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