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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/moduleparam.h>
23#include <linux/device.h>
24#include <linux/err.h>
25#include <linux/slab.h>
26#include <linux/ctype.h>
27
28#ifdef CONFIG_SYSFS
29/* Protects all built-in parameters, modules use their own param_lock */
30static DEFINE_MUTEX(param_lock);
31
32/* Use the module's mutex, or if built-in use the built-in mutex */
33#ifdef CONFIG_MODULES
34#define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock)
35#else
36#define KPARAM_MUTEX(mod) (¶m_lock)
37#endif
38
39static inline void check_kparam_locked(struct module *mod)
40{
41 BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod)));
42}
43#else
44static inline void check_kparam_locked(struct module *mod)
45{
46}
47#endif /* !CONFIG_SYSFS */
48
49/* This just allows us to keep track of which parameters are kmalloced. */
50struct kmalloced_param {
51 struct list_head list;
52 char val[];
53};
54static LIST_HEAD(kmalloced_params);
55static DEFINE_SPINLOCK(kmalloced_params_lock);
56
57static void *kmalloc_parameter(unsigned int size)
58{
59 struct kmalloced_param *p;
60
61 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
62 if (!p)
63 return NULL;
64
65 spin_lock(&kmalloced_params_lock);
66 list_add(&p->list, &kmalloced_params);
67 spin_unlock(&kmalloced_params_lock);
68
69 return p->val;
70}
71
72/* Does nothing if parameter wasn't kmalloced above. */
73static void maybe_kfree_parameter(void *param)
74{
75 struct kmalloced_param *p;
76
77 spin_lock(&kmalloced_params_lock);
78 list_for_each_entry(p, &kmalloced_params, list) {
79 if (p->val == param) {
80 list_del(&p->list);
81 kfree(p);
82 break;
83 }
84 }
85 spin_unlock(&kmalloced_params_lock);
86}
87
88static char dash2underscore(char c)
89{
90 if (c == '-')
91 return '_';
92 return c;
93}
94
95bool parameqn(const char *a, const char *b, size_t n)
96{
97 size_t i;
98
99 for (i = 0; i < n; i++) {
100 if (dash2underscore(a[i]) != dash2underscore(b[i]))
101 return false;
102 }
103 return true;
104}
105
106bool parameq(const char *a, const char *b)
107{
108 return parameqn(a, b, strlen(a)+1);
109}
110
111static void param_check_unsafe(const struct kernel_param *kp)
112{
113 if (kp->flags & KERNEL_PARAM_FL_UNSAFE) {
114 pr_notice("Setting dangerous option %s - tainting kernel\n",
115 kp->name);
116 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
117 }
118}
119
120static int parse_one(char *param,
121 char *val,
122 const char *doing,
123 const struct kernel_param *params,
124 unsigned num_params,
125 s16 min_level,
126 s16 max_level,
127 void *arg,
128 int (*handle_unknown)(char *param, char *val,
129 const char *doing, void *arg))
130{
131 unsigned int i;
132 int err;
133
134 /* Find parameter */
135 for (i = 0; i < num_params; i++) {
136 if (parameq(param, params[i].name)) {
137 if (params[i].level < min_level
138 || params[i].level > max_level)
139 return 0;
140 /* No one handled NULL, so do it here. */
141 if (!val &&
142 !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG))
143 return -EINVAL;
144 pr_debug("handling %s with %p\n", param,
145 params[i].ops->set);
146 kernel_param_lock(params[i].mod);
147 param_check_unsafe(¶ms[i]);
148 err = params[i].ops->set(val, ¶ms[i]);
149 kernel_param_unlock(params[i].mod);
150 return err;
151 }
152 }
153
154 if (handle_unknown) {
155 pr_debug("doing %s: %s='%s'\n", doing, param, val);
156 return handle_unknown(param, val, doing, arg);
157 }
158
159 pr_debug("Unknown argument '%s'\n", param);
160 return -ENOENT;
161}
162
163/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
164char *parse_args(const char *doing,
165 char *args,
166 const struct kernel_param *params,
167 unsigned num,
168 s16 min_level,
169 s16 max_level,
170 void *arg,
171 int (*unknown)(char *param, char *val,
172 const char *doing, void *arg))
173{
174 char *param, *val, *err = NULL;
175
176 /* Chew leading spaces */
177 args = skip_spaces(args);
178
179 if (*args)
180 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
181
182 while (*args) {
183 int ret;
184 int irq_was_disabled;
185
186 args = next_arg(args, ¶m, &val);
187 /* Stop at -- */
188 if (!val && strcmp(param, "--") == 0)
189 return err ?: args;
190 irq_was_disabled = irqs_disabled();
191 ret = parse_one(param, val, doing, params, num,
192 min_level, max_level, arg, unknown);
193 if (irq_was_disabled && !irqs_disabled())
194 pr_warn("%s: option '%s' enabled irq's!\n",
195 doing, param);
196
197 switch (ret) {
198 case 0:
199 continue;
200 case -ENOENT:
201 pr_err("%s: Unknown parameter `%s'\n", doing, param);
202 break;
203 case -ENOSPC:
204 pr_err("%s: `%s' too large for parameter `%s'\n",
205 doing, val ?: "", param);
206 break;
207 default:
208 pr_err("%s: `%s' invalid for parameter `%s'\n",
209 doing, val ?: "", param);
210 break;
211 }
212
213 err = ERR_PTR(ret);
214 }
215
216 return err;
217}
218
219/* Lazy bastard, eh? */
220#define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
221 int param_set_##name(const char *val, const struct kernel_param *kp) \
222 { \
223 return strtolfn(val, 0, (type *)kp->arg); \
224 } \
225 int param_get_##name(char *buffer, const struct kernel_param *kp) \
226 { \
227 return scnprintf(buffer, PAGE_SIZE, format "\n", \
228 *((type *)kp->arg)); \
229 } \
230 const struct kernel_param_ops param_ops_##name = { \
231 .set = param_set_##name, \
232 .get = param_get_##name, \
233 }; \
234 EXPORT_SYMBOL(param_set_##name); \
235 EXPORT_SYMBOL(param_get_##name); \
236 EXPORT_SYMBOL(param_ops_##name)
237
238
239STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
240STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
241STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
242STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
243STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
244STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
245STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
246STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull);
247
248int param_set_charp(const char *val, const struct kernel_param *kp)
249{
250 if (strlen(val) > 1024) {
251 pr_err("%s: string parameter too long\n", kp->name);
252 return -ENOSPC;
253 }
254
255 maybe_kfree_parameter(*(char **)kp->arg);
256
257 /* This is a hack. We can't kmalloc in early boot, and we
258 * don't need to; this mangled commandline is preserved. */
259 if (slab_is_available()) {
260 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
261 if (!*(char **)kp->arg)
262 return -ENOMEM;
263 strcpy(*(char **)kp->arg, val);
264 } else
265 *(const char **)kp->arg = val;
266
267 return 0;
268}
269EXPORT_SYMBOL(param_set_charp);
270
271int param_get_charp(char *buffer, const struct kernel_param *kp)
272{
273 return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg));
274}
275EXPORT_SYMBOL(param_get_charp);
276
277void param_free_charp(void *arg)
278{
279 maybe_kfree_parameter(*((char **)arg));
280}
281EXPORT_SYMBOL(param_free_charp);
282
283const struct kernel_param_ops param_ops_charp = {
284 .set = param_set_charp,
285 .get = param_get_charp,
286 .free = param_free_charp,
287};
288EXPORT_SYMBOL(param_ops_charp);
289
290/* Actually could be a bool or an int, for historical reasons. */
291int param_set_bool(const char *val, const struct kernel_param *kp)
292{
293 /* No equals means "set"... */
294 if (!val) val = "1";
295
296 /* One of =[yYnN01] */
297 return strtobool(val, kp->arg);
298}
299EXPORT_SYMBOL(param_set_bool);
300
301int param_get_bool(char *buffer, const struct kernel_param *kp)
302{
303 /* Y and N chosen as being relatively non-coder friendly */
304 return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N');
305}
306EXPORT_SYMBOL(param_get_bool);
307
308const struct kernel_param_ops param_ops_bool = {
309 .flags = KERNEL_PARAM_OPS_FL_NOARG,
310 .set = param_set_bool,
311 .get = param_get_bool,
312};
313EXPORT_SYMBOL(param_ops_bool);
314
315int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
316{
317 int err = 0;
318 bool new_value;
319 bool orig_value = *(bool *)kp->arg;
320 struct kernel_param dummy_kp = *kp;
321
322 dummy_kp.arg = &new_value;
323
324 err = param_set_bool(val, &dummy_kp);
325 if (err)
326 return err;
327
328 /* Don't let them unset it once it's set! */
329 if (!new_value && orig_value)
330 return -EROFS;
331
332 if (new_value)
333 err = param_set_bool(val, kp);
334
335 return err;
336}
337EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
338
339const struct kernel_param_ops param_ops_bool_enable_only = {
340 .flags = KERNEL_PARAM_OPS_FL_NOARG,
341 .set = param_set_bool_enable_only,
342 .get = param_get_bool,
343};
344EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
345
346/* This one must be bool. */
347int param_set_invbool(const char *val, const struct kernel_param *kp)
348{
349 int ret;
350 bool boolval;
351 struct kernel_param dummy;
352
353 dummy.arg = &boolval;
354 ret = param_set_bool(val, &dummy);
355 if (ret == 0)
356 *(bool *)kp->arg = !boolval;
357 return ret;
358}
359EXPORT_SYMBOL(param_set_invbool);
360
361int param_get_invbool(char *buffer, const struct kernel_param *kp)
362{
363 return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y');
364}
365EXPORT_SYMBOL(param_get_invbool);
366
367const struct kernel_param_ops param_ops_invbool = {
368 .set = param_set_invbool,
369 .get = param_get_invbool,
370};
371EXPORT_SYMBOL(param_ops_invbool);
372
373int param_set_bint(const char *val, const struct kernel_param *kp)
374{
375 /* Match bool exactly, by re-using it. */
376 struct kernel_param boolkp = *kp;
377 bool v;
378 int ret;
379
380 boolkp.arg = &v;
381
382 ret = param_set_bool(val, &boolkp);
383 if (ret == 0)
384 *(int *)kp->arg = v;
385 return ret;
386}
387EXPORT_SYMBOL(param_set_bint);
388
389const struct kernel_param_ops param_ops_bint = {
390 .flags = KERNEL_PARAM_OPS_FL_NOARG,
391 .set = param_set_bint,
392 .get = param_get_int,
393};
394EXPORT_SYMBOL(param_ops_bint);
395
396/* We break the rule and mangle the string. */
397static int param_array(struct module *mod,
398 const char *name,
399 const char *val,
400 unsigned int min, unsigned int max,
401 void *elem, int elemsize,
402 int (*set)(const char *, const struct kernel_param *kp),
403 s16 level,
404 unsigned int *num)
405{
406 int ret;
407 struct kernel_param kp;
408 char save;
409
410 /* Get the name right for errors. */
411 kp.name = name;
412 kp.arg = elem;
413 kp.level = level;
414
415 *num = 0;
416 /* We expect a comma-separated list of values. */
417 do {
418 int len;
419
420 if (*num == max) {
421 pr_err("%s: can only take %i arguments\n", name, max);
422 return -EINVAL;
423 }
424 len = strcspn(val, ",");
425
426 /* nul-terminate and parse */
427 save = val[len];
428 ((char *)val)[len] = '\0';
429 check_kparam_locked(mod);
430 ret = set(val, &kp);
431
432 if (ret != 0)
433 return ret;
434 kp.arg += elemsize;
435 val += len+1;
436 (*num)++;
437 } while (save == ',');
438
439 if (*num < min) {
440 pr_err("%s: needs at least %i arguments\n", name, min);
441 return -EINVAL;
442 }
443 return 0;
444}
445
446static int param_array_set(const char *val, const struct kernel_param *kp)
447{
448 const struct kparam_array *arr = kp->arr;
449 unsigned int temp_num;
450
451 return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem,
452 arr->elemsize, arr->ops->set, kp->level,
453 arr->num ?: &temp_num);
454}
455
456static int param_array_get(char *buffer, const struct kernel_param *kp)
457{
458 int i, off, ret;
459 const struct kparam_array *arr = kp->arr;
460 struct kernel_param p = *kp;
461
462 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
463 /* Replace \n with comma */
464 if (i)
465 buffer[off - 1] = ',';
466 p.arg = arr->elem + arr->elemsize * i;
467 check_kparam_locked(p.mod);
468 ret = arr->ops->get(buffer + off, &p);
469 if (ret < 0)
470 return ret;
471 off += ret;
472 }
473 buffer[off] = '\0';
474 return off;
475}
476
477static void param_array_free(void *arg)
478{
479 unsigned int i;
480 const struct kparam_array *arr = arg;
481
482 if (arr->ops->free)
483 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
484 arr->ops->free(arr->elem + arr->elemsize * i);
485}
486
487const struct kernel_param_ops param_array_ops = {
488 .set = param_array_set,
489 .get = param_array_get,
490 .free = param_array_free,
491};
492EXPORT_SYMBOL(param_array_ops);
493
494int param_set_copystring(const char *val, const struct kernel_param *kp)
495{
496 const struct kparam_string *kps = kp->str;
497
498 if (strlen(val)+1 > kps->maxlen) {
499 pr_err("%s: string doesn't fit in %u chars.\n",
500 kp->name, kps->maxlen-1);
501 return -ENOSPC;
502 }
503 strcpy(kps->string, val);
504 return 0;
505}
506EXPORT_SYMBOL(param_set_copystring);
507
508int param_get_string(char *buffer, const struct kernel_param *kp)
509{
510 const struct kparam_string *kps = kp->str;
511 return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string);
512}
513EXPORT_SYMBOL(param_get_string);
514
515const struct kernel_param_ops param_ops_string = {
516 .set = param_set_copystring,
517 .get = param_get_string,
518};
519EXPORT_SYMBOL(param_ops_string);
520
521/* sysfs output in /sys/modules/XYZ/parameters/ */
522#define to_module_attr(n) container_of(n, struct module_attribute, attr)
523#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
524
525struct param_attribute
526{
527 struct module_attribute mattr;
528 const struct kernel_param *param;
529};
530
531struct module_param_attrs
532{
533 unsigned int num;
534 struct attribute_group grp;
535 struct param_attribute attrs[0];
536};
537
538#ifdef CONFIG_SYSFS
539#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
540
541static ssize_t param_attr_show(struct module_attribute *mattr,
542 struct module_kobject *mk, char *buf)
543{
544 int count;
545 struct param_attribute *attribute = to_param_attr(mattr);
546
547 if (!attribute->param->ops->get)
548 return -EPERM;
549
550 kernel_param_lock(mk->mod);
551 count = attribute->param->ops->get(buf, attribute->param);
552 kernel_param_unlock(mk->mod);
553 return count;
554}
555
556/* sysfs always hands a nul-terminated string in buf. We rely on that. */
557static ssize_t param_attr_store(struct module_attribute *mattr,
558 struct module_kobject *mk,
559 const char *buf, size_t len)
560{
561 int err;
562 struct param_attribute *attribute = to_param_attr(mattr);
563
564 if (!attribute->param->ops->set)
565 return -EPERM;
566
567 kernel_param_lock(mk->mod);
568 param_check_unsafe(attribute->param);
569 err = attribute->param->ops->set(buf, attribute->param);
570 kernel_param_unlock(mk->mod);
571 if (!err)
572 return len;
573 return err;
574}
575#endif
576
577#ifdef CONFIG_MODULES
578#define __modinit
579#else
580#define __modinit __init
581#endif
582
583#ifdef CONFIG_SYSFS
584void kernel_param_lock(struct module *mod)
585{
586 mutex_lock(KPARAM_MUTEX(mod));
587}
588
589void kernel_param_unlock(struct module *mod)
590{
591 mutex_unlock(KPARAM_MUTEX(mod));
592}
593
594EXPORT_SYMBOL(kernel_param_lock);
595EXPORT_SYMBOL(kernel_param_unlock);
596
597/*
598 * add_sysfs_param - add a parameter to sysfs
599 * @mk: struct module_kobject
600 * @kp: the actual parameter definition to add to sysfs
601 * @name: name of parameter
602 *
603 * Create a kobject if for a (per-module) parameter if mp NULL, and
604 * create file in sysfs. Returns an error on out of memory. Always cleans up
605 * if there's an error.
606 */
607static __modinit int add_sysfs_param(struct module_kobject *mk,
608 const struct kernel_param *kp,
609 const char *name)
610{
611 struct module_param_attrs *new_mp;
612 struct attribute **new_attrs;
613 unsigned int i;
614
615 /* We don't bother calling this with invisible parameters. */
616 BUG_ON(!kp->perm);
617
618 if (!mk->mp) {
619 /* First allocation. */
620 mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
621 if (!mk->mp)
622 return -ENOMEM;
623 mk->mp->grp.name = "parameters";
624 /* NULL-terminated attribute array. */
625 mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
626 GFP_KERNEL);
627 /* Caller will cleanup via free_module_param_attrs */
628 if (!mk->mp->grp.attrs)
629 return -ENOMEM;
630 }
631
632 /* Enlarge allocations. */
633 new_mp = krealloc(mk->mp,
634 sizeof(*mk->mp) +
635 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
636 GFP_KERNEL);
637 if (!new_mp)
638 return -ENOMEM;
639 mk->mp = new_mp;
640
641 /* Extra pointer for NULL terminator */
642 new_attrs = krealloc(mk->mp->grp.attrs,
643 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
644 GFP_KERNEL);
645 if (!new_attrs)
646 return -ENOMEM;
647 mk->mp->grp.attrs = new_attrs;
648
649 /* Tack new one on the end. */
650 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
651 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
652 mk->mp->attrs[mk->mp->num].param = kp;
653 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
654 /* Do not allow runtime DAC changes to make param writable. */
655 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
656 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
657 else
658 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
659 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
660 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
661 mk->mp->num++;
662
663 /* Fix up all the pointers, since krealloc can move us */
664 for (i = 0; i < mk->mp->num; i++)
665 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
666 mk->mp->grp.attrs[mk->mp->num] = NULL;
667 return 0;
668}
669
670#ifdef CONFIG_MODULES
671static void free_module_param_attrs(struct module_kobject *mk)
672{
673 if (mk->mp)
674 kfree(mk->mp->grp.attrs);
675 kfree(mk->mp);
676 mk->mp = NULL;
677}
678
679/*
680 * module_param_sysfs_setup - setup sysfs support for one module
681 * @mod: module
682 * @kparam: module parameters (array)
683 * @num_params: number of module parameters
684 *
685 * Adds sysfs entries for module parameters under
686 * /sys/module/[mod->name]/parameters/
687 */
688int module_param_sysfs_setup(struct module *mod,
689 const struct kernel_param *kparam,
690 unsigned int num_params)
691{
692 int i, err;
693 bool params = false;
694
695 for (i = 0; i < num_params; i++) {
696 if (kparam[i].perm == 0)
697 continue;
698 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
699 if (err) {
700 free_module_param_attrs(&mod->mkobj);
701 return err;
702 }
703 params = true;
704 }
705
706 if (!params)
707 return 0;
708
709 /* Create the param group. */
710 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
711 if (err)
712 free_module_param_attrs(&mod->mkobj);
713 return err;
714}
715
716/*
717 * module_param_sysfs_remove - remove sysfs support for one module
718 * @mod: module
719 *
720 * Remove sysfs entries for module parameters and the corresponding
721 * kobject.
722 */
723void module_param_sysfs_remove(struct module *mod)
724{
725 if (mod->mkobj.mp) {
726 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
727 /* We are positive that no one is using any param
728 * attrs at this point. Deallocate immediately. */
729 free_module_param_attrs(&mod->mkobj);
730 }
731}
732#endif
733
734void destroy_params(const struct kernel_param *params, unsigned num)
735{
736 unsigned int i;
737
738 for (i = 0; i < num; i++)
739 if (params[i].ops->free)
740 params[i].ops->free(params[i].arg);
741}
742
743static struct module_kobject * __init locate_module_kobject(const char *name)
744{
745 struct module_kobject *mk;
746 struct kobject *kobj;
747 int err;
748
749 kobj = kset_find_obj(module_kset, name);
750 if (kobj) {
751 mk = to_module_kobject(kobj);
752 } else {
753 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
754 BUG_ON(!mk);
755
756 mk->mod = THIS_MODULE;
757 mk->kobj.kset = module_kset;
758 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
759 "%s", name);
760#ifdef CONFIG_MODULES
761 if (!err)
762 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
763#endif
764 if (err) {
765 kobject_put(&mk->kobj);
766 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
767 name, err);
768 return NULL;
769 }
770
771 /* So that we hold reference in both cases. */
772 kobject_get(&mk->kobj);
773 }
774
775 return mk;
776}
777
778static void __init kernel_add_sysfs_param(const char *name,
779 const struct kernel_param *kparam,
780 unsigned int name_skip)
781{
782 struct module_kobject *mk;
783 int err;
784
785 mk = locate_module_kobject(name);
786 if (!mk)
787 return;
788
789 /* We need to remove old parameters before adding more. */
790 if (mk->mp)
791 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
792
793 /* These should not fail at boot. */
794 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
795 BUG_ON(err);
796 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
797 BUG_ON(err);
798 kobject_uevent(&mk->kobj, KOBJ_ADD);
799 kobject_put(&mk->kobj);
800}
801
802/*
803 * param_sysfs_builtin - add sysfs parameters for built-in modules
804 *
805 * Add module_parameters to sysfs for "modules" built into the kernel.
806 *
807 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
808 * "parameter" name is stored behind a dot in kernel_param->name. So,
809 * extract the "module" name for all built-in kernel_param-eters,
810 * and for all who have the same, call kernel_add_sysfs_param.
811 */
812static void __init param_sysfs_builtin(void)
813{
814 const struct kernel_param *kp;
815 unsigned int name_len;
816 char modname[MODULE_NAME_LEN];
817
818 for (kp = __start___param; kp < __stop___param; kp++) {
819 char *dot;
820
821 if (kp->perm == 0)
822 continue;
823
824 dot = strchr(kp->name, '.');
825 if (!dot) {
826 /* This happens for core_param() */
827 strcpy(modname, "kernel");
828 name_len = 0;
829 } else {
830 name_len = dot - kp->name + 1;
831 strlcpy(modname, kp->name, name_len);
832 }
833 kernel_add_sysfs_param(modname, kp, name_len);
834 }
835}
836
837ssize_t __modver_version_show(struct module_attribute *mattr,
838 struct module_kobject *mk, char *buf)
839{
840 struct module_version_attribute *vattr =
841 container_of(mattr, struct module_version_attribute, mattr);
842
843 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
844}
845
846extern const struct module_version_attribute *__start___modver[];
847extern const struct module_version_attribute *__stop___modver[];
848
849static void __init version_sysfs_builtin(void)
850{
851 const struct module_version_attribute **p;
852 struct module_kobject *mk;
853 int err;
854
855 for (p = __start___modver; p < __stop___modver; p++) {
856 const struct module_version_attribute *vattr = *p;
857
858 mk = locate_module_kobject(vattr->module_name);
859 if (mk) {
860 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
861 WARN_ON_ONCE(err);
862 kobject_uevent(&mk->kobj, KOBJ_ADD);
863 kobject_put(&mk->kobj);
864 }
865 }
866}
867
868/* module-related sysfs stuff */
869
870static ssize_t module_attr_show(struct kobject *kobj,
871 struct attribute *attr,
872 char *buf)
873{
874 struct module_attribute *attribute;
875 struct module_kobject *mk;
876 int ret;
877
878 attribute = to_module_attr(attr);
879 mk = to_module_kobject(kobj);
880
881 if (!attribute->show)
882 return -EIO;
883
884 ret = attribute->show(attribute, mk, buf);
885
886 return ret;
887}
888
889static ssize_t module_attr_store(struct kobject *kobj,
890 struct attribute *attr,
891 const char *buf, size_t len)
892{
893 struct module_attribute *attribute;
894 struct module_kobject *mk;
895 int ret;
896
897 attribute = to_module_attr(attr);
898 mk = to_module_kobject(kobj);
899
900 if (!attribute->store)
901 return -EIO;
902
903 ret = attribute->store(attribute, mk, buf, len);
904
905 return ret;
906}
907
908static const struct sysfs_ops module_sysfs_ops = {
909 .show = module_attr_show,
910 .store = module_attr_store,
911};
912
913static int uevent_filter(struct kset *kset, struct kobject *kobj)
914{
915 struct kobj_type *ktype = get_ktype(kobj);
916
917 if (ktype == &module_ktype)
918 return 1;
919 return 0;
920}
921
922static const struct kset_uevent_ops module_uevent_ops = {
923 .filter = uevent_filter,
924};
925
926struct kset *module_kset;
927int module_sysfs_initialized;
928
929static void module_kobj_release(struct kobject *kobj)
930{
931 struct module_kobject *mk = to_module_kobject(kobj);
932 complete(mk->kobj_completion);
933}
934
935struct kobj_type module_ktype = {
936 .release = module_kobj_release,
937 .sysfs_ops = &module_sysfs_ops,
938};
939
940/*
941 * param_sysfs_init - wrapper for built-in params support
942 */
943static int __init param_sysfs_init(void)
944{
945 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
946 if (!module_kset) {
947 printk(KERN_WARNING "%s (%d): error creating kset\n",
948 __FILE__, __LINE__);
949 return -ENOMEM;
950 }
951 module_sysfs_initialized = 1;
952
953 version_sysfs_builtin();
954 param_sysfs_builtin();
955
956 return 0;
957}
958subsys_initcall(param_sysfs_init);
959
960#endif /* CONFIG_SYSFS */
1/* Helpers for initial module or kernel cmdline parsing
2 Copyright (C) 2001 Rusty Russell.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17*/
18#include <linux/kernel.h>
19#include <linux/string.h>
20#include <linux/errno.h>
21#include <linux/module.h>
22#include <linux/device.h>
23#include <linux/err.h>
24#include <linux/slab.h>
25#include <linux/ctype.h>
26
27/* Protects all parameters, and incidentally kmalloced_param list. */
28static DEFINE_MUTEX(param_lock);
29
30/* This just allows us to keep track of which parameters are kmalloced. */
31struct kmalloced_param {
32 struct list_head list;
33 char val[];
34};
35static LIST_HEAD(kmalloced_params);
36
37static void *kmalloc_parameter(unsigned int size)
38{
39 struct kmalloced_param *p;
40
41 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
42 if (!p)
43 return NULL;
44
45 list_add(&p->list, &kmalloced_params);
46 return p->val;
47}
48
49/* Does nothing if parameter wasn't kmalloced above. */
50static void maybe_kfree_parameter(void *param)
51{
52 struct kmalloced_param *p;
53
54 list_for_each_entry(p, &kmalloced_params, list) {
55 if (p->val == param) {
56 list_del(&p->list);
57 kfree(p);
58 break;
59 }
60 }
61}
62
63static char dash2underscore(char c)
64{
65 if (c == '-')
66 return '_';
67 return c;
68}
69
70bool parameqn(const char *a, const char *b, size_t n)
71{
72 size_t i;
73
74 for (i = 0; i < n; i++) {
75 if (dash2underscore(a[i]) != dash2underscore(b[i]))
76 return false;
77 }
78 return true;
79}
80
81bool parameq(const char *a, const char *b)
82{
83 return parameqn(a, b, strlen(a)+1);
84}
85
86static int parse_one(char *param,
87 char *val,
88 const char *doing,
89 const struct kernel_param *params,
90 unsigned num_params,
91 s16 min_level,
92 s16 max_level,
93 int (*handle_unknown)(char *param, char *val,
94 const char *doing))
95{
96 unsigned int i;
97 int err;
98
99 /* Find parameter */
100 for (i = 0; i < num_params; i++) {
101 if (parameq(param, params[i].name)) {
102 if (params[i].level < min_level
103 || params[i].level > max_level)
104 return 0;
105 /* No one handled NULL, so do it here. */
106 if (!val && params[i].ops->set != param_set_bool
107 && params[i].ops->set != param_set_bint)
108 return -EINVAL;
109 pr_debug("handling %s with %p\n", param,
110 params[i].ops->set);
111 mutex_lock(¶m_lock);
112 err = params[i].ops->set(val, ¶ms[i]);
113 mutex_unlock(¶m_lock);
114 return err;
115 }
116 }
117
118 if (handle_unknown) {
119 pr_debug("doing %s: %s='%s'\n", doing, param, val);
120 return handle_unknown(param, val, doing);
121 }
122
123 pr_debug("Unknown argument '%s'\n", param);
124 return -ENOENT;
125}
126
127/* You can use " around spaces, but can't escape ". */
128/* Hyphens and underscores equivalent in parameter names. */
129static char *next_arg(char *args, char **param, char **val)
130{
131 unsigned int i, equals = 0;
132 int in_quote = 0, quoted = 0;
133 char *next;
134
135 if (*args == '"') {
136 args++;
137 in_quote = 1;
138 quoted = 1;
139 }
140
141 for (i = 0; args[i]; i++) {
142 if (isspace(args[i]) && !in_quote)
143 break;
144 if (equals == 0) {
145 if (args[i] == '=')
146 equals = i;
147 }
148 if (args[i] == '"')
149 in_quote = !in_quote;
150 }
151
152 *param = args;
153 if (!equals)
154 *val = NULL;
155 else {
156 args[equals] = '\0';
157 *val = args + equals + 1;
158
159 /* Don't include quotes in value. */
160 if (**val == '"') {
161 (*val)++;
162 if (args[i-1] == '"')
163 args[i-1] = '\0';
164 }
165 if (quoted && args[i-1] == '"')
166 args[i-1] = '\0';
167 }
168
169 if (args[i]) {
170 args[i] = '\0';
171 next = args + i + 1;
172 } else
173 next = args + i;
174
175 /* Chew up trailing spaces. */
176 return skip_spaces(next);
177}
178
179/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
180int parse_args(const char *doing,
181 char *args,
182 const struct kernel_param *params,
183 unsigned num,
184 s16 min_level,
185 s16 max_level,
186 int (*unknown)(char *param, char *val, const char *doing))
187{
188 char *param, *val;
189
190 /* Chew leading spaces */
191 args = skip_spaces(args);
192
193 if (*args)
194 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
195
196 while (*args) {
197 int ret;
198 int irq_was_disabled;
199
200 args = next_arg(args, ¶m, &val);
201 irq_was_disabled = irqs_disabled();
202 ret = parse_one(param, val, doing, params, num,
203 min_level, max_level, unknown);
204 if (irq_was_disabled && !irqs_disabled())
205 pr_warn("%s: option '%s' enabled irq's!\n",
206 doing, param);
207
208 switch (ret) {
209 case -ENOENT:
210 pr_err("%s: Unknown parameter `%s'\n", doing, param);
211 return ret;
212 case -ENOSPC:
213 pr_err("%s: `%s' too large for parameter `%s'\n",
214 doing, val ?: "", param);
215 return ret;
216 case 0:
217 break;
218 default:
219 pr_err("%s: `%s' invalid for parameter `%s'\n",
220 doing, val ?: "", param);
221 return ret;
222 }
223 }
224
225 /* All parsed OK. */
226 return 0;
227}
228
229/* Lazy bastard, eh? */
230#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
231 int param_set_##name(const char *val, const struct kernel_param *kp) \
232 { \
233 tmptype l; \
234 int ret; \
235 \
236 ret = strtolfn(val, 0, &l); \
237 if (ret < 0 || ((type)l != l)) \
238 return ret < 0 ? ret : -EINVAL; \
239 *((type *)kp->arg) = l; \
240 return 0; \
241 } \
242 int param_get_##name(char *buffer, const struct kernel_param *kp) \
243 { \
244 return sprintf(buffer, format, *((type *)kp->arg)); \
245 } \
246 struct kernel_param_ops param_ops_##name = { \
247 .set = param_set_##name, \
248 .get = param_get_##name, \
249 }; \
250 EXPORT_SYMBOL(param_set_##name); \
251 EXPORT_SYMBOL(param_get_##name); \
252 EXPORT_SYMBOL(param_ops_##name)
253
254
255STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
256STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
257STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
258STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
259STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
260STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
261STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
262
263int param_set_charp(const char *val, const struct kernel_param *kp)
264{
265 if (strlen(val) > 1024) {
266 pr_err("%s: string parameter too long\n", kp->name);
267 return -ENOSPC;
268 }
269
270 maybe_kfree_parameter(*(char **)kp->arg);
271
272 /* This is a hack. We can't kmalloc in early boot, and we
273 * don't need to; this mangled commandline is preserved. */
274 if (slab_is_available()) {
275 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
276 if (!*(char **)kp->arg)
277 return -ENOMEM;
278 strcpy(*(char **)kp->arg, val);
279 } else
280 *(const char **)kp->arg = val;
281
282 return 0;
283}
284EXPORT_SYMBOL(param_set_charp);
285
286int param_get_charp(char *buffer, const struct kernel_param *kp)
287{
288 return sprintf(buffer, "%s", *((char **)kp->arg));
289}
290EXPORT_SYMBOL(param_get_charp);
291
292static void param_free_charp(void *arg)
293{
294 maybe_kfree_parameter(*((char **)arg));
295}
296
297struct kernel_param_ops param_ops_charp = {
298 .set = param_set_charp,
299 .get = param_get_charp,
300 .free = param_free_charp,
301};
302EXPORT_SYMBOL(param_ops_charp);
303
304/* Actually could be a bool or an int, for historical reasons. */
305int param_set_bool(const char *val, const struct kernel_param *kp)
306{
307 /* No equals means "set"... */
308 if (!val) val = "1";
309
310 /* One of =[yYnN01] */
311 return strtobool(val, kp->arg);
312}
313EXPORT_SYMBOL(param_set_bool);
314
315int param_get_bool(char *buffer, const struct kernel_param *kp)
316{
317 /* Y and N chosen as being relatively non-coder friendly */
318 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
319}
320EXPORT_SYMBOL(param_get_bool);
321
322struct kernel_param_ops param_ops_bool = {
323 .set = param_set_bool,
324 .get = param_get_bool,
325};
326EXPORT_SYMBOL(param_ops_bool);
327
328/* This one must be bool. */
329int param_set_invbool(const char *val, const struct kernel_param *kp)
330{
331 int ret;
332 bool boolval;
333 struct kernel_param dummy;
334
335 dummy.arg = &boolval;
336 ret = param_set_bool(val, &dummy);
337 if (ret == 0)
338 *(bool *)kp->arg = !boolval;
339 return ret;
340}
341EXPORT_SYMBOL(param_set_invbool);
342
343int param_get_invbool(char *buffer, const struct kernel_param *kp)
344{
345 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
346}
347EXPORT_SYMBOL(param_get_invbool);
348
349struct kernel_param_ops param_ops_invbool = {
350 .set = param_set_invbool,
351 .get = param_get_invbool,
352};
353EXPORT_SYMBOL(param_ops_invbool);
354
355int param_set_bint(const char *val, const struct kernel_param *kp)
356{
357 struct kernel_param boolkp;
358 bool v;
359 int ret;
360
361 /* Match bool exactly, by re-using it. */
362 boolkp = *kp;
363 boolkp.arg = &v;
364
365 ret = param_set_bool(val, &boolkp);
366 if (ret == 0)
367 *(int *)kp->arg = v;
368 return ret;
369}
370EXPORT_SYMBOL(param_set_bint);
371
372struct kernel_param_ops param_ops_bint = {
373 .set = param_set_bint,
374 .get = param_get_int,
375};
376EXPORT_SYMBOL(param_ops_bint);
377
378/* We break the rule and mangle the string. */
379static int param_array(const char *name,
380 const char *val,
381 unsigned int min, unsigned int max,
382 void *elem, int elemsize,
383 int (*set)(const char *, const struct kernel_param *kp),
384 s16 level,
385 unsigned int *num)
386{
387 int ret;
388 struct kernel_param kp;
389 char save;
390
391 /* Get the name right for errors. */
392 kp.name = name;
393 kp.arg = elem;
394 kp.level = level;
395
396 *num = 0;
397 /* We expect a comma-separated list of values. */
398 do {
399 int len;
400
401 if (*num == max) {
402 pr_err("%s: can only take %i arguments\n", name, max);
403 return -EINVAL;
404 }
405 len = strcspn(val, ",");
406
407 /* nul-terminate and parse */
408 save = val[len];
409 ((char *)val)[len] = '\0';
410 BUG_ON(!mutex_is_locked(¶m_lock));
411 ret = set(val, &kp);
412
413 if (ret != 0)
414 return ret;
415 kp.arg += elemsize;
416 val += len+1;
417 (*num)++;
418 } while (save == ',');
419
420 if (*num < min) {
421 pr_err("%s: needs at least %i arguments\n", name, min);
422 return -EINVAL;
423 }
424 return 0;
425}
426
427static int param_array_set(const char *val, const struct kernel_param *kp)
428{
429 const struct kparam_array *arr = kp->arr;
430 unsigned int temp_num;
431
432 return param_array(kp->name, val, 1, arr->max, arr->elem,
433 arr->elemsize, arr->ops->set, kp->level,
434 arr->num ?: &temp_num);
435}
436
437static int param_array_get(char *buffer, const struct kernel_param *kp)
438{
439 int i, off, ret;
440 const struct kparam_array *arr = kp->arr;
441 struct kernel_param p;
442
443 p = *kp;
444 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
445 if (i)
446 buffer[off++] = ',';
447 p.arg = arr->elem + arr->elemsize * i;
448 BUG_ON(!mutex_is_locked(¶m_lock));
449 ret = arr->ops->get(buffer + off, &p);
450 if (ret < 0)
451 return ret;
452 off += ret;
453 }
454 buffer[off] = '\0';
455 return off;
456}
457
458static void param_array_free(void *arg)
459{
460 unsigned int i;
461 const struct kparam_array *arr = arg;
462
463 if (arr->ops->free)
464 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
465 arr->ops->free(arr->elem + arr->elemsize * i);
466}
467
468struct kernel_param_ops param_array_ops = {
469 .set = param_array_set,
470 .get = param_array_get,
471 .free = param_array_free,
472};
473EXPORT_SYMBOL(param_array_ops);
474
475int param_set_copystring(const char *val, const struct kernel_param *kp)
476{
477 const struct kparam_string *kps = kp->str;
478
479 if (strlen(val)+1 > kps->maxlen) {
480 pr_err("%s: string doesn't fit in %u chars.\n",
481 kp->name, kps->maxlen-1);
482 return -ENOSPC;
483 }
484 strcpy(kps->string, val);
485 return 0;
486}
487EXPORT_SYMBOL(param_set_copystring);
488
489int param_get_string(char *buffer, const struct kernel_param *kp)
490{
491 const struct kparam_string *kps = kp->str;
492 return strlcpy(buffer, kps->string, kps->maxlen);
493}
494EXPORT_SYMBOL(param_get_string);
495
496struct kernel_param_ops param_ops_string = {
497 .set = param_set_copystring,
498 .get = param_get_string,
499};
500EXPORT_SYMBOL(param_ops_string);
501
502/* sysfs output in /sys/modules/XYZ/parameters/ */
503#define to_module_attr(n) container_of(n, struct module_attribute, attr)
504#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
505
506extern struct kernel_param __start___param[], __stop___param[];
507
508struct param_attribute
509{
510 struct module_attribute mattr;
511 const struct kernel_param *param;
512};
513
514struct module_param_attrs
515{
516 unsigned int num;
517 struct attribute_group grp;
518 struct param_attribute attrs[0];
519};
520
521#ifdef CONFIG_SYSFS
522#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
523
524static ssize_t param_attr_show(struct module_attribute *mattr,
525 struct module_kobject *mk, char *buf)
526{
527 int count;
528 struct param_attribute *attribute = to_param_attr(mattr);
529
530 if (!attribute->param->ops->get)
531 return -EPERM;
532
533 mutex_lock(¶m_lock);
534 count = attribute->param->ops->get(buf, attribute->param);
535 mutex_unlock(¶m_lock);
536 if (count > 0) {
537 strcat(buf, "\n");
538 ++count;
539 }
540 return count;
541}
542
543/* sysfs always hands a nul-terminated string in buf. We rely on that. */
544static ssize_t param_attr_store(struct module_attribute *mattr,
545 struct module_kobject *km,
546 const char *buf, size_t len)
547{
548 int err;
549 struct param_attribute *attribute = to_param_attr(mattr);
550
551 if (!attribute->param->ops->set)
552 return -EPERM;
553
554 mutex_lock(¶m_lock);
555 err = attribute->param->ops->set(buf, attribute->param);
556 mutex_unlock(¶m_lock);
557 if (!err)
558 return len;
559 return err;
560}
561#endif
562
563#ifdef CONFIG_MODULES
564#define __modinit
565#else
566#define __modinit __init
567#endif
568
569#ifdef CONFIG_SYSFS
570void __kernel_param_lock(void)
571{
572 mutex_lock(¶m_lock);
573}
574EXPORT_SYMBOL(__kernel_param_lock);
575
576void __kernel_param_unlock(void)
577{
578 mutex_unlock(¶m_lock);
579}
580EXPORT_SYMBOL(__kernel_param_unlock);
581
582/*
583 * add_sysfs_param - add a parameter to sysfs
584 * @mk: struct module_kobject
585 * @kparam: the actual parameter definition to add to sysfs
586 * @name: name of parameter
587 *
588 * Create a kobject if for a (per-module) parameter if mp NULL, and
589 * create file in sysfs. Returns an error on out of memory. Always cleans up
590 * if there's an error.
591 */
592static __modinit int add_sysfs_param(struct module_kobject *mk,
593 const struct kernel_param *kp,
594 const char *name)
595{
596 struct module_param_attrs *new;
597 struct attribute **attrs;
598 int err, num;
599
600 /* We don't bother calling this with invisible parameters. */
601 BUG_ON(!kp->perm);
602
603 if (!mk->mp) {
604 num = 0;
605 attrs = NULL;
606 } else {
607 num = mk->mp->num;
608 attrs = mk->mp->grp.attrs;
609 }
610
611 /* Enlarge. */
612 new = krealloc(mk->mp,
613 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
614 GFP_KERNEL);
615 if (!new) {
616 kfree(mk->mp);
617 err = -ENOMEM;
618 goto fail;
619 }
620 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
621 if (!attrs) {
622 err = -ENOMEM;
623 goto fail_free_new;
624 }
625
626 /* Sysfs wants everything zeroed. */
627 memset(new, 0, sizeof(*new));
628 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
629 memset(&attrs[num], 0, sizeof(attrs[num]));
630 new->grp.name = "parameters";
631 new->grp.attrs = attrs;
632
633 /* Tack new one on the end. */
634 sysfs_attr_init(&new->attrs[num].mattr.attr);
635 new->attrs[num].param = kp;
636 new->attrs[num].mattr.show = param_attr_show;
637 new->attrs[num].mattr.store = param_attr_store;
638 new->attrs[num].mattr.attr.name = (char *)name;
639 new->attrs[num].mattr.attr.mode = kp->perm;
640 new->num = num+1;
641
642 /* Fix up all the pointers, since krealloc can move us */
643 for (num = 0; num < new->num; num++)
644 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
645 new->grp.attrs[num] = NULL;
646
647 mk->mp = new;
648 return 0;
649
650fail_free_new:
651 kfree(new);
652fail:
653 mk->mp = NULL;
654 return err;
655}
656
657#ifdef CONFIG_MODULES
658static void free_module_param_attrs(struct module_kobject *mk)
659{
660 kfree(mk->mp->grp.attrs);
661 kfree(mk->mp);
662 mk->mp = NULL;
663}
664
665/*
666 * module_param_sysfs_setup - setup sysfs support for one module
667 * @mod: module
668 * @kparam: module parameters (array)
669 * @num_params: number of module parameters
670 *
671 * Adds sysfs entries for module parameters under
672 * /sys/module/[mod->name]/parameters/
673 */
674int module_param_sysfs_setup(struct module *mod,
675 const struct kernel_param *kparam,
676 unsigned int num_params)
677{
678 int i, err;
679 bool params = false;
680
681 for (i = 0; i < num_params; i++) {
682 if (kparam[i].perm == 0)
683 continue;
684 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
685 if (err)
686 return err;
687 params = true;
688 }
689
690 if (!params)
691 return 0;
692
693 /* Create the param group. */
694 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
695 if (err)
696 free_module_param_attrs(&mod->mkobj);
697 return err;
698}
699
700/*
701 * module_param_sysfs_remove - remove sysfs support for one module
702 * @mod: module
703 *
704 * Remove sysfs entries for module parameters and the corresponding
705 * kobject.
706 */
707void module_param_sysfs_remove(struct module *mod)
708{
709 if (mod->mkobj.mp) {
710 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
711 /* We are positive that no one is using any param
712 * attrs at this point. Deallocate immediately. */
713 free_module_param_attrs(&mod->mkobj);
714 }
715}
716#endif
717
718void destroy_params(const struct kernel_param *params, unsigned num)
719{
720 unsigned int i;
721
722 for (i = 0; i < num; i++)
723 if (params[i].ops->free)
724 params[i].ops->free(params[i].arg);
725}
726
727static struct module_kobject * __init locate_module_kobject(const char *name)
728{
729 struct module_kobject *mk;
730 struct kobject *kobj;
731 int err;
732
733 kobj = kset_find_obj(module_kset, name);
734 if (kobj) {
735 mk = to_module_kobject(kobj);
736 } else {
737 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
738 BUG_ON(!mk);
739
740 mk->mod = THIS_MODULE;
741 mk->kobj.kset = module_kset;
742 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
743 "%s", name);
744#ifdef CONFIG_MODULES
745 if (!err)
746 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
747#endif
748 if (err) {
749 kobject_put(&mk->kobj);
750 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
751 name, err);
752 return NULL;
753 }
754
755 /* So that we hold reference in both cases. */
756 kobject_get(&mk->kobj);
757 }
758
759 return mk;
760}
761
762static void __init kernel_add_sysfs_param(const char *name,
763 struct kernel_param *kparam,
764 unsigned int name_skip)
765{
766 struct module_kobject *mk;
767 int err;
768
769 mk = locate_module_kobject(name);
770 if (!mk)
771 return;
772
773 /* We need to remove old parameters before adding more. */
774 if (mk->mp)
775 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
776
777 /* These should not fail at boot. */
778 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
779 BUG_ON(err);
780 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
781 BUG_ON(err);
782 kobject_uevent(&mk->kobj, KOBJ_ADD);
783 kobject_put(&mk->kobj);
784}
785
786/*
787 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
788 *
789 * Add module_parameters to sysfs for "modules" built into the kernel.
790 *
791 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
792 * "parameter" name is stored behind a dot in kernel_param->name. So,
793 * extract the "module" name for all built-in kernel_param-eters,
794 * and for all who have the same, call kernel_add_sysfs_param.
795 */
796static void __init param_sysfs_builtin(void)
797{
798 struct kernel_param *kp;
799 unsigned int name_len;
800 char modname[MODULE_NAME_LEN];
801
802 for (kp = __start___param; kp < __stop___param; kp++) {
803 char *dot;
804
805 if (kp->perm == 0)
806 continue;
807
808 dot = strchr(kp->name, '.');
809 if (!dot) {
810 /* This happens for core_param() */
811 strcpy(modname, "kernel");
812 name_len = 0;
813 } else {
814 name_len = dot - kp->name + 1;
815 strlcpy(modname, kp->name, name_len);
816 }
817 kernel_add_sysfs_param(modname, kp, name_len);
818 }
819}
820
821ssize_t __modver_version_show(struct module_attribute *mattr,
822 struct module_kobject *mk, char *buf)
823{
824 struct module_version_attribute *vattr =
825 container_of(mattr, struct module_version_attribute, mattr);
826
827 return sprintf(buf, "%s\n", vattr->version);
828}
829
830extern const struct module_version_attribute *__start___modver[];
831extern const struct module_version_attribute *__stop___modver[];
832
833static void __init version_sysfs_builtin(void)
834{
835 const struct module_version_attribute **p;
836 struct module_kobject *mk;
837 int err;
838
839 for (p = __start___modver; p < __stop___modver; p++) {
840 const struct module_version_attribute *vattr = *p;
841
842 mk = locate_module_kobject(vattr->module_name);
843 if (mk) {
844 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
845 kobject_uevent(&mk->kobj, KOBJ_ADD);
846 kobject_put(&mk->kobj);
847 }
848 }
849}
850
851/* module-related sysfs stuff */
852
853static ssize_t module_attr_show(struct kobject *kobj,
854 struct attribute *attr,
855 char *buf)
856{
857 struct module_attribute *attribute;
858 struct module_kobject *mk;
859 int ret;
860
861 attribute = to_module_attr(attr);
862 mk = to_module_kobject(kobj);
863
864 if (!attribute->show)
865 return -EIO;
866
867 ret = attribute->show(attribute, mk, buf);
868
869 return ret;
870}
871
872static ssize_t module_attr_store(struct kobject *kobj,
873 struct attribute *attr,
874 const char *buf, size_t len)
875{
876 struct module_attribute *attribute;
877 struct module_kobject *mk;
878 int ret;
879
880 attribute = to_module_attr(attr);
881 mk = to_module_kobject(kobj);
882
883 if (!attribute->store)
884 return -EIO;
885
886 ret = attribute->store(attribute, mk, buf, len);
887
888 return ret;
889}
890
891static const struct sysfs_ops module_sysfs_ops = {
892 .show = module_attr_show,
893 .store = module_attr_store,
894};
895
896static int uevent_filter(struct kset *kset, struct kobject *kobj)
897{
898 struct kobj_type *ktype = get_ktype(kobj);
899
900 if (ktype == &module_ktype)
901 return 1;
902 return 0;
903}
904
905static const struct kset_uevent_ops module_uevent_ops = {
906 .filter = uevent_filter,
907};
908
909struct kset *module_kset;
910int module_sysfs_initialized;
911
912struct kobj_type module_ktype = {
913 .sysfs_ops = &module_sysfs_ops,
914};
915
916/*
917 * param_sysfs_init - wrapper for built-in params support
918 */
919static int __init param_sysfs_init(void)
920{
921 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
922 if (!module_kset) {
923 printk(KERN_WARNING "%s (%d): error creating kset\n",
924 __FILE__, __LINE__);
925 return -ENOMEM;
926 }
927 module_sysfs_initialized = 1;
928
929 version_sysfs_builtin();
930 param_sysfs_builtin();
931
932 return 0;
933}
934subsys_initcall(param_sysfs_init);
935
936#endif /* CONFIG_SYSFS */