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>
27 /* We abuse the high bits of "perm" to record whether we kmalloc'ed. */
28 #define KPARAM_KMALLOCED 0x80000000
33 #define DEBUGP(fmt, a...)
36 static inline char dash2underscore(char c)
43 static inline int parameq(const char *input, const char *paramname)
46 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
52 static int parse_one(char *param,
54 struct kernel_param *params,
56 int (*handle_unknown)(char *param, char *val))
61 for (i = 0; i < num_params; i++) {
62 if (parameq(param, params[i].name)) {
63 DEBUGP("They are equal! Calling %p\n",
65 return params[i].set(val, ¶ms[i]);
70 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
71 return handle_unknown(param, val);
74 DEBUGP("Unknown argument `%s'\n", param);
78 /* You can use " around spaces, but can't escape ". */
79 /* Hyphens and underscores equivalent in parameter names. */
80 static char *next_arg(char *args, char **param, char **val)
82 unsigned int i, equals = 0;
83 int in_quote = 0, quoted = 0;
92 for (i = 0; args[i]; i++) {
93 if (args[i] == ' ' && !in_quote)
100 in_quote = !in_quote;
108 *val = args + equals + 1;
110 /* Don't include quotes in value. */
113 if (args[i-1] == '"')
116 if (quoted && args[i-1] == '"')
126 /* Chew up trailing spaces. */
132 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
133 int parse_args(const char *name,
135 struct kernel_param *params,
137 int (*unknown)(char *param, char *val))
141 DEBUGP("Parsing ARGS: %s\n", args);
143 /* Chew leading spaces */
149 int irq_was_disabled;
151 args = next_arg(args, ¶m, &val);
152 irq_was_disabled = irqs_disabled();
153 ret = parse_one(param, val, params, num, unknown);
154 if (irq_was_disabled && !irqs_disabled()) {
155 printk(KERN_WARNING "parse_args(): option '%s' enabled "
160 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
165 "%s: `%s' too large for parameter `%s'\n",
166 name, val ?: "", param);
172 "%s: `%s' invalid for parameter `%s'\n",
173 name, val ?: "", param);
182 /* Lazy bastard, eh? */
183 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
184 int param_set_##name(const char *val, struct kernel_param *kp) \
189 if (!val) return -EINVAL; \
190 ret = strtolfn(val, 0, &l); \
191 if (ret == -EINVAL || ((type)l != l)) \
193 *((type *)kp->arg) = l; \
196 int param_get_##name(char *buffer, struct kernel_param *kp) \
198 return sprintf(buffer, format, *((type *)kp->arg)); \
201 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
202 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
203 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
204 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
205 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
206 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
207 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
209 int param_set_charp(const char *val, struct kernel_param *kp)
212 printk(KERN_ERR "%s: string parameter expected\n",
217 if (strlen(val) > 1024) {
218 printk(KERN_ERR "%s: string parameter too long\n",
223 if (kp->perm & KPARAM_KMALLOCED)
224 kfree(*(char **)kp->arg);
226 /* This is a hack. We can't need to strdup in early boot, and we
227 * don't need to; this mangled commandline is preserved. */
228 if (slab_is_available()) {
229 kp->perm |= KPARAM_KMALLOCED;
230 *(char **)kp->arg = kstrdup(val, GFP_KERNEL);
234 *(const char **)kp->arg = val;
239 int param_get_charp(char *buffer, struct kernel_param *kp)
241 return sprintf(buffer, "%s", *((char **)kp->arg));
244 int param_set_bool(const char *val, struct kernel_param *kp)
246 /* No equals means "set"... */
249 /* One of =[yYnN01] */
251 case 'y': case 'Y': case '1':
254 case 'n': case 'N': case '0':
261 int param_get_bool(char *buffer, struct kernel_param *kp)
263 /* Y and N chosen as being relatively non-coder friendly */
264 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
267 int param_set_invbool(const char *val, struct kernel_param *kp)
270 struct kernel_param dummy;
272 dummy.arg = &boolval;
273 ret = param_set_bool(val, &dummy);
275 *(int *)kp->arg = !boolval;
279 int param_get_invbool(char *buffer, struct kernel_param *kp)
281 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'N' : 'Y');
284 /* We break the rule and mangle the string. */
285 static int param_array(const char *name,
287 unsigned int min, unsigned int max,
288 void *elem, int elemsize,
289 int (*set)(const char *, struct kernel_param *kp),
293 struct kernel_param kp;
296 /* Get the name right for errors. */
300 /* No equals sign? */
302 printk(KERN_ERR "%s: expects arguments\n", name);
307 /* We expect a comma-separated list of values. */
312 printk(KERN_ERR "%s: can only take %i arguments\n",
316 len = strcspn(val, ",");
318 /* nul-terminate and parse */
320 ((char *)val)[len] = '\0';
328 } while (save == ',');
331 printk(KERN_ERR "%s: needs at least %i arguments\n",
338 int param_array_set(const char *val, struct kernel_param *kp)
340 const struct kparam_array *arr = kp->arr;
341 unsigned int temp_num;
343 return param_array(kp->name, val, 1, arr->max, arr->elem,
344 arr->elemsize, arr->set, arr->num ?: &temp_num);
347 int param_array_get(char *buffer, struct kernel_param *kp)
350 const struct kparam_array *arr = kp->arr;
351 struct kernel_param p;
354 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
357 p.arg = arr->elem + arr->elemsize * i;
358 ret = arr->get(buffer + off, &p);
367 int param_set_copystring(const char *val, struct kernel_param *kp)
369 const struct kparam_string *kps = kp->str;
372 printk(KERN_ERR "%s: missing param set value\n", kp->name);
375 if (strlen(val)+1 > kps->maxlen) {
376 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
377 kp->name, kps->maxlen-1);
380 strcpy(kps->string, val);
384 int param_get_string(char *buffer, struct kernel_param *kp)
386 const struct kparam_string *kps = kp->str;
387 return strlcpy(buffer, kps->string, kps->maxlen);
390 /* sysfs output in /sys/modules/XYZ/parameters/ */
391 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
392 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
394 extern struct kernel_param __start___param[], __stop___param[];
396 struct param_attribute
398 struct module_attribute mattr;
399 struct kernel_param *param;
402 struct module_param_attrs
405 struct attribute_group grp;
406 struct param_attribute attrs[0];
410 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
412 static ssize_t param_attr_show(struct module_attribute *mattr,
413 struct module *mod, char *buf)
416 struct param_attribute *attribute = to_param_attr(mattr);
418 if (!attribute->param->get)
421 count = attribute->param->get(buf, attribute->param);
429 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
430 static ssize_t param_attr_store(struct module_attribute *mattr,
431 struct module *owner,
432 const char *buf, size_t len)
435 struct param_attribute *attribute = to_param_attr(mattr);
437 if (!attribute->param->set)
440 err = attribute->param->set(buf, attribute->param);
447 #ifdef CONFIG_MODULES
450 #define __modinit __init
455 * add_sysfs_param - add a parameter to sysfs
456 * @mk: struct module_kobject
457 * @kparam: the actual parameter definition to add to sysfs
458 * @name: name of parameter
460 * Create a kobject if for a (per-module) parameter if mp NULL, and
461 * create file in sysfs. Returns an error on out of memory. Always cleans up
462 * if there's an error.
464 static __modinit int add_sysfs_param(struct module_kobject *mk,
465 struct kernel_param *kp,
468 struct module_param_attrs *new;
469 struct attribute **attrs;
472 /* We don't bother calling this with invisible parameters. */
480 attrs = mk->mp->grp.attrs;
484 new = krealloc(mk->mp,
485 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
492 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
498 /* Sysfs wants everything zeroed. */
499 memset(new, 0, sizeof(*new));
500 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
501 memset(&attrs[num], 0, sizeof(attrs[num]));
502 new->grp.name = "parameters";
503 new->grp.attrs = attrs;
505 /* Tack new one on the end. */
506 new->attrs[num].param = kp;
507 new->attrs[num].mattr.show = param_attr_show;
508 new->attrs[num].mattr.store = param_attr_store;
509 new->attrs[num].mattr.attr.name = (char *)name;
510 new->attrs[num].mattr.attr.mode = kp->perm;
513 /* Fix up all the pointers, since krealloc can move us */
514 for (num = 0; num < new->num; num++)
515 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
516 new->grp.attrs[num] = NULL;
528 #ifdef CONFIG_MODULES
529 static void free_module_param_attrs(struct module_kobject *mk)
531 kfree(mk->mp->grp.attrs);
537 * module_param_sysfs_setup - setup sysfs support for one module
539 * @kparam: module parameters (array)
540 * @num_params: number of module parameters
542 * Adds sysfs entries for module parameters under
543 * /sys/module/[mod->name]/parameters/
545 int module_param_sysfs_setup(struct module *mod,
546 struct kernel_param *kparam,
547 unsigned int num_params)
552 for (i = 0; i < num_params; i++) {
553 if (kparam[i].perm == 0)
555 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
564 /* Create the param group. */
565 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
567 free_module_param_attrs(&mod->mkobj);
572 * module_param_sysfs_remove - remove sysfs support for one module
575 * Remove sysfs entries for module parameters and the corresponding
578 void module_param_sysfs_remove(struct module *mod)
581 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
582 /* We are positive that no one is using any param
583 * attrs at this point. Deallocate immediately. */
584 free_module_param_attrs(&mod->mkobj);
589 void destroy_params(const struct kernel_param *params, unsigned num)
593 for (i = 0; i < num; i++)
594 if (params[i].perm & KPARAM_KMALLOCED)
595 kfree(*(char **)params[i].arg);
598 static void __init kernel_add_sysfs_param(const char *name,
599 struct kernel_param *kparam,
600 unsigned int name_skip)
602 struct module_kobject *mk;
603 struct kobject *kobj;
606 kobj = kset_find_obj(module_kset, name);
608 /* We already have one. Remove params so we can add more. */
609 mk = to_module_kobject(kobj);
610 /* We need to remove it before adding parameters. */
611 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
613 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
616 mk->mod = THIS_MODULE;
617 mk->kobj.kset = module_kset;
618 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
621 kobject_put(&mk->kobj);
622 printk(KERN_ERR "Module '%s' failed add to sysfs, "
623 "error number %d\n", name, err);
624 printk(KERN_ERR "The system will be unstable now.\n");
627 /* So that exit path is even. */
628 kobject_get(&mk->kobj);
631 /* These should not fail at boot. */
632 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
634 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
636 kobject_uevent(&mk->kobj, KOBJ_ADD);
637 kobject_put(&mk->kobj);
641 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
643 * Add module_parameters to sysfs for "modules" built into the kernel.
645 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
646 * "parameter" name is stored behind a dot in kernel_param->name. So,
647 * extract the "module" name for all built-in kernel_param-eters,
648 * and for all who have the same, call kernel_add_sysfs_param.
650 static void __init param_sysfs_builtin(void)
652 struct kernel_param *kp;
653 unsigned int name_len;
654 char modname[MODULE_NAME_LEN];
656 for (kp = __start___param; kp < __stop___param; kp++) {
662 dot = strchr(kp->name, '.');
664 /* This happens for core_param() */
665 strcpy(modname, "kernel");
668 name_len = dot - kp->name + 1;
669 strlcpy(modname, kp->name, name_len);
671 kernel_add_sysfs_param(modname, kp, name_len);
676 /* module-related sysfs stuff */
678 static ssize_t module_attr_show(struct kobject *kobj,
679 struct attribute *attr,
682 struct module_attribute *attribute;
683 struct module_kobject *mk;
686 attribute = to_module_attr(attr);
687 mk = to_module_kobject(kobj);
689 if (!attribute->show)
692 ret = attribute->show(attribute, mk->mod, buf);
697 static ssize_t module_attr_store(struct kobject *kobj,
698 struct attribute *attr,
699 const char *buf, size_t len)
701 struct module_attribute *attribute;
702 struct module_kobject *mk;
705 attribute = to_module_attr(attr);
706 mk = to_module_kobject(kobj);
708 if (!attribute->store)
711 ret = attribute->store(attribute, mk->mod, buf, len);
716 static struct sysfs_ops module_sysfs_ops = {
717 .show = module_attr_show,
718 .store = module_attr_store,
721 static int uevent_filter(struct kset *kset, struct kobject *kobj)
723 struct kobj_type *ktype = get_ktype(kobj);
725 if (ktype == &module_ktype)
730 static struct kset_uevent_ops module_uevent_ops = {
731 .filter = uevent_filter,
734 struct kset *module_kset;
735 int module_sysfs_initialized;
737 struct kobj_type module_ktype = {
738 .sysfs_ops = &module_sysfs_ops,
742 * param_sysfs_init - wrapper for built-in params support
744 static int __init param_sysfs_init(void)
746 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
748 printk(KERN_WARNING "%s (%d): error creating kset\n",
752 module_sysfs_initialized = 1;
754 param_sysfs_builtin();
758 subsys_initcall(param_sysfs_init);
760 #endif /* CONFIG_SYSFS */
762 EXPORT_SYMBOL(param_set_byte);
763 EXPORT_SYMBOL(param_get_byte);
764 EXPORT_SYMBOL(param_set_short);
765 EXPORT_SYMBOL(param_get_short);
766 EXPORT_SYMBOL(param_set_ushort);
767 EXPORT_SYMBOL(param_get_ushort);
768 EXPORT_SYMBOL(param_set_int);
769 EXPORT_SYMBOL(param_get_int);
770 EXPORT_SYMBOL(param_set_uint);
771 EXPORT_SYMBOL(param_get_uint);
772 EXPORT_SYMBOL(param_set_long);
773 EXPORT_SYMBOL(param_get_long);
774 EXPORT_SYMBOL(param_set_ulong);
775 EXPORT_SYMBOL(param_get_ulong);
776 EXPORT_SYMBOL(param_set_charp);
777 EXPORT_SYMBOL(param_get_charp);
778 EXPORT_SYMBOL(param_set_bool);
779 EXPORT_SYMBOL(param_get_bool);
780 EXPORT_SYMBOL(param_set_invbool);
781 EXPORT_SYMBOL(param_get_invbool);
782 EXPORT_SYMBOL(param_array_set);
783 EXPORT_SYMBOL(param_array_get);
784 EXPORT_SYMBOL(param_set_copystring);
785 EXPORT_SYMBOL(param_get_string);