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 char *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);
202 if (!val && strcmp(param, "--") == 0)
204 irq_was_disabled = irqs_disabled();
205 ret = parse_one(param, val, doing, params, num,
206 min_level, max_level, unknown);
207 if (irq_was_disabled && !irqs_disabled())
208 pr_warn("%s: option '%s' enabled irq's!\n",
213 pr_err("%s: Unknown parameter `%s'\n", doing, param);
216 pr_err("%s: `%s' too large for parameter `%s'\n",
217 doing, val ?: "", param);
222 pr_err("%s: `%s' invalid for parameter `%s'\n",
223 doing, val ?: "", param);
232 /* Lazy bastard, eh? */
233 #define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
234 int param_set_##name(const char *val, const struct kernel_param *kp) \
236 return strtolfn(val, 0, (type *)kp->arg); \
238 int param_get_##name(char *buffer, const struct kernel_param *kp) \
240 return scnprintf(buffer, PAGE_SIZE, format, \
241 *((type *)kp->arg)); \
243 struct kernel_param_ops param_ops_##name = { \
244 .set = param_set_##name, \
245 .get = param_get_##name, \
247 EXPORT_SYMBOL(param_set_##name); \
248 EXPORT_SYMBOL(param_get_##name); \
249 EXPORT_SYMBOL(param_ops_##name)
252 STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
253 STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
254 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
255 STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
256 STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
257 STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
258 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
260 int param_set_charp(const char *val, const struct kernel_param *kp)
262 if (strlen(val) > 1024) {
263 pr_err("%s: string parameter too long\n", kp->name);
267 maybe_kfree_parameter(*(char **)kp->arg);
269 /* This is a hack. We can't kmalloc in early boot, and we
270 * don't need to; this mangled commandline is preserved. */
271 if (slab_is_available()) {
272 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
273 if (!*(char **)kp->arg)
275 strcpy(*(char **)kp->arg, val);
277 *(const char **)kp->arg = val;
281 EXPORT_SYMBOL(param_set_charp);
283 int param_get_charp(char *buffer, const struct kernel_param *kp)
285 return scnprintf(buffer, PAGE_SIZE, "%s", *((char **)kp->arg));
287 EXPORT_SYMBOL(param_get_charp);
289 static void param_free_charp(void *arg)
291 maybe_kfree_parameter(*((char **)arg));
294 struct kernel_param_ops param_ops_charp = {
295 .set = param_set_charp,
296 .get = param_get_charp,
297 .free = param_free_charp,
299 EXPORT_SYMBOL(param_ops_charp);
301 /* Actually could be a bool or an int, for historical reasons. */
302 int param_set_bool(const char *val, const struct kernel_param *kp)
304 /* No equals means "set"... */
307 /* One of =[yYnN01] */
308 return strtobool(val, kp->arg);
310 EXPORT_SYMBOL(param_set_bool);
312 int param_get_bool(char *buffer, const struct kernel_param *kp)
314 /* Y and N chosen as being relatively non-coder friendly */
315 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
317 EXPORT_SYMBOL(param_get_bool);
319 struct kernel_param_ops param_ops_bool = {
320 .flags = KERNEL_PARAM_FL_NOARG,
321 .set = param_set_bool,
322 .get = param_get_bool,
324 EXPORT_SYMBOL(param_ops_bool);
326 /* This one must be bool. */
327 int param_set_invbool(const char *val, const struct kernel_param *kp)
331 struct kernel_param dummy;
333 dummy.arg = &boolval;
334 ret = param_set_bool(val, &dummy);
336 *(bool *)kp->arg = !boolval;
339 EXPORT_SYMBOL(param_set_invbool);
341 int param_get_invbool(char *buffer, const struct kernel_param *kp)
343 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
345 EXPORT_SYMBOL(param_get_invbool);
347 struct kernel_param_ops param_ops_invbool = {
348 .set = param_set_invbool,
349 .get = param_get_invbool,
351 EXPORT_SYMBOL(param_ops_invbool);
353 int param_set_bint(const char *val, const struct kernel_param *kp)
355 struct kernel_param boolkp;
359 /* Match bool exactly, by re-using it. */
363 ret = param_set_bool(val, &boolkp);
368 EXPORT_SYMBOL(param_set_bint);
370 struct kernel_param_ops param_ops_bint = {
371 .flags = KERNEL_PARAM_FL_NOARG,
372 .set = param_set_bint,
373 .get = param_get_int,
375 EXPORT_SYMBOL(param_ops_bint);
377 /* We break the rule and mangle the string. */
378 static int param_array(const char *name,
380 unsigned int min, unsigned int max,
381 void *elem, int elemsize,
382 int (*set)(const char *, const struct kernel_param *kp),
387 struct kernel_param kp;
390 /* Get the name right for errors. */
396 /* We expect a comma-separated list of values. */
401 pr_err("%s: can only take %i arguments\n", name, max);
404 len = strcspn(val, ",");
406 /* nul-terminate and parse */
408 ((char *)val)[len] = '\0';
409 BUG_ON(!mutex_is_locked(¶m_lock));
417 } while (save == ',');
420 pr_err("%s: needs at least %i arguments\n", name, min);
426 static int param_array_set(const char *val, const struct kernel_param *kp)
428 const struct kparam_array *arr = kp->arr;
429 unsigned int temp_num;
431 return param_array(kp->name, val, 1, arr->max, arr->elem,
432 arr->elemsize, arr->ops->set, kp->level,
433 arr->num ?: &temp_num);
436 static int param_array_get(char *buffer, const struct kernel_param *kp)
439 const struct kparam_array *arr = kp->arr;
440 struct kernel_param p;
443 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
446 p.arg = arr->elem + arr->elemsize * i;
447 BUG_ON(!mutex_is_locked(¶m_lock));
448 ret = arr->ops->get(buffer + off, &p);
457 static void param_array_free(void *arg)
460 const struct kparam_array *arr = arg;
463 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
464 arr->ops->free(arr->elem + arr->elemsize * i);
467 struct kernel_param_ops param_array_ops = {
468 .set = param_array_set,
469 .get = param_array_get,
470 .free = param_array_free,
472 EXPORT_SYMBOL(param_array_ops);
474 int param_set_copystring(const char *val, const struct kernel_param *kp)
476 const struct kparam_string *kps = kp->str;
478 if (strlen(val)+1 > kps->maxlen) {
479 pr_err("%s: string doesn't fit in %u chars.\n",
480 kp->name, kps->maxlen-1);
483 strcpy(kps->string, val);
486 EXPORT_SYMBOL(param_set_copystring);
488 int param_get_string(char *buffer, const struct kernel_param *kp)
490 const struct kparam_string *kps = kp->str;
491 return strlcpy(buffer, kps->string, kps->maxlen);
493 EXPORT_SYMBOL(param_get_string);
495 struct kernel_param_ops param_ops_string = {
496 .set = param_set_copystring,
497 .get = param_get_string,
499 EXPORT_SYMBOL(param_ops_string);
501 /* sysfs output in /sys/modules/XYZ/parameters/ */
502 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
503 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
505 extern struct kernel_param __start___param[], __stop___param[];
507 struct param_attribute
509 struct module_attribute mattr;
510 const struct kernel_param *param;
513 struct module_param_attrs
516 struct attribute_group grp;
517 struct param_attribute attrs[0];
521 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
523 static ssize_t param_attr_show(struct module_attribute *mattr,
524 struct module_kobject *mk, char *buf)
527 struct param_attribute *attribute = to_param_attr(mattr);
529 if (!attribute->param->ops->get)
532 mutex_lock(¶m_lock);
533 count = attribute->param->ops->get(buf, attribute->param);
534 mutex_unlock(¶m_lock);
542 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
543 static ssize_t param_attr_store(struct module_attribute *mattr,
544 struct module_kobject *km,
545 const char *buf, size_t len)
548 struct param_attribute *attribute = to_param_attr(mattr);
550 if (!attribute->param->ops->set)
553 mutex_lock(¶m_lock);
554 err = attribute->param->ops->set(buf, attribute->param);
555 mutex_unlock(¶m_lock);
562 #ifdef CONFIG_MODULES
565 #define __modinit __init
569 void __kernel_param_lock(void)
571 mutex_lock(¶m_lock);
573 EXPORT_SYMBOL(__kernel_param_lock);
575 void __kernel_param_unlock(void)
577 mutex_unlock(¶m_lock);
579 EXPORT_SYMBOL(__kernel_param_unlock);
582 * add_sysfs_param - add a parameter to sysfs
583 * @mk: struct module_kobject
584 * @kparam: the actual parameter definition to add to sysfs
585 * @name: name of parameter
587 * Create a kobject if for a (per-module) parameter if mp NULL, and
588 * create file in sysfs. Returns an error on out of memory. Always cleans up
589 * if there's an error.
591 static __modinit int add_sysfs_param(struct module_kobject *mk,
592 const struct kernel_param *kp,
595 struct module_param_attrs *new;
596 struct attribute **attrs;
599 /* We don't bother calling this with invisible parameters. */
607 attrs = mk->mp->grp.attrs;
611 new = krealloc(mk->mp,
612 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
619 /* Despite looking like the typical realloc() bug, this is safe.
620 * We *want* the old 'attrs' to be freed either way, and we'll store
621 * the new one in the success case. */
622 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
628 /* Sysfs wants everything zeroed. */
629 memset(new, 0, sizeof(*new));
630 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
631 memset(&attrs[num], 0, sizeof(attrs[num]));
632 new->grp.name = "parameters";
633 new->grp.attrs = attrs;
635 /* Tack new one on the end. */
636 sysfs_attr_init(&new->attrs[num].mattr.attr);
637 new->attrs[num].param = kp;
638 new->attrs[num].mattr.show = param_attr_show;
639 new->attrs[num].mattr.store = param_attr_store;
640 new->attrs[num].mattr.attr.name = (char *)name;
641 new->attrs[num].mattr.attr.mode = kp->perm;
644 /* Fix up all the pointers, since krealloc can move us */
645 for (num = 0; num < new->num; num++)
646 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
647 new->grp.attrs[num] = NULL;
659 #ifdef CONFIG_MODULES
660 static void free_module_param_attrs(struct module_kobject *mk)
662 kfree(mk->mp->grp.attrs);
668 * module_param_sysfs_setup - setup sysfs support for one module
670 * @kparam: module parameters (array)
671 * @num_params: number of module parameters
673 * Adds sysfs entries for module parameters under
674 * /sys/module/[mod->name]/parameters/
676 int module_param_sysfs_setup(struct module *mod,
677 const struct kernel_param *kparam,
678 unsigned int num_params)
683 for (i = 0; i < num_params; i++) {
684 if (kparam[i].perm == 0)
686 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
695 /* Create the param group. */
696 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
698 free_module_param_attrs(&mod->mkobj);
703 * module_param_sysfs_remove - remove sysfs support for one module
706 * Remove sysfs entries for module parameters and the corresponding
709 void module_param_sysfs_remove(struct module *mod)
712 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
713 /* We are positive that no one is using any param
714 * attrs at this point. Deallocate immediately. */
715 free_module_param_attrs(&mod->mkobj);
720 void destroy_params(const struct kernel_param *params, unsigned num)
724 for (i = 0; i < num; i++)
725 if (params[i].ops->free)
726 params[i].ops->free(params[i].arg);
729 static struct module_kobject * __init locate_module_kobject(const char *name)
731 struct module_kobject *mk;
732 struct kobject *kobj;
735 kobj = kset_find_obj(module_kset, name);
737 mk = to_module_kobject(kobj);
739 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
742 mk->mod = THIS_MODULE;
743 mk->kobj.kset = module_kset;
744 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
746 #ifdef CONFIG_MODULES
748 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
751 kobject_put(&mk->kobj);
752 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\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 sysfs 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_kobject *mk, char *buf)
826 struct module_version_attribute *vattr =
827 container_of(mattr, struct module_version_attribute, mattr);
829 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
832 extern const struct module_version_attribute *__start___modver[];
833 extern const struct module_version_attribute *__stop___modver[];
835 static void __init version_sysfs_builtin(void)
837 const struct module_version_attribute **p;
838 struct module_kobject *mk;
841 for (p = __start___modver; p < __stop___modver; p++) {
842 const struct module_version_attribute *vattr = *p;
844 mk = locate_module_kobject(vattr->module_name);
846 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
847 kobject_uevent(&mk->kobj, KOBJ_ADD);
848 kobject_put(&mk->kobj);
853 /* module-related sysfs stuff */
855 static ssize_t module_attr_show(struct kobject *kobj,
856 struct attribute *attr,
859 struct module_attribute *attribute;
860 struct module_kobject *mk;
863 attribute = to_module_attr(attr);
864 mk = to_module_kobject(kobj);
866 if (!attribute->show)
869 ret = attribute->show(attribute, mk, buf);
874 static ssize_t module_attr_store(struct kobject *kobj,
875 struct attribute *attr,
876 const char *buf, size_t len)
878 struct module_attribute *attribute;
879 struct module_kobject *mk;
882 attribute = to_module_attr(attr);
883 mk = to_module_kobject(kobj);
885 if (!attribute->store)
888 ret = attribute->store(attribute, mk, buf, len);
893 static const struct sysfs_ops module_sysfs_ops = {
894 .show = module_attr_show,
895 .store = module_attr_store,
898 static int uevent_filter(struct kset *kset, struct kobject *kobj)
900 struct kobj_type *ktype = get_ktype(kobj);
902 if (ktype == &module_ktype)
907 static const struct kset_uevent_ops module_uevent_ops = {
908 .filter = uevent_filter,
911 struct kset *module_kset;
912 int module_sysfs_initialized;
914 static void module_kobj_release(struct kobject *kobj)
916 struct module_kobject *mk = to_module_kobject(kobj);
917 complete(mk->kobj_completion);
920 struct kobj_type module_ktype = {
921 .release = module_kobj_release,
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 */