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/module.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/module.h>
23 #include <linux/device.h>
24 #include <linux/err.h>
25 #include <linux/slab.h>
26 #include <linux/ctype.h>
28 /* Protects all parameters, and incidentally kmalloced_param list. */
29 static DEFINE_MUTEX(param_lock);
31 /* This just allows us to keep track of which parameters are kmalloced. */
32 struct kmalloced_param {
33 struct list_head list;
36 static LIST_HEAD(kmalloced_params);
38 static void *kmalloc_parameter(unsigned int size)
40 struct kmalloced_param *p;
42 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
46 list_add(&p->list, &kmalloced_params);
50 /* Does nothing if parameter wasn't kmalloced above. */
51 static void maybe_kfree_parameter(void *param)
53 struct kmalloced_param *p;
55 list_for_each_entry(p, &kmalloced_params, list) {
56 if (p->val == param) {
64 static char dash2underscore(char c)
71 bool parameqn(const char *a, const char *b, size_t n)
75 for (i = 0; i < n; i++) {
76 if (dash2underscore(a[i]) != dash2underscore(b[i]))
82 bool parameq(const char *a, const char *b)
84 return parameqn(a, b, strlen(a)+1);
87 static int parse_one(char *param,
89 const struct kernel_param *params,
91 int (*handle_unknown)(char *param, char *val))
97 for (i = 0; i < num_params; i++) {
98 if (parameq(param, params[i].name)) {
99 /* No one handled NULL, so do it here. */
100 if (!val && params[i].ops->set != param_set_bool)
102 pr_debug("They are equal! Calling %p\n",
104 mutex_lock(¶m_lock);
105 err = params[i].ops->set(val, ¶ms[i]);
106 mutex_unlock(¶m_lock);
111 if (handle_unknown) {
112 pr_debug("Unknown argument: calling %p\n", handle_unknown);
113 return handle_unknown(param, val);
116 pr_debug("Unknown argument `%s'\n", param);
120 /* You can use " around spaces, but can't escape ". */
121 /* Hyphens and underscores equivalent in parameter names. */
122 static char *next_arg(char *args, char **param, char **val)
124 unsigned int i, equals = 0;
125 int in_quote = 0, quoted = 0;
134 for (i = 0; args[i]; i++) {
135 if (isspace(args[i]) && !in_quote)
142 in_quote = !in_quote;
150 *val = args + equals + 1;
152 /* Don't include quotes in value. */
155 if (args[i-1] == '"')
158 if (quoted && args[i-1] == '"')
168 /* Chew up trailing spaces. */
169 return skip_spaces(next);
172 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
173 int parse_args(const char *name,
175 const struct kernel_param *params,
177 int (*unknown)(char *param, char *val))
181 pr_debug("Parsing ARGS: %s\n", args);
183 /* Chew leading spaces */
184 args = skip_spaces(args);
188 int irq_was_disabled;
190 args = next_arg(args, ¶m, &val);
191 irq_was_disabled = irqs_disabled();
192 ret = parse_one(param, val, params, num, unknown);
193 if (irq_was_disabled && !irqs_disabled()) {
194 printk(KERN_WARNING "parse_args(): option '%s' enabled "
199 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
204 "%s: `%s' too large for parameter `%s'\n",
205 name, val ?: "", param);
211 "%s: `%s' invalid for parameter `%s'\n",
212 name, val ?: "", param);
221 /* Lazy bastard, eh? */
222 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
223 int param_set_##name(const char *val, const struct kernel_param *kp) \
228 ret = strtolfn(val, 0, &l); \
229 if (ret < 0 || ((type)l != l)) \
230 return ret < 0 ? ret : -EINVAL; \
231 *((type *)kp->arg) = l; \
234 int param_get_##name(char *buffer, const struct kernel_param *kp) \
236 return sprintf(buffer, format, *((type *)kp->arg)); \
238 struct kernel_param_ops param_ops_##name = { \
239 .set = param_set_##name, \
240 .get = param_get_##name, \
242 EXPORT_SYMBOL(param_set_##name); \
243 EXPORT_SYMBOL(param_get_##name); \
244 EXPORT_SYMBOL(param_ops_##name)
247 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
248 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
249 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
250 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
251 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
252 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
253 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
255 int param_set_charp(const char *val, const struct kernel_param *kp)
257 if (strlen(val) > 1024) {
258 printk(KERN_ERR "%s: string parameter too long\n",
263 maybe_kfree_parameter(*(char **)kp->arg);
265 /* This is a hack. We can't kmalloc in early boot, and we
266 * don't need to; this mangled commandline is preserved. */
267 if (slab_is_available()) {
268 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
269 if (!*(char **)kp->arg)
271 strcpy(*(char **)kp->arg, val);
273 *(const char **)kp->arg = val;
277 EXPORT_SYMBOL(param_set_charp);
279 int param_get_charp(char *buffer, const struct kernel_param *kp)
281 return sprintf(buffer, "%s", *((char **)kp->arg));
283 EXPORT_SYMBOL(param_get_charp);
285 static void param_free_charp(void *arg)
287 maybe_kfree_parameter(*((char **)arg));
290 struct kernel_param_ops param_ops_charp = {
291 .set = param_set_charp,
292 .get = param_get_charp,
293 .free = param_free_charp,
295 EXPORT_SYMBOL(param_ops_charp);
297 /* Actually could be a bool or an int, for historical reasons. */
298 int param_set_bool(const char *val, const struct kernel_param *kp)
303 /* No equals means "set"... */
306 /* One of =[yYnN01] */
307 ret = strtobool(val, &v);
311 if (kp->flags & KPARAM_ISBOOL)
312 *(bool *)kp->arg = v;
317 EXPORT_SYMBOL(param_set_bool);
319 int param_get_bool(char *buffer, const struct kernel_param *kp)
322 if (kp->flags & KPARAM_ISBOOL)
323 val = *(bool *)kp->arg;
325 val = *(int *)kp->arg;
327 /* Y and N chosen as being relatively non-coder friendly */
328 return sprintf(buffer, "%c", val ? 'Y' : 'N');
330 EXPORT_SYMBOL(param_get_bool);
332 struct kernel_param_ops param_ops_bool = {
333 .set = param_set_bool,
334 .get = param_get_bool,
336 EXPORT_SYMBOL(param_ops_bool);
338 /* This one must be bool. */
339 int param_set_invbool(const char *val, const struct kernel_param *kp)
343 struct kernel_param dummy;
345 dummy.arg = &boolval;
346 dummy.flags = KPARAM_ISBOOL;
347 ret = param_set_bool(val, &dummy);
349 *(bool *)kp->arg = !boolval;
352 EXPORT_SYMBOL(param_set_invbool);
354 int param_get_invbool(char *buffer, const struct kernel_param *kp)
356 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
358 EXPORT_SYMBOL(param_get_invbool);
360 struct kernel_param_ops param_ops_invbool = {
361 .set = param_set_invbool,
362 .get = param_get_invbool,
364 EXPORT_SYMBOL(param_ops_invbool);
366 /* We break the rule and mangle the string. */
367 static int param_array(const char *name,
369 unsigned int min, unsigned int max,
370 void *elem, int elemsize,
371 int (*set)(const char *, const struct kernel_param *kp),
376 struct kernel_param kp;
379 /* Get the name right for errors. */
385 /* We expect a comma-separated list of values. */
390 printk(KERN_ERR "%s: can only take %i arguments\n",
394 len = strcspn(val, ",");
396 /* nul-terminate and parse */
398 ((char *)val)[len] = '\0';
399 BUG_ON(!mutex_is_locked(¶m_lock));
407 } while (save == ',');
410 printk(KERN_ERR "%s: needs at least %i arguments\n",
417 static int param_array_set(const char *val, const struct kernel_param *kp)
419 const struct kparam_array *arr = kp->arr;
420 unsigned int temp_num;
422 return param_array(kp->name, val, 1, arr->max, arr->elem,
423 arr->elemsize, arr->ops->set, kp->flags,
424 arr->num ?: &temp_num);
427 static int param_array_get(char *buffer, const struct kernel_param *kp)
430 const struct kparam_array *arr = kp->arr;
431 struct kernel_param p;
434 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
437 p.arg = arr->elem + arr->elemsize * i;
438 BUG_ON(!mutex_is_locked(¶m_lock));
439 ret = arr->ops->get(buffer + off, &p);
448 static void param_array_free(void *arg)
451 const struct kparam_array *arr = arg;
454 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
455 arr->ops->free(arr->elem + arr->elemsize * i);
458 struct kernel_param_ops param_array_ops = {
459 .set = param_array_set,
460 .get = param_array_get,
461 .free = param_array_free,
463 EXPORT_SYMBOL(param_array_ops);
465 int param_set_copystring(const char *val, const struct kernel_param *kp)
467 const struct kparam_string *kps = kp->str;
469 if (strlen(val)+1 > kps->maxlen) {
470 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
471 kp->name, kps->maxlen-1);
474 strcpy(kps->string, val);
477 EXPORT_SYMBOL(param_set_copystring);
479 int param_get_string(char *buffer, const struct kernel_param *kp)
481 const struct kparam_string *kps = kp->str;
482 return strlcpy(buffer, kps->string, kps->maxlen);
484 EXPORT_SYMBOL(param_get_string);
486 struct kernel_param_ops param_ops_string = {
487 .set = param_set_copystring,
488 .get = param_get_string,
490 EXPORT_SYMBOL(param_ops_string);
492 /* sysfs output in /sys/modules/XYZ/parameters/ */
493 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
494 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
496 extern struct kernel_param __start___param[], __stop___param[];
498 struct param_attribute
500 struct module_attribute mattr;
501 const struct kernel_param *param;
504 struct module_param_attrs
507 struct attribute_group grp;
508 struct param_attribute attrs[0];
512 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
514 static ssize_t param_attr_show(struct module_attribute *mattr,
515 struct module_kobject *mk, char *buf)
518 struct param_attribute *attribute = to_param_attr(mattr);
520 if (!attribute->param->ops->get)
523 mutex_lock(¶m_lock);
524 count = attribute->param->ops->get(buf, attribute->param);
525 mutex_unlock(¶m_lock);
533 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
534 static ssize_t param_attr_store(struct module_attribute *mattr,
535 struct module_kobject *km,
536 const char *buf, size_t len)
539 struct param_attribute *attribute = to_param_attr(mattr);
541 if (!attribute->param->ops->set)
544 mutex_lock(¶m_lock);
545 err = attribute->param->ops->set(buf, attribute->param);
546 mutex_unlock(¶m_lock);
553 #ifdef CONFIG_MODULES
556 #define __modinit __init
560 void __kernel_param_lock(void)
562 mutex_lock(¶m_lock);
564 EXPORT_SYMBOL(__kernel_param_lock);
566 void __kernel_param_unlock(void)
568 mutex_unlock(¶m_lock);
570 EXPORT_SYMBOL(__kernel_param_unlock);
573 * add_sysfs_param - add a parameter to sysfs
574 * @mk: struct module_kobject
575 * @kparam: the actual parameter definition to add to sysfs
576 * @name: name of parameter
578 * Create a kobject if for a (per-module) parameter if mp NULL, and
579 * create file in sysfs. Returns an error on out of memory. Always cleans up
580 * if there's an error.
582 static __modinit int add_sysfs_param(struct module_kobject *mk,
583 const struct kernel_param *kp,
586 struct module_param_attrs *new;
587 struct attribute **attrs;
590 /* We don't bother calling this with invisible parameters. */
598 attrs = mk->mp->grp.attrs;
602 new = krealloc(mk->mp,
603 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
610 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
616 /* Sysfs wants everything zeroed. */
617 memset(new, 0, sizeof(*new));
618 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
619 memset(&attrs[num], 0, sizeof(attrs[num]));
620 new->grp.name = "parameters";
621 new->grp.attrs = attrs;
623 /* Tack new one on the end. */
624 sysfs_attr_init(&new->attrs[num].mattr.attr);
625 new->attrs[num].param = kp;
626 new->attrs[num].mattr.show = param_attr_show;
627 new->attrs[num].mattr.store = param_attr_store;
628 new->attrs[num].mattr.attr.name = (char *)name;
629 new->attrs[num].mattr.attr.mode = kp->perm;
632 /* Fix up all the pointers, since krealloc can move us */
633 for (num = 0; num < new->num; num++)
634 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
635 new->grp.attrs[num] = NULL;
647 #ifdef CONFIG_MODULES
648 static void free_module_param_attrs(struct module_kobject *mk)
650 kfree(mk->mp->grp.attrs);
656 * module_param_sysfs_setup - setup sysfs support for one module
658 * @kparam: module parameters (array)
659 * @num_params: number of module parameters
661 * Adds sysfs entries for module parameters under
662 * /sys/module/[mod->name]/parameters/
664 int module_param_sysfs_setup(struct module *mod,
665 const struct kernel_param *kparam,
666 unsigned int num_params)
671 for (i = 0; i < num_params; i++) {
672 if (kparam[i].perm == 0)
674 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
683 /* Create the param group. */
684 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
686 free_module_param_attrs(&mod->mkobj);
691 * module_param_sysfs_remove - remove sysfs support for one module
694 * Remove sysfs entries for module parameters and the corresponding
697 void module_param_sysfs_remove(struct module *mod)
700 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
701 /* We are positive that no one is using any param
702 * attrs at this point. Deallocate immediately. */
703 free_module_param_attrs(&mod->mkobj);
708 void destroy_params(const struct kernel_param *params, unsigned num)
712 for (i = 0; i < num; i++)
713 if (params[i].ops->free)
714 params[i].ops->free(params[i].arg);
717 static struct module_kobject * __init locate_module_kobject(const char *name)
719 struct module_kobject *mk;
720 struct kobject *kobj;
723 kobj = kset_find_obj(module_kset, name);
725 mk = to_module_kobject(kobj);
727 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
730 mk->mod = THIS_MODULE;
731 mk->kobj.kset = module_kset;
732 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
734 #ifdef CONFIG_MODULES
736 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
739 kobject_put(&mk->kobj);
741 "Module '%s' failed add to sysfs, error number %d\n",
744 "The system will be unstable now.\n");
748 /* So that we hold reference in both cases. */
749 kobject_get(&mk->kobj);
755 static void __init kernel_add_sysfs_param(const char *name,
756 struct kernel_param *kparam,
757 unsigned int name_skip)
759 struct module_kobject *mk;
762 mk = locate_module_kobject(name);
766 /* We need to remove old parameters before adding more. */
768 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
770 /* These should not fail at boot. */
771 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
773 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
775 kobject_uevent(&mk->kobj, KOBJ_ADD);
776 kobject_put(&mk->kobj);
780 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
782 * Add module_parameters to sysfs for "modules" built into the kernel.
784 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
785 * "parameter" name is stored behind a dot in kernel_param->name. So,
786 * extract the "module" name for all built-in kernel_param-eters,
787 * and for all who have the same, call kernel_add_sysfs_param.
789 static void __init param_sysfs_builtin(void)
791 struct kernel_param *kp;
792 unsigned int name_len;
793 char modname[MODULE_NAME_LEN];
795 for (kp = __start___param; kp < __stop___param; kp++) {
801 dot = strchr(kp->name, '.');
803 /* This happens for core_param() */
804 strcpy(modname, "kernel");
807 name_len = dot - kp->name + 1;
808 strlcpy(modname, kp->name, name_len);
810 kernel_add_sysfs_param(modname, kp, name_len);
814 ssize_t __modver_version_show(struct module_attribute *mattr,
815 struct module_kobject *mk, char *buf)
817 struct module_version_attribute *vattr =
818 container_of(mattr, struct module_version_attribute, mattr);
820 return sprintf(buf, "%s\n", vattr->version);
823 extern const struct module_version_attribute *__start___modver[];
824 extern const struct module_version_attribute *__stop___modver[];
826 static void __init version_sysfs_builtin(void)
828 const struct module_version_attribute **p;
829 struct module_kobject *mk;
832 for (p = __start___modver; p < __stop___modver; p++) {
833 const struct module_version_attribute *vattr = *p;
835 mk = locate_module_kobject(vattr->module_name);
837 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
838 kobject_uevent(&mk->kobj, KOBJ_ADD);
839 kobject_put(&mk->kobj);
844 /* module-related sysfs stuff */
846 static ssize_t module_attr_show(struct kobject *kobj,
847 struct attribute *attr,
850 struct module_attribute *attribute;
851 struct module_kobject *mk;
854 attribute = to_module_attr(attr);
855 mk = to_module_kobject(kobj);
857 if (!attribute->show)
860 ret = attribute->show(attribute, mk, buf);
865 static ssize_t module_attr_store(struct kobject *kobj,
866 struct attribute *attr,
867 const char *buf, size_t len)
869 struct module_attribute *attribute;
870 struct module_kobject *mk;
873 attribute = to_module_attr(attr);
874 mk = to_module_kobject(kobj);
876 if (!attribute->store)
879 ret = attribute->store(attribute, mk, buf, len);
884 static const struct sysfs_ops module_sysfs_ops = {
885 .show = module_attr_show,
886 .store = module_attr_store,
889 static int uevent_filter(struct kset *kset, struct kobject *kobj)
891 struct kobj_type *ktype = get_ktype(kobj);
893 if (ktype == &module_ktype)
898 static const struct kset_uevent_ops module_uevent_ops = {
899 .filter = uevent_filter,
902 struct kset *module_kset;
903 int module_sysfs_initialized;
905 struct kobj_type module_ktype = {
906 .sysfs_ops = &module_sysfs_ops,
910 * param_sysfs_init - wrapper for built-in params support
912 static int __init param_sysfs_init(void)
914 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
916 printk(KERN_WARNING "%s (%d): error creating kset\n",
920 module_sysfs_initialized = 1;
922 version_sysfs_builtin();
923 param_sysfs_builtin();
927 subsys_initcall(param_sysfs_init);
929 #endif /* CONFIG_SYSFS */