blob: 08107d1817582000af8df78667db22e6d88e5f59 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* 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*/
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#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>
Tim Schmielau4e57b682005-10-30 15:03:48 -080025#include <linux/slab.h>
Peter Oberparleiter26d052b2009-07-06 17:11:22 +020026#include <linux/ctype.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28#if 0
29#define DEBUGP printk
30#else
31#define DEBUGP(fmt, a...)
32#endif
33
Rusty Russell907b29e2010-08-11 23:04:19 -060034/* Protects all parameters, and incidentally kmalloced_param list. */
35static DEFINE_MUTEX(param_lock);
36
Rusty Russella1054322010-08-11 23:04:18 -060037/* This just allows us to keep track of which parameters are kmalloced. */
38struct kmalloced_param {
39 struct list_head list;
40 char val[];
41};
Rusty Russella1054322010-08-11 23:04:18 -060042static LIST_HEAD(kmalloced_params);
43
44static void *kmalloc_parameter(unsigned int size)
45{
46 struct kmalloced_param *p;
47
48 p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
49 if (!p)
50 return NULL;
51
Rusty Russella1054322010-08-11 23:04:18 -060052 list_add(&p->list, &kmalloced_params);
Rusty Russella1054322010-08-11 23:04:18 -060053 return p->val;
54}
55
56/* Does nothing if parameter wasn't kmalloced above. */
57static void maybe_kfree_parameter(void *param)
58{
59 struct kmalloced_param *p;
60
Rusty Russella1054322010-08-11 23:04:18 -060061 list_for_each_entry(p, &kmalloced_params, list) {
62 if (p->val == param) {
63 list_del(&p->list);
64 kfree(p);
65 break;
66 }
67 }
Rusty Russella1054322010-08-11 23:04:18 -060068}
69
Eric Sesterhennb9e20a92006-03-28 01:56:24 -080070static inline char dash2underscore(char c)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071{
72 if (c == '-')
73 return '_';
74 return c;
75}
76
77static inline int parameq(const char *input, const char *paramname)
78{
79 unsigned int i;
80 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
81 if (input[i] == '\0')
82 return 1;
83 return 0;
84}
85
86static int parse_one(char *param,
87 char *val,
Rusty Russell914dcaa2010-08-11 23:04:18 -060088 const struct kernel_param *params,
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 unsigned num_params,
90 int (*handle_unknown)(char *param, char *val))
91{
92 unsigned int i;
Rusty Russell907b29e2010-08-11 23:04:19 -060093 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
95 /* Find parameter */
96 for (i = 0; i < num_params; i++) {
97 if (parameq(param, params[i].name)) {
Rusty Russell2e9fb992010-08-11 23:04:10 -060098 /* Noone handled NULL, so do it here. */
Rusty Russell9bbb9e52010-08-11 23:04:12 -060099 if (!val && params[i].ops->set != param_set_bool)
Rusty Russell2e9fb992010-08-11 23:04:10 -0600100 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 DEBUGP("They are equal! Calling %p\n",
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600102 params[i].ops->set);
Rusty Russell907b29e2010-08-11 23:04:19 -0600103 mutex_lock(&param_lock);
104 err = params[i].ops->set(val, &params[i]);
105 mutex_unlock(&param_lock);
106 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 }
108 }
109
110 if (handle_unknown) {
111 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
112 return handle_unknown(param, val);
113 }
114
115 DEBUGP("Unknown argument `%s'\n", param);
116 return -ENOENT;
117}
118
119/* You can use " around spaces, but can't escape ". */
120/* Hyphens and underscores equivalent in parameter names. */
121static char *next_arg(char *args, char **param, char **val)
122{
123 unsigned int i, equals = 0;
124 int in_quote = 0, quoted = 0;
125 char *next;
126
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 if (*args == '"') {
128 args++;
129 in_quote = 1;
130 quoted = 1;
131 }
132
133 for (i = 0; args[i]; i++) {
Peter Oberparleiter26d052b2009-07-06 17:11:22 +0200134 if (isspace(args[i]) && !in_quote)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 break;
136 if (equals == 0) {
137 if (args[i] == '=')
138 equals = i;
139 }
140 if (args[i] == '"')
141 in_quote = !in_quote;
142 }
143
144 *param = args;
145 if (!equals)
146 *val = NULL;
147 else {
148 args[equals] = '\0';
149 *val = args + equals + 1;
150
151 /* Don't include quotes in value. */
152 if (**val == '"') {
153 (*val)++;
154 if (args[i-1] == '"')
155 args[i-1] = '\0';
156 }
157 if (quoted && args[i-1] == '"')
158 args[i-1] = '\0';
159 }
160
161 if (args[i]) {
162 args[i] = '\0';
163 next = args + i + 1;
164 } else
165 next = args + i;
Rusty Russellf36462f2005-09-27 21:45:34 -0700166
167 /* Chew up trailing spaces. */
André Goddard Rosae7d28602009-12-14 18:01:06 -0800168 return skip_spaces(next);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169}
170
171/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
172int parse_args(const char *name,
173 char *args,
Rusty Russell914dcaa2010-08-11 23:04:18 -0600174 const struct kernel_param *params,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 unsigned num,
176 int (*unknown)(char *param, char *val))
177{
178 char *param, *val;
179
180 DEBUGP("Parsing ARGS: %s\n", args);
181
Rusty Russellf36462f2005-09-27 21:45:34 -0700182 /* Chew leading spaces */
André Goddard Rosae7d28602009-12-14 18:01:06 -0800183 args = skip_spaces(args);
Rusty Russellf36462f2005-09-27 21:45:34 -0700184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 while (*args) {
186 int ret;
Ard van Breemena416aba2007-01-05 16:36:20 -0800187 int irq_was_disabled;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
189 args = next_arg(args, &param, &val);
Ard van Breemena416aba2007-01-05 16:36:20 -0800190 irq_was_disabled = irqs_disabled();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 ret = parse_one(param, val, params, num, unknown);
Ard van Breemena416aba2007-01-05 16:36:20 -0800192 if (irq_was_disabled && !irqs_disabled()) {
193 printk(KERN_WARNING "parse_args(): option '%s' enabled "
194 "irq's!\n", param);
195 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 switch (ret) {
197 case -ENOENT:
198 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
199 name, param);
200 return ret;
201 case -ENOSPC:
202 printk(KERN_ERR
203 "%s: `%s' too large for parameter `%s'\n",
204 name, val ?: "", param);
205 return ret;
206 case 0:
207 break;
208 default:
209 printk(KERN_ERR
210 "%s: `%s' invalid for parameter `%s'\n",
211 name, val ?: "", param);
212 return ret;
213 }
214 }
215
216 /* All parsed OK. */
217 return 0;
218}
219
220/* Lazy bastard, eh? */
221#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600222 int param_set_##name(const char *val, const struct kernel_param *kp) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 { \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 tmptype l; \
Yi Yang06b2a762008-02-08 04:21:57 -0800225 int ret; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 \
Yi Yang06b2a762008-02-08 04:21:57 -0800227 ret = strtolfn(val, 0, &l); \
228 if (ret == -EINVAL || ((type)l != l)) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 return -EINVAL; \
230 *((type *)kp->arg) = l; \
231 return 0; \
232 } \
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600233 int param_get_##name(char *buffer, const struct kernel_param *kp) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 { \
235 return sprintf(buffer, format, *((type *)kp->arg)); \
Rusty Russella14fe242010-08-11 23:04:11 -0600236 } \
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600237 struct kernel_param_ops param_ops_##name = { \
238 .set = param_set_##name, \
239 .get = param_get_##name, \
240 }; \
Rusty Russella14fe242010-08-11 23:04:11 -0600241 EXPORT_SYMBOL(param_set_##name); \
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600242 EXPORT_SYMBOL(param_get_##name); \
243 EXPORT_SYMBOL(param_ops_##name)
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
Yi Yang06b2a762008-02-08 04:21:57 -0800246STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
247STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
248STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
249STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
250STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
251STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
252STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600254int param_set_charp(const char *val, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 if (strlen(val) > 1024) {
257 printk(KERN_ERR "%s: string parameter too long\n",
258 kp->name);
259 return -ENOSPC;
260 }
261
Rusty Russella1054322010-08-11 23:04:18 -0600262 maybe_kfree_parameter(*(char **)kp->arg);
263
264 /* This is a hack. We can't kmalloc in early boot, and we
Rusty Russelle180a6b2009-03-31 13:05:29 -0600265 * don't need to; this mangled commandline is preserved. */
266 if (slab_is_available()) {
Rusty Russella1054322010-08-11 23:04:18 -0600267 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
Rusty Russelld553ad82009-10-29 08:56:17 -0600268 if (!*(char **)kp->arg)
Rusty Russelle180a6b2009-03-31 13:05:29 -0600269 return -ENOMEM;
Rusty Russella1054322010-08-11 23:04:18 -0600270 strcpy(*(char **)kp->arg, val);
Rusty Russelle180a6b2009-03-31 13:05:29 -0600271 } else
272 *(const char **)kp->arg = val;
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 return 0;
275}
Rusty Russella14fe242010-08-11 23:04:11 -0600276EXPORT_SYMBOL(param_set_charp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600278int param_get_charp(char *buffer, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279{
280 return sprintf(buffer, "%s", *((char **)kp->arg));
281}
Rusty Russella14fe242010-08-11 23:04:11 -0600282EXPORT_SYMBOL(param_get_charp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
Rusty Russella1054322010-08-11 23:04:18 -0600284static void param_free_charp(void *arg)
285{
286 maybe_kfree_parameter(*((char **)arg));
287}
288
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600289struct kernel_param_ops param_ops_charp = {
290 .set = param_set_charp,
291 .get = param_get_charp,
Rusty Russella1054322010-08-11 23:04:18 -0600292 .free = param_free_charp,
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600293};
294EXPORT_SYMBOL(param_ops_charp);
295
Rusty Russellfddd5202009-06-12 21:46:57 -0600296/* Actually could be a bool or an int, for historical reasons. */
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600297int param_set_bool(const char *val, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298{
Rusty Russellfddd5202009-06-12 21:46:57 -0600299 bool v;
300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 /* No equals means "set"... */
302 if (!val) val = "1";
303
304 /* One of =[yYnN01] */
305 switch (val[0]) {
306 case 'y': case 'Y': case '1':
Rusty Russellfddd5202009-06-12 21:46:57 -0600307 v = true;
308 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 case 'n': case 'N': case '0':
Rusty Russellfddd5202009-06-12 21:46:57 -0600310 v = false;
311 break;
312 default:
313 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 }
Rusty Russellfddd5202009-06-12 21:46:57 -0600315
316 if (kp->flags & KPARAM_ISBOOL)
317 *(bool *)kp->arg = v;
318 else
319 *(int *)kp->arg = v;
320 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321}
Rusty Russella14fe242010-08-11 23:04:11 -0600322EXPORT_SYMBOL(param_set_bool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600324int param_get_bool(char *buffer, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325{
Rusty Russellfddd5202009-06-12 21:46:57 -0600326 bool val;
327 if (kp->flags & KPARAM_ISBOOL)
328 val = *(bool *)kp->arg;
329 else
330 val = *(int *)kp->arg;
331
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 /* Y and N chosen as being relatively non-coder friendly */
Rusty Russellfddd5202009-06-12 21:46:57 -0600333 return sprintf(buffer, "%c", val ? 'Y' : 'N');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334}
Rusty Russella14fe242010-08-11 23:04:11 -0600335EXPORT_SYMBOL(param_get_bool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600337struct kernel_param_ops param_ops_bool = {
338 .set = param_set_bool,
339 .get = param_get_bool,
340};
341EXPORT_SYMBOL(param_ops_bool);
342
Rusty Russellfddd5202009-06-12 21:46:57 -0600343/* This one must be bool. */
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600344int param_set_invbool(const char *val, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345{
Rusty Russellfddd5202009-06-12 21:46:57 -0600346 int ret;
347 bool boolval;
Jan Beulich22e48ea2007-10-16 23:29:34 -0700348 struct kernel_param dummy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
Jan Beulich22e48ea2007-10-16 23:29:34 -0700350 dummy.arg = &boolval;
Rusty Russellfddd5202009-06-12 21:46:57 -0600351 dummy.flags = KPARAM_ISBOOL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 ret = param_set_bool(val, &dummy);
353 if (ret == 0)
Rusty Russell9a71af22009-06-12 21:46:53 -0600354 *(bool *)kp->arg = !boolval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 return ret;
356}
Rusty Russella14fe242010-08-11 23:04:11 -0600357EXPORT_SYMBOL(param_set_invbool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600359int param_get_invbool(char *buffer, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360{
Rusty Russell9a71af22009-06-12 21:46:53 -0600361 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362}
Rusty Russella14fe242010-08-11 23:04:11 -0600363EXPORT_SYMBOL(param_get_invbool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600365struct kernel_param_ops param_ops_invbool = {
366 .set = param_set_invbool,
367 .get = param_get_invbool,
368};
369EXPORT_SYMBOL(param_ops_invbool);
370
Bert Wesarg9730b5b2007-05-08 00:28:50 -0700371/* We break the rule and mangle the string. */
Adrian Bunk98717282006-03-25 03:07:06 -0800372static int param_array(const char *name,
373 const char *val,
374 unsigned int min, unsigned int max,
375 void *elem, int elemsize,
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600376 int (*set)(const char *, const struct kernel_param *kp),
Rusty Russell3c7d76e2009-10-29 08:56:19 -0600377 u16 flags,
Richard Knutssoneb38a992008-02-06 01:37:50 -0800378 unsigned int *num)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379{
380 int ret;
381 struct kernel_param kp;
382 char save;
383
384 /* Get the name right for errors. */
385 kp.name = name;
386 kp.arg = elem;
Rusty Russell3c7d76e2009-10-29 08:56:19 -0600387 kp.flags = flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 *num = 0;
390 /* We expect a comma-separated list of values. */
391 do {
392 int len;
393
394 if (*num == max) {
395 printk(KERN_ERR "%s: can only take %i arguments\n",
396 name, max);
397 return -EINVAL;
398 }
399 len = strcspn(val, ",");
400
401 /* nul-terminate and parse */
402 save = val[len];
403 ((char *)val)[len] = '\0';
Rusty Russell907b29e2010-08-11 23:04:19 -0600404 BUG_ON(!mutex_is_locked(&param_lock));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 ret = set(val, &kp);
406
407 if (ret != 0)
408 return ret;
409 kp.arg += elemsize;
410 val += len+1;
411 (*num)++;
412 } while (save == ',');
413
414 if (*num < min) {
415 printk(KERN_ERR "%s: needs at least %i arguments\n",
416 name, min);
417 return -EINVAL;
418 }
419 return 0;
420}
421
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600422static int param_array_set(const char *val, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423{
Jan Beulich22e48ea2007-10-16 23:29:34 -0700424 const struct kparam_array *arr = kp->arr;
Bert Wesarg31143a12005-04-16 15:25:42 -0700425 unsigned int temp_num;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 return param_array(kp->name, val, 1, arr->max, arr->elem,
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600428 arr->elemsize, arr->ops->set, kp->flags,
Rusty Russell3c7d76e2009-10-29 08:56:19 -0600429 arr->num ?: &temp_num);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430}
431
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600432static int param_array_get(char *buffer, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433{
434 int i, off, ret;
Jan Beulich22e48ea2007-10-16 23:29:34 -0700435 const struct kparam_array *arr = kp->arr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 struct kernel_param p;
437
438 p = *kp;
439 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
440 if (i)
441 buffer[off++] = ',';
442 p.arg = arr->elem + arr->elemsize * i;
Rusty Russell907b29e2010-08-11 23:04:19 -0600443 BUG_ON(!mutex_is_locked(&param_lock));
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600444 ret = arr->ops->get(buffer + off, &p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 if (ret < 0)
446 return ret;
447 off += ret;
448 }
449 buffer[off] = '\0';
450 return off;
451}
452
Rusty Russelle6df34a2010-08-11 23:04:17 -0600453static void param_array_free(void *arg)
454{
455 unsigned int i;
456 const struct kparam_array *arr = arg;
457
458 if (arr->ops->free)
459 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
460 arr->ops->free(arr->elem + arr->elemsize * i);
461}
462
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600463struct kernel_param_ops param_array_ops = {
464 .set = param_array_set,
465 .get = param_array_get,
Rusty Russelle6df34a2010-08-11 23:04:17 -0600466 .free = param_array_free,
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600467};
468EXPORT_SYMBOL(param_array_ops);
469
470int param_set_copystring(const char *val, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471{
Jan Beulich22e48ea2007-10-16 23:29:34 -0700472 const struct kparam_string *kps = kp->str;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473
474 if (strlen(val)+1 > kps->maxlen) {
475 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
476 kp->name, kps->maxlen-1);
477 return -ENOSPC;
478 }
479 strcpy(kps->string, val);
480 return 0;
481}
Rusty Russella14fe242010-08-11 23:04:11 -0600482EXPORT_SYMBOL(param_set_copystring);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600484int param_get_string(char *buffer, const struct kernel_param *kp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485{
Jan Beulich22e48ea2007-10-16 23:29:34 -0700486 const struct kparam_string *kps = kp->str;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 return strlcpy(buffer, kps->string, kps->maxlen);
488}
Rusty Russella14fe242010-08-11 23:04:11 -0600489EXPORT_SYMBOL(param_get_string);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600491struct kernel_param_ops param_ops_string = {
492 .set = param_set_copystring,
493 .get = param_get_string,
494};
495EXPORT_SYMBOL(param_ops_string);
496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497/* sysfs output in /sys/modules/XYZ/parameters/ */
Edward Z. Yang350f8252010-02-01 18:26:59 -0500498#define to_module_attr(n) container_of(n, struct module_attribute, attr)
499#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500
501extern struct kernel_param __start___param[], __stop___param[];
502
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503struct param_attribute
504{
505 struct module_attribute mattr;
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600506 const struct kernel_param *param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507};
508
509struct module_param_attrs
510{
Rusty Russell9b473de2008-10-22 10:00:22 -0500511 unsigned int num;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 struct attribute_group grp;
513 struct param_attribute attrs[0];
514};
515
Randy Dunlapef665c12007-02-13 15:19:06 -0800516#ifdef CONFIG_SYSFS
Edward Z. Yang350f8252010-02-01 18:26:59 -0500517#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518
519static ssize_t param_attr_show(struct module_attribute *mattr,
520 struct module *mod, char *buf)
521{
522 int count;
523 struct param_attribute *attribute = to_param_attr(mattr);
524
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600525 if (!attribute->param->ops->get)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 return -EPERM;
527
Rusty Russell907b29e2010-08-11 23:04:19 -0600528 mutex_lock(&param_lock);
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600529 count = attribute->param->ops->get(buf, attribute->param);
Rusty Russell907b29e2010-08-11 23:04:19 -0600530 mutex_unlock(&param_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 if (count > 0) {
532 strcat(buf, "\n");
533 ++count;
534 }
535 return count;
536}
537
538/* sysfs always hands a nul-terminated string in buf. We rely on that. */
539static ssize_t param_attr_store(struct module_attribute *mattr,
540 struct module *owner,
541 const char *buf, size_t len)
542{
543 int err;
544 struct param_attribute *attribute = to_param_attr(mattr);
545
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600546 if (!attribute->param->ops->set)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 return -EPERM;
548
Rusty Russell907b29e2010-08-11 23:04:19 -0600549 mutex_lock(&param_lock);
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600550 err = attribute->param->ops->set(buf, attribute->param);
Rusty Russell907b29e2010-08-11 23:04:19 -0600551 mutex_unlock(&param_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 if (!err)
553 return len;
554 return err;
555}
Randy Dunlapef665c12007-02-13 15:19:06 -0800556#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557
558#ifdef CONFIG_MODULES
559#define __modinit
560#else
561#define __modinit __init
562#endif
563
Randy Dunlapef665c12007-02-13 15:19:06 -0800564#ifdef CONFIG_SYSFS
Rusty Russell907b29e2010-08-11 23:04:19 -0600565void __kernel_param_lock(void)
566{
567 mutex_lock(&param_lock);
568}
569EXPORT_SYMBOL(__kernel_param_lock);
570
571void __kernel_param_unlock(void)
572{
573 mutex_unlock(&param_lock);
574}
575EXPORT_SYMBOL(__kernel_param_unlock);
576
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577/*
Rusty Russell9b473de2008-10-22 10:00:22 -0500578 * add_sysfs_param - add a parameter to sysfs
579 * @mk: struct module_kobject
580 * @kparam: the actual parameter definition to add to sysfs
581 * @name: name of parameter
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 *
Rusty Russell9b473de2008-10-22 10:00:22 -0500583 * Create a kobject if for a (per-module) parameter if mp NULL, and
584 * create file in sysfs. Returns an error on out of memory. Always cleans up
585 * if there's an error.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 */
Rusty Russell9b473de2008-10-22 10:00:22 -0500587static __modinit int add_sysfs_param(struct module_kobject *mk,
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600588 const struct kernel_param *kp,
Rusty Russell9b473de2008-10-22 10:00:22 -0500589 const char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590{
Rusty Russell9b473de2008-10-22 10:00:22 -0500591 struct module_param_attrs *new;
592 struct attribute **attrs;
593 int err, num;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
Rusty Russell9b473de2008-10-22 10:00:22 -0500595 /* We don't bother calling this with invisible parameters. */
596 BUG_ON(!kp->perm);
597
598 if (!mk->mp) {
599 num = 0;
600 attrs = NULL;
601 } else {
602 num = mk->mp->num;
603 attrs = mk->mp->grp.attrs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 }
605
Rusty Russell9b473de2008-10-22 10:00:22 -0500606 /* Enlarge. */
607 new = krealloc(mk->mp,
608 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
609 GFP_KERNEL);
610 if (!new) {
611 kfree(mk->mp);
612 err = -ENOMEM;
613 goto fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 }
Rusty Russell9b473de2008-10-22 10:00:22 -0500615 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
616 if (!attrs) {
617 err = -ENOMEM;
618 goto fail_free_new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 }
Rusty Russell9b473de2008-10-22 10:00:22 -0500620
621 /* Sysfs wants everything zeroed. */
622 memset(new, 0, sizeof(*new));
623 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
624 memset(&attrs[num], 0, sizeof(attrs[num]));
625 new->grp.name = "parameters";
626 new->grp.attrs = attrs;
627
628 /* Tack new one on the end. */
Eric W. Biedermana07e4152010-02-11 15:23:05 -0800629 sysfs_attr_init(&new->attrs[num].mattr.attr);
Rusty Russell9b473de2008-10-22 10:00:22 -0500630 new->attrs[num].param = kp;
631 new->attrs[num].mattr.show = param_attr_show;
632 new->attrs[num].mattr.store = param_attr_store;
633 new->attrs[num].mattr.attr.name = (char *)name;
634 new->attrs[num].mattr.attr.mode = kp->perm;
635 new->num = num+1;
636
637 /* Fix up all the pointers, since krealloc can move us */
638 for (num = 0; num < new->num; num++)
639 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
640 new->grp.attrs[num] = NULL;
641
642 mk->mp = new;
643 return 0;
644
645fail_free_new:
646 kfree(new);
647fail:
648 mk->mp = NULL;
649 return err;
650}
651
Linus Torvaldsd2441182008-10-23 12:07:17 -0700652#ifdef CONFIG_MODULES
Rusty Russell9b473de2008-10-22 10:00:22 -0500653static void free_module_param_attrs(struct module_kobject *mk)
654{
655 kfree(mk->mp->grp.attrs);
656 kfree(mk->mp);
657 mk->mp = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658}
659
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660/*
661 * module_param_sysfs_setup - setup sysfs support for one module
662 * @mod: module
663 * @kparam: module parameters (array)
664 * @num_params: number of module parameters
665 *
Rusty Russell9b473de2008-10-22 10:00:22 -0500666 * Adds sysfs entries for module parameters under
667 * /sys/module/[mod->name]/parameters/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 */
669int module_param_sysfs_setup(struct module *mod,
Rusty Russell9bbb9e52010-08-11 23:04:12 -0600670 const struct kernel_param *kparam,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 unsigned int num_params)
672{
Rusty Russell9b473de2008-10-22 10:00:22 -0500673 int i, err;
674 bool params = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
Rusty Russell9b473de2008-10-22 10:00:22 -0500676 for (i = 0; i < num_params; i++) {
677 if (kparam[i].perm == 0)
678 continue;
679 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
680 if (err)
681 return err;
682 params = true;
683 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
Rusty Russell9b473de2008-10-22 10:00:22 -0500685 if (!params)
686 return 0;
687
688 /* Create the param group. */
689 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
690 if (err)
691 free_module_param_attrs(&mod->mkobj);
692 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693}
694
695/*
696 * module_param_sysfs_remove - remove sysfs support for one module
697 * @mod: module
698 *
699 * Remove sysfs entries for module parameters and the corresponding
700 * kobject.
701 */
702void module_param_sysfs_remove(struct module *mod)
703{
Rusty Russell9b473de2008-10-22 10:00:22 -0500704 if (mod->mkobj.mp) {
705 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 /* We are positive that no one is using any param
707 * attrs at this point. Deallocate immediately. */
Rusty Russell9b473de2008-10-22 10:00:22 -0500708 free_module_param_attrs(&mod->mkobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 }
710}
711#endif
712
Rusty Russelle180a6b2009-03-31 13:05:29 -0600713void destroy_params(const struct kernel_param *params, unsigned num)
714{
Rusty Russelle6df34a2010-08-11 23:04:17 -0600715 unsigned int i;
716
717 for (i = 0; i < num; i++)
718 if (params[i].ops->free)
719 params[i].ops->free(params[i].arg);
Rusty Russelle180a6b2009-03-31 13:05:29 -0600720}
721
Rusty Russell9b473de2008-10-22 10:00:22 -0500722static void __init kernel_add_sysfs_param(const char *name,
723 struct kernel_param *kparam,
724 unsigned int name_skip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725{
726 struct module_kobject *mk;
Rusty Russell9b473de2008-10-22 10:00:22 -0500727 struct kobject *kobj;
728 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
Rusty Russell9b473de2008-10-22 10:00:22 -0500730 kobj = kset_find_obj(module_kset, name);
731 if (kobj) {
732 /* We already have one. Remove params so we can add more. */
733 mk = to_module_kobject(kobj);
734 /* We need to remove it before adding parameters. */
735 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
736 } else {
737 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
738 BUG_ON(!mk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739
Rusty Russell9b473de2008-10-22 10:00:22 -0500740 mk->mod = THIS_MODULE;
741 mk->kobj.kset = module_kset;
742 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
743 "%s", name);
744 if (err) {
745 kobject_put(&mk->kobj);
746 printk(KERN_ERR "Module '%s' failed add to sysfs, "
747 "error number %d\n", name, err);
748 printk(KERN_ERR "The system will be unstable now.\n");
749 return;
750 }
751 /* So that exit path is even. */
752 kobject_get(&mk->kobj);
Greg Kroah-Hartman74c5b592007-07-30 11:26:38 -0700753 }
Rusty Russell9b473de2008-10-22 10:00:22 -0500754
755 /* These should not fail at boot. */
756 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
757 BUG_ON(err);
758 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
759 BUG_ON(err);
Kay Sieversf30c53a2007-01-15 20:22:02 +0100760 kobject_uevent(&mk->kobj, KOBJ_ADD);
Rusty Russell9b473de2008-10-22 10:00:22 -0500761 kobject_put(&mk->kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762}
763
764/*
765 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
766 *
767 * Add module_parameters to sysfs for "modules" built into the kernel.
768 *
769 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
770 * "parameter" name is stored behind a dot in kernel_param->name. So,
771 * extract the "module" name for all built-in kernel_param-eters,
Rusty Russell9b473de2008-10-22 10:00:22 -0500772 * and for all who have the same, call kernel_add_sysfs_param.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 */
774static void __init param_sysfs_builtin(void)
775{
Rusty Russell9b473de2008-10-22 10:00:22 -0500776 struct kernel_param *kp;
777 unsigned int name_len;
778 char modname[MODULE_NAME_LEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
Rusty Russell9b473de2008-10-22 10:00:22 -0500780 for (kp = __start___param; kp < __stop___param; kp++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 char *dot;
782
Rusty Russell9b473de2008-10-22 10:00:22 -0500783 if (kp->perm == 0)
784 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785
Rusty Russell730b69d2008-10-22 10:00:22 -0500786 dot = strchr(kp->name, '.');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 if (!dot) {
Rusty Russell67e67ce2008-10-22 10:00:23 -0500788 /* This happens for core_param() */
789 strcpy(modname, "kernel");
790 name_len = 0;
791 } else {
792 name_len = dot - kp->name + 1;
793 strlcpy(modname, kp->name, name_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 }
Rusty Russell67e67ce2008-10-22 10:00:23 -0500795 kernel_add_sysfs_param(modname, kp, name_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797}
798
799
800/* module-related sysfs stuff */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802static ssize_t module_attr_show(struct kobject *kobj,
803 struct attribute *attr,
804 char *buf)
805{
806 struct module_attribute *attribute;
807 struct module_kobject *mk;
808 int ret;
809
810 attribute = to_module_attr(attr);
811 mk = to_module_kobject(kobj);
812
813 if (!attribute->show)
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500814 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 ret = attribute->show(attribute, mk->mod, buf);
817
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 return ret;
819}
820
821static ssize_t module_attr_store(struct kobject *kobj,
822 struct attribute *attr,
823 const char *buf, size_t len)
824{
825 struct module_attribute *attribute;
826 struct module_kobject *mk;
827 int ret;
828
829 attribute = to_module_attr(attr);
830 mk = to_module_kobject(kobj);
831
832 if (!attribute->store)
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500833 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 ret = attribute->store(attribute, mk->mod, buf, len);
836
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 return ret;
838}
839
Emese Revfy52cf25d2010-01-19 02:58:23 +0100840static const struct sysfs_ops module_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 .show = module_attr_show,
842 .store = module_attr_store,
843};
844
Kay Sievers270a6c42007-01-18 13:26:15 +0100845static int uevent_filter(struct kset *kset, struct kobject *kobj)
846{
847 struct kobj_type *ktype = get_ktype(kobj);
848
849 if (ktype == &module_ktype)
850 return 1;
851 return 0;
852}
853
Emese Revfy9cd43612009-12-31 14:52:51 +0100854static const struct kset_uevent_ops module_uevent_ops = {
Kay Sievers270a6c42007-01-18 13:26:15 +0100855 .filter = uevent_filter,
856};
857
Greg Kroah-Hartman7405c1e2007-11-01 10:39:50 -0700858struct kset *module_kset;
Greg Kroah-Hartman823bccf2007-04-13 13:15:19 -0700859int module_sysfs_initialized;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860
Greg Kroah-Hartman7405c1e2007-11-01 10:39:50 -0700861struct kobj_type module_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 .sysfs_ops = &module_sysfs_ops,
863};
864
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865/*
866 * param_sysfs_init - wrapper for built-in params support
867 */
868static int __init param_sysfs_init(void)
869{
Greg Kroah-Hartman7405c1e2007-11-01 10:39:50 -0700870 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
871 if (!module_kset) {
872 printk(KERN_WARNING "%s (%d): error creating kset\n",
873 __FILE__, __LINE__);
874 return -ENOMEM;
Randy Dunlapd8c76492006-09-29 01:58:55 -0700875 }
Greg Kroah-Hartman823bccf2007-04-13 13:15:19 -0700876 module_sysfs_initialized = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877
878 param_sysfs_builtin();
879
880 return 0;
881}
Mark Huangd10be6d2006-09-29 01:59:34 -0700882subsys_initcall(param_sysfs_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
Greg Kroah-Hartman7405c1e2007-11-01 10:39:50 -0700884#endif /* CONFIG_SYSFS */