Linux 2.6.28-rc5
[cris-mirror.git] / kernel / params.c
bloba1e3025b19a9aed003967a0a9e2ff3d05456428b
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 #if 0
28 #define DEBUGP printk
29 #else
30 #define DEBUGP(fmt, a...)
31 #endif
33 static inline char dash2underscore(char c)
35 if (c == '-')
36 return '_';
37 return c;
40 static inline int parameq(const char *input, const char *paramname)
42 unsigned int i;
43 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
44 if (input[i] == '\0')
45 return 1;
46 return 0;
49 static int parse_one(char *param,
50 char *val,
51 struct kernel_param *params,
52 unsigned num_params,
53 int (*handle_unknown)(char *param, char *val))
55 unsigned int i;
57 /* Find parameter */
58 for (i = 0; i < num_params; i++) {
59 if (parameq(param, params[i].name)) {
60 DEBUGP("They are equal! Calling %p\n",
61 params[i].set);
62 return params[i].set(val, &params[i]);
66 if (handle_unknown) {
67 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
68 return handle_unknown(param, val);
71 DEBUGP("Unknown argument `%s'\n", param);
72 return -ENOENT;
75 /* You can use " around spaces, but can't escape ". */
76 /* Hyphens and underscores equivalent in parameter names. */
77 static char *next_arg(char *args, char **param, char **val)
79 unsigned int i, equals = 0;
80 int in_quote = 0, quoted = 0;
81 char *next;
83 if (*args == '"') {
84 args++;
85 in_quote = 1;
86 quoted = 1;
89 for (i = 0; args[i]; i++) {
90 if (args[i] == ' ' && !in_quote)
91 break;
92 if (equals == 0) {
93 if (args[i] == '=')
94 equals = i;
96 if (args[i] == '"')
97 in_quote = !in_quote;
100 *param = args;
101 if (!equals)
102 *val = NULL;
103 else {
104 args[equals] = '\0';
105 *val = args + equals + 1;
107 /* Don't include quotes in value. */
108 if (**val == '"') {
109 (*val)++;
110 if (args[i-1] == '"')
111 args[i-1] = '\0';
113 if (quoted && args[i-1] == '"')
114 args[i-1] = '\0';
117 if (args[i]) {
118 args[i] = '\0';
119 next = args + i + 1;
120 } else
121 next = args + i;
123 /* Chew up trailing spaces. */
124 while (*next == ' ')
125 next++;
126 return next;
129 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
130 int parse_args(const char *name,
131 char *args,
132 struct kernel_param *params,
133 unsigned num,
134 int (*unknown)(char *param, char *val))
136 char *param, *val;
138 DEBUGP("Parsing ARGS: %s\n", args);
140 /* Chew leading spaces */
141 while (*args == ' ')
142 args++;
144 while (*args) {
145 int ret;
146 int irq_was_disabled;
148 args = next_arg(args, &param, &val);
149 irq_was_disabled = irqs_disabled();
150 ret = parse_one(param, val, params, num, unknown);
151 if (irq_was_disabled && !irqs_disabled()) {
152 printk(KERN_WARNING "parse_args(): option '%s' enabled "
153 "irq's!\n", param);
155 switch (ret) {
156 case -ENOENT:
157 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
158 name, param);
159 return ret;
160 case -ENOSPC:
161 printk(KERN_ERR
162 "%s: `%s' too large for parameter `%s'\n",
163 name, val ?: "", param);
164 return ret;
165 case 0:
166 break;
167 default:
168 printk(KERN_ERR
169 "%s: `%s' invalid for parameter `%s'\n",
170 name, val ?: "", param);
171 return ret;
175 /* All parsed OK. */
176 return 0;
179 /* Lazy bastard, eh? */
180 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
181 int param_set_##name(const char *val, struct kernel_param *kp) \
183 tmptype l; \
184 int ret; \
186 if (!val) return -EINVAL; \
187 ret = strtolfn(val, 0, &l); \
188 if (ret == -EINVAL || ((type)l != l)) \
189 return -EINVAL; \
190 *((type *)kp->arg) = l; \
191 return 0; \
193 int param_get_##name(char *buffer, struct kernel_param *kp) \
195 return sprintf(buffer, format, *((type *)kp->arg)); \
198 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
199 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
200 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
201 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
202 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
203 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
204 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
206 int param_set_charp(const char *val, struct kernel_param *kp)
208 if (!val) {
209 printk(KERN_ERR "%s: string parameter expected\n",
210 kp->name);
211 return -EINVAL;
214 if (strlen(val) > 1024) {
215 printk(KERN_ERR "%s: string parameter too long\n",
216 kp->name);
217 return -ENOSPC;
220 *(char **)kp->arg = (char *)val;
221 return 0;
224 int param_get_charp(char *buffer, struct kernel_param *kp)
226 return sprintf(buffer, "%s", *((char **)kp->arg));
229 int param_set_bool(const char *val, struct kernel_param *kp)
231 /* No equals means "set"... */
232 if (!val) val = "1";
234 /* One of =[yYnN01] */
235 switch (val[0]) {
236 case 'y': case 'Y': case '1':
237 *(int *)kp->arg = 1;
238 return 0;
239 case 'n': case 'N': case '0':
240 *(int *)kp->arg = 0;
241 return 0;
243 return -EINVAL;
246 int param_get_bool(char *buffer, struct kernel_param *kp)
248 /* Y and N chosen as being relatively non-coder friendly */
249 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
252 int param_set_invbool(const char *val, struct kernel_param *kp)
254 int boolval, ret;
255 struct kernel_param dummy;
257 dummy.arg = &boolval;
258 ret = param_set_bool(val, &dummy);
259 if (ret == 0)
260 *(int *)kp->arg = !boolval;
261 return ret;
264 int param_get_invbool(char *buffer, struct kernel_param *kp)
266 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'N' : 'Y');
269 /* We break the rule and mangle the string. */
270 static int param_array(const char *name,
271 const char *val,
272 unsigned int min, unsigned int max,
273 void *elem, int elemsize,
274 int (*set)(const char *, struct kernel_param *kp),
275 unsigned int *num)
277 int ret;
278 struct kernel_param kp;
279 char save;
281 /* Get the name right for errors. */
282 kp.name = name;
283 kp.arg = elem;
285 /* No equals sign? */
286 if (!val) {
287 printk(KERN_ERR "%s: expects arguments\n", name);
288 return -EINVAL;
291 *num = 0;
292 /* We expect a comma-separated list of values. */
293 do {
294 int len;
296 if (*num == max) {
297 printk(KERN_ERR "%s: can only take %i arguments\n",
298 name, max);
299 return -EINVAL;
301 len = strcspn(val, ",");
303 /* nul-terminate and parse */
304 save = val[len];
305 ((char *)val)[len] = '\0';
306 ret = set(val, &kp);
308 if (ret != 0)
309 return ret;
310 kp.arg += elemsize;
311 val += len+1;
312 (*num)++;
313 } while (save == ',');
315 if (*num < min) {
316 printk(KERN_ERR "%s: needs at least %i arguments\n",
317 name, min);
318 return -EINVAL;
320 return 0;
323 int param_array_set(const char *val, struct kernel_param *kp)
325 const struct kparam_array *arr = kp->arr;
326 unsigned int temp_num;
328 return param_array(kp->name, val, 1, arr->max, arr->elem,
329 arr->elemsize, arr->set, arr->num ?: &temp_num);
332 int param_array_get(char *buffer, struct kernel_param *kp)
334 int i, off, ret;
335 const struct kparam_array *arr = kp->arr;
336 struct kernel_param p;
338 p = *kp;
339 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
340 if (i)
341 buffer[off++] = ',';
342 p.arg = arr->elem + arr->elemsize * i;
343 ret = arr->get(buffer + off, &p);
344 if (ret < 0)
345 return ret;
346 off += ret;
348 buffer[off] = '\0';
349 return off;
352 int param_set_copystring(const char *val, struct kernel_param *kp)
354 const struct kparam_string *kps = kp->str;
356 if (!val) {
357 printk(KERN_ERR "%s: missing param set value\n", kp->name);
358 return -EINVAL;
360 if (strlen(val)+1 > kps->maxlen) {
361 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
362 kp->name, kps->maxlen-1);
363 return -ENOSPC;
365 strcpy(kps->string, val);
366 return 0;
369 int param_get_string(char *buffer, struct kernel_param *kp)
371 const struct kparam_string *kps = kp->str;
372 return strlcpy(buffer, kps->string, kps->maxlen);
375 /* sysfs output in /sys/modules/XYZ/parameters/ */
376 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
377 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
379 extern struct kernel_param __start___param[], __stop___param[];
381 struct param_attribute
383 struct module_attribute mattr;
384 struct kernel_param *param;
387 struct module_param_attrs
389 unsigned int num;
390 struct attribute_group grp;
391 struct param_attribute attrs[0];
394 #ifdef CONFIG_SYSFS
395 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
397 static ssize_t param_attr_show(struct module_attribute *mattr,
398 struct module *mod, char *buf)
400 int count;
401 struct param_attribute *attribute = to_param_attr(mattr);
403 if (!attribute->param->get)
404 return -EPERM;
406 count = attribute->param->get(buf, attribute->param);
407 if (count > 0) {
408 strcat(buf, "\n");
409 ++count;
411 return count;
414 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
415 static ssize_t param_attr_store(struct module_attribute *mattr,
416 struct module *owner,
417 const char *buf, size_t len)
419 int err;
420 struct param_attribute *attribute = to_param_attr(mattr);
422 if (!attribute->param->set)
423 return -EPERM;
425 err = attribute->param->set(buf, attribute->param);
426 if (!err)
427 return len;
428 return err;
430 #endif
432 #ifdef CONFIG_MODULES
433 #define __modinit
434 #else
435 #define __modinit __init
436 #endif
438 #ifdef CONFIG_SYSFS
440 * add_sysfs_param - add a parameter to sysfs
441 * @mk: struct module_kobject
442 * @kparam: the actual parameter definition to add to sysfs
443 * @name: name of parameter
445 * Create a kobject if for a (per-module) parameter if mp NULL, and
446 * create file in sysfs. Returns an error on out of memory. Always cleans up
447 * if there's an error.
449 static __modinit int add_sysfs_param(struct module_kobject *mk,
450 struct kernel_param *kp,
451 const char *name)
453 struct module_param_attrs *new;
454 struct attribute **attrs;
455 int err, num;
457 /* We don't bother calling this with invisible parameters. */
458 BUG_ON(!kp->perm);
460 if (!mk->mp) {
461 num = 0;
462 attrs = NULL;
463 } else {
464 num = mk->mp->num;
465 attrs = mk->mp->grp.attrs;
468 /* Enlarge. */
469 new = krealloc(mk->mp,
470 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
471 GFP_KERNEL);
472 if (!new) {
473 kfree(mk->mp);
474 err = -ENOMEM;
475 goto fail;
477 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
478 if (!attrs) {
479 err = -ENOMEM;
480 goto fail_free_new;
483 /* Sysfs wants everything zeroed. */
484 memset(new, 0, sizeof(*new));
485 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
486 memset(&attrs[num], 0, sizeof(attrs[num]));
487 new->grp.name = "parameters";
488 new->grp.attrs = attrs;
490 /* Tack new one on the end. */
491 new->attrs[num].param = kp;
492 new->attrs[num].mattr.show = param_attr_show;
493 new->attrs[num].mattr.store = param_attr_store;
494 new->attrs[num].mattr.attr.name = (char *)name;
495 new->attrs[num].mattr.attr.mode = kp->perm;
496 new->num = num+1;
498 /* Fix up all the pointers, since krealloc can move us */
499 for (num = 0; num < new->num; num++)
500 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
501 new->grp.attrs[num] = NULL;
503 mk->mp = new;
504 return 0;
506 fail_free_new:
507 kfree(new);
508 fail:
509 mk->mp = NULL;
510 return err;
513 #ifdef CONFIG_MODULES
514 static void free_module_param_attrs(struct module_kobject *mk)
516 kfree(mk->mp->grp.attrs);
517 kfree(mk->mp);
518 mk->mp = NULL;
522 * module_param_sysfs_setup - setup sysfs support for one module
523 * @mod: module
524 * @kparam: module parameters (array)
525 * @num_params: number of module parameters
527 * Adds sysfs entries for module parameters under
528 * /sys/module/[mod->name]/parameters/
530 int module_param_sysfs_setup(struct module *mod,
531 struct kernel_param *kparam,
532 unsigned int num_params)
534 int i, err;
535 bool params = false;
537 for (i = 0; i < num_params; i++) {
538 if (kparam[i].perm == 0)
539 continue;
540 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
541 if (err)
542 return err;
543 params = true;
546 if (!params)
547 return 0;
549 /* Create the param group. */
550 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
551 if (err)
552 free_module_param_attrs(&mod->mkobj);
553 return err;
557 * module_param_sysfs_remove - remove sysfs support for one module
558 * @mod: module
560 * Remove sysfs entries for module parameters and the corresponding
561 * kobject.
563 void module_param_sysfs_remove(struct module *mod)
565 if (mod->mkobj.mp) {
566 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
567 /* We are positive that no one is using any param
568 * attrs at this point. Deallocate immediately. */
569 free_module_param_attrs(&mod->mkobj);
572 #endif
574 static void __init kernel_add_sysfs_param(const char *name,
575 struct kernel_param *kparam,
576 unsigned int name_skip)
578 struct module_kobject *mk;
579 struct kobject *kobj;
580 int err;
582 kobj = kset_find_obj(module_kset, name);
583 if (kobj) {
584 /* We already have one. Remove params so we can add more. */
585 mk = to_module_kobject(kobj);
586 /* We need to remove it before adding parameters. */
587 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
588 } else {
589 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
590 BUG_ON(!mk);
592 mk->mod = THIS_MODULE;
593 mk->kobj.kset = module_kset;
594 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
595 "%s", name);
596 if (err) {
597 kobject_put(&mk->kobj);
598 printk(KERN_ERR "Module '%s' failed add to sysfs, "
599 "error number %d\n", name, err);
600 printk(KERN_ERR "The system will be unstable now.\n");
601 return;
603 /* So that exit path is even. */
604 kobject_get(&mk->kobj);
607 /* These should not fail at boot. */
608 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
609 BUG_ON(err);
610 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
611 BUG_ON(err);
612 kobject_uevent(&mk->kobj, KOBJ_ADD);
613 kobject_put(&mk->kobj);
617 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
619 * Add module_parameters to sysfs for "modules" built into the kernel.
621 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
622 * "parameter" name is stored behind a dot in kernel_param->name. So,
623 * extract the "module" name for all built-in kernel_param-eters,
624 * and for all who have the same, call kernel_add_sysfs_param.
626 static void __init param_sysfs_builtin(void)
628 struct kernel_param *kp;
629 unsigned int name_len;
630 char modname[MODULE_NAME_LEN];
632 for (kp = __start___param; kp < __stop___param; kp++) {
633 char *dot;
635 if (kp->perm == 0)
636 continue;
638 dot = strchr(kp->name, '.');
639 if (!dot) {
640 /* This happens for core_param() */
641 strcpy(modname, "kernel");
642 name_len = 0;
643 } else {
644 name_len = dot - kp->name + 1;
645 strlcpy(modname, kp->name, name_len);
647 kernel_add_sysfs_param(modname, kp, name_len);
652 /* module-related sysfs stuff */
654 static ssize_t module_attr_show(struct kobject *kobj,
655 struct attribute *attr,
656 char *buf)
658 struct module_attribute *attribute;
659 struct module_kobject *mk;
660 int ret;
662 attribute = to_module_attr(attr);
663 mk = to_module_kobject(kobj);
665 if (!attribute->show)
666 return -EIO;
668 ret = attribute->show(attribute, mk->mod, buf);
670 return ret;
673 static ssize_t module_attr_store(struct kobject *kobj,
674 struct attribute *attr,
675 const char *buf, size_t len)
677 struct module_attribute *attribute;
678 struct module_kobject *mk;
679 int ret;
681 attribute = to_module_attr(attr);
682 mk = to_module_kobject(kobj);
684 if (!attribute->store)
685 return -EIO;
687 ret = attribute->store(attribute, mk->mod, buf, len);
689 return ret;
692 static struct sysfs_ops module_sysfs_ops = {
693 .show = module_attr_show,
694 .store = module_attr_store,
697 static int uevent_filter(struct kset *kset, struct kobject *kobj)
699 struct kobj_type *ktype = get_ktype(kobj);
701 if (ktype == &module_ktype)
702 return 1;
703 return 0;
706 static struct kset_uevent_ops module_uevent_ops = {
707 .filter = uevent_filter,
710 struct kset *module_kset;
711 int module_sysfs_initialized;
713 struct kobj_type module_ktype = {
714 .sysfs_ops = &module_sysfs_ops,
718 * param_sysfs_init - wrapper for built-in params support
720 static int __init param_sysfs_init(void)
722 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
723 if (!module_kset) {
724 printk(KERN_WARNING "%s (%d): error creating kset\n",
725 __FILE__, __LINE__);
726 return -ENOMEM;
728 module_sysfs_initialized = 1;
730 param_sysfs_builtin();
732 return 0;
734 subsys_initcall(param_sysfs_init);
736 #endif /* CONFIG_SYSFS */
738 EXPORT_SYMBOL(param_set_byte);
739 EXPORT_SYMBOL(param_get_byte);
740 EXPORT_SYMBOL(param_set_short);
741 EXPORT_SYMBOL(param_get_short);
742 EXPORT_SYMBOL(param_set_ushort);
743 EXPORT_SYMBOL(param_get_ushort);
744 EXPORT_SYMBOL(param_set_int);
745 EXPORT_SYMBOL(param_get_int);
746 EXPORT_SYMBOL(param_set_uint);
747 EXPORT_SYMBOL(param_get_uint);
748 EXPORT_SYMBOL(param_set_long);
749 EXPORT_SYMBOL(param_get_long);
750 EXPORT_SYMBOL(param_set_ulong);
751 EXPORT_SYMBOL(param_get_ulong);
752 EXPORT_SYMBOL(param_set_charp);
753 EXPORT_SYMBOL(param_get_charp);
754 EXPORT_SYMBOL(param_set_bool);
755 EXPORT_SYMBOL(param_get_bool);
756 EXPORT_SYMBOL(param_set_invbool);
757 EXPORT_SYMBOL(param_get_invbool);
758 EXPORT_SYMBOL(param_array_set);
759 EXPORT_SYMBOL(param_array_get);
760 EXPORT_SYMBOL(param_set_copystring);
761 EXPORT_SYMBOL(param_get_string);