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