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>
26 #include <linux/ctype.h>
31 #define DEBUGP(fmt, a...)
34 static inline char 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 /* Noone handled NULL, so do it here. */
62 if (!val && params[i].set != param_set_bool)
64 DEBUGP("They are equal! Calling %p\n",
66 return params[i].set(val, ¶ms[i]);
71 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
72 return handle_unknown(param, val);
75 DEBUGP("Unknown argument `%s'\n", param);
79 /* You can use " around spaces, but can't escape ". */
80 /* Hyphens and underscores equivalent in parameter names. */
81 static char *next_arg(char *args, char **param, char **val)
83 unsigned int i, equals = 0;
84 int in_quote = 0, quoted = 0;
93 for (i = 0; args[i]; i++) {
94 if (isspace(args[i]) && !in_quote)
101 in_quote = !in_quote;
109 *val = args + equals + 1;
111 /* Don't include quotes in value. */
114 if (args[i-1] == '"')
117 if (quoted && args[i-1] == '"')
127 /* Chew up trailing spaces. */
128 return skip_spaces(next);
131 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
132 int parse_args(const char *name,
134 struct kernel_param *params,
136 int (*unknown)(char *param, char *val))
140 DEBUGP("Parsing ARGS: %s\n", args);
142 /* Chew leading spaces */
143 args = skip_spaces(args);
147 int irq_was_disabled;
149 args = next_arg(args, ¶m, &val);
150 irq_was_disabled = irqs_disabled();
151 ret = parse_one(param, val, params, num, unknown);
152 if (irq_was_disabled && !irqs_disabled()) {
153 printk(KERN_WARNING "parse_args(): option '%s' enabled "
158 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
163 "%s: `%s' too large for parameter `%s'\n",
164 name, val ?: "", param);
170 "%s: `%s' invalid for parameter `%s'\n",
171 name, val ?: "", param);
180 /* Lazy bastard, eh? */
181 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
182 int param_set_##name(const char *val, struct kernel_param *kp) \
187 ret = strtolfn(val, 0, &l); \
188 if (ret == -EINVAL || ((type)l != l)) \
190 *((type *)kp->arg) = l; \
193 int param_get_##name(char *buffer, struct kernel_param *kp) \
195 return sprintf(buffer, format, *((type *)kp->arg)); \
197 EXPORT_SYMBOL(param_set_##name); \
198 EXPORT_SYMBOL(param_get_##name)
200 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
201 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
202 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
203 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
204 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
205 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
206 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
208 int param_set_charp(const char *val, struct kernel_param *kp)
210 if (strlen(val) > 1024) {
211 printk(KERN_ERR "%s: string parameter too long\n",
216 /* This is a hack. We can't need to strdup in early boot, and we
217 * don't need to; this mangled commandline is preserved. */
218 if (slab_is_available()) {
219 *(char **)kp->arg = kstrdup(val, GFP_KERNEL);
220 if (!*(char **)kp->arg)
223 *(const char **)kp->arg = val;
227 EXPORT_SYMBOL(param_set_charp);
229 int param_get_charp(char *buffer, struct kernel_param *kp)
231 return sprintf(buffer, "%s", *((char **)kp->arg));
233 EXPORT_SYMBOL(param_get_charp);
235 /* Actually could be a bool or an int, for historical reasons. */
236 int param_set_bool(const char *val, struct kernel_param *kp)
240 /* No equals means "set"... */
243 /* One of =[yYnN01] */
245 case 'y': case 'Y': case '1':
248 case 'n': case 'N': case '0':
255 if (kp->flags & KPARAM_ISBOOL)
256 *(bool *)kp->arg = v;
261 EXPORT_SYMBOL(param_set_bool);
263 int param_get_bool(char *buffer, struct kernel_param *kp)
266 if (kp->flags & KPARAM_ISBOOL)
267 val = *(bool *)kp->arg;
269 val = *(int *)kp->arg;
271 /* Y and N chosen as being relatively non-coder friendly */
272 return sprintf(buffer, "%c", val ? 'Y' : 'N');
274 EXPORT_SYMBOL(param_get_bool);
276 /* This one must be bool. */
277 int param_set_invbool(const char *val, struct kernel_param *kp)
281 struct kernel_param dummy;
283 dummy.arg = &boolval;
284 dummy.flags = KPARAM_ISBOOL;
285 ret = param_set_bool(val, &dummy);
287 *(bool *)kp->arg = !boolval;
290 EXPORT_SYMBOL(param_set_invbool);
292 int param_get_invbool(char *buffer, struct kernel_param *kp)
294 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
296 EXPORT_SYMBOL(param_get_invbool);
298 /* We break the rule and mangle the string. */
299 static int param_array(const char *name,
301 unsigned int min, unsigned int max,
302 void *elem, int elemsize,
303 int (*set)(const char *, struct kernel_param *kp),
308 struct kernel_param kp;
311 /* Get the name right for errors. */
317 /* We expect a comma-separated list of values. */
322 printk(KERN_ERR "%s: can only take %i arguments\n",
326 len = strcspn(val, ",");
328 /* nul-terminate and parse */
330 ((char *)val)[len] = '\0';
338 } while (save == ',');
341 printk(KERN_ERR "%s: needs at least %i arguments\n",
348 int param_array_set(const char *val, struct kernel_param *kp)
350 const struct kparam_array *arr = kp->arr;
351 unsigned int temp_num;
353 return param_array(kp->name, val, 1, arr->max, arr->elem,
354 arr->elemsize, arr->set, kp->flags,
355 arr->num ?: &temp_num);
357 EXPORT_SYMBOL(param_array_set);
359 int param_array_get(char *buffer, struct kernel_param *kp)
362 const struct kparam_array *arr = kp->arr;
363 struct kernel_param p;
366 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
369 p.arg = arr->elem + arr->elemsize * i;
370 ret = arr->get(buffer + off, &p);
378 EXPORT_SYMBOL(param_array_get);
380 int param_set_copystring(const char *val, struct kernel_param *kp)
382 const struct kparam_string *kps = kp->str;
384 if (strlen(val)+1 > kps->maxlen) {
385 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
386 kp->name, kps->maxlen-1);
389 strcpy(kps->string, val);
392 EXPORT_SYMBOL(param_set_copystring);
394 int param_get_string(char *buffer, struct kernel_param *kp)
396 const struct kparam_string *kps = kp->str;
397 return strlcpy(buffer, kps->string, kps->maxlen);
399 EXPORT_SYMBOL(param_get_string);
401 /* sysfs output in /sys/modules/XYZ/parameters/ */
402 #define to_module_attr(n) container_of(n, struct module_attribute, attr)
403 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
405 extern struct kernel_param __start___param[], __stop___param[];
407 struct param_attribute
409 struct module_attribute mattr;
410 struct kernel_param *param;
413 struct module_param_attrs
416 struct attribute_group grp;
417 struct param_attribute attrs[0];
421 #define to_param_attr(n) container_of(n, struct param_attribute, mattr)
423 static ssize_t param_attr_show(struct module_attribute *mattr,
424 struct module *mod, char *buf)
427 struct param_attribute *attribute = to_param_attr(mattr);
429 if (!attribute->param->get)
432 count = attribute->param->get(buf, attribute->param);
440 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
441 static ssize_t param_attr_store(struct module_attribute *mattr,
442 struct module *owner,
443 const char *buf, size_t len)
446 struct param_attribute *attribute = to_param_attr(mattr);
448 if (!attribute->param->set)
451 err = attribute->param->set(buf, attribute->param);
458 #ifdef CONFIG_MODULES
461 #define __modinit __init
466 * add_sysfs_param - add a parameter to sysfs
467 * @mk: struct module_kobject
468 * @kparam: the actual parameter definition to add to sysfs
469 * @name: name of parameter
471 * Create a kobject if for a (per-module) parameter if mp NULL, and
472 * create file in sysfs. Returns an error on out of memory. Always cleans up
473 * if there's an error.
475 static __modinit int add_sysfs_param(struct module_kobject *mk,
476 struct kernel_param *kp,
479 struct module_param_attrs *new;
480 struct attribute **attrs;
483 /* We don't bother calling this with invisible parameters. */
491 attrs = mk->mp->grp.attrs;
495 new = krealloc(mk->mp,
496 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
503 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
509 /* Sysfs wants everything zeroed. */
510 memset(new, 0, sizeof(*new));
511 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
512 memset(&attrs[num], 0, sizeof(attrs[num]));
513 new->grp.name = "parameters";
514 new->grp.attrs = attrs;
516 /* Tack new one on the end. */
517 sysfs_attr_init(&new->attrs[num].mattr.attr);
518 new->attrs[num].param = kp;
519 new->attrs[num].mattr.show = param_attr_show;
520 new->attrs[num].mattr.store = param_attr_store;
521 new->attrs[num].mattr.attr.name = (char *)name;
522 new->attrs[num].mattr.attr.mode = kp->perm;
525 /* Fix up all the pointers, since krealloc can move us */
526 for (num = 0; num < new->num; num++)
527 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
528 new->grp.attrs[num] = NULL;
540 #ifdef CONFIG_MODULES
541 static void free_module_param_attrs(struct module_kobject *mk)
543 kfree(mk->mp->grp.attrs);
549 * module_param_sysfs_setup - setup sysfs support for one module
551 * @kparam: module parameters (array)
552 * @num_params: number of module parameters
554 * Adds sysfs entries for module parameters under
555 * /sys/module/[mod->name]/parameters/
557 int module_param_sysfs_setup(struct module *mod,
558 struct kernel_param *kparam,
559 unsigned int num_params)
564 for (i = 0; i < num_params; i++) {
565 if (kparam[i].perm == 0)
567 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
576 /* Create the param group. */
577 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
579 free_module_param_attrs(&mod->mkobj);
584 * module_param_sysfs_remove - remove sysfs support for one module
587 * Remove sysfs entries for module parameters and the corresponding
590 void module_param_sysfs_remove(struct module *mod)
593 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
594 /* We are positive that no one is using any param
595 * attrs at this point. Deallocate immediately. */
596 free_module_param_attrs(&mod->mkobj);
601 void destroy_params(const struct kernel_param *params, unsigned num)
603 /* FIXME: This should free kmalloced charp parameters. It doesn't. */
606 static void __init kernel_add_sysfs_param(const char *name,
607 struct kernel_param *kparam,
608 unsigned int name_skip)
610 struct module_kobject *mk;
611 struct kobject *kobj;
614 kobj = kset_find_obj(module_kset, name);
616 /* We already have one. Remove params so we can add more. */
617 mk = to_module_kobject(kobj);
618 /* We need to remove it before adding parameters. */
619 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
621 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
624 mk->mod = THIS_MODULE;
625 mk->kobj.kset = module_kset;
626 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
629 kobject_put(&mk->kobj);
630 printk(KERN_ERR "Module '%s' failed add to sysfs, "
631 "error number %d\n", name, err);
632 printk(KERN_ERR "The system will be unstable now.\n");
635 /* So that exit path is even. */
636 kobject_get(&mk->kobj);
639 /* These should not fail at boot. */
640 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
642 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
644 kobject_uevent(&mk->kobj, KOBJ_ADD);
645 kobject_put(&mk->kobj);
649 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
651 * Add module_parameters to sysfs for "modules" built into the kernel.
653 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
654 * "parameter" name is stored behind a dot in kernel_param->name. So,
655 * extract the "module" name for all built-in kernel_param-eters,
656 * and for all who have the same, call kernel_add_sysfs_param.
658 static void __init param_sysfs_builtin(void)
660 struct kernel_param *kp;
661 unsigned int name_len;
662 char modname[MODULE_NAME_LEN];
664 for (kp = __start___param; kp < __stop___param; kp++) {
670 dot = strchr(kp->name, '.');
672 /* This happens for core_param() */
673 strcpy(modname, "kernel");
676 name_len = dot - kp->name + 1;
677 strlcpy(modname, kp->name, name_len);
679 kernel_add_sysfs_param(modname, kp, name_len);
684 /* module-related sysfs stuff */
686 static ssize_t module_attr_show(struct kobject *kobj,
687 struct attribute *attr,
690 struct module_attribute *attribute;
691 struct module_kobject *mk;
694 attribute = to_module_attr(attr);
695 mk = to_module_kobject(kobj);
697 if (!attribute->show)
700 ret = attribute->show(attribute, mk->mod, buf);
705 static ssize_t module_attr_store(struct kobject *kobj,
706 struct attribute *attr,
707 const char *buf, size_t len)
709 struct module_attribute *attribute;
710 struct module_kobject *mk;
713 attribute = to_module_attr(attr);
714 mk = to_module_kobject(kobj);
716 if (!attribute->store)
719 ret = attribute->store(attribute, mk->mod, buf, len);
724 static const struct sysfs_ops module_sysfs_ops = {
725 .show = module_attr_show,
726 .store = module_attr_store,
729 static int uevent_filter(struct kset *kset, struct kobject *kobj)
731 struct kobj_type *ktype = get_ktype(kobj);
733 if (ktype == &module_ktype)
738 static const struct kset_uevent_ops module_uevent_ops = {
739 .filter = uevent_filter,
742 struct kset *module_kset;
743 int module_sysfs_initialized;
745 struct kobj_type module_ktype = {
746 .sysfs_ops = &module_sysfs_ops,
750 * param_sysfs_init - wrapper for built-in params support
752 static int __init param_sysfs_init(void)
754 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
756 printk(KERN_WARNING "%s (%d): error creating kset\n",
760 module_sysfs_initialized = 1;
762 param_sysfs_builtin();
766 subsys_initcall(param_sysfs_init);
768 #endif /* CONFIG_SYSFS */