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 void param_check_unsafe(const struct kernel_param *kp)
88 if (kp->flags & KERNEL_PARAM_FL_UNSAFE) {
89 pr_warn("Setting dangerous option %s - tainting kernel\n",
91 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
95 static int parse_one(char *param,
98 const struct kernel_param *params,
102 int (*handle_unknown)(char *param, char *val,
109 for (i = 0; i < num_params; i++) {
110 if (parameq(param, params[i].name)) {
111 if (params[i].level < min_level
112 || params[i].level > max_level)
114 /* No one handled NULL, so do it here. */
116 !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG))
118 pr_debug("handling %s with %p\n", param,
120 mutex_lock(¶m_lock);
121 param_check_unsafe(¶ms[i]);
122 err = params[i].ops->set(val, ¶ms[i]);
123 mutex_unlock(¶m_lock);
128 if (handle_unknown) {
129 pr_debug("doing %s: %s='%s'\n", doing, param, val);
130 return handle_unknown(param, val, doing);
133 pr_debug("Unknown argument '%s'\n", param);
137 /* You can use " around spaces, but can't escape ". */
138 /* Hyphens and underscores equivalent in parameter names. */
139 static char *next_arg(char *args, char **param, char **val)
141 unsigned int i, equals = 0;
142 int in_quote = 0, quoted = 0;
151 for (i = 0; args[i]; i++) {
152 if (isspace(args[i]) && !in_quote)
159 in_quote = !in_quote;
167 *val = args + equals + 1;
169 /* Don't include quotes in value. */
172 if (args[i-1] == '"')
175 if (quoted && args[i-1] == '"')
185 /* Chew up trailing spaces. */
186 return skip_spaces(next);
189 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
190 char *parse_args(const char *doing,
192 const struct kernel_param *params,
196 int (*unknown)(char *param, char *val, const char *doing))
200 /* Chew leading spaces */
201 args = skip_spaces(args);
204 pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
208 int irq_was_disabled;
210 args = next_arg(args, ¶m, &val);
212 if (!val && strcmp(param, "--") == 0)
214 irq_was_disabled = irqs_disabled();
215 ret = parse_one(param, val, doing, params, num,
216 min_level, max_level, unknown);
217 if (irq_was_disabled && !irqs_disabled())
218 pr_warn("%s: option '%s' enabled irq's!\n",
223 pr_err("%s: Unknown parameter `%s'\n", doing, param);
226 pr_err("%s: `%s' too large for parameter `%s'\n",
227 doing, val ?: "", param);
232 pr_err("%s: `%s' invalid for parameter `%s'\n",
233 doing, val ?: "", param);
242 /* Lazy bastard, eh? */
243 #define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
244 int param_set_##name(const char *val, const struct kernel_param *kp) \
246 return strtolfn(val, 0, (type *)kp->arg); \
248 int param_get_##name(char *buffer, const struct kernel_param *kp) \
250 return scnprintf(buffer, PAGE_SIZE, format, \
251 *((type *)kp->arg)); \
253 struct kernel_param_ops param_ops_##name = { \
254 .set = param_set_##name, \
255 .get = param_get_##name, \
257 EXPORT_SYMBOL(param_set_##name); \
258 EXPORT_SYMBOL(param_get_##name); \
259 EXPORT_SYMBOL(param_ops_##name)
262 STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
263 STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
264 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
265 STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
266 STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
267 STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
268 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
269 STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull);
271 int param_set_charp(const char *val, const struct kernel_param *kp)
273 if (strlen(val) > 1024) {
274 pr_err("%s: string parameter too long\n", kp->name);
278 maybe_kfree_parameter(*(char **)kp->arg);
280 /* This is a hack. We can't kmalloc in early boot, and we
281 * don't need to; this mangled commandline is preserved. */
282 if (slab_is_available()) {
283 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
284 if (!*(char **)kp->arg)
286 strcpy(*(char **)kp->arg, val);
288 *(const char **)kp->arg = val;
292 EXPORT_SYMBOL(param_set_charp);
294 int param_get_charp(char *buffer, const struct kernel_param *kp)
296 return scnprintf(buffer, PAGE_SIZE, "%s", *((char **)kp->arg));
298 EXPORT_SYMBOL(param_get_charp);
300 static void param_free_charp(void *arg)
302 maybe_kfree_parameter(*((char **)arg));
305 struct kernel_param_ops param_ops_charp = {
306 .set = param_set_charp,
307 .get = param_get_charp,
308 .free = param_free_charp,
310 EXPORT_SYMBOL(param_ops_charp);
312 /* Actually could be a bool or an int, for historical reasons. */
313 int param_set_bool(const char *val, const struct kernel_param *kp)
315 /* No equals means "set"... */
318 /* One of =[yYnN01] */
319 return strtobool(val, kp->arg);
321 EXPORT_SYMBOL(param_set_bool);
323 int param_get_bool(char *buffer, const struct kernel_param *kp)
325 /* Y and N chosen as being relatively non-coder friendly */
326 return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
328 EXPORT_SYMBOL(param_get_bool);
330 struct kernel_param_ops param_ops_bool = {
331 .flags = KERNEL_PARAM_OPS_FL_NOARG,
332 .set = param_set_bool,
333 .get = param_get_bool,
335 EXPORT_SYMBOL(param_ops_bool);
337 /* This one must be bool. */
338 int param_set_invbool(const char *val, const struct kernel_param *kp)
342 struct kernel_param dummy;
344 dummy.arg = &boolval;
345 ret = param_set_bool(val, &dummy);
347 *(bool *)kp->arg = !boolval;
350 EXPORT_SYMBOL(param_set_invbool);
352 int param_get_invbool(char *buffer, const struct kernel_param *kp)
354 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
356 EXPORT_SYMBOL(param_get_invbool);
358 struct kernel_param_ops param_ops_invbool = {
359 .set = param_set_invbool,
360 .get = param_get_invbool,
362 EXPORT_SYMBOL(param_ops_invbool);
364 int param_set_bint(const char *val, const struct kernel_param *kp)
366 struct kernel_param boolkp;
370 /* Match bool exactly, by re-using it. */
374 ret = param_set_bool(val, &boolkp);
379 EXPORT_SYMBOL(param_set_bint);
381 struct kernel_param_ops param_ops_bint = {
382 .flags = KERNEL_PARAM_OPS_FL_NOARG,
383 .set = param_set_bint,
384 .get = param_get_int,
386 EXPORT_SYMBOL(param_ops_bint);
388 /* We break the rule and mangle the string. */
389 static int param_array(const char *name,
391 unsigned int min, unsigned int max,
392 void *elem, int elemsize,
393 int (*set)(const char *, const struct kernel_param *kp),
398 struct kernel_param kp;
401 /* Get the name right for errors. */
407 /* We expect a comma-separated list of values. */
412 pr_err("%s: can only take %i arguments\n", name, max);
415 len = strcspn(val, ",");
417 /* nul-terminate and parse */
419 ((char *)val)[len] = '\0';
420 BUG_ON(!mutex_is_locked(¶m_lock));
428 } while (save == ',');
431 pr_err("%s: needs at least %i arguments\n", name, min);
437 static int param_array_set(const char *val, const struct kernel_param *kp)
439 const struct kparam_array *arr = kp->arr;
440 unsigned int temp_num;
442 return param_array(kp->name, val, 1, arr->max, arr->elem,
443 arr->elemsize, arr->ops->set, kp->level,
444 arr->num ?: &temp_num);
447 static int param_array_get(char *buffer, const struct kernel_param *kp)
450 const struct kparam_array *arr = kp->arr;
451 struct kernel_param p;
454 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
457 p.arg = arr->elem + arr->elemsize * i;
458 BUG_ON(!mutex_is_locked(¶m_lock));
459 ret = arr->ops->get(buffer + off, &p);
468 static void param_array_free(void *arg)
471 const struct kparam_array *arr = arg;
474 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
475 arr->ops->free(arr->elem + arr->elemsize * i);
478 struct kernel_param_ops param_array_ops = {
479 .set = param_array_set,
480 .get = param_array_get,
481 .free = param_array_free,
483 EXPORT_SYMBOL(param_array_ops);
485 int param_set_copystring(const char *val, const struct kernel_param *kp)
487 const struct kparam_string *kps = kp->str;
489 if (strlen(val)+1 > kps->maxlen) {
490 pr_err("%s: string doesn't fit in %u chars.\n",
491 kp->name, kps->maxlen-1);
494 strcpy(kps->string, val);
497 EXPORT_SYMBOL(param_set_copystring);
499 int param_get_string(char *buffer, const struct kernel_param *kp)
501 const struct kparam_string *kps = kp->str;
502 return strlcpy(buffer, kps->string, kps->maxlen);
504 EXPORT_SYMBOL(param_get_string);
506 struct kernel_param_ops param_ops_string = {
507 .set = param_set_copystring,
508 .get = param_get_string,
510 EXPORT_SYMBOL(param_ops_string);
512 /* sysfs output in /sys/modules/XYZ/parameters/ */
513 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
514 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
516 extern struct kernel_param __start___param[], __stop___param[];
518 struct param_attribute
520 struct module_attribute mattr;
521 const struct kernel_param *param;
524 struct module_param_attrs
527 struct attribute_group grp;
528 struct param_attribute attrs[0];
532 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
534 static ssize_t param_attr_show(struct module_attribute *mattr,
535 struct module_kobject *mk, char *buf)
538 struct param_attribute *attribute = to_param_attr(mattr);
540 if (!attribute->param->ops->get)
543 mutex_lock(¶m_lock);
544 count = attribute->param->ops->get(buf, attribute->param);
545 mutex_unlock(¶m_lock);
553 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
554 static ssize_t param_attr_store(struct module_attribute *mattr,
555 struct module_kobject *km,
556 const char *buf, size_t len)
559 struct param_attribute *attribute = to_param_attr(mattr);
561 if (!attribute->param->ops->set)
564 mutex_lock(¶m_lock);
565 param_check_unsafe(attribute->param);
566 err = attribute->param->ops->set(buf, attribute->param);
567 mutex_unlock(¶m_lock);
574 #ifdef CONFIG_MODULES
577 #define __modinit __init
581 void __kernel_param_lock(void)
583 mutex_lock(¶m_lock);
585 EXPORT_SYMBOL(__kernel_param_lock);
587 void __kernel_param_unlock(void)
589 mutex_unlock(¶m_lock);
591 EXPORT_SYMBOL(__kernel_param_unlock);
594 * add_sysfs_param - add a parameter to sysfs
595 * @mk: struct module_kobject
596 * @kparam: the actual parameter definition to add to sysfs
597 * @name: name of parameter
599 * Create a kobject if for a (per-module) parameter if mp NULL, and
600 * create file in sysfs. Returns an error on out of memory. Always cleans up
601 * if there's an error.
603 static __modinit int add_sysfs_param(struct module_kobject *mk,
604 const struct kernel_param *kp,
607 struct module_param_attrs *new;
608 struct attribute **attrs;
611 /* We don't bother calling this with invisible parameters. */
619 attrs = mk->mp->grp.attrs;
623 new = krealloc(mk->mp,
624 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
631 /* Despite looking like the typical realloc() bug, this is safe.
632 * We *want* the old 'attrs' to be freed either way, and we'll store
633 * the new one in the success case. */
634 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
640 /* Sysfs wants everything zeroed. */
641 memset(new, 0, sizeof(*new));
642 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
643 memset(&attrs[num], 0, sizeof(attrs[num]));
644 new->grp.name = "parameters";
645 new->grp.attrs = attrs;
647 /* Tack new one on the end. */
648 sysfs_attr_init(&new->attrs[num].mattr.attr);
649 new->attrs[num].param = kp;
650 new->attrs[num].mattr.show = param_attr_show;
651 new->attrs[num].mattr.store = param_attr_store;
652 new->attrs[num].mattr.attr.name = (char *)name;
653 new->attrs[num].mattr.attr.mode = kp->perm;
656 /* Fix up all the pointers, since krealloc can move us */
657 for (num = 0; num < new->num; num++)
658 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
659 new->grp.attrs[num] = NULL;
671 #ifdef CONFIG_MODULES
672 static void free_module_param_attrs(struct module_kobject *mk)
674 kfree(mk->mp->grp.attrs);
680 * module_param_sysfs_setup - setup sysfs support for one module
682 * @kparam: module parameters (array)
683 * @num_params: number of module parameters
685 * Adds sysfs entries for module parameters under
686 * /sys/module/[mod->name]/parameters/
688 int module_param_sysfs_setup(struct module *mod,
689 const struct kernel_param *kparam,
690 unsigned int num_params)
695 for (i = 0; i < num_params; i++) {
696 if (kparam[i].perm == 0)
698 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
707 /* Create the param group. */
708 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
710 free_module_param_attrs(&mod->mkobj);
715 * module_param_sysfs_remove - remove sysfs support for one module
718 * Remove sysfs entries for module parameters and the corresponding
721 void module_param_sysfs_remove(struct module *mod)
724 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
725 /* We are positive that no one is using any param
726 * attrs at this point. Deallocate immediately. */
727 free_module_param_attrs(&mod->mkobj);
732 void destroy_params(const struct kernel_param *params, unsigned num)
736 for (i = 0; i < num; i++)
737 if (params[i].ops->free)
738 params[i].ops->free(params[i].arg);
741 static struct module_kobject * __init locate_module_kobject(const char *name)
743 struct module_kobject *mk;
744 struct kobject *kobj;
747 kobj = kset_find_obj(module_kset, name);
749 mk = to_module_kobject(kobj);
751 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
754 mk->mod = THIS_MODULE;
755 mk->kobj.kset = module_kset;
756 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
758 #ifdef CONFIG_MODULES
760 err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
763 kobject_put(&mk->kobj);
764 pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
769 /* So that we hold reference in both cases. */
770 kobject_get(&mk->kobj);
776 static void __init kernel_add_sysfs_param(const char *name,
777 struct kernel_param *kparam,
778 unsigned int name_skip)
780 struct module_kobject *mk;
783 mk = locate_module_kobject(name);
787 /* We need to remove old parameters before adding more. */
789 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
791 /* These should not fail at boot. */
792 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
794 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
796 kobject_uevent(&mk->kobj, KOBJ_ADD);
797 kobject_put(&mk->kobj);
801 * param_sysfs_builtin - add sysfs parameters for built-in modules
803 * Add module_parameters to sysfs for "modules" built into the kernel.
805 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
806 * "parameter" name is stored behind a dot in kernel_param->name. So,
807 * extract the "module" name for all built-in kernel_param-eters,
808 * and for all who have the same, call kernel_add_sysfs_param.
810 static void __init param_sysfs_builtin(void)
812 struct kernel_param *kp;
813 unsigned int name_len;
814 char modname[MODULE_NAME_LEN];
816 for (kp = __start___param; kp < __stop___param; kp++) {
822 dot = strchr(kp->name, '.');
824 /* This happens for core_param() */
825 strcpy(modname, "kernel");
828 name_len = dot - kp->name + 1;
829 strlcpy(modname, kp->name, name_len);
831 kernel_add_sysfs_param(modname, kp, name_len);
835 ssize_t __modver_version_show(struct module_attribute *mattr,
836 struct module_kobject *mk, char *buf)
838 struct module_version_attribute *vattr =
839 container_of(mattr, struct module_version_attribute, mattr);
841 return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
844 extern const struct module_version_attribute *__start___modver[];
845 extern const struct module_version_attribute *__stop___modver[];
847 static void __init version_sysfs_builtin(void)
849 const struct module_version_attribute **p;
850 struct module_kobject *mk;
853 for (p = __start___modver; p < __stop___modver; p++) {
854 const struct module_version_attribute *vattr = *p;
856 mk = locate_module_kobject(vattr->module_name);
858 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
859 kobject_uevent(&mk->kobj, KOBJ_ADD);
860 kobject_put(&mk->kobj);
865 /* module-related sysfs stuff */
867 static ssize_t module_attr_show(struct kobject *kobj,
868 struct attribute *attr,
871 struct module_attribute *attribute;
872 struct module_kobject *mk;
875 attribute = to_module_attr(attr);
876 mk = to_module_kobject(kobj);
878 if (!attribute->show)
881 ret = attribute->show(attribute, mk, buf);
886 static ssize_t module_attr_store(struct kobject *kobj,
887 struct attribute *attr,
888 const char *buf, size_t len)
890 struct module_attribute *attribute;
891 struct module_kobject *mk;
894 attribute = to_module_attr(attr);
895 mk = to_module_kobject(kobj);
897 if (!attribute->store)
900 ret = attribute->store(attribute, mk, buf, len);
905 static const struct sysfs_ops module_sysfs_ops = {
906 .show = module_attr_show,
907 .store = module_attr_store,
910 static int uevent_filter(struct kset *kset, struct kobject *kobj)
912 struct kobj_type *ktype = get_ktype(kobj);
914 if (ktype == &module_ktype)
919 static const struct kset_uevent_ops module_uevent_ops = {
920 .filter = uevent_filter,
923 struct kset *module_kset;
924 int module_sysfs_initialized;
926 static void module_kobj_release(struct kobject *kobj)
928 struct module_kobject *mk = to_module_kobject(kobj);
929 complete(mk->kobj_completion);
932 struct kobj_type module_ktype = {
933 .release = module_kobj_release,
934 .sysfs_ops = &module_sysfs_ops,
938 * param_sysfs_init - wrapper for built-in params support
940 static int __init param_sysfs_init(void)
942 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
944 printk(KERN_WARNING "%s (%d): error creating kset\n",
948 module_sysfs_initialized = 1;
950 version_sysfs_builtin();
951 param_sysfs_builtin();
955 subsys_initcall(param_sysfs_init);
957 #endif /* CONFIG_SYSFS */