projects/linux·blob v2.6.30-rc6 · refs

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1/* Helpers for initial module or kernel cmdline parsing
2 Copyright (C) 2001 Rusty Russell.
3
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.
8
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.
13
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
17*/
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
27/* We abuse the high bits of "perm" to record whether we kmalloc'ed. */
28#define KPARAM_KMALLOCED 0x80000000
29
30#if 0
31#define DEBUGP printk
32#else
33#define DEBUGP(fmt, a...)
34#endif
35
36static inline char dash2underscore(char c)
37{
38 if (c == '-')
39 return '_';
40 return c;
41}
42
43static inline int parameq(const char *input, const char *paramname)
44{
45 unsigned int i;
46 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
47 if (input[i] == '\0')
48 return 1;
49 return 0;
50}
51
52static int parse_one(char *param,
53 char *val,
54 struct kernel_param *params,
55 unsigned num_params,
56 int (*handle_unknown)(char *param, char *val))
57{
58 unsigned int i;
59
60 /* Find parameter */
61 for (i = 0; i < num_params; i++) {
62 if (parameq(param, params[i].name)) {
63 DEBUGP("They are equal! Calling %p\n",
64 params[i].set);
65 return params[i].set(val, &params[i]);
66 }
67 }
68
69 if (handle_unknown) {
70 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
71 return handle_unknown(param, val);
72 }
73
74 DEBUGP("Unknown argument `%s'\n", param);
75 return -ENOENT;
76}
77
78/* You can use " around spaces, but can't escape ". */
79/* Hyphens and underscores equivalent in parameter names. */
80static char *next_arg(char *args, char **param, char **val)
81{
82 unsigned int i, equals = 0;
83 int in_quote = 0, quoted = 0;
84 char *next;
85
86 if (*args == '"') {
87 args++;
88 in_quote = 1;
89 quoted = 1;
90 }
91
92 for (i = 0; args[i]; i++) {
93 if (args[i] == ' ' && !in_quote)
94 break;
95 if (equals == 0) {
96 if (args[i] == '=')
97 equals = i;
98 }
99 if (args[i] == '"')
100 in_quote = !in_quote;
101 }
102
103 *param = args;
104 if (!equals)
105 *val = NULL;
106 else {
107 args[equals] = '\0';
108 *val = args + equals + 1;
109
110 /* Don't include quotes in value. */
111 if (**val == '"') {
112 (*val)++;
113 if (args[i-1] == '"')
114 args[i-1] = '\0';
115 }
116 if (quoted && args[i-1] == '"')
117 args[i-1] = '\0';
118 }
119
120 if (args[i]) {
121 args[i] = '\0';
122 next = args + i + 1;
123 } else
124 next = args + i;
125
126 /* Chew up trailing spaces. */
127 while (*next == ' ')
128 next++;
129 return next;
130}
131
132/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
133int parse_args(const char *name,
134 char *args,
135 struct kernel_param *params,
136 unsigned num,
137 int (*unknown)(char *param, char *val))
138{
139 char *param, *val;
140
141 DEBUGP("Parsing ARGS: %s\n", args);
142
143 /* Chew leading spaces */
144 while (*args == ' ')
145 args++;
146
147 while (*args) {
148 int ret;
149 int irq_was_disabled;
150
151 args = next_arg(args, &param, &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 "
156 "irq's!\n", param);
157 }
158 switch (ret) {
159 case -ENOENT:
160 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
161 name, param);
162 return ret;
163 case -ENOSPC:
164 printk(KERN_ERR
165 "%s: `%s' too large for parameter `%s'\n",
166 name, val ?: "", param);
167 return ret;
168 case 0:
169 break;
170 default:
171 printk(KERN_ERR
172 "%s: `%s' invalid for parameter `%s'\n",
173 name, val ?: "", param);
174 return ret;
175 }
176 }
177
178 /* All parsed OK. */
179 return 0;
180}
181
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) \
185 { \
186 tmptype l; \
187 int ret; \
188 \
189 if (!val) return -EINVAL; \
190 ret = strtolfn(val, 0, &l); \
191 if (ret == -EINVAL || ((type)l != l)) \
192 return -EINVAL; \
193 *((type *)kp->arg) = l; \
194 return 0; \
195 } \
196 int param_get_##name(char *buffer, struct kernel_param *kp) \
197 { \
198 return sprintf(buffer, format, *((type *)kp->arg)); \
199 }
200
201STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
202STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
203STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
204STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
205STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
206STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
207STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
208
209int param_set_charp(const char *val, struct kernel_param *kp)
210{
211 if (!val) {
212 printk(KERN_ERR "%s: string parameter expected\n",
213 kp->name);
214 return -EINVAL;
215 }
216
217 if (strlen(val) > 1024) {
218 printk(KERN_ERR "%s: string parameter too long\n",
219 kp->name);
220 return -ENOSPC;
221 }
222
223 if (kp->perm & KPARAM_KMALLOCED)
224 kfree(*(char **)kp->arg);
225
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);
231 if (!kp->arg)
232 return -ENOMEM;
233 } else
234 *(const char **)kp->arg = val;
235
236 return 0;
237}
238
239int param_get_charp(char *buffer, struct kernel_param *kp)
240{
241 return sprintf(buffer, "%s", *((char **)kp->arg));
242}
243
244int param_set_bool(const char *val, struct kernel_param *kp)
245{
246 /* No equals means "set"... */
247 if (!val) val = "1";
248
249 /* One of =[yYnN01] */
250 switch (val[0]) {
251 case 'y': case 'Y': case '1':
252 *(int *)kp->arg = 1;
253 return 0;
254 case 'n': case 'N': case '0':
255 *(int *)kp->arg = 0;
256 return 0;
257 }
258 return -EINVAL;
259}
260
261int param_get_bool(char *buffer, struct kernel_param *kp)
262{
263 /* Y and N chosen as being relatively non-coder friendly */
264 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
265}
266
267int param_set_invbool(const char *val, struct kernel_param *kp)
268{
269 int boolval, ret;
270 struct kernel_param dummy;
271
272 dummy.arg = &boolval;
273 ret = param_set_bool(val, &dummy);
274 if (ret == 0)
275 *(int *)kp->arg = !boolval;
276 return ret;
277}
278
279int param_get_invbool(char *buffer, struct kernel_param *kp)
280{
281 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'N' : 'Y');
282}
283
284/* We break the rule and mangle the string. */
285static int param_array(const char *name,
286 const char *val,
287 unsigned int min, unsigned int max,
288 void *elem, int elemsize,
289 int (*set)(const char *, struct kernel_param *kp),
290 unsigned int *num)
291{
292 int ret;
293 struct kernel_param kp;
294 char save;
295
296 /* Get the name right for errors. */
297 kp.name = name;
298 kp.arg = elem;
299
300 /* No equals sign? */
301 if (!val) {
302 printk(KERN_ERR "%s: expects arguments\n", name);
303 return -EINVAL;
304 }
305
306 *num = 0;
307 /* We expect a comma-separated list of values. */
308 do {
309 int len;
310
311 if (*num == max) {
312 printk(KERN_ERR "%s: can only take %i arguments\n",
313 name, max);
314 return -EINVAL;
315 }
316 len = strcspn(val, ",");
317
318 /* nul-terminate and parse */
319 save = val[len];
320 ((char *)val)[len] = '\0';
321 ret = set(val, &kp);
322
323 if (ret != 0)
324 return ret;
325 kp.arg += elemsize;
326 val += len+1;
327 (*num)++;
328 } while (save == ',');
329
330 if (*num < min) {
331 printk(KERN_ERR "%s: needs at least %i arguments\n",
332 name, min);
333 return -EINVAL;
334 }
335 return 0;
336}
337
338int param_array_set(const char *val, struct kernel_param *kp)
339{
340 const struct kparam_array *arr = kp->arr;
341 unsigned int temp_num;
342
343 return param_array(kp->name, val, 1, arr->max, arr->elem,
344 arr->elemsize, arr->set, arr->num ?: &temp_num);
345}
346
347int param_array_get(char *buffer, struct kernel_param *kp)
348{
349 int i, off, ret;
350 const struct kparam_array *arr = kp->arr;
351 struct kernel_param p;
352
353 p = *kp;
354 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
355 if (i)
356 buffer[off++] = ',';
357 p.arg = arr->elem + arr->elemsize * i;
358 ret = arr->get(buffer + off, &p);
359 if (ret < 0)
360 return ret;
361 off += ret;
362 }
363 buffer[off] = '\0';
364 return off;
365}
366
367int param_set_copystring(const char *val, struct kernel_param *kp)
368{
369 const struct kparam_string *kps = kp->str;
370
371 if (!val) {
372 printk(KERN_ERR "%s: missing param set value\n", kp->name);
373 return -EINVAL;
374 }
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);
378 return -ENOSPC;
379 }
380 strcpy(kps->string, val);
381 return 0;
382}
383
384int param_get_string(char *buffer, struct kernel_param *kp)
385{
386 const struct kparam_string *kps = kp->str;
387 return strlcpy(buffer, kps->string, kps->maxlen);
388}
389
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);
393
394extern struct kernel_param __start___param[], __stop___param[];
395
396struct param_attribute
397{
398 struct module_attribute mattr;
399 struct kernel_param *param;
400};
401
402struct module_param_attrs
403{
404 unsigned int num;
405 struct attribute_group grp;
406 struct param_attribute attrs[0];
407};
408
409#ifdef CONFIG_SYSFS
410#define to_param_attr(n) container_of(n, struct param_attribute, mattr);
411
412static ssize_t param_attr_show(struct module_attribute *mattr,
413 struct module *mod, char *buf)
414{
415 int count;
416 struct param_attribute *attribute = to_param_attr(mattr);
417
418 if (!attribute->param->get)
419 return -EPERM;
420
421 count = attribute->param->get(buf, attribute->param);
422 if (count > 0) {
423 strcat(buf, "\n");
424 ++count;
425 }
426 return count;
427}
428
429/* sysfs always hands a nul-terminated string in buf. We rely on that. */
430static ssize_t param_attr_store(struct module_attribute *mattr,
431 struct module *owner,
432 const char *buf, size_t len)
433{
434 int err;
435 struct param_attribute *attribute = to_param_attr(mattr);
436
437 if (!attribute->param->set)
438 return -EPERM;
439
440 err = attribute->param->set(buf, attribute->param);
441 if (!err)
442 return len;
443 return err;
444}
445#endif
446
447#ifdef CONFIG_MODULES
448#define __modinit
449#else
450#define __modinit __init
451#endif
452
453#ifdef CONFIG_SYSFS
454/*
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
459 *
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.
463 */
464static __modinit int add_sysfs_param(struct module_kobject *mk,
465 struct kernel_param *kp,
466 const char *name)
467{
468 struct module_param_attrs *new;
469 struct attribute **attrs;
470 int err, num;
471
472 /* We don't bother calling this with invisible parameters. */
473 BUG_ON(!kp->perm);
474
475 if (!mk->mp) {
476 num = 0;
477 attrs = NULL;
478 } else {
479 num = mk->mp->num;
480 attrs = mk->mp->grp.attrs;
481 }
482
483 /* Enlarge. */
484 new = krealloc(mk->mp,
485 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
486 GFP_KERNEL);
487 if (!new) {
488 kfree(mk->mp);
489 err = -ENOMEM;
490 goto fail;
491 }
492 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
493 if (!attrs) {
494 err = -ENOMEM;
495 goto fail_free_new;
496 }
497
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;
504
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;
511 new->num = num+1;
512
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;
517
518 mk->mp = new;
519 return 0;
520
521fail_free_new:
522 kfree(new);
523fail:
524 mk->mp = NULL;
525 return err;
526}
527
528#ifdef CONFIG_MODULES
529static void free_module_param_attrs(struct module_kobject *mk)
530{
531 kfree(mk->mp->grp.attrs);
532 kfree(mk->mp);
533 mk->mp = NULL;
534}
535
536/*
537 * module_param_sysfs_setup - setup sysfs support for one module
538 * @mod: module
539 * @kparam: module parameters (array)
540 * @num_params: number of module parameters
541 *
542 * Adds sysfs entries for module parameters under
543 * /sys/module/[mod->name]/parameters/
544 */
545int module_param_sysfs_setup(struct module *mod,
546 struct kernel_param *kparam,
547 unsigned int num_params)
548{
549 int i, err;
550 bool params = false;
551
552 for (i = 0; i < num_params; i++) {
553 if (kparam[i].perm == 0)
554 continue;
555 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
556 if (err)
557 return err;
558 params = true;
559 }
560
561 if (!params)
562 return 0;
563
564 /* Create the param group. */
565 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
566 if (err)
567 free_module_param_attrs(&mod->mkobj);
568 return err;
569}
570
571/*
572 * module_param_sysfs_remove - remove sysfs support for one module
573 * @mod: module
574 *
575 * Remove sysfs entries for module parameters and the corresponding
576 * kobject.
577 */
578void module_param_sysfs_remove(struct module *mod)
579{
580 if (mod->mkobj.mp) {
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);
585 }
586}
587#endif
588
589void destroy_params(const struct kernel_param *params, unsigned num)
590{
591 unsigned int i;
592
593 for (i = 0; i < num; i++)
594 if (params[i].perm & KPARAM_KMALLOCED)
595 kfree(*(char **)params[i].arg);
596}
597
598static void __init kernel_add_sysfs_param(const char *name,
599 struct kernel_param *kparam,
600 unsigned int name_skip)
601{
602 struct module_kobject *mk;
603 struct kobject *kobj;
604 int err;
605
606 kobj = kset_find_obj(module_kset, name);
607 if (kobj) {
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);
612 } else {
613 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
614 BUG_ON(!mk);
615
616 mk->mod = THIS_MODULE;
617 mk->kobj.kset = module_kset;
618 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
619 "%s", name);
620 if (err) {
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");
625 return;
626 }
627 /* So that exit path is even. */
628 kobject_get(&mk->kobj);
629 }
630
631 /* These should not fail at boot. */
632 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
633 BUG_ON(err);
634 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
635 BUG_ON(err);
636 kobject_uevent(&mk->kobj, KOBJ_ADD);
637 kobject_put(&mk->kobj);
638}
639
640/*
641 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
642 *
643 * Add module_parameters to sysfs for "modules" built into the kernel.
644 *
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.
649 */
650static void __init param_sysfs_builtin(void)
651{
652 struct kernel_param *kp;
653 unsigned int name_len;
654 char modname[MODULE_NAME_LEN];
655
656 for (kp = __start___param; kp < __stop___param; kp++) {
657 char *dot;
658
659 if (kp->perm == 0)
660 continue;
661
662 dot = strchr(kp->name, '.');
663 if (!dot) {
664 /* This happens for core_param() */
665 strcpy(modname, "kernel");
666 name_len = 0;
667 } else {
668 name_len = dot - kp->name + 1;
669 strlcpy(modname, kp->name, name_len);
670 }
671 kernel_add_sysfs_param(modname, kp, name_len);
672 }
673}
674
675
676/* module-related sysfs stuff */
677
678static ssize_t module_attr_show(struct kobject *kobj,
679 struct attribute *attr,
680 char *buf)
681{
682 struct module_attribute *attribute;
683 struct module_kobject *mk;
684 int ret;
685
686 attribute = to_module_attr(attr);
687 mk = to_module_kobject(kobj);
688
689 if (!attribute->show)
690 return -EIO;
691
692 ret = attribute->show(attribute, mk->mod, buf);
693
694 return ret;
695}
696
697static ssize_t module_attr_store(struct kobject *kobj,
698 struct attribute *attr,
699 const char *buf, size_t len)
700{
701 struct module_attribute *attribute;
702 struct module_kobject *mk;
703 int ret;
704
705 attribute = to_module_attr(attr);
706 mk = to_module_kobject(kobj);
707
708 if (!attribute->store)
709 return -EIO;
710
711 ret = attribute->store(attribute, mk->mod, buf, len);
712
713 return ret;
714}
715
716static struct sysfs_ops module_sysfs_ops = {
717 .show = module_attr_show,
718 .store = module_attr_store,
719};
720
721static int uevent_filter(struct kset *kset, struct kobject *kobj)
722{
723 struct kobj_type *ktype = get_ktype(kobj);
724
725 if (ktype == &module_ktype)
726 return 1;
727 return 0;
728}
729
730static struct kset_uevent_ops module_uevent_ops = {
731 .filter = uevent_filter,
732};
733
734struct kset *module_kset;
735int module_sysfs_initialized;
736
737struct kobj_type module_ktype = {
738 .sysfs_ops = &module_sysfs_ops,
739};
740
741/*
742 * param_sysfs_init - wrapper for built-in params support
743 */
744static int __init param_sysfs_init(void)
745{
746 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
747 if (!module_kset) {
748 printk(KERN_WARNING "%s (%d): error creating kset\n",
749 __FILE__, __LINE__);
750 return -ENOMEM;
751 }
752 module_sysfs_initialized = 1;
753
754 param_sysfs_builtin();
755
756 return 0;
757}
758subsys_initcall(param_sysfs_init);
759
760#endif /* CONFIG_SYSFS */
761
762EXPORT_SYMBOL(param_set_byte);
763EXPORT_SYMBOL(param_get_byte);
764EXPORT_SYMBOL(param_set_short);
765EXPORT_SYMBOL(param_get_short);
766EXPORT_SYMBOL(param_set_ushort);
767EXPORT_SYMBOL(param_get_ushort);
768EXPORT_SYMBOL(param_set_int);
769EXPORT_SYMBOL(param_get_int);
770EXPORT_SYMBOL(param_set_uint);
771EXPORT_SYMBOL(param_get_uint);
772EXPORT_SYMBOL(param_set_long);
773EXPORT_SYMBOL(param_get_long);
774EXPORT_SYMBOL(param_set_ulong);
775EXPORT_SYMBOL(param_get_ulong);
776EXPORT_SYMBOL(param_set_charp);
777EXPORT_SYMBOL(param_get_charp);
778EXPORT_SYMBOL(param_set_bool);
779EXPORT_SYMBOL(param_get_bool);
780EXPORT_SYMBOL(param_set_invbool);
781EXPORT_SYMBOL(param_get_invbool);
782EXPORT_SYMBOL(param_array_set);
783EXPORT_SYMBOL(param_array_get);
784EXPORT_SYMBOL(param_set_copystring);
785EXPORT_SYMBOL(param_get_string);