summaryrefslogtreecommitdiff
path: root/kernel/params.c (plain)
blob: a6d6149c0fe60df1ca38d9a66acef281b78ee79d
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 : &param_lock)
35#else
36#define KPARAM_MUTEX(mod) (&param_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_warn("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(&params[i]);
148 err = params[i].ops->set(val, &params[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/* You can use " around spaces, but can't escape ". */
164/* Hyphens and underscores equivalent in parameter names. */
165static char *next_arg(char *args, char **param, char **val)
166{
167 unsigned int i, equals = 0;
168 int in_quote = 0, quoted = 0;
169 char *next;
170
171 if (*args == '"') {
172 args++;
173 in_quote = 1;
174 quoted = 1;
175 }
176
177 for (i = 0; args[i]; i++) {
178 if (isspace(args[i]) && !in_quote)
179 break;
180 if (equals == 0) {
181 if (args[i] == '=')
182 equals = i;
183 }
184 if (args[i] == '"')
185 in_quote = !in_quote;
186 }
187
188 *param = args;
189 if (!equals)
190 *val = NULL;
191 else {
192 args[equals] = '\0';
193 *val = args + equals + 1;
194
195 /* Don't include quotes in value. */
196 if (**val == '"') {
197 (*val)++;
198 if (args[i-1] == '"')
199 args[i-1] = '\0';
200 }
201 }
202 if (quoted && args[i-1] == '"')
203 args[i-1] = '\0';
204
205 if (args[i]) {
206 args[i] = '\0';
207 next = args + i + 1;
208 } else
209 next = args + i;
210
211 /* Chew up trailing spaces. */
212 return skip_spaces(next);
213}
214
215/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
216char *parse_args(const char *doing,
217 char *args,
218 const struct kernel_param *params,
219 unsigned num,
220 s16 min_level,
221 s16 max_level,
222 void *arg,
223 int (*unknown)(char *param, char *val,
224 const char *doing, void *arg))
225{
226 char *param, *val, *err = NULL;
227
228 /* Chew leading spaces */
229 args = skip_spaces(args);
230
231 if (*args)
232 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
233
234 while (*args) {
235 int ret;
236 int irq_was_disabled;
237
238 args = next_arg(args, &param, &val);
239 /* Stop at -- */
240 if (!val && strcmp(param, "--") == 0)
241 return err ?: args;
242 irq_was_disabled = irqs_disabled();
243 ret = parse_one(param, val, doing, params, num,
244 min_level, max_level, arg, unknown);
245 if (irq_was_disabled && !irqs_disabled())
246 pr_warn("%s: option '%s' enabled irq's!\n",
247 doing, param);
248
249 switch (ret) {
250 case 0:
251 continue;
252 case -ENOENT:
253 pr_err("%s: Unknown parameter `%s'\n", doing, param);
254 break;
255 case -ENOSPC:
256 pr_err("%s: `%s' too large for parameter `%s'\n",
257 doing, val ?: "", param);
258 break;
259 default:
260 pr_err("%s: `%s' invalid for parameter `%s'\n",
261 doing, val ?: "", param);
262 break;
263 }
264
265 err = ERR_PTR(ret);
266 }
267
268 return err;
269}
270
271/* Lazy bastard, eh? */
272#define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
273 int param_set_##name(const char *val, const struct kernel_param *kp) \
274 { \
275 return strtolfn(val, 0, (type *)kp->arg); \
276 } \
277 int param_get_##name(char *buffer, const struct kernel_param *kp) \
278 { \
279 return scnprintf(buffer, PAGE_SIZE, format, \
280 *((type *)kp->arg)); \
281 } \
282 const struct kernel_param_ops param_ops_##name = { \
283 .set = param_set_##name, \
284 .get = param_get_##name, \
285 }; \
286 EXPORT_SYMBOL(param_set_##name); \
287 EXPORT_SYMBOL(param_get_##name); \
288 EXPORT_SYMBOL(param_ops_##name)
289
290
291STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
292STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
293STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
294STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
295STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
296STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
297STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
298STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull);
299
300int param_set_charp(const char *val, const struct kernel_param *kp)
301{
302 if (strlen(val) > 1024) {
303 pr_err("%s: string parameter too long\n", kp->name);
304 return -ENOSPC;
305 }
306
307 maybe_kfree_parameter(*(char **)kp->arg);
308
309 /* This is a hack. We can't kmalloc in early boot, and we
310 * don't need to; this mangled commandline is preserved. */
311 if (slab_is_available()) {
312 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
313 if (!*(char **)kp->arg)
314 return -ENOMEM;
315 strcpy(*(char **)kp->arg, val);
316 } else
317 *(const char **)kp->arg = val;
318
319 return 0;
320}
321EXPORT_SYMBOL(param_set_charp);
322
323int param_get_charp(char *buffer, const struct kernel_param *kp)
324{
325 return scnprintf(buffer, PAGE_SIZE, "%s", *((char **)kp->arg));
326}
327EXPORT_SYMBOL(param_get_charp);
328
329void param_free_charp(void *arg)
330{
331 maybe_kfree_parameter(*((char **)arg));
332}
333EXPORT_SYMBOL(param_free_charp);
334
335const struct kernel_param_ops param_ops_charp = {
336 .set = param_set_charp,
337 .get = param_get_charp,
338 .free = param_free_charp,
339};
340EXPORT_SYMBOL(param_ops_charp);
341
342/* Actually could be a bool or an int, for historical reasons. */
343int param_set_bool(const char *val, const struct kernel_param *kp)
344{
345 /* No equals means "set"... */
346 if (!val) val = "1";
347
348 /* One of =[yYnN01] */
349 return strtobool(val, kp->arg);
350}
351EXPORT_SYMBOL(param_set_bool);
352
353int param_get_bool(char *buffer, const struct kernel_param *kp)
354{
355 /* Y and N chosen as being relatively non-coder friendly */
356 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
357}
358EXPORT_SYMBOL(param_get_bool);
359
360const struct kernel_param_ops param_ops_bool = {
361 .flags = KERNEL_PARAM_OPS_FL_NOARG,
362 .set = param_set_bool,
363 .get = param_get_bool,
364};
365EXPORT_SYMBOL(param_ops_bool);
366
367int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
368{
369 int err = 0;
370 bool new_value;
371 bool orig_value = *(bool *)kp->arg;
372 struct kernel_param dummy_kp = *kp;
373
374 dummy_kp.arg = &new_value;
375
376 err = param_set_bool(val, &dummy_kp);
377 if (err)
378 return err;
379
380 /* Don't let them unset it once it's set! */
381 if (!new_value && orig_value)
382 return -EROFS;
383
384 if (new_value)
385 err = param_set_bool(val, kp);
386
387 return err;
388}
389EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
390
391const struct kernel_param_ops param_ops_bool_enable_only = {
392 .flags = KERNEL_PARAM_OPS_FL_NOARG,
393 .set = param_set_bool_enable_only,
394 .get = param_get_bool,
395};
396EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
397
398/* This one must be bool. */
399int param_set_invbool(const char *val, const struct kernel_param *kp)
400{
401 int ret;
402 bool boolval;
403 struct kernel_param dummy;
404
405 dummy.arg = &boolval;
406 ret = param_set_bool(val, &dummy);
407 if (ret == 0)
408 *(bool *)kp->arg = !boolval;
409 return ret;
410}
411EXPORT_SYMBOL(param_set_invbool);
412
413int param_get_invbool(char *buffer, const struct kernel_param *kp)
414{
415 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
416}
417EXPORT_SYMBOL(param_get_invbool);
418
419const struct kernel_param_ops param_ops_invbool = {
420 .set = param_set_invbool,
421 .get = param_get_invbool,
422};
423EXPORT_SYMBOL(param_ops_invbool);
424
425int param_set_bint(const char *val, const struct kernel_param *kp)
426{
427 /* Match bool exactly, by re-using it. */
428 struct kernel_param boolkp = *kp;
429 bool v;
430 int ret;
431
432 boolkp.arg = &v;
433
434 ret = param_set_bool(val, &boolkp);
435 if (ret == 0)
436 *(int *)kp->arg = v;
437 return ret;
438}
439EXPORT_SYMBOL(param_set_bint);
440
441const struct kernel_param_ops param_ops_bint = {
442 .flags = KERNEL_PARAM_OPS_FL_NOARG,
443 .set = param_set_bint,
444 .get = param_get_int,
445};
446EXPORT_SYMBOL(param_ops_bint);
447
448/* We break the rule and mangle the string. */
449static int param_array(struct module *mod,
450 const char *name,
451 const char *val,
452 unsigned int min, unsigned int max,
453 void *elem, int elemsize,
454 int (*set)(const char *, const struct kernel_param *kp),
455 s16 level,
456 unsigned int *num)
457{
458 int ret;
459 struct kernel_param kp;
460 char save;
461
462 /* Get the name right for errors. */
463 kp.name = name;
464 kp.arg = elem;
465 kp.level = level;
466
467 *num = 0;
468 /* We expect a comma-separated list of values. */
469 do {
470 int len;
471
472 if (*num == max) {
473 pr_err("%s: can only take %i arguments\n", name, max);
474 return -EINVAL;
475 }
476 len = strcspn(val, ",");
477
478 /* nul-terminate and parse */
479 save = val[len];
480 ((char *)val)[len] = '\0';
481 check_kparam_locked(mod);
482 ret = set(val, &kp);
483
484 if (ret != 0)
485 return ret;
486 kp.arg += elemsize;
487 val += len+1;
488 (*num)++;
489 } while (save == ',');
490
491 if (*num < min) {
492 pr_err("%s: needs at least %i arguments\n", name, min);
493 return -EINVAL;
494 }
495 return 0;
496}
497
498static int param_array_set(const char *val, const struct kernel_param *kp)
499{
500 const struct kparam_array *arr = kp->arr;
501 unsigned int temp_num;
502
503 return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem,
504 arr->elemsize, arr->ops->set, kp->level,
505 arr->num ?: &temp_num);
506}
507
508static int param_array_get(char *buffer, const struct kernel_param *kp)
509{
510 int i, off, ret;
511 const struct kparam_array *arr = kp->arr;
512 struct kernel_param p = *kp;
513
514 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
515 if (i)
516 buffer[off++] = ',';
517 p.arg = arr->elem + arr->elemsize * i;
518 check_kparam_locked(p.mod);
519 ret = arr->ops->get(buffer + off, &p);
520 if (ret < 0)
521 return ret;
522 off += ret;
523 }
524 buffer[off] = '\0';
525 return off;
526}
527
528static void param_array_free(void *arg)
529{
530 unsigned int i;
531 const struct kparam_array *arr = arg;
532
533 if (arr->ops->free)
534 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
535 arr->ops->free(arr->elem + arr->elemsize * i);
536}
537
538const struct kernel_param_ops param_array_ops = {
539 .set = param_array_set,
540 .get = param_array_get,
541 .free = param_array_free,
542};
543EXPORT_SYMBOL(param_array_ops);
544
545int param_set_copystring(const char *val, const struct kernel_param *kp)
546{
547 const struct kparam_string *kps = kp->str;
548
549 if (strlen(val)+1 > kps->maxlen) {
550 pr_err("%s: string doesn't fit in %u chars.\n",
551 kp->name, kps->maxlen-1);
552 return -ENOSPC;
553 }
554 strcpy(kps->string, val);
555 return 0;
556}
557EXPORT_SYMBOL(param_set_copystring);
558
559int param_get_string(char *buffer, const struct kernel_param *kp)
560{
561 const struct kparam_string *kps = kp->str;
562 return strlcpy(buffer, kps->string, kps->maxlen);
563}
564EXPORT_SYMBOL(param_get_string);
565
566const struct kernel_param_ops param_ops_string = {
567 .set = param_set_copystring,
568 .get = param_get_string,
569};
570EXPORT_SYMBOL(param_ops_string);
571
572/* sysfs output in /sys/modules/XYZ/parameters/ */
573#define to_module_attr(n) container_of(n, struct module_attribute, attr)
574#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
575
576struct param_attribute
577{
578 struct module_attribute mattr;
579 const struct kernel_param *param;
580};
581
582struct module_param_attrs
583{
584 unsigned int num;
585 struct attribute_group grp;
586 struct param_attribute attrs[0];
587};
588
589#ifdef CONFIG_SYSFS
590#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
591
592static ssize_t param_attr_show(struct module_attribute *mattr,
593 struct module_kobject *mk, char *buf)
594{
595 int count;
596 struct param_attribute *attribute = to_param_attr(mattr);
597
598 if (!attribute->param->ops->get)
599 return -EPERM;
600
601 kernel_param_lock(mk->mod);
602 count = attribute->param->ops->get(buf, attribute->param);
603 kernel_param_unlock(mk->mod);
604 if (count > 0) {
605 strcat(buf, "\n");
606 ++count;
607 }
608 return count;
609}
610
611/* sysfs always hands a nul-terminated string in buf. We rely on that. */
612static ssize_t param_attr_store(struct module_attribute *mattr,
613 struct module_kobject *mk,
614 const char *buf, size_t len)
615{
616 int err;
617 struct param_attribute *attribute = to_param_attr(mattr);
618
619 if (!attribute->param->ops->set)
620 return -EPERM;
621
622 kernel_param_lock(mk->mod);
623 param_check_unsafe(attribute->param);
624 err = attribute->param->ops->set(buf, attribute->param);
625 kernel_param_unlock(mk->mod);
626 if (!err)
627 return len;
628 return err;
629}
630#endif
631
632#ifdef CONFIG_MODULES
633#define __modinit
634#else
635#define __modinit __init
636#endif
637
638#ifdef CONFIG_SYSFS
639void kernel_param_lock(struct module *mod)
640{
641 mutex_lock(KPARAM_MUTEX(mod));
642}
643
644void kernel_param_unlock(struct module *mod)
645{
646 mutex_unlock(KPARAM_MUTEX(mod));
647}
648
649EXPORT_SYMBOL(kernel_param_lock);
650EXPORT_SYMBOL(kernel_param_unlock);
651
652/*
653 * add_sysfs_param - add a parameter to sysfs
654 * @mk: struct module_kobject
655 * @kparam: the actual parameter definition to add to sysfs
656 * @name: name of parameter
657 *
658 * Create a kobject if for a (per-module) parameter if mp NULL, and
659 * create file in sysfs. Returns an error on out of memory. Always cleans up
660 * if there's an error.
661 */
662static __modinit int add_sysfs_param(struct module_kobject *mk,
663 const struct kernel_param *kp,
664 const char *name)
665{
666 struct module_param_attrs *new_mp;
667 struct attribute **new_attrs;
668 unsigned int i;
669
670 /* We don't bother calling this with invisible parameters. */
671 BUG_ON(!kp->perm);
672
673 if (!mk->mp) {
674 /* First allocation. */
675 mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
676 if (!mk->mp)
677 return -ENOMEM;
678 mk->mp->grp.name = "parameters";
679 /* NULL-terminated attribute array. */
680 mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
681 GFP_KERNEL);
682 /* Caller will cleanup via free_module_param_attrs */
683 if (!mk->mp->grp.attrs)
684 return -ENOMEM;
685 }
686
687 /* Enlarge allocations. */
688 new_mp = krealloc(mk->mp,
689 sizeof(*mk->mp) +
690 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
691 GFP_KERNEL);
692 if (!new_mp)
693 return -ENOMEM;
694 mk->mp = new_mp;
695
696 /* Extra pointer for NULL terminator */
697 new_attrs = krealloc(mk->mp->grp.attrs,
698 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
699 GFP_KERNEL);
700 if (!new_attrs)
701 return -ENOMEM;
702 mk->mp->grp.attrs = new_attrs;
703
704 /* Tack new one on the end. */
705 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
706 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
707 mk->mp->attrs[mk->mp->num].param = kp;
708 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
709 /* Do not allow runtime DAC changes to make param writable. */
710 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
711 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
712 else
713 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
714 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
715 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
716 mk->mp->num++;
717
718 /* Fix up all the pointers, since krealloc can move us */
719 for (i = 0; i < mk->mp->num; i++)
720 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
721 mk->mp->grp.attrs[mk->mp->num] = NULL;
722 return 0;
723}
724
725#ifdef CONFIG_MODULES
726static void free_module_param_attrs(struct module_kobject *mk)
727{
728 if (mk->mp)
729 kfree(mk->mp->grp.attrs);
730 kfree(mk->mp);
731 mk->mp = NULL;
732}
733
734/*
735 * module_param_sysfs_setup - setup sysfs support for one module
736 * @mod: module
737 * @kparam: module parameters (array)
738 * @num_params: number of module parameters
739 *
740 * Adds sysfs entries for module parameters under
741 * /sys/module/[mod->name]/parameters/
742 */
743int module_param_sysfs_setup(struct module *mod,
744 const struct kernel_param *kparam,
745 unsigned int num_params)
746{
747 int i, err;
748 bool params = false;
749
750 for (i = 0; i < num_params; i++) {
751 if (kparam[i].perm == 0)
752 continue;
753 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
754 if (err) {
755 free_module_param_attrs(&mod->mkobj);
756 return err;
757 }
758 params = true;
759 }
760
761 if (!params)
762 return 0;
763
764 /* Create the param group. */
765 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
766 if (err)
767 free_module_param_attrs(&mod->mkobj);
768 return err;
769}
770
771/*
772 * module_param_sysfs_remove - remove sysfs support for one module
773 * @mod: module
774 *
775 * Remove sysfs entries for module parameters and the corresponding
776 * kobject.
777 */
778void module_param_sysfs_remove(struct module *mod)
779{
780 if (mod->mkobj.mp) {
781 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
782 /* We are positive that no one is using any param
783 * attrs at this point. Deallocate immediately. */
784 free_module_param_attrs(&mod->mkobj);
785 }
786}
787#endif
788
789void destroy_params(const struct kernel_param *params, unsigned num)
790{
791 unsigned int i;
792
793 for (i = 0; i < num; i++)
794 if (params[i].ops->free)
795 params[i].ops->free(params[i].arg);
796}
797
798static struct module_kobject * __init locate_module_kobject(const char *name)
799{
800 struct module_kobject *mk;
801 struct kobject *kobj;
802 int err;
803
804 kobj = kset_find_obj(module_kset, name);
805 if (kobj) {
806 mk = to_module_kobject(kobj);
807 } else {
808 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
809 BUG_ON(!mk);
810
811 mk->mod = THIS_MODULE;
812 mk->kobj.kset = module_kset;
813 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
814 "%s", name);
815#ifdef CONFIG_MODULES
816 if (!err)
817 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
818#endif
819 if (err) {
820 kobject_put(&mk->kobj);
821 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
822 name, err);
823 return NULL;
824 }
825
826 /* So that we hold reference in both cases. */
827 kobject_get(&mk->kobj);
828 }
829
830 return mk;
831}
832
833static void __init kernel_add_sysfs_param(const char *name,
834 const struct kernel_param *kparam,
835 unsigned int name_skip)
836{
837 struct module_kobject *mk;
838 int err;
839
840 mk = locate_module_kobject(name);
841 if (!mk)
842 return;
843
844 /* We need to remove old parameters before adding more. */
845 if (mk->mp)
846 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
847
848 /* These should not fail at boot. */
849 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
850 BUG_ON(err);
851 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
852 BUG_ON(err);
853 kobject_uevent(&mk->kobj, KOBJ_ADD);
854 kobject_put(&mk->kobj);
855}
856
857/*
858 * param_sysfs_builtin - add sysfs parameters for built-in modules
859 *
860 * Add module_parameters to sysfs for "modules" built into the kernel.
861 *
862 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
863 * "parameter" name is stored behind a dot in kernel_param->name. So,
864 * extract the "module" name for all built-in kernel_param-eters,
865 * and for all who have the same, call kernel_add_sysfs_param.
866 */
867static void __init param_sysfs_builtin(void)
868{
869 const struct kernel_param *kp;
870 unsigned int name_len;
871 char modname[MODULE_NAME_LEN];
872
873 for (kp = __start___param; kp < __stop___param; kp++) {
874 char *dot;
875
876 if (kp->perm == 0)
877 continue;
878
879 dot = strchr(kp->name, '.');
880 if (!dot) {
881 /* This happens for core_param() */
882 strcpy(modname, "kernel");
883 name_len = 0;
884 } else {
885 name_len = dot - kp->name + 1;
886 strlcpy(modname, kp->name, name_len);
887 }
888 kernel_add_sysfs_param(modname, kp, name_len);
889 }
890}
891
892ssize_t __modver_version_show(struct module_attribute *mattr,
893 struct module_kobject *mk, char *buf)
894{
895 struct module_version_attribute *vattr =
896 container_of(mattr, struct module_version_attribute, mattr);
897
898 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
899}
900
901extern const struct module_version_attribute *__start___modver[];
902extern const struct module_version_attribute *__stop___modver[];
903
904static void __init version_sysfs_builtin(void)
905{
906 const struct module_version_attribute **p;
907 struct module_kobject *mk;
908 int err;
909
910 for (p = __start___modver; p < __stop___modver; p++) {
911 const struct module_version_attribute *vattr = *p;
912
913 mk = locate_module_kobject(vattr->module_name);
914 if (mk) {
915 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
916 WARN_ON_ONCE(err);
917 kobject_uevent(&mk->kobj, KOBJ_ADD);
918 kobject_put(&mk->kobj);
919 }
920 }
921}
922
923/* module-related sysfs stuff */
924
925static ssize_t module_attr_show(struct kobject *kobj,
926 struct attribute *attr,
927 char *buf)
928{
929 struct module_attribute *attribute;
930 struct module_kobject *mk;
931 int ret;
932
933 attribute = to_module_attr(attr);
934 mk = to_module_kobject(kobj);
935
936 if (!attribute->show)
937 return -EIO;
938
939 ret = attribute->show(attribute, mk, buf);
940
941 return ret;
942}
943
944static ssize_t module_attr_store(struct kobject *kobj,
945 struct attribute *attr,
946 const char *buf, size_t len)
947{
948 struct module_attribute *attribute;
949 struct module_kobject *mk;
950 int ret;
951
952 attribute = to_module_attr(attr);
953 mk = to_module_kobject(kobj);
954
955 if (!attribute->store)
956 return -EIO;
957
958 ret = attribute->store(attribute, mk, buf, len);
959
960 return ret;
961}
962
963static const struct sysfs_ops module_sysfs_ops = {
964 .show = module_attr_show,
965 .store = module_attr_store,
966};
967
968static int uevent_filter(struct kset *kset, struct kobject *kobj)
969{
970 struct kobj_type *ktype = get_ktype(kobj);
971
972 if (ktype == &module_ktype)
973 return 1;
974 return 0;
975}
976
977static const struct kset_uevent_ops module_uevent_ops = {
978 .filter = uevent_filter,
979};
980
981struct kset *module_kset;
982int module_sysfs_initialized;
983
984static void module_kobj_release(struct kobject *kobj)
985{
986 struct module_kobject *mk = to_module_kobject(kobj);
987 complete(mk->kobj_completion);
988}
989
990struct kobj_type module_ktype = {
991 .release = module_kobj_release,
992 .sysfs_ops = &module_sysfs_ops,
993};
994
995/*
996 * param_sysfs_init - wrapper for built-in params support
997 */
998static int __init param_sysfs_init(void)
999{
1000 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
1001 if (!module_kset) {
1002 printk(KERN_WARNING "%s (%d): error creating kset\n",
1003 __FILE__, __LINE__);
1004 return -ENOMEM;
1005 }
1006 module_sysfs_initialized = 1;
1007
1008 version_sysfs_builtin();
1009 param_sysfs_builtin();
1010
1011 return 0;
1012}
1013subsys_initcall(param_sysfs_init);
1014
1015#endif /* CONFIG_SYSFS */
1016
generated by cgit at 2024-05-18 14:17:34 (GMT)