746 * attrs at this point. Deallocate immediately. */
747 free_module_param_attrs(&mod->mkobj);
748 }
749}
750#endif
751
752void destroy_params(const struct kernel_param *params, unsigned num)
753{
754 unsigned int i;
755
756 for (i = 0; i < num; i++)
757 if (params[i].ops->free)
758 params[i].ops->free(params[i].arg);
759}
760
761static struct module_kobject * __init locate_module_kobject(const char *name)
762{
763 struct module_kobject *mk;
764 struct kobject *kobj;
765 int err;
766
767 kobj = kset_find_obj(module_kset, name);
768 if (kobj) {
769 mk = to_module_kobject(kobj);
770 } else {
771 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
772 BUG_ON(!mk);
773
774 mk->mod = THIS_MODULE;
775 mk->kobj.kset = module_kset;
776 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
777 "%s", name);
778#ifdef CONFIG_MODULES
779 if (!err)
780 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
781#endif
782 if (err) {
783 kobject_put(&mk->kobj);
784 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
785 name, err);
786 return NULL;
787 }
788
789 /* So that we hold reference in both cases. */
790 kobject_get(&mk->kobj);
791 }
792
793 return mk;
794}
795
796static void __init kernel_add_sysfs_param(const char *name,
797 const struct kernel_param *kparam,
798 unsigned int name_skip)
799{
800 struct module_kobject *mk;
801 int err;
802
803 mk = locate_module_kobject(name);
804 if (!mk)
805 return;
806
807 /* We need to remove old parameters before adding more. */
808 if (mk->mp)
809 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
810
811 /* These should not fail at boot. */
812 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
813 BUG_ON(err);
814 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
815 BUG_ON(err);
816 kobject_uevent(&mk->kobj, KOBJ_ADD);
817 kobject_put(&mk->kobj);
818}
819
820/*
821 * param_sysfs_builtin - add sysfs parameters for built-in modules
822 *
823 * Add module_parameters to sysfs for "modules" built into the kernel.
824 *
825 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
826 * "parameter" name is stored behind a dot in kernel_param->name. So,
827 * extract the "module" name for all built-in kernel_param-eters,
828 * and for all who have the same, call kernel_add_sysfs_param.
829 */
830static void __init param_sysfs_builtin(void)
831{
832 const struct kernel_param *kp;
833 unsigned int name_len;
834 char modname[MODULE_NAME_LEN];
835
836 for (kp = __start___param; kp < __stop___param; kp++) {
837 char *dot;
838
839 if (kp->perm == 0)
840 continue;
841
842 dot = strchr(kp->name, '.');
843 if (!dot) {
844 /* This happens for core_param() */
845 strcpy(modname, "kernel");
846 name_len = 0;
847 } else {
848 name_len = dot - kp->name + 1;
849 strlcpy(modname, kp->name, name_len);
850 }
851 kernel_add_sysfs_param(modname, kp, name_len);
852 }
853}
854
855ssize_t __modver_version_show(struct module_attribute *mattr,
856 struct module_kobject *mk, char *buf)
857{
858 struct module_version_attribute *vattr =
859 container_of(mattr, struct module_version_attribute, mattr);
860
861 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
862}
863
864extern const struct module_version_attribute __start___modver[];
865extern const struct module_version_attribute __stop___modver[];
866
867static void __init version_sysfs_builtin(void)
868{
869 const struct module_version_attribute *vattr;
870 struct module_kobject *mk;
871 int err;
872
873 for (vattr = __start___modver; vattr < __stop___modver; vattr++) {
874 mk = locate_module_kobject(vattr->module_name);
875 if (mk) {
876 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
877 WARN_ON_ONCE(err);
878 kobject_uevent(&mk->kobj, KOBJ_ADD);
879 kobject_put(&mk->kobj);
880 }
881 }
882}
883
884/* module-related sysfs stuff */
885
886static ssize_t module_attr_show(struct kobject *kobj,
887 struct attribute *attr,
888 char *buf)
889{
890 struct module_attribute *attribute;
891 struct module_kobject *mk;
892 int ret;
893
894 attribute = to_module_attr(attr);
895 mk = to_module_kobject(kobj);
896
897 if (!attribute->show)
898 return -EIO;
899
900 ret = attribute->show(attribute, mk, buf);
901
902 return ret;
903}
904
905static ssize_t module_attr_store(struct kobject *kobj,
906 struct attribute *attr,
907 const char *buf, size_t len)
908{
909 struct module_attribute *attribute;
910 struct module_kobject *mk;
911 int ret;
912
913 attribute = to_module_attr(attr);
914 mk = to_module_kobject(kobj);
915
916 if (!attribute->store)
917 return -EIO;
918
919 ret = attribute->store(attribute, mk, buf, len);
920
921 return ret;
922}
923
924static const struct sysfs_ops module_sysfs_ops = {
925 .show = module_attr_show,
926 .store = module_attr_store,
927};
928
929static int uevent_filter(const struct kobject *kobj)
930{
931 const struct kobj_type *ktype = get_ktype(kobj);
932
933 if (ktype == &module_ktype)
934 return 1;
935 return 0;
936}
937
938static const struct kset_uevent_ops module_uevent_ops = {
939 .filter = uevent_filter,
940};
941
942struct kset *module_kset;
943
944static void module_kobj_release(struct kobject *kobj)
945{
946 struct module_kobject *mk = to_module_kobject(kobj);
947 complete(mk->kobj_completion);
948}
949
950struct kobj_type module_ktype = {
951 .release = module_kobj_release,
952 .sysfs_ops = &module_sysfs_ops,
953};
954
955/*
956 * param_sysfs_init - create "module" kset
957 *
958 * This must be done before the initramfs is unpacked and
959 * request_module() thus becomes possible, because otherwise the
960 * module load would fail in mod_sysfs_init.
961 */
962static int __init param_sysfs_init(void)
963{
964 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
965 if (!module_kset) {
966 printk(KERN_WARNING "%s (%d): error creating kset\n",
967 __FILE__, __LINE__);
968 return -ENOMEM;
969 }
970
971 return 0;
972}
973subsys_initcall(param_sysfs_init);
974
975/*
976 * param_sysfs_builtin_init - add sysfs version and parameter
977 * attributes for built-in modules
978 */
979static int __init param_sysfs_builtin_init(void)
980{
981 if (!module_kset)
982 return -ENOMEM;
983
984 version_sysfs_builtin();
985 param_sysfs_builtin();
986
987 return 0;
988}
989late_initcall(param_sysfs_builtin_init);
990
991#endif /* CONFIG_SYSFS */