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. */
106 if (!val && params[i].ops->set != param_set_bool
107 && params[i].ops->set != param_set_bint)
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 printk(KERN_WARNING "parse_args(): option '%s' enabled "
210 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
215 "%s: `%s' too large for parameter `%s'\n",
216 doing, val ?: "", param);
222 "%s: `%s' invalid for parameter `%s'\n",
223 doing, val ?: "", param);
232 /* Lazy bastard, eh? */
233 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
234 int param_set_##name(const char *val, const struct kernel_param *kp) \
239 ret = strtolfn(val, 0, &l); \
240 if (ret < 0 || ((type)l != l)) \
241 return ret < 0 ? ret : -EINVAL; \
242 *((type *)kp->arg) = l; \
245 int param_get_##name(char *buffer, const struct kernel_param *kp) \
247 return sprintf(buffer, format, *((type *)kp->arg)); \
249 struct kernel_param_ops param_ops_##name = { \
250 .set = param_set_##name, \
251 .get = param_get_##name, \
253 EXPORT_SYMBOL(param_set_##name); \
254 EXPORT_SYMBOL(param_get_##name); \
255 EXPORT_SYMBOL(param_ops_##name)
258 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
259 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
260 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
261 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
262 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
263 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
264 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
266 int param_set_charp(const char *val, const struct kernel_param *kp)
268 if (strlen(val) > 1024) {
269 printk(KERN_ERR "%s: string parameter too long\n",
274 maybe_kfree_parameter(*(char **)kp->arg);
276 /* This is a hack. We can't kmalloc in early boot, and we
277 * don't need to; this mangled commandline is preserved. */
278 if (slab_is_available()) {
279 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
280 if (!*(char **)kp->arg)
282 strcpy(*(char **)kp->arg, val);
284 *(const char **)kp->arg = val;
288 EXPORT_SYMBOL(param_set_charp);
290 int param_get_charp(char *buffer, const struct kernel_param *kp)
292 return sprintf(buffer, "%s", *((char **)kp->arg));
294 EXPORT_SYMBOL(param_get_charp);
296 static void param_free_charp(void *arg)
298 maybe_kfree_parameter(*((char **)arg));
301 struct kernel_param_ops param_ops_charp = {
302 .set = param_set_charp,
303 .get = param_get_charp,
304 .free = param_free_charp,
306 EXPORT_SYMBOL(param_ops_charp);
308 /* Actually could be a bool or an int, for historical reasons. */
309 int param_set_bool(const char *val, const struct kernel_param *kp)
311 /* No equals means "set"... */
314 /* One of =[yYnN01] */
315 return strtobool(val, kp->arg);
317 EXPORT_SYMBOL(param_set_bool);
319 int param_get_bool(char *buffer, const struct kernel_param *kp)
321 /* Y and N chosen as being relatively non-coder friendly */
322 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
324 EXPORT_SYMBOL(param_get_bool);
326 struct kernel_param_ops param_ops_bool = {
327 .set = param_set_bool,
328 .get = param_get_bool,
330 EXPORT_SYMBOL(param_ops_bool);
332 /* This one must be bool. */
333 int param_set_invbool(const char *val, const struct kernel_param *kp)
337 struct kernel_param dummy;
339 dummy.arg = &boolval;
340 ret = param_set_bool(val, &dummy);
342 *(bool *)kp->arg = !boolval;
345 EXPORT_SYMBOL(param_set_invbool);
347 int param_get_invbool(char *buffer, const struct kernel_param *kp)
349 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
351 EXPORT_SYMBOL(param_get_invbool);
353 struct kernel_param_ops param_ops_invbool = {
354 .set = param_set_invbool,
355 .get = param_get_invbool,
357 EXPORT_SYMBOL(param_ops_invbool);
359 int param_set_bint(const char *val, const struct kernel_param *kp)
361 struct kernel_param boolkp;
365 /* Match bool exactly, by re-using it. */
369 ret = param_set_bool(val, &boolkp);
374 EXPORT_SYMBOL(param_set_bint);
376 struct kernel_param_ops param_ops_bint = {
377 .set = param_set_bint,
378 .get = param_get_int,
380 EXPORT_SYMBOL(param_ops_bint);
382 /* We break the rule and mangle the string. */
383 static int param_array(const char *name,
385 unsigned int min, unsigned int max,
386 void *elem, int elemsize,
387 int (*set)(const char *, const struct kernel_param *kp),
392 struct kernel_param kp;
395 /* Get the name right for errors. */
401 /* We expect a comma-separated list of values. */
406 printk(KERN_ERR "%s: can only take %i arguments\n",
410 len = strcspn(val, ",");
412 /* nul-terminate and parse */
414 ((char *)val)[len] = '\0';
415 BUG_ON(!mutex_is_locked(¶m_lock));
423 } while (save == ',');
426 printk(KERN_ERR "%s: needs at least %i arguments\n",
433 static int param_array_set(const char *val, const struct kernel_param *kp)
435 const struct kparam_array *arr = kp->arr;
436 unsigned int temp_num;
438 return param_array(kp->name, val, 1, arr->max, arr->elem,
439 arr->elemsize, arr->ops->set, kp->level,
440 arr->num ?: &temp_num);
443 static int param_array_get(char *buffer, const struct kernel_param *kp)
446 const struct kparam_array *arr = kp->arr;
447 struct kernel_param p;
450 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
453 p.arg = arr->elem + arr->elemsize * i;
454 BUG_ON(!mutex_is_locked(¶m_lock));
455 ret = arr->ops->get(buffer + off, &p);
464 static void param_array_free(void *arg)
467 const struct kparam_array *arr = arg;
470 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
471 arr->ops->free(arr->elem + arr->elemsize * i);
474 struct kernel_param_ops param_array_ops = {
475 .set = param_array_set,
476 .get = param_array_get,
477 .free = param_array_free,
479 EXPORT_SYMBOL(param_array_ops);
481 int param_set_copystring(const char *val, const struct kernel_param *kp)
483 const struct kparam_string *kps = kp->str;
485 if (strlen(val)+1 > kps->maxlen) {
486 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
487 kp->name, kps->maxlen-1);
490 strcpy(kps->string, val);
493 EXPORT_SYMBOL(param_set_copystring);
495 int param_get_string(char *buffer, const struct kernel_param *kp)
497 const struct kparam_string *kps = kp->str;
498 return strlcpy(buffer, kps->string, kps->maxlen);
500 EXPORT_SYMBOL(param_get_string);
502 struct kernel_param_ops param_ops_string = {
503 .set = param_set_copystring,
504 .get = param_get_string,
506 EXPORT_SYMBOL(param_ops_string);
508 /* sysfs output in /sys/modules/XYZ/parameters/ */
509 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
510 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
512 extern struct kernel_param __start___param[], __stop___param[];
514 struct param_attribute
516 struct module_attribute mattr;
517 const struct kernel_param *param;
520 struct module_param_attrs
523 struct attribute_group grp;
524 struct param_attribute attrs[0];
528 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
530 static ssize_t param_attr_show(struct module_attribute *mattr,
531 struct module_kobject *mk, char *buf)
534 struct param_attribute *attribute = to_param_attr(mattr);
536 if (!attribute->param->ops->get)
539 mutex_lock(¶m_lock);
540 count = attribute->param->ops->get(buf, attribute->param);
541 mutex_unlock(¶m_lock);
549 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
550 static ssize_t param_attr_store(struct module_attribute *mattr,
551 struct module_kobject *km,
552 const char *buf, size_t len)
555 struct param_attribute *attribute = to_param_attr(mattr);
557 if (!attribute->param->ops->set)
560 mutex_lock(¶m_lock);
561 err = attribute->param->ops->set(buf, attribute->param);
562 mutex_unlock(¶m_lock);
569 #ifdef CONFIG_MODULES
572 #define __modinit __init
576 void __kernel_param_lock(void)
578 mutex_lock(¶m_lock);
580 EXPORT_SYMBOL(__kernel_param_lock);
582 void __kernel_param_unlock(void)
584 mutex_unlock(¶m_lock);
586 EXPORT_SYMBOL(__kernel_param_unlock);
589 * add_sysfs_param - add a parameter to sysfs
590 * @mk: struct module_kobject
591 * @kparam: the actual parameter definition to add to sysfs
592 * @name: name of parameter
594 * Create a kobject if for a (per-module) parameter if mp NULL, and
595 * create file in sysfs. Returns an error on out of memory. Always cleans up
596 * if there's an error.
598 static __modinit int add_sysfs_param(struct module_kobject *mk,
599 const struct kernel_param *kp,
602 struct module_param_attrs *new;
603 struct attribute **attrs;
606 /* We don't bother calling this with invisible parameters. */
614 attrs = mk->mp->grp.attrs;
618 new = krealloc(mk->mp,
619 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
626 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
632 /* Sysfs wants everything zeroed. */
633 memset(new, 0, sizeof(*new));
634 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
635 memset(&attrs[num], 0, sizeof(attrs[num]));
636 new->grp.name = "parameters";
637 new->grp.attrs = attrs;
639 /* Tack new one on the end. */
640 sysfs_attr_init(&new->attrs[num].mattr.attr);
641 new->attrs[num].param = kp;
642 new->attrs[num].mattr.show = param_attr_show;
643 new->attrs[num].mattr.store = param_attr_store;
644 new->attrs[num].mattr.attr.name = (char *)name;
645 new->attrs[num].mattr.attr.mode = kp->perm;
648 /* Fix up all the pointers, since krealloc can move us */
649 for (num = 0; num < new->num; num++)
650 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
651 new->grp.attrs[num] = NULL;
663 #ifdef CONFIG_MODULES
664 static void free_module_param_attrs(struct module_kobject *mk)
666 kfree(mk->mp->grp.attrs);
672 * module_param_sysfs_setup - setup sysfs support for one module
674 * @kparam: module parameters (array)
675 * @num_params: number of module parameters
677 * Adds sysfs entries for module parameters under
678 * /sys/module/[mod->name]/parameters/
680 int module_param_sysfs_setup(struct module *mod,
681 const struct kernel_param *kparam,
682 unsigned int num_params)
687 for (i = 0; i < num_params; i++) {
688 if (kparam[i].perm == 0)
690 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
699 /* Create the param group. */
700 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
702 free_module_param_attrs(&mod->mkobj);
707 * module_param_sysfs_remove - remove sysfs support for one module
710 * Remove sysfs entries for module parameters and the corresponding
713 void module_param_sysfs_remove(struct module *mod)
716 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
717 /* We are positive that no one is using any param
718 * attrs at this point. Deallocate immediately. */
719 free_module_param_attrs(&mod->mkobj);
724 void destroy_params(const struct kernel_param *params, unsigned num)
728 for (i = 0; i < num; i++)
729 if (params[i].ops->free)
730 params[i].ops->free(params[i].arg);
733 static struct module_kobject * __init locate_module_kobject(const char *name)
735 struct module_kobject *mk;
736 struct kobject *kobj;
739 kobj = kset_find_obj(module_kset, name);
741 mk = to_module_kobject(kobj);
743 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
746 mk->mod = THIS_MODULE;
747 mk->kobj.kset = module_kset;
748 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
750 #ifdef CONFIG_MODULES
752 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
755 kobject_put(&mk->kobj);
757 "Module '%s' failed add to sysfs, error number %d\n",
760 "The system will be unstable now.\n");
764 /* So that we hold reference in both cases. */
765 kobject_get(&mk->kobj);
771 static void __init kernel_add_sysfs_param(const char *name,
772 struct kernel_param *kparam,
773 unsigned int name_skip)
775 struct module_kobject *mk;
778 mk = locate_module_kobject(name);
782 /* We need to remove old parameters before adding more. */
784 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
786 /* These should not fail at boot. */
787 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
789 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
791 kobject_uevent(&mk->kobj, KOBJ_ADD);
792 kobject_put(&mk->kobj);
796 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
798 * Add module_parameters to sysfs for "modules" built into the kernel.
800 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
801 * "parameter" name is stored behind a dot in kernel_param->name. So,
802 * extract the "module" name for all built-in kernel_param-eters,
803 * and for all who have the same, call kernel_add_sysfs_param.
805 static void __init param_sysfs_builtin(void)
807 struct kernel_param *kp;
808 unsigned int name_len;
809 char modname[MODULE_NAME_LEN];
811 for (kp = __start___param; kp < __stop___param; kp++) {
817 dot = strchr(kp->name, '.');
819 /* This happens for core_param() */
820 strcpy(modname, "kernel");
823 name_len = dot - kp->name + 1;
824 strlcpy(modname, kp->name, name_len);
826 kernel_add_sysfs_param(modname, kp, name_len);
830 ssize_t __modver_version_show(struct module_attribute *mattr,
831 struct module_kobject *mk, char *buf)
833 struct module_version_attribute *vattr =
834 container_of(mattr, struct module_version_attribute, mattr);
836 return sprintf(buf, "%s\n", vattr->version);
839 extern const struct module_version_attribute *__start___modver[];
840 extern const struct module_version_attribute *__stop___modver[];
842 static void __init version_sysfs_builtin(void)
844 const struct module_version_attribute **p;
845 struct module_kobject *mk;
848 for (p = __start___modver; p < __stop___modver; p++) {
849 const struct module_version_attribute *vattr = *p;
851 mk = locate_module_kobject(vattr->module_name);
853 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
854 kobject_uevent(&mk->kobj, KOBJ_ADD);
855 kobject_put(&mk->kobj);
860 /* module-related sysfs stuff */
862 static ssize_t module_attr_show(struct kobject *kobj,
863 struct attribute *attr,
866 struct module_attribute *attribute;
867 struct module_kobject *mk;
870 attribute = to_module_attr(attr);
871 mk = to_module_kobject(kobj);
873 if (!attribute->show)
876 ret = attribute->show(attribute, mk, buf);
881 static ssize_t module_attr_store(struct kobject *kobj,
882 struct attribute *attr,
883 const char *buf, size_t len)
885 struct module_attribute *attribute;
886 struct module_kobject *mk;
889 attribute = to_module_attr(attr);
890 mk = to_module_kobject(kobj);
892 if (!attribute->store)
895 ret = attribute->store(attribute, mk, buf, len);
900 static const struct sysfs_ops module_sysfs_ops = {
901 .show = module_attr_show,
902 .store = module_attr_store,
905 static int uevent_filter(struct kset *kset, struct kobject *kobj)
907 struct kobj_type *ktype = get_ktype(kobj);
909 if (ktype == &module_ktype)
914 static const struct kset_uevent_ops module_uevent_ops = {
915 .filter = uevent_filter,
918 struct kset *module_kset;
919 int module_sysfs_initialized;
921 struct kobj_type module_ktype = {
922 .sysfs_ops = &module_sysfs_ops,
926 * param_sysfs_init - wrapper for built-in params support
928 static int __init param_sysfs_init(void)
930 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
932 printk(KERN_WARNING "%s (%d): error creating kset\n",
936 module_sysfs_initialized = 1;
938 version_sysfs_builtin();
939 param_sysfs_builtin();
943 subsys_initcall(param_sysfs_init);
945 #endif /* CONFIG_SYSFS */