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/config.h>
19 #include <linux/moduleparam.h>
20 #include <linux/kernel.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include <linux/module.h>
24 #include <linux/device.h>
25 #include <linux/err.h>
26 #include <linux/slab.h>
31 #define DEBUGP(fmt, a...)
34 static inline int dash2underscore(char c)
41 static inline int parameq(const char *input, const char *paramname)
44 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
50 static int parse_one(char *param,
52 struct kernel_param *params,
54 int (*handle_unknown)(char *param, char *val))
59 for (i = 0; i < num_params; i++) {
60 if (parameq(param, params[i].name)) {
61 DEBUGP("They are equal! Calling %p\n",
63 return params[i].set(val, ¶ms[i]);
68 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
69 return handle_unknown(param, val);
72 DEBUGP("Unknown argument `%s'\n", param);
76 /* You can use " around spaces, but can't escape ". */
77 /* Hyphens and underscores equivalent in parameter names. */
78 static char *next_arg(char *args, char **param, char **val)
80 unsigned int i, equals = 0;
81 int in_quote = 0, quoted = 0;
90 for (i = 0; args[i]; i++) {
91 if (args[i] == ' ' && !in_quote)
106 *val = args + equals + 1;
108 /* Don't include quotes in value. */
111 if (args[i-1] == '"')
114 if (quoted && args[i-1] == '"')
124 /* Chew up trailing spaces. */
130 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
131 int parse_args(const char *name,
133 struct kernel_param *params,
135 int (*unknown)(char *param, char *val))
139 DEBUGP("Parsing ARGS: %s\n", args);
141 /* Chew leading spaces */
148 args = next_arg(args, ¶m, &val);
149 ret = parse_one(param, val, params, num, unknown);
152 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
157 "%s: `%s' too large for parameter `%s'\n",
158 name, val ?: "", param);
164 "%s: `%s' invalid for parameter `%s'\n",
165 name, val ?: "", param);
174 /* Lazy bastard, eh? */
175 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
176 int param_set_##name(const char *val, struct kernel_param *kp) \
181 if (!val) return -EINVAL; \
182 l = strtolfn(val, &endp, 0); \
183 if (endp == val || ((type)l != l)) \
185 *((type *)kp->arg) = l; \
188 int param_get_##name(char *buffer, struct kernel_param *kp) \
190 return sprintf(buffer, format, *((type *)kp->arg)); \
193 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, simple_strtoul);
194 STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol);
195 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, simple_strtoul);
196 STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol);
197 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, simple_strtoul);
198 STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol);
199 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_strtoul);
201 int param_set_charp(const char *val, struct kernel_param *kp)
204 printk(KERN_ERR "%s: string parameter expected\n",
209 if (strlen(val) > 1024) {
210 printk(KERN_ERR "%s: string parameter too long\n",
215 *(char **)kp->arg = (char *)val;
219 int param_get_charp(char *buffer, struct kernel_param *kp)
221 return sprintf(buffer, "%s", *((char **)kp->arg));
224 int param_set_bool(const char *val, struct kernel_param *kp)
226 /* No equals means "set"... */
229 /* One of =[yYnN01] */
231 case 'y': case 'Y': case '1':
234 case 'n': case 'N': case '0':
241 int param_get_bool(char *buffer, struct kernel_param *kp)
243 /* Y and N chosen as being relatively non-coder friendly */
244 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
247 int param_set_invbool(const char *val, struct kernel_param *kp)
250 struct kernel_param dummy = { .arg = &boolval };
252 ret = param_set_bool(val, &dummy);
254 *(int *)kp->arg = !boolval;
258 int param_get_invbool(char *buffer, struct kernel_param *kp)
261 struct kernel_param dummy = { .arg = &val };
263 val = !*(int *)kp->arg;
264 return param_get_bool(buffer, &dummy);
267 /* We cheat here and temporarily mangle the string. */
268 int param_array(const char *name,
270 unsigned int min, unsigned int max,
271 void *elem, int elemsize,
272 int (*set)(const char *, struct kernel_param *kp),
276 struct kernel_param kp;
279 /* Get the name right for errors. */
283 /* No equals sign? */
285 printk(KERN_ERR "%s: expects arguments\n", name);
290 /* We expect a comma-separated list of values. */
295 printk(KERN_ERR "%s: can only take %i arguments\n",
299 len = strcspn(val, ",");
301 /* nul-terminate and parse */
303 ((char *)val)[len] = '\0';
311 } while (save == ',');
314 printk(KERN_ERR "%s: needs at least %i arguments\n",
321 int param_array_set(const char *val, struct kernel_param *kp)
323 struct kparam_array *arr = kp->arg;
324 unsigned int temp_num;
326 return param_array(kp->name, val, 1, arr->max, arr->elem,
327 arr->elemsize, arr->set, arr->num ?: &temp_num);
330 int param_array_get(char *buffer, struct kernel_param *kp)
333 struct kparam_array *arr = kp->arg;
334 struct kernel_param p;
337 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
340 p.arg = arr->elem + arr->elemsize * i;
341 ret = arr->get(buffer + off, &p);
350 int param_set_copystring(const char *val, struct kernel_param *kp)
352 struct kparam_string *kps = kp->arg;
354 if (strlen(val)+1 > kps->maxlen) {
355 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
356 kp->name, kps->maxlen-1);
359 strcpy(kps->string, val);
363 int param_get_string(char *buffer, struct kernel_param *kp)
365 struct kparam_string *kps = kp->arg;
366 return strlcpy(buffer, kps->string, kps->maxlen);
369 /* sysfs output in /sys/modules/XYZ/parameters/ */
371 extern struct kernel_param __start___param[], __stop___param[];
373 #define MAX_KBUILD_MODNAME KOBJ_NAME_LEN
375 struct param_attribute
377 struct module_attribute mattr;
378 struct kernel_param *param;
381 struct module_param_attrs
383 struct attribute_group grp;
384 struct param_attribute attrs[0];
387 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
389 static ssize_t param_attr_show(struct module_attribute *mattr,
390 struct module *mod, char *buf)
393 struct param_attribute *attribute = to_param_attr(mattr);
395 if (!attribute->param->get)
398 count = attribute->param->get(buf, attribute->param);
406 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
407 static ssize_t param_attr_store(struct module_attribute *mattr,
408 struct module *owner,
409 const char *buf, size_t len)
412 struct param_attribute *attribute = to_param_attr(mattr);
414 if (!attribute->param->set)
417 err = attribute->param->set(buf, attribute->param);
423 #ifdef CONFIG_MODULES
426 #define __modinit __init
430 * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME
431 * @mk: struct module_kobject (contains parent kobject)
432 * @kparam: array of struct kernel_param, the actual parameter definitions
433 * @num_params: number of entries in array
434 * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules"
436 * Create a kobject for a (per-module) group of parameters, and create files
437 * in sysfs. A pointer to the param_kobject is returned on success,
438 * NULL if there's no parameter to export, or other ERR_PTR(err).
440 static __modinit struct module_param_attrs *
441 param_sysfs_setup(struct module_kobject *mk,
442 struct kernel_param *kparam,
443 unsigned int num_params,
444 unsigned int name_skip)
446 struct module_param_attrs *mp;
447 unsigned int valid_attrs = 0;
448 unsigned int i, size[2];
449 struct param_attribute *pattr;
450 struct attribute **gattr;
453 for (i=0; i<num_params; i++) {
461 size[0] = ALIGN(sizeof(*mp) +
462 valid_attrs * sizeof(mp->attrs[0]),
463 sizeof(mp->grp.attrs[0]));
464 size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]);
466 mp = kmalloc(size[0] + size[1], GFP_KERNEL);
468 return ERR_PTR(-ENOMEM);
470 mp->grp.name = "parameters";
471 mp->grp.attrs = (void *)mp + size[0];
473 pattr = &mp->attrs[0];
474 gattr = &mp->grp.attrs[0];
475 for (i = 0; i < num_params; i++) {
476 struct kernel_param *kp = &kparam[i];
479 pattr->mattr.show = param_attr_show;
480 pattr->mattr.store = param_attr_store;
481 pattr->mattr.attr.name = (char *)&kp->name[name_skip];
482 pattr->mattr.attr.owner = mk->mod;
483 pattr->mattr.attr.mode = kp->perm;
484 *(gattr++) = &(pattr++)->mattr.attr;
489 if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) {
497 #ifdef CONFIG_MODULES
500 * module_param_sysfs_setup - setup sysfs support for one module
502 * @kparam: module parameters (array)
503 * @num_params: number of module parameters
505 * Adds sysfs entries for module parameters, and creates a link from
506 * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/
508 int module_param_sysfs_setup(struct module *mod,
509 struct kernel_param *kparam,
510 unsigned int num_params)
512 struct module_param_attrs *mp;
514 mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
518 mod->param_attrs = mp;
523 * module_param_sysfs_remove - remove sysfs support for one module
526 * Remove sysfs entries for module parameters and the corresponding
529 void module_param_sysfs_remove(struct module *mod)
531 if (mod->param_attrs) {
532 sysfs_remove_group(&mod->mkobj.kobj,
533 &mod->param_attrs->grp);
534 /* We are positive that no one is using any param
535 * attrs at this point. Deallocate immediately. */
536 kfree(mod->param_attrs);
537 mod->param_attrs = NULL;
543 * kernel_param_sysfs_setup - wrapper for built-in params support
545 static void __init kernel_param_sysfs_setup(const char *name,
546 struct kernel_param *kparam,
547 unsigned int num_params,
548 unsigned int name_skip)
550 struct module_kobject *mk;
552 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
555 mk->mod = THIS_MODULE;
556 kobj_set_kset_s(mk, module_subsys);
557 kobject_set_name(&mk->kobj, name);
558 kobject_register(&mk->kobj);
560 /* no need to keep the kobject if no parameter is exported */
561 if (!param_sysfs_setup(mk, kparam, num_params, name_skip)) {
562 kobject_unregister(&mk->kobj);
568 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
570 * Add module_parameters to sysfs for "modules" built into the kernel.
572 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
573 * "parameter" name is stored behind a dot in kernel_param->name. So,
574 * extract the "module" name for all built-in kernel_param-eters,
575 * and for all who have the same, call kernel_param_sysfs_setup.
577 static void __init param_sysfs_builtin(void)
579 struct kernel_param *kp, *kp_begin = NULL;
580 unsigned int i, name_len, count = 0;
581 char modname[MAX_KBUILD_MODNAME + 1] = "";
583 for (i=0; i < __stop___param - __start___param; i++) {
586 kp = &__start___param[i];
588 /* We do not handle args without periods. */
589 dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME);
591 DEBUGP("couldn't find period in %s\n", kp->name);
594 name_len = dot - kp->name;
596 /* new kbuild_modname? */
597 if (strlen(modname) != name_len
598 || strncmp(modname, kp->name, name_len) != 0) {
599 /* add a new kobject for previous kernel_params. */
601 kernel_param_sysfs_setup(modname,
606 strncpy(modname, kp->name, name_len);
607 modname[name_len] = '\0';
614 /* last kernel_params need to be registered as well */
616 kernel_param_sysfs_setup(modname, kp_begin, count,
621 /* module-related sysfs stuff */
622 #ifdef CONFIG_MODULES
624 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
625 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
627 static ssize_t module_attr_show(struct kobject *kobj,
628 struct attribute *attr,
631 struct module_attribute *attribute;
632 struct module_kobject *mk;
635 attribute = to_module_attr(attr);
636 mk = to_module_kobject(kobj);
638 if (!attribute->show)
641 if (!try_module_get(mk->mod))
644 ret = attribute->show(attribute, mk->mod, buf);
651 static ssize_t module_attr_store(struct kobject *kobj,
652 struct attribute *attr,
653 const char *buf, size_t len)
655 struct module_attribute *attribute;
656 struct module_kobject *mk;
659 attribute = to_module_attr(attr);
660 mk = to_module_kobject(kobj);
662 if (!attribute->store)
665 if (!try_module_get(mk->mod))
668 ret = attribute->store(attribute, mk->mod, buf, len);
675 static struct sysfs_ops module_sysfs_ops = {
676 .show = module_attr_show,
677 .store = module_attr_store,
681 static struct sysfs_ops module_sysfs_ops = {
687 static struct kobj_type module_ktype = {
688 .sysfs_ops = &module_sysfs_ops,
691 decl_subsys(module, &module_ktype, NULL);
694 * param_sysfs_init - wrapper for built-in params support
696 static int __init param_sysfs_init(void)
698 subsystem_register(&module_subsys);
700 param_sysfs_builtin();
704 __initcall(param_sysfs_init);
706 EXPORT_SYMBOL(param_set_byte);
707 EXPORT_SYMBOL(param_get_byte);
708 EXPORT_SYMBOL(param_set_short);
709 EXPORT_SYMBOL(param_get_short);
710 EXPORT_SYMBOL(param_set_ushort);
711 EXPORT_SYMBOL(param_get_ushort);
712 EXPORT_SYMBOL(param_set_int);
713 EXPORT_SYMBOL(param_get_int);
714 EXPORT_SYMBOL(param_set_uint);
715 EXPORT_SYMBOL(param_get_uint);
716 EXPORT_SYMBOL(param_set_long);
717 EXPORT_SYMBOL(param_get_long);
718 EXPORT_SYMBOL(param_set_ulong);
719 EXPORT_SYMBOL(param_get_ulong);
720 EXPORT_SYMBOL(param_set_charp);
721 EXPORT_SYMBOL(param_get_charp);
722 EXPORT_SYMBOL(param_set_bool);
723 EXPORT_SYMBOL(param_get_bool);
724 EXPORT_SYMBOL(param_set_invbool);
725 EXPORT_SYMBOL(param_get_invbool);
726 EXPORT_SYMBOL(param_array_set);
727 EXPORT_SYMBOL(param_array_get);
728 EXPORT_SYMBOL(param_set_copystring);
729 EXPORT_SYMBOL(param_get_string);