1 /* Helpers for initial module or kernel cmdline parsing
2 Copyright (C) 2001 Rusty Russell.
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.
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.
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
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/errno.h>
21 #include <linux/module.h>
22 #include <linux/device.h>
23 #include <linux/err.h>
24 #include <linux/slab.h>
25 #include <linux/ctype.h>
27 /* Protects all parameters, and incidentally kmalloced_param list. */
28 static DEFINE_MUTEX(param_lock);
30 /* This just allows us to keep track of which parameters are kmalloced. */
31 struct kmalloced_param {
32 struct list_head list;
35 static LIST_HEAD(kmalloced_params);
37 static void *kmalloc_parameter(unsigned int size)
39 struct kmalloced_param *p;
41 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
45 list_add(&p->list, &kmalloced_params);
49 /* Does nothing if parameter wasn't kmalloced above. */
50 static void maybe_kfree_parameter(void *param)
52 struct kmalloced_param *p;
54 list_for_each_entry(p, &kmalloced_params, list) {
55 if (p->val == param) {
63 static char dash2underscore(char c)
70 bool parameqn(const char *a, const char *b, size_t n)
74 for (i = 0; i < n; i++) {
75 if (dash2underscore(a[i]) != dash2underscore(b[i]))
81 bool parameq(const char *a, const char *b)
83 return parameqn(a, b, strlen(a)+1);
86 static int parse_one(char *param,
89 const struct kernel_param *params,
93 int (*handle_unknown)(char *param, char *val,
100 for (i = 0; i < num_params; i++) {
101 if (parameq(param, params[i].name)) {
102 if (params[i].level < min_level
103 || params[i].level > max_level)
105 /* No one handled NULL, so do it here. */
107 !(params[i].ops->flags & KERNEL_PARAM_FL_NOARG))
109 pr_debug("handling %s with %p\n", param,
111 mutex_lock(¶m_lock);
112 err = params[i].ops->set(val, ¶ms[i]);
113 mutex_unlock(¶m_lock);
118 if (handle_unknown) {
119 pr_debug("doing %s: %s='%s'\n", doing, param, val);
120 return handle_unknown(param, val, doing);
123 pr_debug("Unknown argument '%s'\n", param);
127 /* You can use " around spaces, but can't escape ". */
128 /* Hyphens and underscores equivalent in parameter names. */
129 static char *next_arg(char *args, char **param, char **val)
131 unsigned int i, equals = 0;
132 int in_quote = 0, quoted = 0;
141 for (i = 0; args[i]; i++) {
142 if (isspace(args[i]) && !in_quote)
149 in_quote = !in_quote;
157 *val = args + equals + 1;
159 /* Don't include quotes in value. */
162 if (args[i-1] == '"')
165 if (quoted && args[i-1] == '"')
175 /* Chew up trailing spaces. */
176 return skip_spaces(next);
179 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
180 int parse_args(const char *doing,
182 const struct kernel_param *params,
186 int (*unknown)(char *param, char *val, const char *doing))
190 /* Chew leading spaces */
191 args = skip_spaces(args);
194 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
198 int irq_was_disabled;
200 args = next_arg(args, ¶m, &val);
201 irq_was_disabled = irqs_disabled();
202 ret = parse_one(param, val, doing, params, num,
203 min_level, max_level, unknown);
204 if (irq_was_disabled && !irqs_disabled())
205 pr_warn("%s: option '%s' enabled irq's!\n",
210 pr_err("%s: Unknown parameter `%s'\n", doing, param);
213 pr_err("%s: `%s' too large for parameter `%s'\n",
214 doing, val ?: "", param);
219 pr_err("%s: `%s' invalid for parameter `%s'\n",
220 doing, val ?: "", param);
229 /* Lazy bastard, eh? */
230 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
231 int param_set_##name(const char *val, const struct kernel_param *kp) \
236 ret = strtolfn(val, 0, &l); \
237 if (ret < 0 || ((type)l != l)) \
238 return ret < 0 ? ret : -EINVAL; \
239 *((type *)kp->arg) = l; \
242 int param_get_##name(char *buffer, const struct kernel_param *kp) \
244 return sprintf(buffer, format, *((type *)kp->arg)); \
246 struct kernel_param_ops param_ops_##name = { \
247 .set = param_set_##name, \
248 .get = param_get_##name, \
250 EXPORT_SYMBOL(param_set_##name); \
251 EXPORT_SYMBOL(param_get_##name); \
252 EXPORT_SYMBOL(param_ops_##name)
255 STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", unsigned long, strict_strtoul);
256 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
257 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
258 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
259 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
260 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
261 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
263 int param_set_charp(const char *val, const struct kernel_param *kp)
265 if (strlen(val) > 1024) {
266 pr_err("%s: string parameter too long\n", kp->name);
270 maybe_kfree_parameter(*(char **)kp->arg);
272 /* This is a hack. We can't kmalloc in early boot, and we
273 * don't need to; this mangled commandline is preserved. */
274 if (slab_is_available()) {
275 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
276 if (!*(char **)kp->arg)
278 strcpy(*(char **)kp->arg, val);
280 *(const char **)kp->arg = val;
284 EXPORT_SYMBOL(param_set_charp);
286 int param_get_charp(char *buffer, const struct kernel_param *kp)
288 return sprintf(buffer, "%s", *((char **)kp->arg));
290 EXPORT_SYMBOL(param_get_charp);
292 static void param_free_charp(void *arg)
294 maybe_kfree_parameter(*((char **)arg));
297 struct kernel_param_ops param_ops_charp = {
298 .set = param_set_charp,
299 .get = param_get_charp,
300 .free = param_free_charp,
302 EXPORT_SYMBOL(param_ops_charp);
304 /* Actually could be a bool or an int, for historical reasons. */
305 int param_set_bool(const char *val, const struct kernel_param *kp)
307 /* No equals means "set"... */
310 /* One of =[yYnN01] */
311 return strtobool(val, kp->arg);
313 EXPORT_SYMBOL(param_set_bool);
315 int param_get_bool(char *buffer, const struct kernel_param *kp)
317 /* Y and N chosen as being relatively non-coder friendly */
318 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
320 EXPORT_SYMBOL(param_get_bool);
322 struct kernel_param_ops param_ops_bool = {
323 .flags = KERNEL_PARAM_FL_NOARG,
324 .set = param_set_bool,
325 .get = param_get_bool,
327 EXPORT_SYMBOL(param_ops_bool);
329 /* This one must be bool. */
330 int param_set_invbool(const char *val, const struct kernel_param *kp)
334 struct kernel_param dummy;
336 dummy.arg = &boolval;
337 ret = param_set_bool(val, &dummy);
339 *(bool *)kp->arg = !boolval;
342 EXPORT_SYMBOL(param_set_invbool);
344 int param_get_invbool(char *buffer, const struct kernel_param *kp)
346 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
348 EXPORT_SYMBOL(param_get_invbool);
350 struct kernel_param_ops param_ops_invbool = {
351 .set = param_set_invbool,
352 .get = param_get_invbool,
354 EXPORT_SYMBOL(param_ops_invbool);
356 int param_set_bint(const char *val, const struct kernel_param *kp)
358 struct kernel_param boolkp;
362 /* Match bool exactly, by re-using it. */
366 ret = param_set_bool(val, &boolkp);
371 EXPORT_SYMBOL(param_set_bint);
373 struct kernel_param_ops param_ops_bint = {
374 .flags = KERNEL_PARAM_FL_NOARG,
375 .set = param_set_bint,
376 .get = param_get_int,
378 EXPORT_SYMBOL(param_ops_bint);
380 /* We break the rule and mangle the string. */
381 static int param_array(const char *name,
383 unsigned int min, unsigned int max,
384 void *elem, int elemsize,
385 int (*set)(const char *, const struct kernel_param *kp),
390 struct kernel_param kp;
393 /* Get the name right for errors. */
399 /* We expect a comma-separated list of values. */
404 pr_err("%s: can only take %i arguments\n", name, max);
407 len = strcspn(val, ",");
409 /* nul-terminate and parse */
411 ((char *)val)[len] = '\0';
412 BUG_ON(!mutex_is_locked(¶m_lock));
420 } while (save == ',');
423 pr_err("%s: needs at least %i arguments\n", name, min);
429 static int param_array_set(const char *val, const struct kernel_param *kp)
431 const struct kparam_array *arr = kp->arr;
432 unsigned int temp_num;
434 return param_array(kp->name, val, 1, arr->max, arr->elem,
435 arr->elemsize, arr->ops->set, kp->level,
436 arr->num ?: &temp_num);
439 static int param_array_get(char *buffer, const struct kernel_param *kp)
442 const struct kparam_array *arr = kp->arr;
443 struct kernel_param p;
446 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
449 p.arg = arr->elem + arr->elemsize * i;
450 BUG_ON(!mutex_is_locked(¶m_lock));
451 ret = arr->ops->get(buffer + off, &p);
460 static void param_array_free(void *arg)
463 const struct kparam_array *arr = arg;
466 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
467 arr->ops->free(arr->elem + arr->elemsize * i);
470 struct kernel_param_ops param_array_ops = {
471 .set = param_array_set,
472 .get = param_array_get,
473 .free = param_array_free,
475 EXPORT_SYMBOL(param_array_ops);
477 int param_set_copystring(const char *val, const struct kernel_param *kp)
479 const struct kparam_string *kps = kp->str;
481 if (strlen(val)+1 > kps->maxlen) {
482 pr_err("%s: string doesn't fit in %u chars.\n",
483 kp->name, kps->maxlen-1);
486 strcpy(kps->string, val);
489 EXPORT_SYMBOL(param_set_copystring);
491 int param_get_string(char *buffer, const struct kernel_param *kp)
493 const struct kparam_string *kps = kp->str;
494 return strlcpy(buffer, kps->string, kps->maxlen);
496 EXPORT_SYMBOL(param_get_string);
498 struct kernel_param_ops param_ops_string = {
499 .set = param_set_copystring,
500 .get = param_get_string,
502 EXPORT_SYMBOL(param_ops_string);
504 /* sysfs output in /sys/modules/XYZ/parameters/ */
505 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
506 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
508 extern struct kernel_param __start___param[], __stop___param[];
510 struct param_attribute
512 struct module_attribute mattr;
513 const struct kernel_param *param;
516 struct module_param_attrs
519 struct attribute_group grp;
520 struct param_attribute attrs[0];
524 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
526 static ssize_t param_attr_show(struct module_attribute *mattr,
527 struct module_kobject *mk, char *buf)
530 struct param_attribute *attribute = to_param_attr(mattr);
532 if (!attribute->param->ops->get)
535 mutex_lock(¶m_lock);
536 count = attribute->param->ops->get(buf, attribute->param);
537 mutex_unlock(¶m_lock);
545 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
546 static ssize_t param_attr_store(struct module_attribute *mattr,
547 struct module_kobject *km,
548 const char *buf, size_t len)
551 struct param_attribute *attribute = to_param_attr(mattr);
553 if (!attribute->param->ops->set)
556 mutex_lock(¶m_lock);
557 err = attribute->param->ops->set(buf, attribute->param);
558 mutex_unlock(¶m_lock);
565 #ifdef CONFIG_MODULES
568 #define __modinit __init
572 void __kernel_param_lock(void)
574 mutex_lock(¶m_lock);
576 EXPORT_SYMBOL(__kernel_param_lock);
578 void __kernel_param_unlock(void)
580 mutex_unlock(¶m_lock);
582 EXPORT_SYMBOL(__kernel_param_unlock);
585 * add_sysfs_param - add a parameter to sysfs
586 * @mk: struct module_kobject
587 * @kparam: the actual parameter definition to add to sysfs
588 * @name: name of parameter
590 * Create a kobject if for a (per-module) parameter if mp NULL, and
591 * create file in sysfs. Returns an error on out of memory. Always cleans up
592 * if there's an error.
594 static __modinit int add_sysfs_param(struct module_kobject *mk,
595 const struct kernel_param *kp,
598 struct module_param_attrs *new;
599 struct attribute **attrs;
602 /* We don't bother calling this with invisible parameters. */
610 attrs = mk->mp->grp.attrs;
614 new = krealloc(mk->mp,
615 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
622 /* Despite looking like the typical realloc() bug, this is safe.
623 * We *want* the old 'attrs' to be freed either way, and we'll store
624 * the new one in the success case. */
625 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
631 /* Sysfs wants everything zeroed. */
632 memset(new, 0, sizeof(*new));
633 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
634 memset(&attrs[num], 0, sizeof(attrs[num]));
635 new->grp.name = "parameters";
636 new->grp.attrs = attrs;
638 /* Tack new one on the end. */
639 sysfs_attr_init(&new->attrs[num].mattr.attr);
640 new->attrs[num].param = kp;
641 new->attrs[num].mattr.show = param_attr_show;
642 new->attrs[num].mattr.store = param_attr_store;
643 new->attrs[num].mattr.attr.name = (char *)name;
644 new->attrs[num].mattr.attr.mode = kp->perm;
647 /* Fix up all the pointers, since krealloc can move us */
648 for (num = 0; num < new->num; num++)
649 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
650 new->grp.attrs[num] = NULL;
662 #ifdef CONFIG_MODULES
663 static void free_module_param_attrs(struct module_kobject *mk)
665 kfree(mk->mp->grp.attrs);
671 * module_param_sysfs_setup - setup sysfs support for one module
673 * @kparam: module parameters (array)
674 * @num_params: number of module parameters
676 * Adds sysfs entries for module parameters under
677 * /sys/module/[mod->name]/parameters/
679 int module_param_sysfs_setup(struct module *mod,
680 const struct kernel_param *kparam,
681 unsigned int num_params)
686 for (i = 0; i < num_params; i++) {
687 if (kparam[i].perm == 0)
689 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
698 /* Create the param group. */
699 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
701 free_module_param_attrs(&mod->mkobj);
706 * module_param_sysfs_remove - remove sysfs support for one module
709 * Remove sysfs entries for module parameters and the corresponding
712 void module_param_sysfs_remove(struct module *mod)
715 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
716 /* We are positive that no one is using any param
717 * attrs at this point. Deallocate immediately. */
718 free_module_param_attrs(&mod->mkobj);
723 void destroy_params(const struct kernel_param *params, unsigned num)
727 for (i = 0; i < num; i++)
728 if (params[i].ops->free)
729 params[i].ops->free(params[i].arg);
732 static struct module_kobject * __init locate_module_kobject(const char *name)
734 struct module_kobject *mk;
735 struct kobject *kobj;
738 kobj = kset_find_obj(module_kset, name);
740 mk = to_module_kobject(kobj);
742 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
745 mk->mod = THIS_MODULE;
746 mk->kobj.kset = module_kset;
747 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
749 #ifdef CONFIG_MODULES
751 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
754 kobject_put(&mk->kobj);
755 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
760 /* So that we hold reference in both cases. */
761 kobject_get(&mk->kobj);
767 static void __init kernel_add_sysfs_param(const char *name,
768 struct kernel_param *kparam,
769 unsigned int name_skip)
771 struct module_kobject *mk;
774 mk = locate_module_kobject(name);
778 /* We need to remove old parameters before adding more. */
780 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
782 /* These should not fail at boot. */
783 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
785 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
787 kobject_uevent(&mk->kobj, KOBJ_ADD);
788 kobject_put(&mk->kobj);
792 * param_sysfs_builtin - add sysfs parameters for built-in modules
794 * Add module_parameters to sysfs for "modules" built into the kernel.
796 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
797 * "parameter" name is stored behind a dot in kernel_param->name. So,
798 * extract the "module" name for all built-in kernel_param-eters,
799 * and for all who have the same, call kernel_add_sysfs_param.
801 static void __init param_sysfs_builtin(void)
803 struct kernel_param *kp;
804 unsigned int name_len;
805 char modname[MODULE_NAME_LEN];
807 for (kp = __start___param; kp < __stop___param; kp++) {
813 dot = strchr(kp->name, '.');
815 /* This happens for core_param() */
816 strcpy(modname, "kernel");
819 name_len = dot - kp->name + 1;
820 strlcpy(modname, kp->name, name_len);
822 kernel_add_sysfs_param(modname, kp, name_len);
826 ssize_t __modver_version_show(struct module_attribute *mattr,
827 struct module_kobject *mk, char *buf)
829 struct module_version_attribute *vattr =
830 container_of(mattr, struct module_version_attribute, mattr);
832 return sprintf(buf, "%s\n", vattr->version);
835 extern const struct module_version_attribute *__start___modver[];
836 extern const struct module_version_attribute *__stop___modver[];
838 static void __init version_sysfs_builtin(void)
840 const struct module_version_attribute **p;
841 struct module_kobject *mk;
844 for (p = __start___modver; p < __stop___modver; p++) {
845 const struct module_version_attribute *vattr = *p;
847 mk = locate_module_kobject(vattr->module_name);
849 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
850 kobject_uevent(&mk->kobj, KOBJ_ADD);
851 kobject_put(&mk->kobj);
856 /* module-related sysfs stuff */
858 static ssize_t module_attr_show(struct kobject *kobj,
859 struct attribute *attr,
862 struct module_attribute *attribute;
863 struct module_kobject *mk;
866 attribute = to_module_attr(attr);
867 mk = to_module_kobject(kobj);
869 if (!attribute->show)
872 ret = attribute->show(attribute, mk, buf);
877 static ssize_t module_attr_store(struct kobject *kobj,
878 struct attribute *attr,
879 const char *buf, size_t len)
881 struct module_attribute *attribute;
882 struct module_kobject *mk;
885 attribute = to_module_attr(attr);
886 mk = to_module_kobject(kobj);
888 if (!attribute->store)
891 ret = attribute->store(attribute, mk, buf, len);
896 static const struct sysfs_ops module_sysfs_ops = {
897 .show = module_attr_show,
898 .store = module_attr_store,
901 static int uevent_filter(struct kset *kset, struct kobject *kobj)
903 struct kobj_type *ktype = get_ktype(kobj);
905 if (ktype == &module_ktype)
910 static const struct kset_uevent_ops module_uevent_ops = {
911 .filter = uevent_filter,
914 struct kset *module_kset;
915 int module_sysfs_initialized;
917 struct kobj_type module_ktype = {
918 .sysfs_ops = &module_sysfs_ops,
922 * param_sysfs_init - wrapper for built-in params support
924 static int __init param_sysfs_init(void)
926 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
928 printk(KERN_WARNING "%s (%d): error creating kset\n",
932 module_sysfs_initialized = 1;
934 version_sysfs_builtin();
935 param_sysfs_builtin();
939 subsys_initcall(param_sysfs_init);
941 #endif /* CONFIG_SYSFS */