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 struct kernel_param boolkp;
402 /* Match bool exactly, by re-using it. */
406 ret = param_set_bool(val, &boolkp);
411 EXPORT_SYMBOL(param_set_bint);
413 const struct kernel_param_ops param_ops_bint = {
414 .flags = KERNEL_PARAM_OPS_FL_NOARG,
415 .set = param_set_bint,
416 .get = param_get_int,
418 EXPORT_SYMBOL(param_ops_bint);
420 /* We break the rule and mangle the string. */
421 static int param_array(const char *name,
423 unsigned int min, unsigned int max,
424 void *elem, int elemsize,
425 int (*set)(const char *, const struct kernel_param *kp),
430 struct kernel_param kp;
433 /* Get the name right for errors. */
439 /* We expect a comma-separated list of values. */
444 pr_err("%s: can only take %i arguments\n", name, max);
447 len = strcspn(val, ",");
449 /* nul-terminate and parse */
451 ((char *)val)[len] = '\0';
452 BUG_ON(!mutex_is_locked(¶m_lock));
460 } while (save == ',');
463 pr_err("%s: needs at least %i arguments\n", name, min);
469 static int param_array_set(const char *val, const struct kernel_param *kp)
471 const struct kparam_array *arr = kp->arr;
472 unsigned int temp_num;
474 return param_array(kp->name, val, 1, arr->max, arr->elem,
475 arr->elemsize, arr->ops->set, kp->level,
476 arr->num ?: &temp_num);
479 static int param_array_get(char *buffer, const struct kernel_param *kp)
482 const struct kparam_array *arr = kp->arr;
483 struct kernel_param p;
486 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
489 p.arg = arr->elem + arr->elemsize * i;
490 BUG_ON(!mutex_is_locked(¶m_lock));
491 ret = arr->ops->get(buffer + off, &p);
500 static void param_array_free(void *arg)
503 const struct kparam_array *arr = arg;
506 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
507 arr->ops->free(arr->elem + arr->elemsize * i);
510 const struct kernel_param_ops param_array_ops = {
511 .set = param_array_set,
512 .get = param_array_get,
513 .free = param_array_free,
515 EXPORT_SYMBOL(param_array_ops);
517 int param_set_copystring(const char *val, const struct kernel_param *kp)
519 const struct kparam_string *kps = kp->str;
521 if (strlen(val)+1 > kps->maxlen) {
522 pr_err("%s: string doesn't fit in %u chars.\n",
523 kp->name, kps->maxlen-1);
526 strcpy(kps->string, val);
529 EXPORT_SYMBOL(param_set_copystring);
531 int param_get_string(char *buffer, const struct kernel_param *kp)
533 const struct kparam_string *kps = kp->str;
534 return strlcpy(buffer, kps->string, kps->maxlen);
536 EXPORT_SYMBOL(param_get_string);
538 const struct kernel_param_ops param_ops_string = {
539 .set = param_set_copystring,
540 .get = param_get_string,
542 EXPORT_SYMBOL(param_ops_string);
544 /* sysfs output in /sys/modules/XYZ/parameters/ */
545 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
546 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
548 struct param_attribute
550 struct module_attribute mattr;
551 const struct kernel_param *param;
554 struct module_param_attrs
557 struct attribute_group grp;
558 struct param_attribute attrs[0];
562 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
564 static ssize_t param_attr_show(struct module_attribute *mattr,
565 struct module_kobject *mk, char *buf)
568 struct param_attribute *attribute = to_param_attr(mattr);
570 if (!attribute->param->ops->get)
573 mutex_lock(¶m_lock);
574 count = attribute->param->ops->get(buf, attribute->param);
575 mutex_unlock(¶m_lock);
583 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
584 static ssize_t param_attr_store(struct module_attribute *mattr,
585 struct module_kobject *km,
586 const char *buf, size_t len)
589 struct param_attribute *attribute = to_param_attr(mattr);
591 if (!attribute->param->ops->set)
594 mutex_lock(¶m_lock);
595 param_check_unsafe(attribute->param);
596 err = attribute->param->ops->set(buf, attribute->param);
597 mutex_unlock(¶m_lock);
604 #ifdef CONFIG_MODULES
607 #define __modinit __init
611 void __kernel_param_lock(void)
613 mutex_lock(¶m_lock);
615 EXPORT_SYMBOL(__kernel_param_lock);
617 void __kernel_param_unlock(void)
619 mutex_unlock(¶m_lock);
621 EXPORT_SYMBOL(__kernel_param_unlock);
624 * add_sysfs_param - add a parameter to sysfs
625 * @mk: struct module_kobject
626 * @kparam: the actual parameter definition to add to sysfs
627 * @name: name of parameter
629 * Create a kobject if for a (per-module) parameter if mp NULL, and
630 * create file in sysfs. Returns an error on out of memory. Always cleans up
631 * if there's an error.
633 static __modinit int add_sysfs_param(struct module_kobject *mk,
634 const struct kernel_param *kp,
637 struct module_param_attrs *new_mp;
638 struct attribute **new_attrs;
641 /* We don't bother calling this with invisible parameters. */
645 /* First allocation. */
646 mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL);
649 mk->mp->grp.name = "parameters";
650 /* NULL-terminated attribute array. */
651 mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]),
653 /* Caller will cleanup via free_module_param_attrs */
654 if (!mk->mp->grp.attrs)
658 /* Enlarge allocations. */
659 new_mp = krealloc(mk->mp,
661 sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1),
667 /* Extra pointer for NULL terminator */
668 new_attrs = krealloc(mk->mp->grp.attrs,
669 sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2),
673 mk->mp->grp.attrs = new_attrs;
675 /* Tack new one on the end. */
676 memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0]));
677 sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr);
678 mk->mp->attrs[mk->mp->num].param = kp;
679 mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show;
680 /* Do not allow runtime DAC changes to make param writable. */
681 if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0)
682 mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store;
684 mk->mp->attrs[mk->mp->num].mattr.store = NULL;
685 mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name;
686 mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm;
689 /* Fix up all the pointers, since krealloc can move us */
690 for (i = 0; i < mk->mp->num; i++)
691 mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr;
692 mk->mp->grp.attrs[mk->mp->num] = NULL;
696 #ifdef CONFIG_MODULES
697 static void free_module_param_attrs(struct module_kobject *mk)
700 kfree(mk->mp->grp.attrs);
706 * module_param_sysfs_setup - setup sysfs support for one module
708 * @kparam: module parameters (array)
709 * @num_params: number of module parameters
711 * Adds sysfs entries for module parameters under
712 * /sys/module/[mod->name]/parameters/
714 int module_param_sysfs_setup(struct module *mod,
715 const struct kernel_param *kparam,
716 unsigned int num_params)
721 for (i = 0; i < num_params; i++) {
722 if (kparam[i].perm == 0)
724 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
726 free_module_param_attrs(&mod->mkobj);
735 /* Create the param group. */
736 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
738 free_module_param_attrs(&mod->mkobj);
743 * module_param_sysfs_remove - remove sysfs support for one module
746 * Remove sysfs entries for module parameters and the corresponding
749 void module_param_sysfs_remove(struct module *mod)
752 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
753 /* We are positive that no one is using any param
754 * attrs at this point. Deallocate immediately. */
755 free_module_param_attrs(&mod->mkobj);
760 void destroy_params(const struct kernel_param *params, unsigned num)
764 for (i = 0; i < num; i++)
765 if (params[i].ops->free)
766 params[i].ops->free(params[i].arg);
769 static struct module_kobject * __init locate_module_kobject(const char *name)
771 struct module_kobject *mk;
772 struct kobject *kobj;
775 kobj = kset_find_obj(module_kset, name);
777 mk = to_module_kobject(kobj);
779 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
782 mk->mod = THIS_MODULE;
783 mk->kobj.kset = module_kset;
784 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
786 #ifdef CONFIG_MODULES
788 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
791 kobject_put(&mk->kobj);
792 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
797 /* So that we hold reference in both cases. */
798 kobject_get(&mk->kobj);
804 static void __init kernel_add_sysfs_param(const char *name,
805 const struct kernel_param *kparam,
806 unsigned int name_skip)
808 struct module_kobject *mk;
811 mk = locate_module_kobject(name);
815 /* We need to remove old parameters before adding more. */
817 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
819 /* These should not fail at boot. */
820 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
822 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
824 kobject_uevent(&mk->kobj, KOBJ_ADD);
825 kobject_put(&mk->kobj);
829 * param_sysfs_builtin - add sysfs parameters for built-in modules
831 * Add module_parameters to sysfs for "modules" built into the kernel.
833 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
834 * "parameter" name is stored behind a dot in kernel_param->name. So,
835 * extract the "module" name for all built-in kernel_param-eters,
836 * and for all who have the same, call kernel_add_sysfs_param.
838 static void __init param_sysfs_builtin(void)
840 const struct kernel_param *kp;
841 unsigned int name_len;
842 char modname[MODULE_NAME_LEN];
844 for (kp = __start___param; kp < __stop___param; kp++) {
850 dot = strchr(kp->name, '.');
852 /* This happens for core_param() */
853 strcpy(modname, "kernel");
856 name_len = dot - kp->name + 1;
857 strlcpy(modname, kp->name, name_len);
859 kernel_add_sysfs_param(modname, kp, name_len);
863 ssize_t __modver_version_show(struct module_attribute *mattr,
864 struct module_kobject *mk, char *buf)
866 struct module_version_attribute *vattr =
867 container_of(mattr, struct module_version_attribute, mattr);
869 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
872 extern const struct module_version_attribute *__start___modver[];
873 extern const struct module_version_attribute *__stop___modver[];
875 static void __init version_sysfs_builtin(void)
877 const struct module_version_attribute **p;
878 struct module_kobject *mk;
881 for (p = __start___modver; p < __stop___modver; p++) {
882 const struct module_version_attribute *vattr = *p;
884 mk = locate_module_kobject(vattr->module_name);
886 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
888 kobject_uevent(&mk->kobj, KOBJ_ADD);
889 kobject_put(&mk->kobj);
894 /* module-related sysfs stuff */
896 static ssize_t module_attr_show(struct kobject *kobj,
897 struct attribute *attr,
900 struct module_attribute *attribute;
901 struct module_kobject *mk;
904 attribute = to_module_attr(attr);
905 mk = to_module_kobject(kobj);
907 if (!attribute->show)
910 ret = attribute->show(attribute, mk, buf);
915 static ssize_t module_attr_store(struct kobject *kobj,
916 struct attribute *attr,
917 const char *buf, size_t len)
919 struct module_attribute *attribute;
920 struct module_kobject *mk;
923 attribute = to_module_attr(attr);
924 mk = to_module_kobject(kobj);
926 if (!attribute->store)
929 ret = attribute->store(attribute, mk, buf, len);
934 static const struct sysfs_ops module_sysfs_ops = {
935 .show = module_attr_show,
936 .store = module_attr_store,
939 static int uevent_filter(struct kset *kset, struct kobject *kobj)
941 struct kobj_type *ktype = get_ktype(kobj);
943 if (ktype == &module_ktype)
948 static const struct kset_uevent_ops module_uevent_ops = {
949 .filter = uevent_filter,
952 struct kset *module_kset;
953 int module_sysfs_initialized;
955 static void module_kobj_release(struct kobject *kobj)
957 struct module_kobject *mk = to_module_kobject(kobj);
958 complete(mk->kobj_completion);
961 struct kobj_type module_ktype = {
962 .release = module_kobj_release,
963 .sysfs_ops = &module_sysfs_ops,
967 * param_sysfs_init - wrapper for built-in params support
969 static int __init param_sysfs_init(void)
971 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
973 printk(KERN_WARNING "%s (%d): error creating kset\n",
977 module_sysfs_initialized = 1;
979 version_sysfs_builtin();
980 param_sysfs_builtin();
984 subsys_initcall(param_sysfs_init);
986 #endif /* CONFIG_SYSFS */