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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Helpers for initial module or kernel cmdline parsing
3 Copyright (C) 2001 Rusty Russell.
4
5*/
6#include <linux/kernel.h>
7#include <linux/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 */
1/* Helpers for initial module or kernel cmdline parsing
2 Copyright (C) 2001 Rusty Russell.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17*/
18#include <linux/moduleparam.h>
19#include <linux/kernel.h>
20#include <linux/string.h>
21#include <linux/errno.h>
22#include <linux/module.h>
23#include <linux/device.h>
24#include <linux/err.h>
25#include <linux/slab.h>
26#include <linux/ctype.h>
27
28#if 0
29#define DEBUGP printk
30#else
31#define DEBUGP(fmt, a...)
32#endif
33
34/* Protects all parameters, and incidentally kmalloced_param list. */
35static DEFINE_MUTEX(param_lock);
36
37/* This just allows us to keep track of which parameters are kmalloced. */
38struct kmalloced_param {
39 struct list_head list;
40 char val[];
41};
42static LIST_HEAD(kmalloced_params);
43
44static void *kmalloc_parameter(unsigned int size)
45{
46 struct kmalloced_param *p;
47
48 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
49 if (!p)
50 return NULL;
51
52 list_add(&p->list, &kmalloced_params);
53 return p->val;
54}
55
56/* Does nothing if parameter wasn't kmalloced above. */
57static void maybe_kfree_parameter(void *param)
58{
59 struct kmalloced_param *p;
60
61 list_for_each_entry(p, &kmalloced_params, list) {
62 if (p->val == param) {
63 list_del(&p->list);
64 kfree(p);
65 break;
66 }
67 }
68}
69
70static inline char dash2underscore(char c)
71{
72 if (c == '-')
73 return '_';
74 return c;
75}
76
77static inline int parameq(const char *input, const char *paramname)
78{
79 unsigned int i;
80 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
81 if (input[i] == '\0')
82 return 1;
83 return 0;
84}
85
86static int parse_one(char *param,
87 char *val,
88 const struct kernel_param *params,
89 unsigned num_params,
90 int (*handle_unknown)(char *param, char *val))
91{
92 unsigned int i;
93 int err;
94
95 /* Find parameter */
96 for (i = 0; i < num_params; i++) {
97 if (parameq(param, params[i].name)) {
98 /* No one handled NULL, so do it here. */
99 if (!val && params[i].ops->set != param_set_bool)
100 return -EINVAL;
101 DEBUGP("They are equal! Calling %p\n",
102 params[i].ops->set);
103 mutex_lock(¶m_lock);
104 err = params[i].ops->set(val, ¶ms[i]);
105 mutex_unlock(¶m_lock);
106 return err;
107 }
108 }
109
110 if (handle_unknown) {
111 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
112 return handle_unknown(param, val);
113 }
114
115 DEBUGP("Unknown argument `%s'\n", param);
116 return -ENOENT;
117}
118
119/* You can use " around spaces, but can't escape ". */
120/* Hyphens and underscores equivalent in parameter names. */
121static char *next_arg(char *args, char **param, char **val)
122{
123 unsigned int i, equals = 0;
124 int in_quote = 0, quoted = 0;
125 char *next;
126
127 if (*args == '"') {
128 args++;
129 in_quote = 1;
130 quoted = 1;
131 }
132
133 for (i = 0; args[i]; i++) {
134 if (isspace(args[i]) && !in_quote)
135 break;
136 if (equals == 0) {
137 if (args[i] == '=')
138 equals = i;
139 }
140 if (args[i] == '"')
141 in_quote = !in_quote;
142 }
143
144 *param = args;
145 if (!equals)
146 *val = NULL;
147 else {
148 args[equals] = '\0';
149 *val = args + equals + 1;
150
151 /* Don't include quotes in value. */
152 if (**val == '"') {
153 (*val)++;
154 if (args[i-1] == '"')
155 args[i-1] = '\0';
156 }
157 if (quoted && args[i-1] == '"')
158 args[i-1] = '\0';
159 }
160
161 if (args[i]) {
162 args[i] = '\0';
163 next = args + i + 1;
164 } else
165 next = args + i;
166
167 /* Chew up trailing spaces. */
168 return skip_spaces(next);
169}
170
171/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
172int parse_args(const char *name,
173 char *args,
174 const struct kernel_param *params,
175 unsigned num,
176 int (*unknown)(char *param, char *val))
177{
178 char *param, *val;
179
180 DEBUGP("Parsing ARGS: %s\n", args);
181
182 /* Chew leading spaces */
183 args = skip_spaces(args);
184
185 while (*args) {
186 int ret;
187 int irq_was_disabled;
188
189 args = next_arg(args, ¶m, &val);
190 irq_was_disabled = irqs_disabled();
191 ret = parse_one(param, val, params, num, unknown);
192 if (irq_was_disabled && !irqs_disabled()) {
193 printk(KERN_WARNING "parse_args(): option '%s' enabled "
194 "irq's!\n", param);
195 }
196 switch (ret) {
197 case -ENOENT:
198 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
199 name, param);
200 return ret;
201 case -ENOSPC:
202 printk(KERN_ERR
203 "%s: `%s' too large for parameter `%s'\n",
204 name, val ?: "", param);
205 return ret;
206 case 0:
207 break;
208 default:
209 printk(KERN_ERR
210 "%s: `%s' invalid for parameter `%s'\n",
211 name, val ?: "", param);
212 return ret;
213 }
214 }
215
216 /* All parsed OK. */
217 return 0;
218}
219
220/* Lazy bastard, eh? */
221#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
222 int param_set_##name(const char *val, const struct kernel_param *kp) \
223 { \
224 tmptype l; \
225 int ret; \
226 \
227 ret = strtolfn(val, 0, &l); \
228 if (ret < 0 || ((type)l != l)) \
229 return ret < 0 ? ret : -EINVAL; \
230 *((type *)kp->arg) = l; \
231 return 0; \
232 } \
233 int param_get_##name(char *buffer, const struct kernel_param *kp) \
234 { \
235 return sprintf(buffer, format, *((type *)kp->arg)); \
236 } \
237 struct kernel_param_ops param_ops_##name = { \
238 .set = param_set_##name, \
239 .get = param_get_##name, \
240 }; \
241 EXPORT_SYMBOL(param_set_##name); \
242 EXPORT_SYMBOL(param_get_##name); \
243 EXPORT_SYMBOL(param_ops_##name)
244
245
246STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
247STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
248STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
249STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
250STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
251STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
252STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
253
254int param_set_charp(const char *val, const struct kernel_param *kp)
255{
256 if (strlen(val) > 1024) {
257 printk(KERN_ERR "%s: string parameter too long\n",
258 kp->name);
259 return -ENOSPC;
260 }
261
262 maybe_kfree_parameter(*(char **)kp->arg);
263
264 /* This is a hack. We can't kmalloc in early boot, and we
265 * don't need to; this mangled commandline is preserved. */
266 if (slab_is_available()) {
267 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
268 if (!*(char **)kp->arg)
269 return -ENOMEM;
270 strcpy(*(char **)kp->arg, val);
271 } else
272 *(const char **)kp->arg = val;
273
274 return 0;
275}
276EXPORT_SYMBOL(param_set_charp);
277
278int param_get_charp(char *buffer, const struct kernel_param *kp)
279{
280 return sprintf(buffer, "%s", *((char **)kp->arg));
281}
282EXPORT_SYMBOL(param_get_charp);
283
284static void param_free_charp(void *arg)
285{
286 maybe_kfree_parameter(*((char **)arg));
287}
288
289struct kernel_param_ops param_ops_charp = {
290 .set = param_set_charp,
291 .get = param_get_charp,
292 .free = param_free_charp,
293};
294EXPORT_SYMBOL(param_ops_charp);
295
296/* Actually could be a bool or an int, for historical reasons. */
297int param_set_bool(const char *val, const struct kernel_param *kp)
298{
299 bool v;
300 int ret;
301
302 /* No equals means "set"... */
303 if (!val) val = "1";
304
305 /* One of =[yYnN01] */
306 ret = strtobool(val, &v);
307 if (ret)
308 return ret;
309
310 if (kp->flags & KPARAM_ISBOOL)
311 *(bool *)kp->arg = v;
312 else
313 *(int *)kp->arg = v;
314 return 0;
315}
316EXPORT_SYMBOL(param_set_bool);
317
318int param_get_bool(char *buffer, const struct kernel_param *kp)
319{
320 bool val;
321 if (kp->flags & KPARAM_ISBOOL)
322 val = *(bool *)kp->arg;
323 else
324 val = *(int *)kp->arg;
325
326 /* Y and N chosen as being relatively non-coder friendly */
327 return sprintf(buffer, "%c", val ? 'Y' : 'N');
328}
329EXPORT_SYMBOL(param_get_bool);
330
331struct kernel_param_ops param_ops_bool = {
332 .set = param_set_bool,
333 .get = param_get_bool,
334};
335EXPORT_SYMBOL(param_ops_bool);
336
337/* This one must be bool. */
338int param_set_invbool(const char *val, const struct kernel_param *kp)
339{
340 int ret;
341 bool boolval;
342 struct kernel_param dummy;
343
344 dummy.arg = &boolval;
345 dummy.flags = KPARAM_ISBOOL;
346 ret = param_set_bool(val, &dummy);
347 if (ret == 0)
348 *(bool *)kp->arg = !boolval;
349 return ret;
350}
351EXPORT_SYMBOL(param_set_invbool);
352
353int param_get_invbool(char *buffer, const struct kernel_param *kp)
354{
355 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
356}
357EXPORT_SYMBOL(param_get_invbool);
358
359struct kernel_param_ops param_ops_invbool = {
360 .set = param_set_invbool,
361 .get = param_get_invbool,
362};
363EXPORT_SYMBOL(param_ops_invbool);
364
365/* We break the rule and mangle the string. */
366static int param_array(const char *name,
367 const char *val,
368 unsigned int min, unsigned int max,
369 void *elem, int elemsize,
370 int (*set)(const char *, const struct kernel_param *kp),
371 u16 flags,
372 unsigned int *num)
373{
374 int ret;
375 struct kernel_param kp;
376 char save;
377
378 /* Get the name right for errors. */
379 kp.name = name;
380 kp.arg = elem;
381 kp.flags = flags;
382
383 *num = 0;
384 /* We expect a comma-separated list of values. */
385 do {
386 int len;
387
388 if (*num == max) {
389 printk(KERN_ERR "%s: can only take %i arguments\n",
390 name, max);
391 return -EINVAL;
392 }
393 len = strcspn(val, ",");
394
395 /* nul-terminate and parse */
396 save = val[len];
397 ((char *)val)[len] = '\0';
398 BUG_ON(!mutex_is_locked(¶m_lock));
399 ret = set(val, &kp);
400
401 if (ret != 0)
402 return ret;
403 kp.arg += elemsize;
404 val += len+1;
405 (*num)++;
406 } while (save == ',');
407
408 if (*num < min) {
409 printk(KERN_ERR "%s: needs at least %i arguments\n",
410 name, min);
411 return -EINVAL;
412 }
413 return 0;
414}
415
416static int param_array_set(const char *val, const struct kernel_param *kp)
417{
418 const struct kparam_array *arr = kp->arr;
419 unsigned int temp_num;
420
421 return param_array(kp->name, val, 1, arr->max, arr->elem,
422 arr->elemsize, arr->ops->set, kp->flags,
423 arr->num ?: &temp_num);
424}
425
426static int param_array_get(char *buffer, const struct kernel_param *kp)
427{
428 int i, off, ret;
429 const struct kparam_array *arr = kp->arr;
430 struct kernel_param p;
431
432 p = *kp;
433 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
434 if (i)
435 buffer[off++] = ',';
436 p.arg = arr->elem + arr->elemsize * i;
437 BUG_ON(!mutex_is_locked(¶m_lock));
438 ret = arr->ops->get(buffer + off, &p);
439 if (ret < 0)
440 return ret;
441 off += ret;
442 }
443 buffer[off] = '\0';
444 return off;
445}
446
447static void param_array_free(void *arg)
448{
449 unsigned int i;
450 const struct kparam_array *arr = arg;
451
452 if (arr->ops->free)
453 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
454 arr->ops->free(arr->elem + arr->elemsize * i);
455}
456
457struct kernel_param_ops param_array_ops = {
458 .set = param_array_set,
459 .get = param_array_get,
460 .free = param_array_free,
461};
462EXPORT_SYMBOL(param_array_ops);
463
464int param_set_copystring(const char *val, const struct kernel_param *kp)
465{
466 const struct kparam_string *kps = kp->str;
467
468 if (strlen(val)+1 > kps->maxlen) {
469 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
470 kp->name, kps->maxlen-1);
471 return -ENOSPC;
472 }
473 strcpy(kps->string, val);
474 return 0;
475}
476EXPORT_SYMBOL(param_set_copystring);
477
478int param_get_string(char *buffer, const struct kernel_param *kp)
479{
480 const struct kparam_string *kps = kp->str;
481 return strlcpy(buffer, kps->string, kps->maxlen);
482}
483EXPORT_SYMBOL(param_get_string);
484
485struct kernel_param_ops param_ops_string = {
486 .set = param_set_copystring,
487 .get = param_get_string,
488};
489EXPORT_SYMBOL(param_ops_string);
490
491/* sysfs output in /sys/modules/XYZ/parameters/ */
492#define to_module_attr(n) container_of(n, struct module_attribute, attr)
493#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
494
495extern struct kernel_param __start___param[], __stop___param[];
496
497struct param_attribute
498{
499 struct module_attribute mattr;
500 const struct kernel_param *param;
501};
502
503struct module_param_attrs
504{
505 unsigned int num;
506 struct attribute_group grp;
507 struct param_attribute attrs[0];
508};
509
510#ifdef CONFIG_SYSFS
511#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
512
513static ssize_t param_attr_show(struct module_attribute *mattr,
514 struct module_kobject *mk, char *buf)
515{
516 int count;
517 struct param_attribute *attribute = to_param_attr(mattr);
518
519 if (!attribute->param->ops->get)
520 return -EPERM;
521
522 mutex_lock(¶m_lock);
523 count = attribute->param->ops->get(buf, attribute->param);
524 mutex_unlock(¶m_lock);
525 if (count > 0) {
526 strcat(buf, "\n");
527 ++count;
528 }
529 return count;
530}
531
532/* sysfs always hands a nul-terminated string in buf. We rely on that. */
533static ssize_t param_attr_store(struct module_attribute *mattr,
534 struct module_kobject *km,
535 const char *buf, size_t len)
536{
537 int err;
538 struct param_attribute *attribute = to_param_attr(mattr);
539
540 if (!attribute->param->ops->set)
541 return -EPERM;
542
543 mutex_lock(¶m_lock);
544 err = attribute->param->ops->set(buf, attribute->param);
545 mutex_unlock(¶m_lock);
546 if (!err)
547 return len;
548 return err;
549}
550#endif
551
552#ifdef CONFIG_MODULES
553#define __modinit
554#else
555#define __modinit __init
556#endif
557
558#ifdef CONFIG_SYSFS
559void __kernel_param_lock(void)
560{
561 mutex_lock(¶m_lock);
562}
563EXPORT_SYMBOL(__kernel_param_lock);
564
565void __kernel_param_unlock(void)
566{
567 mutex_unlock(¶m_lock);
568}
569EXPORT_SYMBOL(__kernel_param_unlock);
570
571/*
572 * add_sysfs_param - add a parameter to sysfs
573 * @mk: struct module_kobject
574 * @kparam: the actual parameter definition to add to sysfs
575 * @name: name of parameter
576 *
577 * Create a kobject if for a (per-module) parameter if mp NULL, and
578 * create file in sysfs. Returns an error on out of memory. Always cleans up
579 * if there's an error.
580 */
581static __modinit int add_sysfs_param(struct module_kobject *mk,
582 const struct kernel_param *kp,
583 const char *name)
584{
585 struct module_param_attrs *new;
586 struct attribute **attrs;
587 int err, num;
588
589 /* We don't bother calling this with invisible parameters. */
590 BUG_ON(!kp->perm);
591
592 if (!mk->mp) {
593 num = 0;
594 attrs = NULL;
595 } else {
596 num = mk->mp->num;
597 attrs = mk->mp->grp.attrs;
598 }
599
600 /* Enlarge. */
601 new = krealloc(mk->mp,
602 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
603 GFP_KERNEL);
604 if (!new) {
605 kfree(mk->mp);
606 err = -ENOMEM;
607 goto fail;
608 }
609 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
610 if (!attrs) {
611 err = -ENOMEM;
612 goto fail_free_new;
613 }
614
615 /* Sysfs wants everything zeroed. */
616 memset(new, 0, sizeof(*new));
617 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
618 memset(&attrs[num], 0, sizeof(attrs[num]));
619 new->grp.name = "parameters";
620 new->grp.attrs = attrs;
621
622 /* Tack new one on the end. */
623 sysfs_attr_init(&new->attrs[num].mattr.attr);
624 new->attrs[num].param = kp;
625 new->attrs[num].mattr.show = param_attr_show;
626 new->attrs[num].mattr.store = param_attr_store;
627 new->attrs[num].mattr.attr.name = (char *)name;
628 new->attrs[num].mattr.attr.mode = kp->perm;
629 new->num = num+1;
630
631 /* Fix up all the pointers, since krealloc can move us */
632 for (num = 0; num < new->num; num++)
633 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
634 new->grp.attrs[num] = NULL;
635
636 mk->mp = new;
637 return 0;
638
639fail_free_new:
640 kfree(new);
641fail:
642 mk->mp = NULL;
643 return err;
644}
645
646#ifdef CONFIG_MODULES
647static void free_module_param_attrs(struct module_kobject *mk)
648{
649 kfree(mk->mp->grp.attrs);
650 kfree(mk->mp);
651 mk->mp = NULL;
652}
653
654/*
655 * module_param_sysfs_setup - setup sysfs support for one module
656 * @mod: module
657 * @kparam: module parameters (array)
658 * @num_params: number of module parameters
659 *
660 * Adds sysfs entries for module parameters under
661 * /sys/module/[mod->name]/parameters/
662 */
663int module_param_sysfs_setup(struct module *mod,
664 const struct kernel_param *kparam,
665 unsigned int num_params)
666{
667 int i, err;
668 bool params = false;
669
670 for (i = 0; i < num_params; i++) {
671 if (kparam[i].perm == 0)
672 continue;
673 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
674 if (err)
675 return err;
676 params = true;
677 }
678
679 if (!params)
680 return 0;
681
682 /* Create the param group. */
683 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
684 if (err)
685 free_module_param_attrs(&mod->mkobj);
686 return err;
687}
688
689/*
690 * module_param_sysfs_remove - remove sysfs support for one module
691 * @mod: module
692 *
693 * Remove sysfs entries for module parameters and the corresponding
694 * kobject.
695 */
696void module_param_sysfs_remove(struct module *mod)
697{
698 if (mod->mkobj.mp) {
699 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
700 /* We are positive that no one is using any param
701 * attrs at this point. Deallocate immediately. */
702 free_module_param_attrs(&mod->mkobj);
703 }
704}
705#endif
706
707void destroy_params(const struct kernel_param *params, unsigned num)
708{
709 unsigned int i;
710
711 for (i = 0; i < num; i++)
712 if (params[i].ops->free)
713 params[i].ops->free(params[i].arg);
714}
715
716static struct module_kobject * __init locate_module_kobject(const char *name)
717{
718 struct module_kobject *mk;
719 struct kobject *kobj;
720 int err;
721
722 kobj = kset_find_obj(module_kset, name);
723 if (kobj) {
724 mk = to_module_kobject(kobj);
725 } else {
726 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
727 BUG_ON(!mk);
728
729 mk->mod = THIS_MODULE;
730 mk->kobj.kset = module_kset;
731 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
732 "%s", name);
733#ifdef CONFIG_MODULES
734 if (!err)
735 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
736#endif
737 if (err) {
738 kobject_put(&mk->kobj);
739 printk(KERN_ERR
740 "Module '%s' failed add to sysfs, error number %d\n",
741 name, err);
742 printk(KERN_ERR
743 "The system will be unstable now.\n");
744 return NULL;
745 }
746
747 /* So that we hold reference in both cases. */
748 kobject_get(&mk->kobj);
749 }
750
751 return mk;
752}
753
754static void __init kernel_add_sysfs_param(const char *name,
755 struct kernel_param *kparam,
756 unsigned int name_skip)
757{
758 struct module_kobject *mk;
759 int err;
760
761 mk = locate_module_kobject(name);
762 if (!mk)
763 return;
764
765 /* We need to remove old parameters before adding more. */
766 if (mk->mp)
767 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
768
769 /* These should not fail at boot. */
770 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
771 BUG_ON(err);
772 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
773 BUG_ON(err);
774 kobject_uevent(&mk->kobj, KOBJ_ADD);
775 kobject_put(&mk->kobj);
776}
777
778/*
779 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
780 *
781 * Add module_parameters to sysfs for "modules" built into the kernel.
782 *
783 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
784 * "parameter" name is stored behind a dot in kernel_param->name. So,
785 * extract the "module" name for all built-in kernel_param-eters,
786 * and for all who have the same, call kernel_add_sysfs_param.
787 */
788static void __init param_sysfs_builtin(void)
789{
790 struct kernel_param *kp;
791 unsigned int name_len;
792 char modname[MODULE_NAME_LEN];
793
794 for (kp = __start___param; kp < __stop___param; kp++) {
795 char *dot;
796
797 if (kp->perm == 0)
798 continue;
799
800 dot = strchr(kp->name, '.');
801 if (!dot) {
802 /* This happens for core_param() */
803 strcpy(modname, "kernel");
804 name_len = 0;
805 } else {
806 name_len = dot - kp->name + 1;
807 strlcpy(modname, kp->name, name_len);
808 }
809 kernel_add_sysfs_param(modname, kp, name_len);
810 }
811}
812
813ssize_t __modver_version_show(struct module_attribute *mattr,
814 struct module_kobject *mk, char *buf)
815{
816 struct module_version_attribute *vattr =
817 container_of(mattr, struct module_version_attribute, mattr);
818
819 return sprintf(buf, "%s\n", vattr->version);
820}
821
822extern const struct module_version_attribute *__start___modver[];
823extern const struct module_version_attribute *__stop___modver[];
824
825static void __init version_sysfs_builtin(void)
826{
827 const struct module_version_attribute **p;
828 struct module_kobject *mk;
829 int err;
830
831 for (p = __start___modver; p < __stop___modver; p++) {
832 const struct module_version_attribute *vattr = *p;
833
834 mk = locate_module_kobject(vattr->module_name);
835 if (mk) {
836 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
837 kobject_uevent(&mk->kobj, KOBJ_ADD);
838 kobject_put(&mk->kobj);
839 }
840 }
841}
842
843/* module-related sysfs stuff */
844
845static ssize_t module_attr_show(struct kobject *kobj,
846 struct attribute *attr,
847 char *buf)
848{
849 struct module_attribute *attribute;
850 struct module_kobject *mk;
851 int ret;
852
853 attribute = to_module_attr(attr);
854 mk = to_module_kobject(kobj);
855
856 if (!attribute->show)
857 return -EIO;
858
859 ret = attribute->show(attribute, mk, buf);
860
861 return ret;
862}
863
864static ssize_t module_attr_store(struct kobject *kobj,
865 struct attribute *attr,
866 const char *buf, size_t len)
867{
868 struct module_attribute *attribute;
869 struct module_kobject *mk;
870 int ret;
871
872 attribute = to_module_attr(attr);
873 mk = to_module_kobject(kobj);
874
875 if (!attribute->store)
876 return -EIO;
877
878 ret = attribute->store(attribute, mk, buf, len);
879
880 return ret;
881}
882
883static const struct sysfs_ops module_sysfs_ops = {
884 .show = module_attr_show,
885 .store = module_attr_store,
886};
887
888static int uevent_filter(struct kset *kset, struct kobject *kobj)
889{
890 struct kobj_type *ktype = get_ktype(kobj);
891
892 if (ktype == &module_ktype)
893 return 1;
894 return 0;
895}
896
897static const struct kset_uevent_ops module_uevent_ops = {
898 .filter = uevent_filter,
899};
900
901struct kset *module_kset;
902int module_sysfs_initialized;
903
904struct kobj_type module_ktype = {
905 .sysfs_ops = &module_sysfs_ops,
906};
907
908/*
909 * param_sysfs_init - wrapper for built-in params support
910 */
911static int __init param_sysfs_init(void)
912{
913 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
914 if (!module_kset) {
915 printk(KERN_WARNING "%s (%d): error creating kset\n",
916 __FILE__, __LINE__);
917 return -ENOMEM;
918 }
919 module_sysfs_initialized = 1;
920
921 version_sysfs_builtin();
922 param_sysfs_builtin();
923
924 return 0;
925}
926subsys_initcall(param_sysfs_init);
927
928#endif /* CONFIG_SYSFS */