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_unknown)(char *param, char *val))
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)
101 DEBUGP("They are equal! Calling %p\n",
103 mutex_lock(¶m_lock);
104 err = params[i].ops->set(val, ¶ms[i]);
105 mutex_unlock(¶m_lock);
110 if (handle_unknown) {
111 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
112 return handle_unknown(param, val);
115 DEBUGP("Unknown argument `%s'\n", param);
119 /* You can use " around spaces, but can't escape ". */
120 /* Hyphens and underscores equivalent in parameter names. */
121 static char *next_arg(char *args, char **param, char **val)
123 unsigned int i, equals = 0;
124 int in_quote = 0, quoted = 0;
133 for (i = 0; args[i]; i++) {
134 if (isspace(args[i]) && !in_quote)
141 in_quote = !in_quote;
149 *val = args + equals + 1;
151 /* Don't include quotes in value. */
154 if (args[i-1] == '"')
157 if (quoted && args[i-1] == '"')
167 /* Chew up trailing spaces. */
168 return skip_spaces(next);
171 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
172 int parse_args(const char *name,
174 const struct kernel_param *params,
176 int (*unknown)(char *param, char *val))
180 DEBUGP("Parsing ARGS: %s\n", args);
182 /* Chew leading spaces */
183 args = skip_spaces(args);
187 int irq_was_disabled;
189 args = next_arg(args, ¶m, &val);
190 irq_was_disabled = irqs_disabled();
191 ret = parse_one(param, val, params, num, unknown);
192 if (irq_was_disabled && !irqs_disabled()) {
193 printk(KERN_WARNING "parse_args(): option '%s' enabled "
198 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
203 "%s: `%s' too large for parameter `%s'\n",
204 name, val ?: "", param);
210 "%s: `%s' invalid for parameter `%s'\n",
211 name, val ?: "", param);
220 /* Lazy bastard, eh? */
221 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
222 int param_set_##name(const char *val, const struct kernel_param *kp) \
227 ret = strtolfn(val, 0, &l); \
228 if (ret == -EINVAL || ((type)l != l)) \
230 *((type *)kp->arg) = l; \
233 int param_get_##name(char *buffer, const struct kernel_param *kp) \
235 return sprintf(buffer, format, *((type *)kp->arg)); \
237 struct kernel_param_ops param_ops_##name = { \
238 .set = param_set_##name, \
239 .get = param_get_##name, \
241 EXPORT_SYMBOL(param_set_##name); \
242 EXPORT_SYMBOL(param_get_##name); \
243 EXPORT_SYMBOL(param_ops_##name)
246 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
247 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
248 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
249 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
250 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
251 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
252 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
254 int param_set_charp(const char *val, const struct kernel_param *kp)
256 if (strlen(val) > 1024) {
257 printk(KERN_ERR "%s: string parameter too long\n",
262 maybe_kfree_parameter(*(char **)kp->arg);
264 /* This is a hack. We can't kmalloc in early boot, and we
265 * don't need to; this mangled commandline is preserved. */
266 if (slab_is_available()) {
267 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
268 if (!*(char **)kp->arg)
270 strcpy(*(char **)kp->arg, val);
272 *(const char **)kp->arg = val;
276 EXPORT_SYMBOL(param_set_charp);
278 int param_get_charp(char *buffer, const struct kernel_param *kp)
280 return sprintf(buffer, "%s", *((char **)kp->arg));
282 EXPORT_SYMBOL(param_get_charp);
284 static void param_free_charp(void *arg)
286 maybe_kfree_parameter(*((char **)arg));
289 struct kernel_param_ops param_ops_charp = {
290 .set = param_set_charp,
291 .get = param_get_charp,
292 .free = param_free_charp,
294 EXPORT_SYMBOL(param_ops_charp);
296 /* Actually could be a bool or an int, for historical reasons. */
297 int param_set_bool(const char *val, const struct kernel_param *kp)
301 /* No equals means "set"... */
304 /* One of =[yYnN01] */
306 case 'y': case 'Y': case '1':
309 case 'n': case 'N': case '0':
316 if (kp->flags & KPARAM_ISBOOL)
317 *(bool *)kp->arg = v;
322 EXPORT_SYMBOL(param_set_bool);
324 int param_get_bool(char *buffer, const struct kernel_param *kp)
327 if (kp->flags & KPARAM_ISBOOL)
328 val = *(bool *)kp->arg;
330 val = *(int *)kp->arg;
332 /* Y and N chosen as being relatively non-coder friendly */
333 return sprintf(buffer, "%c", val ? 'Y' : 'N');
335 EXPORT_SYMBOL(param_get_bool);
337 struct kernel_param_ops param_ops_bool = {
338 .set = param_set_bool,
339 .get = param_get_bool,
341 EXPORT_SYMBOL(param_ops_bool);
343 /* This one must be bool. */
344 int param_set_invbool(const char *val, const struct kernel_param *kp)
348 struct kernel_param dummy;
350 dummy.arg = &boolval;
351 dummy.flags = KPARAM_ISBOOL;
352 ret = param_set_bool(val, &dummy);
354 *(bool *)kp->arg = !boolval;
357 EXPORT_SYMBOL(param_set_invbool);
359 int param_get_invbool(char *buffer, const struct kernel_param *kp)
361 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
363 EXPORT_SYMBOL(param_get_invbool);
365 struct kernel_param_ops param_ops_invbool = {
366 .set = param_set_invbool,
367 .get = param_get_invbool,
369 EXPORT_SYMBOL(param_ops_invbool);
371 /* We break the rule and mangle the string. */
372 static int param_array(const char *name,
374 unsigned int min, unsigned int max,
375 void *elem, int elemsize,
376 int (*set)(const char *, const struct kernel_param *kp),
381 struct kernel_param kp;
384 /* Get the name right for errors. */
390 /* We expect a comma-separated list of values. */
395 printk(KERN_ERR "%s: can only take %i arguments\n",
399 len = strcspn(val, ",");
401 /* nul-terminate and parse */
403 ((char *)val)[len] = '\0';
404 BUG_ON(!mutex_is_locked(¶m_lock));
412 } while (save == ',');
415 printk(KERN_ERR "%s: needs at least %i arguments\n",
422 static int param_array_set(const char *val, const struct kernel_param *kp)
424 const struct kparam_array *arr = kp->arr;
425 unsigned int temp_num;
427 return param_array(kp->name, val, 1, arr->max, arr->elem,
428 arr->elemsize, arr->ops->set, kp->flags,
429 arr->num ?: &temp_num);
432 static int param_array_get(char *buffer, const struct kernel_param *kp)
435 const struct kparam_array *arr = kp->arr;
436 struct kernel_param p;
439 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
442 p.arg = arr->elem + arr->elemsize * i;
443 BUG_ON(!mutex_is_locked(¶m_lock));
444 ret = arr->ops->get(buffer + off, &p);
453 static void param_array_free(void *arg)
456 const struct kparam_array *arr = arg;
459 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
460 arr->ops->free(arr->elem + arr->elemsize * i);
463 struct kernel_param_ops param_array_ops = {
464 .set = param_array_set,
465 .get = param_array_get,
466 .free = param_array_free,
468 EXPORT_SYMBOL(param_array_ops);
470 int param_set_copystring(const char *val, const struct kernel_param *kp)
472 const struct kparam_string *kps = kp->str;
474 if (strlen(val)+1 > kps->maxlen) {
475 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
476 kp->name, kps->maxlen-1);
479 strcpy(kps->string, val);
482 EXPORT_SYMBOL(param_set_copystring);
484 int param_get_string(char *buffer, const struct kernel_param *kp)
486 const struct kparam_string *kps = kp->str;
487 return strlcpy(buffer, kps->string, kps->maxlen);
489 EXPORT_SYMBOL(param_get_string);
491 struct kernel_param_ops param_ops_string = {
492 .set = param_set_copystring,
493 .get = param_get_string,
495 EXPORT_SYMBOL(param_ops_string);
497 /* sysfs output in /sys/modules/XYZ/parameters/ */
498 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
499 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
501 extern struct kernel_param __start___param[], __stop___param[];
503 struct param_attribute
505 struct module_attribute mattr;
506 const struct kernel_param *param;
509 struct module_param_attrs
512 struct attribute_group grp;
513 struct param_attribute attrs[0];
517 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
519 static ssize_t param_attr_show(struct module_attribute *mattr,
520 struct module *mod, char *buf)
523 struct param_attribute *attribute = to_param_attr(mattr);
525 if (!attribute->param->ops->get)
528 mutex_lock(¶m_lock);
529 count = attribute->param->ops->get(buf, attribute->param);
530 mutex_unlock(¶m_lock);
538 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
539 static ssize_t param_attr_store(struct module_attribute *mattr,
540 struct module *owner,
541 const char *buf, size_t len)
544 struct param_attribute *attribute = to_param_attr(mattr);
546 if (!attribute->param->ops->set)
549 mutex_lock(¶m_lock);
550 err = attribute->param->ops->set(buf, attribute->param);
551 mutex_unlock(¶m_lock);
558 #ifdef CONFIG_MODULES
561 #define __modinit __init
565 void __kernel_param_lock(void)
567 mutex_lock(¶m_lock);
569 EXPORT_SYMBOL(__kernel_param_lock);
571 void __kernel_param_unlock(void)
573 mutex_unlock(¶m_lock);
575 EXPORT_SYMBOL(__kernel_param_unlock);
578 * add_sysfs_param - add a parameter to sysfs
579 * @mk: struct module_kobject
580 * @kparam: the actual parameter definition to add to sysfs
581 * @name: name of parameter
583 * Create a kobject if for a (per-module) parameter if mp NULL, and
584 * create file in sysfs. Returns an error on out of memory. Always cleans up
585 * if there's an error.
587 static __modinit int add_sysfs_param(struct module_kobject *mk,
588 const struct kernel_param *kp,
591 struct module_param_attrs *new;
592 struct attribute **attrs;
595 /* We don't bother calling this with invisible parameters. */
603 attrs = mk->mp->grp.attrs;
607 new = krealloc(mk->mp,
608 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
615 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
621 /* Sysfs wants everything zeroed. */
622 memset(new, 0, sizeof(*new));
623 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
624 memset(&attrs[num], 0, sizeof(attrs[num]));
625 new->grp.name = "parameters";
626 new->grp.attrs = attrs;
628 /* Tack new one on the end. */
629 sysfs_attr_init(&new->attrs[num].mattr.attr);
630 new->attrs[num].param = kp;
631 new->attrs[num].mattr.show = param_attr_show;
632 new->attrs[num].mattr.store = param_attr_store;
633 new->attrs[num].mattr.attr.name = (char *)name;
634 new->attrs[num].mattr.attr.mode = kp->perm;
637 /* Fix up all the pointers, since krealloc can move us */
638 for (num = 0; num < new->num; num++)
639 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
640 new->grp.attrs[num] = NULL;
652 #ifdef CONFIG_MODULES
653 static void free_module_param_attrs(struct module_kobject *mk)
655 kfree(mk->mp->grp.attrs);
661 * module_param_sysfs_setup - setup sysfs support for one module
663 * @kparam: module parameters (array)
664 * @num_params: number of module parameters
666 * Adds sysfs entries for module parameters under
667 * /sys/module/[mod->name]/parameters/
669 int module_param_sysfs_setup(struct module *mod,
670 const struct kernel_param *kparam,
671 unsigned int num_params)
676 for (i = 0; i < num_params; i++) {
677 if (kparam[i].perm == 0)
679 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
688 /* Create the param group. */
689 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
691 free_module_param_attrs(&mod->mkobj);
696 * module_param_sysfs_remove - remove sysfs support for one module
699 * Remove sysfs entries for module parameters and the corresponding
702 void module_param_sysfs_remove(struct module *mod)
705 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
706 /* We are positive that no one is using any param
707 * attrs at this point. Deallocate immediately. */
708 free_module_param_attrs(&mod->mkobj);
713 void destroy_params(const struct kernel_param *params, unsigned num)
717 for (i = 0; i < num; i++)
718 if (params[i].ops->free)
719 params[i].ops->free(params[i].arg);
722 static void __init kernel_add_sysfs_param(const char *name,
723 struct kernel_param *kparam,
724 unsigned int name_skip)
726 struct module_kobject *mk;
727 struct kobject *kobj;
730 kobj = kset_find_obj(module_kset, name);
732 /* We already have one. Remove params so we can add more. */
733 mk = to_module_kobject(kobj);
734 /* We need to remove it before adding parameters. */
735 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
737 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
740 mk->mod = THIS_MODULE;
741 mk->kobj.kset = module_kset;
742 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
745 kobject_put(&mk->kobj);
746 printk(KERN_ERR "Module '%s' failed add to sysfs, "
747 "error number %d\n", name, err);
748 printk(KERN_ERR "The system will be unstable now.\n");
751 /* So that exit path is even. */
752 kobject_get(&mk->kobj);
755 /* These should not fail at boot. */
756 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
758 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
760 kobject_uevent(&mk->kobj, KOBJ_ADD);
761 kobject_put(&mk->kobj);
765 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
767 * Add module_parameters to sysfs for "modules" built into the kernel.
769 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
770 * "parameter" name is stored behind a dot in kernel_param->name. So,
771 * extract the "module" name for all built-in kernel_param-eters,
772 * and for all who have the same, call kernel_add_sysfs_param.
774 static void __init param_sysfs_builtin(void)
776 struct kernel_param *kp;
777 unsigned int name_len;
778 char modname[MODULE_NAME_LEN];
780 for (kp = __start___param; kp < __stop___param; kp++) {
786 dot = strchr(kp->name, '.');
788 /* This happens for core_param() */
789 strcpy(modname, "kernel");
792 name_len = dot - kp->name + 1;
793 strlcpy(modname, kp->name, name_len);
795 kernel_add_sysfs_param(modname, kp, name_len);
800 /* module-related sysfs stuff */
802 static ssize_t module_attr_show(struct kobject *kobj,
803 struct attribute *attr,
806 struct module_attribute *attribute;
807 struct module_kobject *mk;
810 attribute = to_module_attr(attr);
811 mk = to_module_kobject(kobj);
813 if (!attribute->show)
816 ret = attribute->show(attribute, mk->mod, buf);
821 static ssize_t module_attr_store(struct kobject *kobj,
822 struct attribute *attr,
823 const char *buf, size_t len)
825 struct module_attribute *attribute;
826 struct module_kobject *mk;
829 attribute = to_module_attr(attr);
830 mk = to_module_kobject(kobj);
832 if (!attribute->store)
835 ret = attribute->store(attribute, mk->mod, buf, len);
840 static const struct sysfs_ops module_sysfs_ops = {
841 .show = module_attr_show,
842 .store = module_attr_store,
845 static int uevent_filter(struct kset *kset, struct kobject *kobj)
847 struct kobj_type *ktype = get_ktype(kobj);
849 if (ktype == &module_ktype)
854 static const struct kset_uevent_ops module_uevent_ops = {
855 .filter = uevent_filter,
858 struct kset *module_kset;
859 int module_sysfs_initialized;
861 struct kobj_type module_ktype = {
862 .sysfs_ops = &module_sysfs_ops,
866 * param_sysfs_init - wrapper for built-in params support
868 static int __init param_sysfs_init(void)
870 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
872 printk(KERN_WARNING "%s (%d): error creating kset\n",
876 module_sysfs_initialized = 1;
878 param_sysfs_builtin();
882 subsys_initcall(param_sysfs_init);
884 #endif /* CONFIG_SYSFS */