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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// SPDX-License-Identifier: GPL-2.0-or-later
2/* Helpers for initial module or kernel cmdline parsing
3 Copyright (C) 2001 Rusty Russell.
4
5*/
6#include <linux/kernel.h>
7#include <linux/string.h>
8#include <linux/errno.h>
9#include <linux/module.h>
10#include <linux/moduleparam.h>
11#include <linux/device.h>
12#include <linux/err.h>
13#include <linux/slab.h>
14#include <linux/ctype.h>
15#include <linux/security.h>
16
17#ifdef CONFIG_SYSFS
18/* Protects all built-in parameters, modules use their own param_lock */
19static DEFINE_MUTEX(param_lock);
20
21/* Use the module's mutex, or if built-in use the built-in mutex */
22#ifdef CONFIG_MODULES
23#define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock)
24#else
25#define KPARAM_MUTEX(mod) (¶m_lock)
26#endif
27
28static inline void check_kparam_locked(struct module *mod)
29{
30 BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod)));
31}
32#else
33static inline void check_kparam_locked(struct module *mod)
34{
35}
36#endif /* !CONFIG_SYSFS */
37
38/* This just allows us to keep track of which parameters are kmalloced. */
39struct kmalloced_param {
40 struct list_head list;
41 char val[];
42};
43static LIST_HEAD(kmalloced_params);
44static DEFINE_SPINLOCK(kmalloced_params_lock);
45
46static void *kmalloc_parameter(unsigned int size)
47{
48 struct kmalloced_param *p;
49
50 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
51 if (!p)
52 return NULL;
53
54 spin_lock(&kmalloced_params_lock);
55 list_add(&p->list, &kmalloced_params);
56 spin_unlock(&kmalloced_params_lock);
57
58 return p->val;
59}
60
61/* Does nothing if parameter wasn't kmalloced above. */
62static void maybe_kfree_parameter(void *param)
63{
64 struct kmalloced_param *p;
65
66 spin_lock(&kmalloced_params_lock);
67 list_for_each_entry(p, &kmalloced_params, list) {
68 if (p->val == param) {
69 list_del(&p->list);
70 kfree(p);
71 break;
72 }
73 }
74 spin_unlock(&kmalloced_params_lock);
75}
76
77static char dash2underscore(char c)
78{
79 if (c == '-')
80 return '_';
81 return c;
82}
83
84bool parameqn(const char *a, const char *b, size_t n)
85{
86 size_t i;
87
88 for (i = 0; i < n; i++) {
89 if (dash2underscore(a[i]) != dash2underscore(b[i]))
90 return false;
91 }
92 return true;
93}
94
95bool parameq(const char *a, const char *b)
96{
97 return parameqn(a, b, strlen(a)+1);
98}
99
100static bool param_check_unsafe(const struct kernel_param *kp)
101{
102 if (kp->flags & KERNEL_PARAM_FL_HWPARAM &&
103 security_locked_down(LOCKDOWN_MODULE_PARAMETERS))
104 return false;
105
106 if (kp->flags & KERNEL_PARAM_FL_UNSAFE) {
107 pr_notice("Setting dangerous option %s - tainting kernel\n",
108 kp->name);
109 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
110 }
111
112 return true;
113}
114
115static int parse_one(char *param,
116 char *val,
117 const char *doing,
118 const struct kernel_param *params,
119 unsigned num_params,
120 s16 min_level,
121 s16 max_level,
122 void *arg,
123 int (*handle_unknown)(char *param, char *val,
124 const char *doing, void *arg))
125{
126 unsigned int i;
127 int err;
128
129 /* Find parameter */
130 for (i = 0; i < num_params; i++) {
131 if (parameq(param, params[i].name)) {
132 if (params[i].level < min_level
133 || params[i].level > max_level)
134 return 0;
135 /* No one handled NULL, so do it here. */
136 if (!val &&
137 !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG))
138 return -EINVAL;
139 pr_debug("handling %s with %p\n", param,
140 params[i].ops->set);
141 kernel_param_lock(params[i].mod);
142 if (param_check_unsafe(¶ms[i]))
143 err = params[i].ops->set(val, ¶ms[i]);
144 else
145 err = -EPERM;
146 kernel_param_unlock(params[i].mod);
147 return err;
148 }
149 }
150
151 if (handle_unknown) {
152 pr_debug("doing %s: %s='%s'\n", doing, param, val);
153 return handle_unknown(param, val, doing, arg);
154 }
155
156 pr_debug("Unknown argument '%s'\n", param);
157 return -ENOENT;
158}
159
160/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
161char *parse_args(const char *doing,
162 char *args,
163 const struct kernel_param *params,
164 unsigned num,
165 s16 min_level,
166 s16 max_level,
167 void *arg,
168 int (*unknown)(char *param, char *val,
169 const char *doing, void *arg))
170{
171 char *param, *val, *err = NULL;
172
173 /* Chew leading spaces */
174 args = skip_spaces(args);
175
176 if (*args)
177 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
178
179 while (*args) {
180 int ret;
181 int irq_was_disabled;
182
183 args = next_arg(args, ¶m, &val);
184 /* Stop at -- */
185 if (!val && strcmp(param, "--") == 0)
186 return err ?: args;
187 irq_was_disabled = irqs_disabled();
188 ret = parse_one(param, val, doing, params, num,
189 min_level, max_level, arg, unknown);
190 if (irq_was_disabled && !irqs_disabled())
191 pr_warn("%s: option '%s' enabled irq's!\n",
192 doing, param);
193
194 switch (ret) {
195 case 0:
196 continue;
197 case -ENOENT:
198 pr_err("%s: Unknown parameter `%s'\n", doing, param);
199 break;
200 case -ENOSPC:
201 pr_err("%s: `%s' too large for parameter `%s'\n",
202 doing, val ?: "", param);
203 break;
204 default:
205 pr_err("%s: `%s' invalid for parameter `%s'\n",
206 doing, val ?: "", param);
207 break;
208 }
209
210 err = ERR_PTR(ret);
211 }
212
213 return err;
214}
215
216/* Lazy bastard, eh? */
217#define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
218 int param_set_##name(const char *val, const struct kernel_param *kp) \
219 { \
220 return strtolfn(val, 0, (type *)kp->arg); \
221 } \
222 int param_get_##name(char *buffer, const struct kernel_param *kp) \
223 { \
224 return scnprintf(buffer, PAGE_SIZE, format "\n", \
225 *((type *)kp->arg)); \
226 } \
227 const struct kernel_param_ops param_ops_##name = { \
228 .set = param_set_##name, \
229 .get = param_get_##name, \
230 }; \
231 EXPORT_SYMBOL(param_set_##name); \
232 EXPORT_SYMBOL(param_get_##name); \
233 EXPORT_SYMBOL(param_ops_##name)
234
235
236STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
237STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
238STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
239STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
240STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
241STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
242STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
243STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull);
244
245int param_set_charp(const char *val, const struct kernel_param *kp)
246{
247 if (strlen(val) > 1024) {
248 pr_err("%s: string parameter too long\n", kp->name);
249 return -ENOSPC;
250 }
251
252 maybe_kfree_parameter(*(char **)kp->arg);
253
254 /* This is a hack. We can't kmalloc in early boot, and we
255 * don't need to; this mangled commandline is preserved. */
256 if (slab_is_available()) {
257 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
258 if (!*(char **)kp->arg)
259 return -ENOMEM;
260 strcpy(*(char **)kp->arg, val);
261 } else
262 *(const char **)kp->arg = val;
263
264 return 0;
265}
266EXPORT_SYMBOL(param_set_charp);
267
268int param_get_charp(char *buffer, const struct kernel_param *kp)
269{
270 return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg));
271}
272EXPORT_SYMBOL(param_get_charp);
273
274void param_free_charp(void *arg)
275{
276 maybe_kfree_parameter(*((char **)arg));
277}
278EXPORT_SYMBOL(param_free_charp);
279
280const struct kernel_param_ops param_ops_charp = {
281 .set = param_set_charp,
282 .get = param_get_charp,
283 .free = param_free_charp,
284};
285EXPORT_SYMBOL(param_ops_charp);
286
287/* Actually could be a bool or an int, for historical reasons. */
288int param_set_bool(const char *val, const struct kernel_param *kp)
289{
290 /* No equals means "set"... */
291 if (!val) val = "1";
292
293 /* One of =[yYnN01] */
294 return strtobool(val, kp->arg);
295}
296EXPORT_SYMBOL(param_set_bool);
297
298int param_get_bool(char *buffer, const struct kernel_param *kp)
299{
300 /* Y and N chosen as being relatively non-coder friendly */
301 return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N');
302}
303EXPORT_SYMBOL(param_get_bool);
304
305const struct kernel_param_ops param_ops_bool = {
306 .flags = KERNEL_PARAM_OPS_FL_NOARG,
307 .set = param_set_bool,
308 .get = param_get_bool,
309};
310EXPORT_SYMBOL(param_ops_bool);
311
312int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
313{
314 int err = 0;
315 bool new_value;
316 bool orig_value = *(bool *)kp->arg;
317 struct kernel_param dummy_kp = *kp;
318
319 dummy_kp.arg = &new_value;
320
321 err = param_set_bool(val, &dummy_kp);
322 if (err)
323 return err;
324
325 /* Don't let them unset it once it's set! */
326 if (!new_value && orig_value)
327 return -EROFS;
328
329 if (new_value)
330 err = param_set_bool(val, kp);
331
332 return err;
333}
334EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
335
336const struct kernel_param_ops param_ops_bool_enable_only = {
337 .flags = KERNEL_PARAM_OPS_FL_NOARG,
338 .set = param_set_bool_enable_only,
339 .get = param_get_bool,
340};
341EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
342
343/* This one must be bool. */
344int param_set_invbool(const char *val, const struct kernel_param *kp)
345{
346 int ret;
347 bool boolval;
348 struct kernel_param dummy;
349
350 dummy.arg = &boolval;
351 ret = param_set_bool(val, &dummy);
352 if (ret == 0)
353 *(bool *)kp->arg = !boolval;
354 return ret;
355}
356EXPORT_SYMBOL(param_set_invbool);
357
358int param_get_invbool(char *buffer, const struct kernel_param *kp)
359{
360 return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y');
361}
362EXPORT_SYMBOL(param_get_invbool);
363
364const struct kernel_param_ops param_ops_invbool = {
365 .set = param_set_invbool,
366 .get = param_get_invbool,
367};
368EXPORT_SYMBOL(param_ops_invbool);
369
370int param_set_bint(const char *val, const struct kernel_param *kp)
371{
372 /* Match bool exactly, by re-using it. */
373 struct kernel_param boolkp = *kp;
374 bool v;
375 int ret;
376
377 boolkp.arg = &v;
378
379 ret = param_set_bool(val, &boolkp);
380 if (ret == 0)
381 *(int *)kp->arg = v;
382 return ret;
383}
384EXPORT_SYMBOL(param_set_bint);
385
386const struct kernel_param_ops param_ops_bint = {
387 .flags = KERNEL_PARAM_OPS_FL_NOARG,
388 .set = param_set_bint,
389 .get = param_get_int,
390};
391EXPORT_SYMBOL(param_ops_bint);
392
393/* We break the rule and mangle the string. */
394static int param_array(struct module *mod,
395 const char *name,
396 const char *val,
397 unsigned int min, unsigned int max,
398 void *elem, int elemsize,
399 int (*set)(const char *, const struct kernel_param *kp),
400 s16 level,
401 unsigned int *num)
402{
403 int ret;
404 struct kernel_param kp;
405 char save;
406
407 /* Get the name right for errors. */
408 kp.name = name;
409 kp.arg = elem;
410 kp.level = level;
411
412 *num = 0;
413 /* We expect a comma-separated list of values. */
414 do {
415 int len;
416
417 if (*num == max) {
418 pr_err("%s: can only take %i arguments\n", name, max);
419 return -EINVAL;
420 }
421 len = strcspn(val, ",");
422
423 /* nul-terminate and parse */
424 save = val[len];
425 ((char *)val)[len] = '\0';
426 check_kparam_locked(mod);
427 ret = set(val, &kp);
428
429 if (ret != 0)
430 return ret;
431 kp.arg += elemsize;
432 val += len+1;
433 (*num)++;
434 } while (save == ',');
435
436 if (*num < min) {
437 pr_err("%s: needs at least %i arguments\n", name, min);
438 return -EINVAL;
439 }
440 return 0;
441}
442
443static int param_array_set(const char *val, const struct kernel_param *kp)
444{
445 const struct kparam_array *arr = kp->arr;
446 unsigned int temp_num;
447
448 return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem,
449 arr->elemsize, arr->ops->set, kp->level,
450 arr->num ?: &temp_num);
451}
452
453static int param_array_get(char *buffer, const struct kernel_param *kp)
454{
455 int i, off, ret;
456 const struct kparam_array *arr = kp->arr;
457 struct kernel_param p = *kp;
458
459 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
460 /* Replace \n with comma */
461 if (i)
462 buffer[off - 1] = ',';
463 p.arg = arr->elem + arr->elemsize * i;
464 check_kparam_locked(p.mod);
465 ret = arr->ops->get(buffer + off, &p);
466 if (ret < 0)
467 return ret;
468 off += ret;
469 }
470 buffer[off] = '\0';
471 return off;
472}
473
474static void param_array_free(void *arg)
475{
476 unsigned int i;
477 const struct kparam_array *arr = arg;
478
479 if (arr->ops->free)
480 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
481 arr->ops->free(arr->elem + arr->elemsize * i);
482}
483
484const struct kernel_param_ops param_array_ops = {
485 .set = param_array_set,
486 .get = param_array_get,
487 .free = param_array_free,
488};
489EXPORT_SYMBOL(param_array_ops);
490
491int param_set_copystring(const char *val, const struct kernel_param *kp)
492{
493 const struct kparam_string *kps = kp->str;
494
495 if (strlen(val)+1 > kps->maxlen) {
496 pr_err("%s: string doesn't fit in %u chars.\n",
497 kp->name, kps->maxlen-1);
498 return -ENOSPC;
499 }
500 strcpy(kps->string, val);
501 return 0;
502}
503EXPORT_SYMBOL(param_set_copystring);
504
505int param_get_string(char *buffer, const struct kernel_param *kp)
506{
507 const struct kparam_string *kps = kp->str;
508 return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string);
509}
510EXPORT_SYMBOL(param_get_string);
511
512const struct kernel_param_ops param_ops_string = {
513 .set = param_set_copystring,
514 .get = param_get_string,
515};
516EXPORT_SYMBOL(param_ops_string);
517
518/* sysfs output in /sys/modules/XYZ/parameters/ */
519#define to_module_attr(n) container_of(n, struct module_attribute, attr)
520#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
521
522struct param_attribute
523{
524 struct module_attribute mattr;
525 const struct kernel_param *param;
526};
527
528struct module_param_attrs
529{
530 unsigned int num;
531 struct attribute_group grp;
532 struct param_attribute attrs[0];
533};
534
535#ifdef CONFIG_SYSFS
536#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
537
538static ssize_t param_attr_show(struct module_attribute *mattr,
539 struct module_kobject *mk, char *buf)
540{
541 int count;
542 struct param_attribute *attribute = to_param_attr(mattr);
543
544 if (!attribute->param->ops->get)
545 return -EPERM;
546
547 kernel_param_lock(mk->mod);
548 count = attribute->param->ops->get(buf, attribute->param);
549 kernel_param_unlock(mk->mod);
550 return count;
551}
552
553/* sysfs always hands a nul-terminated string in buf. We rely on that. */
554static ssize_t param_attr_store(struct module_attribute *mattr,
555 struct module_kobject *mk,
556 const char *buf, size_t len)
557{
558 int err;
559 struct param_attribute *attribute = to_param_attr(mattr);
560
561 if (!attribute->param->ops->set)
562 return -EPERM;
563
564 kernel_param_lock(mk->mod);
565 if (param_check_unsafe(attribute->param))
566 err = attribute->param->ops->set(buf, attribute->param);
567 else
568 err = -EPERM;
569 kernel_param_unlock(mk->mod);
570 if (!err)
571 return len;
572 return err;
573}
574#endif
575
576#ifdef CONFIG_MODULES
577#define __modinit
578#else
579#define __modinit __init
580#endif
581
582#ifdef CONFIG_SYSFS
583void kernel_param_lock(struct module *mod)
584{
585 mutex_lock(KPARAM_MUTEX(mod));
586}
587
588void kernel_param_unlock(struct module *mod)
589{
590 mutex_unlock(KPARAM_MUTEX(mod));
591}
592
593EXPORT_SYMBOL(kernel_param_lock);
594EXPORT_SYMBOL(kernel_param_unlock);
595
596/*
597 * add_sysfs_param - add a parameter to sysfs
598 * @mk: struct module_kobject
599 * @kp: the actual parameter definition to add to sysfs
600 * @name: name of parameter
601 *
602 * Create a kobject if for a (per-module) parameter if mp NULL, and
603 * create file in sysfs. Returns an error on out of memory. Always cleans up
604 * if there's an error.
605 */
606static __modinit int add_sysfs_param(struct module_kobject *mk,
607 const struct kernel_param *kp,
608 const char *name)
609{
610 struct module_param_attrs *new_mp;
611 struct attribute **new_attrs;
612 unsigned int i;
613
614 /* We don't bother calling this with invisible parameters. */
615 BUG_ON(!kp->perm);
616
617 if (!mk->mp) {
618 /* First allocation. */
619 mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
620 if (!mk->mp)
621 return -ENOMEM;
622 mk->mp->grp.name = "parameters";
623 /* NULL-terminated attribute array. */
624 mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
625 GFP_KERNEL);
626 /* Caller will cleanup via free_module_param_attrs */
627 if (!mk->mp->grp.attrs)
628 return -ENOMEM;
629 }
630
631 /* Enlarge allocations. */
632 new_mp = krealloc(mk->mp,
633 sizeof(*mk->mp) +
634 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
635 GFP_KERNEL);
636 if (!new_mp)
637 return -ENOMEM;
638 mk->mp = new_mp;
639
640 /* Extra pointer for NULL terminator */
641 new_attrs = krealloc(mk->mp->grp.attrs,
642 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
643 GFP_KERNEL);
644 if (!new_attrs)
645 return -ENOMEM;
646 mk->mp->grp.attrs = new_attrs;
647
648 /* Tack new one on the end. */
649 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
650 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
651 mk->mp->attrs[mk->mp->num].param = kp;
652 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
653 /* Do not allow runtime DAC changes to make param writable. */
654 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
655 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
656 else
657 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
658 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
659 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
660 mk->mp->num++;
661
662 /* Fix up all the pointers, since krealloc can move us */
663 for (i = 0; i < mk->mp->num; i++)
664 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
665 mk->mp->grp.attrs[mk->mp->num] = NULL;
666 return 0;
667}
668
669#ifdef CONFIG_MODULES
670static void free_module_param_attrs(struct module_kobject *mk)
671{
672 if (mk->mp)
673 kfree(mk->mp->grp.attrs);
674 kfree(mk->mp);
675 mk->mp = NULL;
676}
677
678/*
679 * module_param_sysfs_setup - setup sysfs support for one module
680 * @mod: module
681 * @kparam: module parameters (array)
682 * @num_params: number of module parameters
683 *
684 * Adds sysfs entries for module parameters under
685 * /sys/module/[mod->name]/parameters/
686 */
687int module_param_sysfs_setup(struct module *mod,
688 const struct kernel_param *kparam,
689 unsigned int num_params)
690{
691 int i, err;
692 bool params = false;
693
694 for (i = 0; i < num_params; i++) {
695 if (kparam[i].perm == 0)
696 continue;
697 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
698 if (err) {
699 free_module_param_attrs(&mod->mkobj);
700 return err;
701 }
702 params = true;
703 }
704
705 if (!params)
706 return 0;
707
708 /* Create the param group. */
709 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
710 if (err)
711 free_module_param_attrs(&mod->mkobj);
712 return err;
713}
714
715/*
716 * module_param_sysfs_remove - remove sysfs support for one module
717 * @mod: module
718 *
719 * Remove sysfs entries for module parameters and the corresponding
720 * kobject.
721 */
722void module_param_sysfs_remove(struct module *mod)
723{
724 if (mod->mkobj.mp) {
725 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
726 /* We are positive that no one is using any param
727 * attrs at this point. Deallocate immediately. */
728 free_module_param_attrs(&mod->mkobj);
729 }
730}
731#endif
732
733void destroy_params(const struct kernel_param *params, unsigned num)
734{
735 unsigned int i;
736
737 for (i = 0; i < num; i++)
738 if (params[i].ops->free)
739 params[i].ops->free(params[i].arg);
740}
741
742static struct module_kobject * __init locate_module_kobject(const char *name)
743{
744 struct module_kobject *mk;
745 struct kobject *kobj;
746 int err;
747
748 kobj = kset_find_obj(module_kset, name);
749 if (kobj) {
750 mk = to_module_kobject(kobj);
751 } else {
752 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
753 BUG_ON(!mk);
754
755 mk->mod = THIS_MODULE;
756 mk->kobj.kset = module_kset;
757 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
758 "%s", name);
759#ifdef CONFIG_MODULES
760 if (!err)
761 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
762#endif
763 if (err) {
764 kobject_put(&mk->kobj);
765 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
766 name, err);
767 return NULL;
768 }
769
770 /* So that we hold reference in both cases. */
771 kobject_get(&mk->kobj);
772 }
773
774 return mk;
775}
776
777static void __init kernel_add_sysfs_param(const char *name,
778 const struct kernel_param *kparam,
779 unsigned int name_skip)
780{
781 struct module_kobject *mk;
782 int err;
783
784 mk = locate_module_kobject(name);
785 if (!mk)
786 return;
787
788 /* We need to remove old parameters before adding more. */
789 if (mk->mp)
790 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
791
792 /* These should not fail at boot. */
793 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
794 BUG_ON(err);
795 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
796 BUG_ON(err);
797 kobject_uevent(&mk->kobj, KOBJ_ADD);
798 kobject_put(&mk->kobj);
799}
800
801/*
802 * param_sysfs_builtin - add sysfs parameters for built-in modules
803 *
804 * Add module_parameters to sysfs for "modules" built into the kernel.
805 *
806 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
807 * "parameter" name is stored behind a dot in kernel_param->name. So,
808 * extract the "module" name for all built-in kernel_param-eters,
809 * and for all who have the same, call kernel_add_sysfs_param.
810 */
811static void __init param_sysfs_builtin(void)
812{
813 const struct kernel_param *kp;
814 unsigned int name_len;
815 char modname[MODULE_NAME_LEN];
816
817 for (kp = __start___param; kp < __stop___param; kp++) {
818 char *dot;
819
820 if (kp->perm == 0)
821 continue;
822
823 dot = strchr(kp->name, '.');
824 if (!dot) {
825 /* This happens for core_param() */
826 strcpy(modname, "kernel");
827 name_len = 0;
828 } else {
829 name_len = dot - kp->name + 1;
830 strlcpy(modname, kp->name, name_len);
831 }
832 kernel_add_sysfs_param(modname, kp, name_len);
833 }
834}
835
836ssize_t __modver_version_show(struct module_attribute *mattr,
837 struct module_kobject *mk, char *buf)
838{
839 struct module_version_attribute *vattr =
840 container_of(mattr, struct module_version_attribute, mattr);
841
842 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
843}
844
845extern const struct module_version_attribute *__start___modver[];
846extern const struct module_version_attribute *__stop___modver[];
847
848static void __init version_sysfs_builtin(void)
849{
850 const struct module_version_attribute **p;
851 struct module_kobject *mk;
852 int err;
853
854 for (p = __start___modver; p < __stop___modver; p++) {
855 const struct module_version_attribute *vattr = *p;
856
857 mk = locate_module_kobject(vattr->module_name);
858 if (mk) {
859 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
860 WARN_ON_ONCE(err);
861 kobject_uevent(&mk->kobj, KOBJ_ADD);
862 kobject_put(&mk->kobj);
863 }
864 }
865}
866
867/* module-related sysfs stuff */
868
869static ssize_t module_attr_show(struct kobject *kobj,
870 struct attribute *attr,
871 char *buf)
872{
873 struct module_attribute *attribute;
874 struct module_kobject *mk;
875 int ret;
876
877 attribute = to_module_attr(attr);
878 mk = to_module_kobject(kobj);
879
880 if (!attribute->show)
881 return -EIO;
882
883 ret = attribute->show(attribute, mk, buf);
884
885 return ret;
886}
887
888static ssize_t module_attr_store(struct kobject *kobj,
889 struct attribute *attr,
890 const char *buf, size_t len)
891{
892 struct module_attribute *attribute;
893 struct module_kobject *mk;
894 int ret;
895
896 attribute = to_module_attr(attr);
897 mk = to_module_kobject(kobj);
898
899 if (!attribute->store)
900 return -EIO;
901
902 ret = attribute->store(attribute, mk, buf, len);
903
904 return ret;
905}
906
907static const struct sysfs_ops module_sysfs_ops = {
908 .show = module_attr_show,
909 .store = module_attr_store,
910};
911
912static int uevent_filter(struct kset *kset, struct kobject *kobj)
913{
914 struct kobj_type *ktype = get_ktype(kobj);
915
916 if (ktype == &module_ktype)
917 return 1;
918 return 0;
919}
920
921static const struct kset_uevent_ops module_uevent_ops = {
922 .filter = uevent_filter,
923};
924
925struct kset *module_kset;
926int module_sysfs_initialized;
927
928static void module_kobj_release(struct kobject *kobj)
929{
930 struct module_kobject *mk = to_module_kobject(kobj);
931 complete(mk->kobj_completion);
932}
933
934struct kobj_type module_ktype = {
935 .release = module_kobj_release,
936 .sysfs_ops = &module_sysfs_ops,
937};
938
939/*
940 * param_sysfs_init - wrapper for built-in params support
941 */
942static int __init param_sysfs_init(void)
943{
944 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
945 if (!module_kset) {
946 printk(KERN_WARNING "%s (%d): error creating kset\n",
947 __FILE__, __LINE__);
948 return -ENOMEM;
949 }
950 module_sysfs_initialized = 1;
951
952 version_sysfs_builtin();
953 param_sysfs_builtin();
954
955 return 0;
956}
957subsys_initcall(param_sysfs_init);
958
959#endif /* CONFIG_SYSFS */