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/moduleparam.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 void param_check_unsafe(const struct kernel_param *kp)
89 if (kp->flags & KERNEL_PARAM_FL_UNSAFE) {
90 pr_warn("Setting dangerous option %s - tainting kernel\n",
92 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
96 static int parse_one(char *param,
99 const struct kernel_param *params,
103 int (*handle_unknown)(char *param, char *val,
110 for (i = 0; i < num_params; i++) {
111 if (parameq(param, params[i].name)) {
112 if (params[i].level < min_level
113 || params[i].level > max_level)
115 /* No one handled NULL, so do it here. */
117 !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG))
119 pr_debug("handling %s with %p\n", param,
121 mutex_lock(¶m_lock);
122 param_check_unsafe(¶ms[i]);
123 err = params[i].ops->set(val, ¶ms[i]);
124 mutex_unlock(¶m_lock);
129 if (handle_unknown) {
130 pr_debug("doing %s: %s='%s'\n", doing, param, val);
131 return handle_unknown(param, val, doing);
134 pr_debug("Unknown argument '%s'\n", param);
138 /* You can use " around spaces, but can't escape ". */
139 /* Hyphens and underscores equivalent in parameter names. */
140 static char *next_arg(char *args, char **param, char **val)
142 unsigned int i, equals = 0;
143 int in_quote = 0, quoted = 0;
152 for (i = 0; args[i]; i++) {
153 if (isspace(args[i]) && !in_quote)
160 in_quote = !in_quote;
168 *val = args + equals + 1;
170 /* Don't include quotes in value. */
173 if (args[i-1] == '"')
177 if (quoted && args[i-1] == '"')
186 /* Chew up trailing spaces. */
187 return skip_spaces(next);
190 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
191 char *parse_args(const char *doing,
193 const struct kernel_param *params,
197 int (*unknown)(char *param, char *val, const char *doing))
201 /* Chew leading spaces */
202 args = skip_spaces(args);
205 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
209 int irq_was_disabled;
211 args = next_arg(args, ¶m, &val);
213 if (!val && strcmp(param, "--") == 0)
215 irq_was_disabled = irqs_disabled();
216 ret = parse_one(param, val, doing, params, num,
217 min_level, max_level, unknown);
218 if (irq_was_disabled && !irqs_disabled())
219 pr_warn("%s: option '%s' enabled irq's!\n",
224 pr_err("%s: Unknown parameter `%s'\n", doing, param);
227 pr_err("%s: `%s' too large for parameter `%s'\n",
228 doing, val ?: "", param);
233 pr_err("%s: `%s' invalid for parameter `%s'\n",
234 doing, val ?: "", param);
243 /* Lazy bastard, eh? */
244 #define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
245 int param_set_##name(const char *val, const struct kernel_param *kp) \
247 return strtolfn(val, 0, (type *)kp->arg); \
249 int param_get_##name(char *buffer, const struct kernel_param *kp) \
251 return scnprintf(buffer, PAGE_SIZE, format, \
252 *((type *)kp->arg)); \
254 const struct kernel_param_ops param_ops_##name = { \
255 .set = param_set_##name, \
256 .get = param_get_##name, \
258 EXPORT_SYMBOL(param_set_##name); \
259 EXPORT_SYMBOL(param_get_##name); \
260 EXPORT_SYMBOL(param_ops_##name)
263 STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
264 STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
265 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
266 STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
267 STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
268 STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
269 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
270 STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull);
272 int param_set_charp(const char *val, const struct kernel_param *kp)
274 if (strlen(val) > 1024) {
275 pr_err("%s: string parameter too long\n", kp->name);
279 maybe_kfree_parameter(*(char **)kp->arg);
281 /* This is a hack. We can't kmalloc in early boot, and we
282 * don't need to; this mangled commandline is preserved. */
283 if (slab_is_available()) {
284 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
285 if (!*(char **)kp->arg)
287 strcpy(*(char **)kp->arg, val);
289 *(const char **)kp->arg = val;
293 EXPORT_SYMBOL(param_set_charp);
295 int param_get_charp(char *buffer, const struct kernel_param *kp)
297 return scnprintf(buffer, PAGE_SIZE, "%s", *((char **)kp->arg));
299 EXPORT_SYMBOL(param_get_charp);
301 static void param_free_charp(void *arg)
303 maybe_kfree_parameter(*((char **)arg));
306 const struct kernel_param_ops param_ops_charp = {
307 .set = param_set_charp,
308 .get = param_get_charp,
309 .free = param_free_charp,
311 EXPORT_SYMBOL(param_ops_charp);
313 /* Actually could be a bool or an int, for historical reasons. */
314 int param_set_bool(const char *val, const struct kernel_param *kp)
316 /* No equals means "set"... */
319 /* One of =[yYnN01] */
320 return strtobool(val, kp->arg);
322 EXPORT_SYMBOL(param_set_bool);
324 int param_get_bool(char *buffer, const struct kernel_param *kp)
326 /* Y and N chosen as being relatively non-coder friendly */
327 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
329 EXPORT_SYMBOL(param_get_bool);
331 const struct kernel_param_ops param_ops_bool = {
332 .flags = KERNEL_PARAM_OPS_FL_NOARG,
333 .set = param_set_bool,
334 .get = param_get_bool,
336 EXPORT_SYMBOL(param_ops_bool);
338 int param_set_bool_enable_only(const char *val, const struct kernel_param *kp)
342 bool orig_value = *(bool *)kp->arg;
343 struct kernel_param dummy_kp = *kp;
345 dummy_kp.arg = &new_value;
347 err = param_set_bool(val, &dummy_kp);
351 /* Don't let them unset it once it's set! */
352 if (!new_value && orig_value)
356 err = param_set_bool(val, kp);
360 EXPORT_SYMBOL_GPL(param_set_bool_enable_only);
362 const struct kernel_param_ops param_ops_bool_enable_only = {
363 .flags = KERNEL_PARAM_OPS_FL_NOARG,
364 .set = param_set_bool_enable_only,
365 .get = param_get_bool,
367 EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
369 /* This one must be bool. */
370 int param_set_invbool(const char *val, const struct kernel_param *kp)
374 struct kernel_param dummy;
376 dummy.arg = &boolval;
377 ret = param_set_bool(val, &dummy);
379 *(bool *)kp->arg = !boolval;
382 EXPORT_SYMBOL(param_set_invbool);
384 int param_get_invbool(char *buffer, const struct kernel_param *kp)
386 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
388 EXPORT_SYMBOL(param_get_invbool);
390 const struct kernel_param_ops param_ops_invbool = {
391 .set = param_set_invbool,
392 .get = param_get_invbool,
394 EXPORT_SYMBOL(param_ops_invbool);
396 int param_set_bint(const char *val, const struct kernel_param *kp)
398 /* Match bool exactly, by re-using it. */
399 struct kernel_param boolkp = *kp;
405 ret = param_set_bool(val, &boolkp);
410 EXPORT_SYMBOL(param_set_bint);
412 const struct kernel_param_ops param_ops_bint = {
413 .flags = KERNEL_PARAM_OPS_FL_NOARG,
414 .set = param_set_bint,
415 .get = param_get_int,
417 EXPORT_SYMBOL(param_ops_bint);
419 /* We break the rule and mangle the string. */
420 static int param_array(const char *name,
422 unsigned int min, unsigned int max,
423 void *elem, int elemsize,
424 int (*set)(const char *, const struct kernel_param *kp),
429 struct kernel_param kp;
432 /* Get the name right for errors. */
438 /* We expect a comma-separated list of values. */
443 pr_err("%s: can only take %i arguments\n", name, max);
446 len = strcspn(val, ",");
448 /* nul-terminate and parse */
450 ((char *)val)[len] = '\0';
451 BUG_ON(!mutex_is_locked(¶m_lock));
459 } while (save == ',');
462 pr_err("%s: needs at least %i arguments\n", name, min);
468 static int param_array_set(const char *val, const struct kernel_param *kp)
470 const struct kparam_array *arr = kp->arr;
471 unsigned int temp_num;
473 return param_array(kp->name, val, 1, arr->max, arr->elem,
474 arr->elemsize, arr->ops->set, kp->level,
475 arr->num ?: &temp_num);
478 static int param_array_get(char *buffer, const struct kernel_param *kp)
481 const struct kparam_array *arr = kp->arr;
482 struct kernel_param p = *kp;
484 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
487 p.arg = arr->elem + arr->elemsize * i;
488 BUG_ON(!mutex_is_locked(¶m_lock));
489 ret = arr->ops->get(buffer + off, &p);
498 static void param_array_free(void *arg)
501 const struct kparam_array *arr = arg;
504 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
505 arr->ops->free(arr->elem + arr->elemsize * i);
508 const struct kernel_param_ops param_array_ops = {
509 .set = param_array_set,
510 .get = param_array_get,
511 .free = param_array_free,
513 EXPORT_SYMBOL(param_array_ops);
515 int param_set_copystring(const char *val, const struct kernel_param *kp)
517 const struct kparam_string *kps = kp->str;
519 if (strlen(val)+1 > kps->maxlen) {
520 pr_err("%s: string doesn't fit in %u chars.\n",
521 kp->name, kps->maxlen-1);
524 strcpy(kps->string, val);
527 EXPORT_SYMBOL(param_set_copystring);
529 int param_get_string(char *buffer, const struct kernel_param *kp)
531 const struct kparam_string *kps = kp->str;
532 return strlcpy(buffer, kps->string, kps->maxlen);
534 EXPORT_SYMBOL(param_get_string);
536 const struct kernel_param_ops param_ops_string = {
537 .set = param_set_copystring,
538 .get = param_get_string,
540 EXPORT_SYMBOL(param_ops_string);
542 /* sysfs output in /sys/modules/XYZ/parameters/ */
543 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
544 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
546 struct param_attribute
548 struct module_attribute mattr;
549 const struct kernel_param *param;
552 struct module_param_attrs
555 struct attribute_group grp;
556 struct param_attribute attrs[0];
560 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
562 static ssize_t param_attr_show(struct module_attribute *mattr,
563 struct module_kobject *mk, char *buf)
566 struct param_attribute *attribute = to_param_attr(mattr);
568 if (!attribute->param->ops->get)
571 mutex_lock(¶m_lock);
572 count = attribute->param->ops->get(buf, attribute->param);
573 mutex_unlock(¶m_lock);
581 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
582 static ssize_t param_attr_store(struct module_attribute *mattr,
583 struct module_kobject *km,
584 const char *buf, size_t len)
587 struct param_attribute *attribute = to_param_attr(mattr);
589 if (!attribute->param->ops->set)
592 mutex_lock(¶m_lock);
593 param_check_unsafe(attribute->param);
594 err = attribute->param->ops->set(buf, attribute->param);
595 mutex_unlock(¶m_lock);
602 #ifdef CONFIG_MODULES
605 #define __modinit __init
609 void __kernel_param_lock(void)
611 mutex_lock(¶m_lock);
613 EXPORT_SYMBOL(__kernel_param_lock);
615 void __kernel_param_unlock(void)
617 mutex_unlock(¶m_lock);
619 EXPORT_SYMBOL(__kernel_param_unlock);
622 * add_sysfs_param - add a parameter to sysfs
623 * @mk: struct module_kobject
624 * @kparam: the actual parameter definition to add to sysfs
625 * @name: name of parameter
627 * Create a kobject if for a (per-module) parameter if mp NULL, and
628 * create file in sysfs. Returns an error on out of memory. Always cleans up
629 * if there's an error.
631 static __modinit int add_sysfs_param(struct module_kobject *mk,
632 const struct kernel_param *kp,
635 struct module_param_attrs *new_mp;
636 struct attribute **new_attrs;
639 /* We don't bother calling this with invisible parameters. */
643 /* First allocation. */
644 mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
647 mk->mp->grp.name = "parameters";
648 /* NULL-terminated attribute array. */
649 mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
651 /* Caller will cleanup via free_module_param_attrs */
652 if (!mk->mp->grp.attrs)
656 /* Enlarge allocations. */
657 new_mp = krealloc(mk->mp,
659 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
665 /* Extra pointer for NULL terminator */
666 new_attrs = krealloc(mk->mp->grp.attrs,
667 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
671 mk->mp->grp.attrs = new_attrs;
673 /* Tack new one on the end. */
674 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
675 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
676 mk->mp->attrs[mk->mp->num].param = kp;
677 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
678 /* Do not allow runtime DAC changes to make param writable. */
679 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
680 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
682 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
683 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
684 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
687 /* Fix up all the pointers, since krealloc can move us */
688 for (i = 0; i < mk->mp->num; i++)
689 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
690 mk->mp->grp.attrs[mk->mp->num] = NULL;
694 #ifdef CONFIG_MODULES
695 static void free_module_param_attrs(struct module_kobject *mk)
698 kfree(mk->mp->grp.attrs);
704 * module_param_sysfs_setup - setup sysfs support for one module
706 * @kparam: module parameters (array)
707 * @num_params: number of module parameters
709 * Adds sysfs entries for module parameters under
710 * /sys/module/[mod->name]/parameters/
712 int module_param_sysfs_setup(struct module *mod,
713 const struct kernel_param *kparam,
714 unsigned int num_params)
719 for (i = 0; i < num_params; i++) {
720 if (kparam[i].perm == 0)
722 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
724 free_module_param_attrs(&mod->mkobj);
733 /* Create the param group. */
734 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
736 free_module_param_attrs(&mod->mkobj);
741 * module_param_sysfs_remove - remove sysfs support for one module
744 * Remove sysfs entries for module parameters and the corresponding
747 void module_param_sysfs_remove(struct module *mod)
750 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
751 /* We are positive that no one is using any param
752 * attrs at this point. Deallocate immediately. */
753 free_module_param_attrs(&mod->mkobj);
758 void destroy_params(const struct kernel_param *params, unsigned num)
762 for (i = 0; i < num; i++)
763 if (params[i].ops->free)
764 params[i].ops->free(params[i].arg);
767 static struct module_kobject * __init locate_module_kobject(const char *name)
769 struct module_kobject *mk;
770 struct kobject *kobj;
773 kobj = kset_find_obj(module_kset, name);
775 mk = to_module_kobject(kobj);
777 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
780 mk->mod = THIS_MODULE;
781 mk->kobj.kset = module_kset;
782 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
784 #ifdef CONFIG_MODULES
786 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
789 kobject_put(&mk->kobj);
790 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
795 /* So that we hold reference in both cases. */
796 kobject_get(&mk->kobj);
802 static void __init kernel_add_sysfs_param(const char *name,
803 const struct kernel_param *kparam,
804 unsigned int name_skip)
806 struct module_kobject *mk;
809 mk = locate_module_kobject(name);
813 /* We need to remove old parameters before adding more. */
815 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
817 /* These should not fail at boot. */
818 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
820 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
822 kobject_uevent(&mk->kobj, KOBJ_ADD);
823 kobject_put(&mk->kobj);
827 * param_sysfs_builtin - add sysfs parameters for built-in modules
829 * Add module_parameters to sysfs for "modules" built into the kernel.
831 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
832 * "parameter" name is stored behind a dot in kernel_param->name. So,
833 * extract the "module" name for all built-in kernel_param-eters,
834 * and for all who have the same, call kernel_add_sysfs_param.
836 static void __init param_sysfs_builtin(void)
838 const struct kernel_param *kp;
839 unsigned int name_len;
840 char modname[MODULE_NAME_LEN];
842 for (kp = __start___param; kp < __stop___param; kp++) {
848 dot = strchr(kp->name, '.');
850 /* This happens for core_param() */
851 strcpy(modname, "kernel");
854 name_len = dot - kp->name + 1;
855 strlcpy(modname, kp->name, name_len);
857 kernel_add_sysfs_param(modname, kp, name_len);
861 ssize_t __modver_version_show(struct module_attribute *mattr,
862 struct module_kobject *mk, char *buf)
864 struct module_version_attribute *vattr =
865 container_of(mattr, struct module_version_attribute, mattr);
867 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
870 extern const struct module_version_attribute *__start___modver[];
871 extern const struct module_version_attribute *__stop___modver[];
873 static void __init version_sysfs_builtin(void)
875 const struct module_version_attribute **p;
876 struct module_kobject *mk;
879 for (p = __start___modver; p < __stop___modver; p++) {
880 const struct module_version_attribute *vattr = *p;
882 mk = locate_module_kobject(vattr->module_name);
884 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
886 kobject_uevent(&mk->kobj, KOBJ_ADD);
887 kobject_put(&mk->kobj);
892 /* module-related sysfs stuff */
894 static ssize_t module_attr_show(struct kobject *kobj,
895 struct attribute *attr,
898 struct module_attribute *attribute;
899 struct module_kobject *mk;
902 attribute = to_module_attr(attr);
903 mk = to_module_kobject(kobj);
905 if (!attribute->show)
908 ret = attribute->show(attribute, mk, buf);
913 static ssize_t module_attr_store(struct kobject *kobj,
914 struct attribute *attr,
915 const char *buf, size_t len)
917 struct module_attribute *attribute;
918 struct module_kobject *mk;
921 attribute = to_module_attr(attr);
922 mk = to_module_kobject(kobj);
924 if (!attribute->store)
927 ret = attribute->store(attribute, mk, buf, len);
932 static const struct sysfs_ops module_sysfs_ops = {
933 .show = module_attr_show,
934 .store = module_attr_store,
937 static int uevent_filter(struct kset *kset, struct kobject *kobj)
939 struct kobj_type *ktype = get_ktype(kobj);
941 if (ktype == &module_ktype)
946 static const struct kset_uevent_ops module_uevent_ops = {
947 .filter = uevent_filter,
950 struct kset *module_kset;
951 int module_sysfs_initialized;
953 static void module_kobj_release(struct kobject *kobj)
955 struct module_kobject *mk = to_module_kobject(kobj);
956 complete(mk->kobj_completion);
959 struct kobj_type module_ktype = {
960 .release = module_kobj_release,
961 .sysfs_ops = &module_sysfs_ops,
965 * param_sysfs_init - wrapper for built-in params support
967 static int __init param_sysfs_init(void)
969 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
971 printk(KERN_WARNING "%s (%d): error creating kset\n",
975 module_sysfs_initialized = 1;
977 version_sysfs_builtin();
978 param_sysfs_builtin();
982 subsys_initcall(param_sysfs_init);
984 #endif /* CONFIG_SYSFS */