projects/linux·blob v2.6.31-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#if 0
28#define DEBUGP printk
29#else
30#define DEBUGP(fmt, a...)
31#endif
32
33static inline char dash2underscore(char c)
34{
35 if (c == '-')
36 return '_';
37 return c;
38}
39
40static inline int parameq(const char *input, const char *paramname)
41{
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;
47}
48
49static 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))
54{
55 unsigned int i;
56
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]);
63 }
64 }
65
66 if (handle_unknown) {
67 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
68 return handle_unknown(param, val);
69 }
70
71 DEBUGP("Unknown argument `%s'\n", param);
72 return -ENOENT;
73}
74
75/* You can use " around spaces, but can't escape ". */
76/* Hyphens and underscores equivalent in parameter names. */
77static char *next_arg(char *args, char **param, char **val)
78{
79 unsigned int i, equals = 0;
80 int in_quote = 0, quoted = 0;
81 char *next;
82
83 if (*args == '"') {
84 args++;
85 in_quote = 1;
86 quoted = 1;
87 }
88
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;
95 }
96 if (args[i] == '"')
97 in_quote = !in_quote;
98 }
99
100 *param = args;
101 if (!equals)
102 *val = NULL;
103 else {
104 args[equals] = '\0';
105 *val = args + equals + 1;
106
107 /* Don't include quotes in value. */
108 if (**val == '"') {
109 (*val)++;
110 if (args[i-1] == '"')
111 args[i-1] = '\0';
112 }
113 if (quoted && args[i-1] == '"')
114 args[i-1] = '\0';
115 }
116
117 if (args[i]) {
118 args[i] = '\0';
119 next = args + i + 1;
120 } else
121 next = args + i;
122
123 /* Chew up trailing spaces. */
124 while (*next == ' ')
125 next++;
126 return next;
127}
128
129/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
130int parse_args(const char *name,
131 char *args,
132 struct kernel_param *params,
133 unsigned num,
134 int (*unknown)(char *param, char *val))
135{
136 char *param, *val;
137
138 DEBUGP("Parsing ARGS: %s\n", args);
139
140 /* Chew leading spaces */
141 while (*args == ' ')
142 args++;
143
144 while (*args) {
145 int ret;
146 int irq_was_disabled;
147
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);
154 }
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;
172 }
173 }
174
175 /* All parsed OK. */
176 return 0;
177}
178
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) \
182 { \
183 tmptype l; \
184 int ret; \
185 \
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; \
192 } \
193 int param_get_##name(char *buffer, struct kernel_param *kp) \
194 { \
195 return sprintf(buffer, format, *((type *)kp->arg)); \
196 }
197
198STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
199STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
200STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
201STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
202STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
203STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
204STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
205
206int param_set_charp(const char *val, struct kernel_param *kp)
207{
208 if (!val) {
209 printk(KERN_ERR "%s: string parameter expected\n",
210 kp->name);
211 return -EINVAL;
212 }
213
214 if (strlen(val) > 1024) {
215 printk(KERN_ERR "%s: string parameter too long\n",
216 kp->name);
217 return -ENOSPC;
218 }
219
220 if (kp->flags & KPARAM_KMALLOCED)
221 kfree(*(char **)kp->arg);
222
223 /* This is a hack. We can't need to strdup in early boot, and we
224 * don't need to; this mangled commandline is preserved. */
225 if (slab_is_available()) {
226 kp->flags |= KPARAM_KMALLOCED;
227 *(char **)kp->arg = kstrdup(val, GFP_KERNEL);
228 if (!kp->arg)
229 return -ENOMEM;
230 } else
231 *(const char **)kp->arg = val;
232
233 return 0;
234}
235
236int param_get_charp(char *buffer, struct kernel_param *kp)
237{
238 return sprintf(buffer, "%s", *((char **)kp->arg));
239}
240
241/* Actually could be a bool or an int, for historical reasons. */
242int param_set_bool(const char *val, struct kernel_param *kp)
243{
244 bool v;
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 v = true;
253 break;
254 case 'n': case 'N': case '0':
255 v = false;
256 break;
257 default:
258 return -EINVAL;
259 }
260
261 if (kp->flags & KPARAM_ISBOOL)
262 *(bool *)kp->arg = v;
263 else
264 *(int *)kp->arg = v;
265 return 0;
266}
267
268int param_get_bool(char *buffer, struct kernel_param *kp)
269{
270 bool val;
271 if (kp->flags & KPARAM_ISBOOL)
272 val = *(bool *)kp->arg;
273 else
274 val = *(int *)kp->arg;
275
276 /* Y and N chosen as being relatively non-coder friendly */
277 return sprintf(buffer, "%c", val ? 'Y' : 'N');
278}
279
280/* This one must be bool. */
281int param_set_invbool(const char *val, struct kernel_param *kp)
282{
283 int ret;
284 bool boolval;
285 struct kernel_param dummy;
286
287 dummy.arg = &boolval;
288 dummy.flags = KPARAM_ISBOOL;
289 ret = param_set_bool(val, &dummy);
290 if (ret == 0)
291 *(bool *)kp->arg = !boolval;
292 return ret;
293}
294
295int param_get_invbool(char *buffer, struct kernel_param *kp)
296{
297 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
298}
299
300/* We break the rule and mangle the string. */
301static int param_array(const char *name,
302 const char *val,
303 unsigned int min, unsigned int max,
304 void *elem, int elemsize,
305 int (*set)(const char *, struct kernel_param *kp),
306 unsigned int *num)
307{
308 int ret;
309 struct kernel_param kp;
310 char save;
311
312 /* Get the name right for errors. */
313 kp.name = name;
314 kp.arg = elem;
315
316 /* No equals sign? */
317 if (!val) {
318 printk(KERN_ERR "%s: expects arguments\n", name);
319 return -EINVAL;
320 }
321
322 *num = 0;
323 /* We expect a comma-separated list of values. */
324 do {
325 int len;
326
327 if (*num == max) {
328 printk(KERN_ERR "%s: can only take %i arguments\n",
329 name, max);
330 return -EINVAL;
331 }
332 len = strcspn(val, ",");
333
334 /* nul-terminate and parse */
335 save = val[len];
336 ((char *)val)[len] = '\0';
337 ret = set(val, &kp);
338
339 if (ret != 0)
340 return ret;
341 kp.arg += elemsize;
342 val += len+1;
343 (*num)++;
344 } while (save == ',');
345
346 if (*num < min) {
347 printk(KERN_ERR "%s: needs at least %i arguments\n",
348 name, min);
349 return -EINVAL;
350 }
351 return 0;
352}
353
354int param_array_set(const char *val, struct kernel_param *kp)
355{
356 const struct kparam_array *arr = kp->arr;
357 unsigned int temp_num;
358
359 return param_array(kp->name, val, 1, arr->max, arr->elem,
360 arr->elemsize, arr->set, arr->num ?: &temp_num);
361}
362
363int param_array_get(char *buffer, struct kernel_param *kp)
364{
365 int i, off, ret;
366 const struct kparam_array *arr = kp->arr;
367 struct kernel_param p;
368
369 p = *kp;
370 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
371 if (i)
372 buffer[off++] = ',';
373 p.arg = arr->elem + arr->elemsize * i;
374 ret = arr->get(buffer + off, &p);
375 if (ret < 0)
376 return ret;
377 off += ret;
378 }
379 buffer[off] = '\0';
380 return off;
381}
382
383int param_set_copystring(const char *val, struct kernel_param *kp)
384{
385 const struct kparam_string *kps = kp->str;
386
387 if (!val) {
388 printk(KERN_ERR "%s: missing param set value\n", kp->name);
389 return -EINVAL;
390 }
391 if (strlen(val)+1 > kps->maxlen) {
392 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
393 kp->name, kps->maxlen-1);
394 return -ENOSPC;
395 }
396 strcpy(kps->string, val);
397 return 0;
398}
399
400int param_get_string(char *buffer, struct kernel_param *kp)
401{
402 const struct kparam_string *kps = kp->str;
403 return strlcpy(buffer, kps->string, kps->maxlen);
404}
405
406/* sysfs output in /sys/modules/XYZ/parameters/ */
407#define to_module_attr(n) container_of(n, struct module_attribute, attr);
408#define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
409
410extern struct kernel_param __start___param[], __stop___param[];
411
412struct param_attribute
413{
414 struct module_attribute mattr;
415 struct kernel_param *param;
416};
417
418struct module_param_attrs
419{
420 unsigned int num;
421 struct attribute_group grp;
422 struct param_attribute attrs[0];
423};
424
425#ifdef CONFIG_SYSFS
426#define to_param_attr(n) container_of(n, struct param_attribute, mattr);
427
428static ssize_t param_attr_show(struct module_attribute *mattr,
429 struct module *mod, char *buf)
430{
431 int count;
432 struct param_attribute *attribute = to_param_attr(mattr);
433
434 if (!attribute->param->get)
435 return -EPERM;
436
437 count = attribute->param->get(buf, attribute->param);
438 if (count > 0) {
439 strcat(buf, "\n");
440 ++count;
441 }
442 return count;
443}
444
445/* sysfs always hands a nul-terminated string in buf. We rely on that. */
446static ssize_t param_attr_store(struct module_attribute *mattr,
447 struct module *owner,
448 const char *buf, size_t len)
449{
450 int err;
451 struct param_attribute *attribute = to_param_attr(mattr);
452
453 if (!attribute->param->set)
454 return -EPERM;
455
456 err = attribute->param->set(buf, attribute->param);
457 if (!err)
458 return len;
459 return err;
460}
461#endif
462
463#ifdef CONFIG_MODULES
464#define __modinit
465#else
466#define __modinit __init
467#endif
468
469#ifdef CONFIG_SYSFS
470/*
471 * add_sysfs_param - add a parameter to sysfs
472 * @mk: struct module_kobject
473 * @kparam: the actual parameter definition to add to sysfs
474 * @name: name of parameter
475 *
476 * Create a kobject if for a (per-module) parameter if mp NULL, and
477 * create file in sysfs. Returns an error on out of memory. Always cleans up
478 * if there's an error.
479 */
480static __modinit int add_sysfs_param(struct module_kobject *mk,
481 struct kernel_param *kp,
482 const char *name)
483{
484 struct module_param_attrs *new;
485 struct attribute **attrs;
486 int err, num;
487
488 /* We don't bother calling this with invisible parameters. */
489 BUG_ON(!kp->perm);
490
491 if (!mk->mp) {
492 num = 0;
493 attrs = NULL;
494 } else {
495 num = mk->mp->num;
496 attrs = mk->mp->grp.attrs;
497 }
498
499 /* Enlarge. */
500 new = krealloc(mk->mp,
501 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
502 GFP_KERNEL);
503 if (!new) {
504 kfree(mk->mp);
505 err = -ENOMEM;
506 goto fail;
507 }
508 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
509 if (!attrs) {
510 err = -ENOMEM;
511 goto fail_free_new;
512 }
513
514 /* Sysfs wants everything zeroed. */
515 memset(new, 0, sizeof(*new));
516 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
517 memset(&attrs[num], 0, sizeof(attrs[num]));
518 new->grp.name = "parameters";
519 new->grp.attrs = attrs;
520
521 /* Tack new one on the end. */
522 new->attrs[num].param = kp;
523 new->attrs[num].mattr.show = param_attr_show;
524 new->attrs[num].mattr.store = param_attr_store;
525 new->attrs[num].mattr.attr.name = (char *)name;
526 new->attrs[num].mattr.attr.mode = kp->perm;
527 new->num = num+1;
528
529 /* Fix up all the pointers, since krealloc can move us */
530 for (num = 0; num < new->num; num++)
531 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
532 new->grp.attrs[num] = NULL;
533
534 mk->mp = new;
535 return 0;
536
537fail_free_new:
538 kfree(new);
539fail:
540 mk->mp = NULL;
541 return err;
542}
543
544#ifdef CONFIG_MODULES
545static void free_module_param_attrs(struct module_kobject *mk)
546{
547 kfree(mk->mp->grp.attrs);
548 kfree(mk->mp);
549 mk->mp = NULL;
550}
551
552/*
553 * module_param_sysfs_setup - setup sysfs support for one module
554 * @mod: module
555 * @kparam: module parameters (array)
556 * @num_params: number of module parameters
557 *
558 * Adds sysfs entries for module parameters under
559 * /sys/module/[mod->name]/parameters/
560 */
561int module_param_sysfs_setup(struct module *mod,
562 struct kernel_param *kparam,
563 unsigned int num_params)
564{
565 int i, err;
566 bool params = false;
567
568 for (i = 0; i < num_params; i++) {
569 if (kparam[i].perm == 0)
570 continue;
571 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
572 if (err)
573 return err;
574 params = true;
575 }
576
577 if (!params)
578 return 0;
579
580 /* Create the param group. */
581 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
582 if (err)
583 free_module_param_attrs(&mod->mkobj);
584 return err;
585}
586
587/*
588 * module_param_sysfs_remove - remove sysfs support for one module
589 * @mod: module
590 *
591 * Remove sysfs entries for module parameters and the corresponding
592 * kobject.
593 */
594void module_param_sysfs_remove(struct module *mod)
595{
596 if (mod->mkobj.mp) {
597 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
598 /* We are positive that no one is using any param
599 * attrs at this point. Deallocate immediately. */
600 free_module_param_attrs(&mod->mkobj);
601 }
602}
603#endif
604
605void destroy_params(const struct kernel_param *params, unsigned num)
606{
607 unsigned int i;
608
609 for (i = 0; i < num; i++)
610 if (params[i].flags & KPARAM_KMALLOCED)
611 kfree(*(char **)params[i].arg);
612}
613
614static void __init kernel_add_sysfs_param(const char *name,
615 struct kernel_param *kparam,
616 unsigned int name_skip)
617{
618 struct module_kobject *mk;
619 struct kobject *kobj;
620 int err;
621
622 kobj = kset_find_obj(module_kset, name);
623 if (kobj) {
624 /* We already have one. Remove params so we can add more. */
625 mk = to_module_kobject(kobj);
626 /* We need to remove it before adding parameters. */
627 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
628 } else {
629 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
630 BUG_ON(!mk);
631
632 mk->mod = THIS_MODULE;
633 mk->kobj.kset = module_kset;
634 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
635 "%s", name);
636 if (err) {
637 kobject_put(&mk->kobj);
638 printk(KERN_ERR "Module '%s' failed add to sysfs, "
639 "error number %d\n", name, err);
640 printk(KERN_ERR "The system will be unstable now.\n");
641 return;
642 }
643 /* So that exit path is even. */
644 kobject_get(&mk->kobj);
645 }
646
647 /* These should not fail at boot. */
648 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
649 BUG_ON(err);
650 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
651 BUG_ON(err);
652 kobject_uevent(&mk->kobj, KOBJ_ADD);
653 kobject_put(&mk->kobj);
654}
655
656/*
657 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
658 *
659 * Add module_parameters to sysfs for "modules" built into the kernel.
660 *
661 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
662 * "parameter" name is stored behind a dot in kernel_param->name. So,
663 * extract the "module" name for all built-in kernel_param-eters,
664 * and for all who have the same, call kernel_add_sysfs_param.
665 */
666static void __init param_sysfs_builtin(void)
667{
668 struct kernel_param *kp;
669 unsigned int name_len;
670 char modname[MODULE_NAME_LEN];
671
672 for (kp = __start___param; kp < __stop___param; kp++) {
673 char *dot;
674
675 if (kp->perm == 0)
676 continue;
677
678 dot = strchr(kp->name, '.');
679 if (!dot) {
680 /* This happens for core_param() */
681 strcpy(modname, "kernel");
682 name_len = 0;
683 } else {
684 name_len = dot - kp->name + 1;
685 strlcpy(modname, kp->name, name_len);
686 }
687 kernel_add_sysfs_param(modname, kp, name_len);
688 }
689}
690
691
692/* module-related sysfs stuff */
693
694static ssize_t module_attr_show(struct kobject *kobj,
695 struct attribute *attr,
696 char *buf)
697{
698 struct module_attribute *attribute;
699 struct module_kobject *mk;
700 int ret;
701
702 attribute = to_module_attr(attr);
703 mk = to_module_kobject(kobj);
704
705 if (!attribute->show)
706 return -EIO;
707
708 ret = attribute->show(attribute, mk->mod, buf);
709
710 return ret;
711}
712
713static ssize_t module_attr_store(struct kobject *kobj,
714 struct attribute *attr,
715 const char *buf, size_t len)
716{
717 struct module_attribute *attribute;
718 struct module_kobject *mk;
719 int ret;
720
721 attribute = to_module_attr(attr);
722 mk = to_module_kobject(kobj);
723
724 if (!attribute->store)
725 return -EIO;
726
727 ret = attribute->store(attribute, mk->mod, buf, len);
728
729 return ret;
730}
731
732static struct sysfs_ops module_sysfs_ops = {
733 .show = module_attr_show,
734 .store = module_attr_store,
735};
736
737static int uevent_filter(struct kset *kset, struct kobject *kobj)
738{
739 struct kobj_type *ktype = get_ktype(kobj);
740
741 if (ktype == &module_ktype)
742 return 1;
743 return 0;
744}
745
746static struct kset_uevent_ops module_uevent_ops = {
747 .filter = uevent_filter,
748};
749
750struct kset *module_kset;
751int module_sysfs_initialized;
752
753struct kobj_type module_ktype = {
754 .sysfs_ops = &module_sysfs_ops,
755};
756
757/*
758 * param_sysfs_init - wrapper for built-in params support
759 */
760static int __init param_sysfs_init(void)
761{
762 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
763 if (!module_kset) {
764 printk(KERN_WARNING "%s (%d): error creating kset\n",
765 __FILE__, __LINE__);
766 return -ENOMEM;
767 }
768 module_sysfs_initialized = 1;
769
770 param_sysfs_builtin();
771
772 return 0;
773}
774subsys_initcall(param_sysfs_init);
775
776#endif /* CONFIG_SYSFS */
777
778EXPORT_SYMBOL(param_set_byte);
779EXPORT_SYMBOL(param_get_byte);
780EXPORT_SYMBOL(param_set_short);
781EXPORT_SYMBOL(param_get_short);
782EXPORT_SYMBOL(param_set_ushort);
783EXPORT_SYMBOL(param_get_ushort);
784EXPORT_SYMBOL(param_set_int);
785EXPORT_SYMBOL(param_get_int);
786EXPORT_SYMBOL(param_set_uint);
787EXPORT_SYMBOL(param_get_uint);
788EXPORT_SYMBOL(param_set_long);
789EXPORT_SYMBOL(param_get_long);
790EXPORT_SYMBOL(param_set_ulong);
791EXPORT_SYMBOL(param_get_ulong);
792EXPORT_SYMBOL(param_set_charp);
793EXPORT_SYMBOL(param_get_charp);
794EXPORT_SYMBOL(param_set_bool);
795EXPORT_SYMBOL(param_get_bool);
796EXPORT_SYMBOL(param_set_invbool);
797EXPORT_SYMBOL(param_get_invbool);
798EXPORT_SYMBOL(param_array_set);
799EXPORT_SYMBOL(param_array_get);
800EXPORT_SYMBOL(param_set_copystring);
801EXPORT_SYMBOL(param_get_string);