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/moduleparam.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>
31 #define DEBUGP(fmt, a...)
34 /* Protects all parameters, and incidentally kmalloced_param list. */
35 static DEFINE_MUTEX(param_lock);
37 /* This just allows us to keep track of which parameters are kmalloced. */
38 struct kmalloced_param {
39 struct list_head list;
42 static LIST_HEAD(kmalloced_params);
44 static void *kmalloc_parameter(unsigned int size)
46 struct kmalloced_param *p;
48 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
52 list_add(&p->list, &kmalloced_params);
56 /* Does nothing if parameter wasn't kmalloced above. */
57 static void maybe_kfree_parameter(void *param)
59 struct kmalloced_param *p;
61 list_for_each_entry(p, &kmalloced_params, list) {
62 if (p->val == param) {
70 static inline char dash2underscore(char c)
77 static inline int parameq(const char *input, const char *paramname)
80 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
86 static int parse_one(char *param,
88 const struct kernel_param *params,
90 int (*handle_arg)(char *param, char *val, int known))
96 for (i = 0; i < num_params; i++) {
97 if (parameq(param, params[i].name)) {
98 /* Noone handled NULL, so do it here. */
99 if (!val && params[i].ops->set != param_set_bool)
103 DEBUGP("Valid argument: calling %p\n",
105 ret = handle_arg(param, val, 1);
109 DEBUGP("They are equal! Calling %p\n",
111 mutex_lock(¶m_lock);
112 err = params[i].ops->set(val, ¶ms[i]);
113 mutex_unlock(¶m_lock);
119 DEBUGP("Unknown argument: calling %p\n", handle_arg);
120 return handle_arg(param, val, 0);
123 DEBUGP("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 *name,
182 const struct kernel_param *params,
184 int (*handle_arg)(char *param, char *val, int arg))
188 DEBUGP("Parsing ARGS: %s\n", args);
190 /* Chew leading spaces */
191 args = skip_spaces(args);
195 int irq_was_disabled;
197 args = next_arg(args, ¶m, &val);
198 irq_was_disabled = irqs_disabled();
199 ret = parse_one(param, val, params, num, handle_arg);
200 if (irq_was_disabled && !irqs_disabled()) {
201 printk(KERN_WARNING "parse_args(): option '%s' enabled "
206 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
211 "%s: `%s' too large for parameter `%s'\n",
212 name, val ?: "", param);
218 "%s: `%s' invalid for parameter `%s'\n",
219 name, val ?: "", param);
228 /* Lazy bastard, eh? */
229 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
230 int param_set_##name(const char *val, const struct kernel_param *kp) \
235 ret = strtolfn(val, 0, &l); \
236 if (ret == -EINVAL || ((type)l != l)) \
238 *((type *)kp->arg) = l; \
241 int param_get_##name(char *buffer, const struct kernel_param *kp) \
243 return sprintf(buffer, format, *((type *)kp->arg)); \
245 struct kernel_param_ops param_ops_##name = { \
246 .set = param_set_##name, \
247 .get = param_get_##name, \
249 EXPORT_SYMBOL(param_set_##name); \
250 EXPORT_SYMBOL(param_get_##name); \
251 EXPORT_SYMBOL(param_ops_##name)
254 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
255 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
256 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
257 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
258 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
259 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
260 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
262 int param_set_charp(const char *val, const struct kernel_param *kp)
264 if (strlen(val) > 1024) {
265 printk(KERN_ERR "%s: string parameter too long\n",
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)
309 /* No equals means "set"... */
312 /* One of =[yYnN01] */
314 case 'y': case 'Y': case '1':
317 case 'n': case 'N': case '0':
324 if (kp->flags & KPARAM_ISBOOL)
325 *(bool *)kp->arg = v;
330 EXPORT_SYMBOL(param_set_bool);
332 int param_get_bool(char *buffer, const struct kernel_param *kp)
335 if (kp->flags & KPARAM_ISBOOL)
336 val = *(bool *)kp->arg;
338 val = *(int *)kp->arg;
340 /* Y and N chosen as being relatively non-coder friendly */
341 return sprintf(buffer, "%c", val ? 'Y' : 'N');
343 EXPORT_SYMBOL(param_get_bool);
345 struct kernel_param_ops param_ops_bool = {
346 .set = param_set_bool,
347 .get = param_get_bool,
349 EXPORT_SYMBOL(param_ops_bool);
351 /* This one must be bool. */
352 int param_set_invbool(const char *val, const struct kernel_param *kp)
356 struct kernel_param dummy;
358 dummy.arg = &boolval;
359 dummy.flags = KPARAM_ISBOOL;
360 ret = param_set_bool(val, &dummy);
362 *(bool *)kp->arg = !boolval;
365 EXPORT_SYMBOL(param_set_invbool);
367 int param_get_invbool(char *buffer, const struct kernel_param *kp)
369 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
371 EXPORT_SYMBOL(param_get_invbool);
373 struct kernel_param_ops param_ops_invbool = {
374 .set = param_set_invbool,
375 .get = param_get_invbool,
377 EXPORT_SYMBOL(param_ops_invbool);
379 /* We break the rule and mangle the string. */
380 static int param_array(const char *name,
382 unsigned int min, unsigned int max,
383 void *elem, int elemsize,
384 int (*set)(const char *, const struct kernel_param *kp),
389 struct kernel_param kp;
392 /* Get the name right for errors. */
398 /* We expect a comma-separated list of values. */
403 printk(KERN_ERR "%s: can only take %i arguments\n",
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 printk(KERN_ERR "%s: needs at least %i arguments\n",
430 static int param_array_set(const char *val, const struct kernel_param *kp)
432 const struct kparam_array *arr = kp->arr;
433 unsigned int temp_num;
435 return param_array(kp->name, val, 1, arr->max, arr->elem,
436 arr->elemsize, arr->ops->set, kp->flags,
437 arr->num ?: &temp_num);
440 static int param_array_get(char *buffer, const struct kernel_param *kp)
443 const struct kparam_array *arr = kp->arr;
444 struct kernel_param p;
447 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
450 p.arg = arr->elem + arr->elemsize * i;
451 BUG_ON(!mutex_is_locked(¶m_lock));
452 ret = arr->ops->get(buffer + off, &p);
461 static void param_array_free(void *arg)
464 const struct kparam_array *arr = arg;
467 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
468 arr->ops->free(arr->elem + arr->elemsize * i);
471 struct kernel_param_ops param_array_ops = {
472 .set = param_array_set,
473 .get = param_array_get,
474 .free = param_array_free,
476 EXPORT_SYMBOL(param_array_ops);
478 int param_set_copystring(const char *val, const struct kernel_param *kp)
480 const struct kparam_string *kps = kp->str;
482 if (strlen(val)+1 > kps->maxlen) {
483 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
484 kp->name, kps->maxlen-1);
487 strcpy(kps->string, val);
490 EXPORT_SYMBOL(param_set_copystring);
492 int param_get_string(char *buffer, const struct kernel_param *kp)
494 const struct kparam_string *kps = kp->str;
495 return strlcpy(buffer, kps->string, kps->maxlen);
497 EXPORT_SYMBOL(param_get_string);
499 struct kernel_param_ops param_ops_string = {
500 .set = param_set_copystring,
501 .get = param_get_string,
503 EXPORT_SYMBOL(param_ops_string);
505 /* sysfs output in /sys/modules/XYZ/parameters/ */
506 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
507 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
509 extern struct kernel_param __start___param[], __stop___param[];
511 struct param_attribute
513 struct module_attribute mattr;
514 const struct kernel_param *param;
517 struct module_param_attrs
520 struct attribute_group grp;
521 struct param_attribute attrs[0];
525 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
527 static ssize_t param_attr_show(struct module_attribute *mattr,
528 struct module *mod, char *buf)
531 struct param_attribute *attribute = to_param_attr(mattr);
533 if (!attribute->param->ops->get)
536 mutex_lock(¶m_lock);
537 count = attribute->param->ops->get(buf, attribute->param);
538 mutex_unlock(¶m_lock);
546 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
547 static ssize_t param_attr_store(struct module_attribute *mattr,
548 struct module *owner,
549 const char *buf, size_t len)
552 struct param_attribute *attribute = to_param_attr(mattr);
554 if (!attribute->param->ops->set)
557 mutex_lock(¶m_lock);
558 err = attribute->param->ops->set(buf, attribute->param);
559 mutex_unlock(¶m_lock);
566 #ifdef CONFIG_MODULES
569 #define __modinit __init
573 void __kernel_param_lock(void)
575 mutex_lock(¶m_lock);
577 EXPORT_SYMBOL(__kernel_param_lock);
579 void __kernel_param_unlock(void)
581 mutex_unlock(¶m_lock);
583 EXPORT_SYMBOL(__kernel_param_unlock);
586 * add_sysfs_param - add a parameter to sysfs
587 * @mk: struct module_kobject
588 * @kparam: the actual parameter definition to add to sysfs
589 * @name: name of parameter
591 * Create a kobject if for a (per-module) parameter if mp NULL, and
592 * create file in sysfs. Returns an error on out of memory. Always cleans up
593 * if there's an error.
595 static __modinit int add_sysfs_param(struct module_kobject *mk,
596 const struct kernel_param *kp,
599 struct module_param_attrs *new;
600 struct attribute **attrs;
603 /* We don't bother calling this with invisible parameters. */
611 attrs = mk->mp->grp.attrs;
615 new = krealloc(mk->mp,
616 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
623 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
629 /* Sysfs wants everything zeroed. */
630 memset(new, 0, sizeof(*new));
631 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
632 memset(&attrs[num], 0, sizeof(attrs[num]));
633 new->grp.name = "parameters";
634 new->grp.attrs = attrs;
636 /* Tack new one on the end. */
637 sysfs_attr_init(&new->attrs[num].mattr.attr);
638 new->attrs[num].param = kp;
639 new->attrs[num].mattr.show = param_attr_show;
640 new->attrs[num].mattr.store = param_attr_store;
641 new->attrs[num].mattr.attr.name = (char *)name;
642 new->attrs[num].mattr.attr.mode = kp->perm;
645 /* Fix up all the pointers, since krealloc can move us */
646 for (num = 0; num < new->num; num++)
647 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
648 new->grp.attrs[num] = NULL;
660 #ifdef CONFIG_MODULES
661 static void free_module_param_attrs(struct module_kobject *mk)
663 kfree(mk->mp->grp.attrs);
669 * module_param_sysfs_setup - setup sysfs support for one module
671 * @kparam: module parameters (array)
672 * @num_params: number of module parameters
674 * Adds sysfs entries for module parameters under
675 * /sys/module/[mod->name]/parameters/
677 int module_param_sysfs_setup(struct module *mod,
678 const struct kernel_param *kparam,
679 unsigned int num_params)
684 for (i = 0; i < num_params; i++) {
685 if (kparam[i].perm == 0)
687 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
696 /* Create the param group. */
697 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
699 free_module_param_attrs(&mod->mkobj);
704 * module_param_sysfs_remove - remove sysfs support for one module
707 * Remove sysfs entries for module parameters and the corresponding
710 void module_param_sysfs_remove(struct module *mod)
713 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
714 /* We are positive that no one is using any param
715 * attrs at this point. Deallocate immediately. */
716 free_module_param_attrs(&mod->mkobj);
721 void destroy_params(const struct kernel_param *params, unsigned num)
725 for (i = 0; i < num; i++)
726 if (params[i].ops->free)
727 params[i].ops->free(params[i].arg);
730 static struct module_kobject * __init locate_module_kobject(const char *name)
732 struct module_kobject *mk;
733 struct kobject *kobj;
736 kobj = kset_find_obj(module_kset, name);
738 mk = to_module_kobject(kobj);
740 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
743 mk->mod = THIS_MODULE;
744 mk->kobj.kset = module_kset;
745 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
748 kobject_put(&mk->kobj);
750 "Module '%s' failed add to sysfs, error number %d\n",
753 "The system will be unstable now.\n");
757 /* So that we hold reference in both cases. */
758 kobject_get(&mk->kobj);
764 static void __init kernel_add_sysfs_param(const char *name,
765 struct kernel_param *kparam,
766 unsigned int name_skip)
768 struct module_kobject *mk;
771 mk = locate_module_kobject(name);
775 /* We need to remove old parameters before adding more. */
777 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
779 /* These should not fail at boot. */
780 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
782 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
784 kobject_uevent(&mk->kobj, KOBJ_ADD);
785 kobject_put(&mk->kobj);
789 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
791 * Add module_parameters to sysfs for "modules" built into the kernel.
793 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
794 * "parameter" name is stored behind a dot in kernel_param->name. So,
795 * extract the "module" name for all built-in kernel_param-eters,
796 * and for all who have the same, call kernel_add_sysfs_param.
798 static void __init param_sysfs_builtin(void)
800 struct kernel_param *kp;
801 unsigned int name_len;
802 char modname[MODULE_NAME_LEN];
804 for (kp = __start___param; kp < __stop___param; kp++) {
810 dot = strchr(kp->name, '.');
812 /* This happens for core_param() */
813 strcpy(modname, "kernel");
816 name_len = dot - kp->name + 1;
817 strlcpy(modname, kp->name, name_len);
819 kernel_add_sysfs_param(modname, kp, name_len);
823 ssize_t __modver_version_show(struct module_attribute *mattr,
824 struct module *mod, char *buf)
826 struct module_version_attribute *vattr =
827 container_of(mattr, struct module_version_attribute, mattr);
829 return sprintf(buf, "%s\n", vattr->version);
832 extern struct module_version_attribute __start___modver[], __stop___modver[];
834 static void __init version_sysfs_builtin(void)
836 const struct module_version_attribute *vattr;
837 struct module_kobject *mk;
840 for (vattr = __start___modver; vattr < __stop___modver; vattr++) {
841 mk = locate_module_kobject(vattr->module_name);
843 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
844 kobject_uevent(&mk->kobj, KOBJ_ADD);
845 kobject_put(&mk->kobj);
850 /* module-related sysfs stuff */
852 static ssize_t module_attr_show(struct kobject *kobj,
853 struct attribute *attr,
856 struct module_attribute *attribute;
857 struct module_kobject *mk;
860 attribute = to_module_attr(attr);
861 mk = to_module_kobject(kobj);
863 if (!attribute->show)
866 ret = attribute->show(attribute, mk->mod, buf);
871 static ssize_t module_attr_store(struct kobject *kobj,
872 struct attribute *attr,
873 const char *buf, size_t len)
875 struct module_attribute *attribute;
876 struct module_kobject *mk;
879 attribute = to_module_attr(attr);
880 mk = to_module_kobject(kobj);
882 if (!attribute->store)
885 ret = attribute->store(attribute, mk->mod, buf, len);
890 static const struct sysfs_ops module_sysfs_ops = {
891 .show = module_attr_show,
892 .store = module_attr_store,
895 static int uevent_filter(struct kset *kset, struct kobject *kobj)
897 struct kobj_type *ktype = get_ktype(kobj);
899 if (ktype == &module_ktype)
904 static const struct kset_uevent_ops module_uevent_ops = {
905 .filter = uevent_filter,
908 struct kset *module_kset;
909 int module_sysfs_initialized;
911 struct kobj_type module_ktype = {
912 .sysfs_ops = &module_sysfs_ops,
916 * param_sysfs_init - wrapper for built-in params support
918 static int __init param_sysfs_init(void)
920 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
922 printk(KERN_WARNING "%s (%d): error creating kset\n",
926 module_sysfs_initialized = 1;
928 version_sysfs_builtin();
929 param_sysfs_builtin();
933 subsys_initcall(param_sysfs_init);
935 #endif /* CONFIG_SYSFS */