Root/kernel/params.c

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#include <linux/ctype.h>
27
28#if 0
29#define DEBUGP printk
30#else
31#define DEBUGP(fmt, a...)
32#endif
33
34/* Protects all parameters, and incidentally kmalloced_param list. */
35static DEFINE_MUTEX(param_lock);
36
37/* This just allows us to keep track of which parameters are kmalloced. */
38struct kmalloced_param {
39    struct list_head list;
40    char val[];
41};
42static 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
52    list_add(&p->list, &kmalloced_params);
53    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
61    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    }
68}
69
70static inline char dash2underscore(char c)
71{
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,
88             const struct kernel_param *params,
89             unsigned num_params,
90             int (*handle_unknown)(char *param, char *val))
91{
92    unsigned int i;
93    int err;
94
95    /* Find parameter */
96    for (i = 0; i < num_params; i++) {
97        if (parameq(param, params[i].name)) {
98            /* No one handled NULL, so do it here. */
99            if (!val && params[i].ops->set != param_set_bool)
100                return -EINVAL;
101            DEBUGP("They are equal! Calling %p\n",
102                   params[i].ops->set);
103            mutex_lock(&param_lock);
104            err = params[i].ops->set(val, &params[i]);
105            mutex_unlock(&param_lock);
106            return err;
107        }
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
127    if (*args == '"') {
128        args++;
129        in_quote = 1;
130        quoted = 1;
131    }
132
133    for (i = 0; args[i]; i++) {
134        if (isspace(args[i]) && !in_quote)
135            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;
166
167    /* Chew up trailing spaces. */
168    return skip_spaces(next);
169}
170
171/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
172int parse_args(const char *name,
173           char *args,
174           const struct kernel_param *params,
175           unsigned num,
176           int (*unknown)(char *param, char *val))
177{
178    char *param, *val;
179
180    DEBUGP("Parsing ARGS: %s\n", args);
181
182    /* Chew leading spaces */
183    args = skip_spaces(args);
184
185    while (*args) {
186        int ret;
187        int irq_was_disabled;
188
189        args = next_arg(args, &param, &val);
190        irq_was_disabled = irqs_disabled();
191        ret = parse_one(param, val, params, num, unknown);
192        if (irq_was_disabled && !irqs_disabled()) {
193            printk(KERN_WARNING "parse_args(): option '%s' enabled "
194                    "irq's!\n", param);
195        }
196        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) \
222    int param_set_##name(const char *val, const struct kernel_param *kp) \
223    { \
224        tmptype l; \
225        int ret; \
226                                    \
227        ret = strtolfn(val, 0, &l); \
228        if (ret == -EINVAL || ((type)l != l)) \
229            return -EINVAL; \
230        *((type *)kp->arg) = l; \
231        return 0; \
232    } \
233    int param_get_##name(char *buffer, const struct kernel_param *kp) \
234    { \
235        return sprintf(buffer, format, *((type *)kp->arg)); \
236    } \
237    struct kernel_param_ops param_ops_##name = { \
238        .set = param_set_##name, \
239        .get = param_get_##name, \
240    }; \
241    EXPORT_SYMBOL(param_set_##name); \
242    EXPORT_SYMBOL(param_get_##name); \
243    EXPORT_SYMBOL(param_ops_##name)
244
245
246STANDARD_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);
253
254int param_set_charp(const char *val, const struct kernel_param *kp)
255{
256    if (strlen(val) > 1024) {
257        printk(KERN_ERR "%s: string parameter too long\n",
258               kp->name);
259        return -ENOSPC;
260    }
261
262    maybe_kfree_parameter(*(char **)kp->arg);
263
264    /* This is a hack. We can't kmalloc in early boot, and we
265     * don't need to; this mangled commandline is preserved. */
266    if (slab_is_available()) {
267        *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
268        if (!*(char **)kp->arg)
269            return -ENOMEM;
270        strcpy(*(char **)kp->arg, val);
271    } else
272        *(const char **)kp->arg = val;
273
274    return 0;
275}
276EXPORT_SYMBOL(param_set_charp);
277
278int param_get_charp(char *buffer, const struct kernel_param *kp)
279{
280    return sprintf(buffer, "%s", *((char **)kp->arg));
281}
282EXPORT_SYMBOL(param_get_charp);
283
284static void param_free_charp(void *arg)
285{
286    maybe_kfree_parameter(*((char **)arg));
287}
288
289struct kernel_param_ops param_ops_charp = {
290    .set = param_set_charp,
291    .get = param_get_charp,
292    .free = param_free_charp,
293};
294EXPORT_SYMBOL(param_ops_charp);
295
296/* Actually could be a bool or an int, for historical reasons. */
297int param_set_bool(const char *val, const struct kernel_param *kp)
298{
299    bool v;
300    int ret;
301
302    /* No equals means "set"... */
303    if (!val) val = "1";
304
305    /* One of =[yYnN01] */
306    ret = strtobool(val, &v);
307    if (ret)
308        return ret;
309
310    if (kp->flags & KPARAM_ISBOOL)
311        *(bool *)kp->arg = v;
312    else
313        *(int *)kp->arg = v;
314    return 0;
315}
316EXPORT_SYMBOL(param_set_bool);
317
318int param_get_bool(char *buffer, const struct kernel_param *kp)
319{
320    bool val;
321    if (kp->flags & KPARAM_ISBOOL)
322        val = *(bool *)kp->arg;
323    else
324        val = *(int *)kp->arg;
325
326    /* Y and N chosen as being relatively non-coder friendly */
327    return sprintf(buffer, "%c", val ? 'Y' : 'N');
328}
329EXPORT_SYMBOL(param_get_bool);
330
331struct kernel_param_ops param_ops_bool = {
332    .set = param_set_bool,
333    .get = param_get_bool,
334};
335EXPORT_SYMBOL(param_ops_bool);
336
337/* This one must be bool. */
338int param_set_invbool(const char *val, const struct kernel_param *kp)
339{
340    int ret;
341    bool boolval;
342    struct kernel_param dummy;
343
344    dummy.arg = &boolval;
345    dummy.flags = KPARAM_ISBOOL;
346    ret = param_set_bool(val, &dummy);
347    if (ret == 0)
348        *(bool *)kp->arg = !boolval;
349    return ret;
350}
351EXPORT_SYMBOL(param_set_invbool);
352
353int param_get_invbool(char *buffer, const struct kernel_param *kp)
354{
355    return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
356}
357EXPORT_SYMBOL(param_get_invbool);
358
359struct kernel_param_ops param_ops_invbool = {
360    .set = param_set_invbool,
361    .get = param_get_invbool,
362};
363EXPORT_SYMBOL(param_ops_invbool);
364
365/* We break the rule and mangle the string. */
366static int param_array(const char *name,
367               const char *val,
368               unsigned int min, unsigned int max,
369               void *elem, int elemsize,
370               int (*set)(const char *, const struct kernel_param *kp),
371               u16 flags,
372               unsigned int *num)
373{
374    int ret;
375    struct kernel_param kp;
376    char save;
377
378    /* Get the name right for errors. */
379    kp.name = name;
380    kp.arg = elem;
381    kp.flags = flags;
382
383    *num = 0;
384    /* We expect a comma-separated list of values. */
385    do {
386        int len;
387
388        if (*num == max) {
389            printk(KERN_ERR "%s: can only take %i arguments\n",
390                   name, max);
391            return -EINVAL;
392        }
393        len = strcspn(val, ",");
394
395        /* nul-terminate and parse */
396        save = val[len];
397        ((char *)val)[len] = '\0';
398        BUG_ON(!mutex_is_locked(&param_lock));
399        ret = set(val, &kp);
400
401        if (ret != 0)
402            return ret;
403        kp.arg += elemsize;
404        val += len+1;
405        (*num)++;
406    } while (save == ',');
407
408    if (*num < min) {
409        printk(KERN_ERR "%s: needs at least %i arguments\n",
410               name, min);
411        return -EINVAL;
412    }
413    return 0;
414}
415
416static int param_array_set(const char *val, const struct kernel_param *kp)
417{
418    const struct kparam_array *arr = kp->arr;
419    unsigned int temp_num;
420
421    return param_array(kp->name, val, 1, arr->max, arr->elem,
422               arr->elemsize, arr->ops->set, kp->flags,
423               arr->num ?: &temp_num);
424}
425
426static int param_array_get(char *buffer, const struct kernel_param *kp)
427{
428    int i, off, ret;
429    const struct kparam_array *arr = kp->arr;
430    struct kernel_param p;
431
432    p = *kp;
433    for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
434        if (i)
435            buffer[off++] = ',';
436        p.arg = arr->elem + arr->elemsize * i;
437        BUG_ON(!mutex_is_locked(&param_lock));
438        ret = arr->ops->get(buffer + off, &p);
439        if (ret < 0)
440            return ret;
441        off += ret;
442    }
443    buffer[off] = '\0';
444    return off;
445}
446
447static void param_array_free(void *arg)
448{
449    unsigned int i;
450    const struct kparam_array *arr = arg;
451
452    if (arr->ops->free)
453        for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
454            arr->ops->free(arr->elem + arr->elemsize * i);
455}
456
457struct kernel_param_ops param_array_ops = {
458    .set = param_array_set,
459    .get = param_array_get,
460    .free = param_array_free,
461};
462EXPORT_SYMBOL(param_array_ops);
463
464int param_set_copystring(const char *val, const struct kernel_param *kp)
465{
466    const struct kparam_string *kps = kp->str;
467
468    if (strlen(val)+1 > kps->maxlen) {
469        printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
470               kp->name, kps->maxlen-1);
471        return -ENOSPC;
472    }
473    strcpy(kps->string, val);
474    return 0;
475}
476EXPORT_SYMBOL(param_set_copystring);
477
478int param_get_string(char *buffer, const struct kernel_param *kp)
479{
480    const struct kparam_string *kps = kp->str;
481    return strlcpy(buffer, kps->string, kps->maxlen);
482}
483EXPORT_SYMBOL(param_get_string);
484
485struct kernel_param_ops param_ops_string = {
486    .set = param_set_copystring,
487    .get = param_get_string,
488};
489EXPORT_SYMBOL(param_ops_string);
490
491/* sysfs output in /sys/modules/XYZ/parameters/ */
492#define to_module_attr(n) container_of(n, struct module_attribute, attr)
493#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
494
495extern struct kernel_param __start___param[], __stop___param[];
496
497struct param_attribute
498{
499    struct module_attribute mattr;
500    const struct kernel_param *param;
501};
502
503struct module_param_attrs
504{
505    unsigned int num;
506    struct attribute_group grp;
507    struct param_attribute attrs[0];
508};
509
510#ifdef CONFIG_SYSFS
511#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
512
513static ssize_t param_attr_show(struct module_attribute *mattr,
514                   struct module *mod, char *buf)
515{
516    int count;
517    struct param_attribute *attribute = to_param_attr(mattr);
518
519    if (!attribute->param->ops->get)
520        return -EPERM;
521
522    mutex_lock(&param_lock);
523    count = attribute->param->ops->get(buf, attribute->param);
524    mutex_unlock(&param_lock);
525    if (count > 0) {
526        strcat(buf, "\n");
527        ++count;
528    }
529    return count;
530}
531
532/* sysfs always hands a nul-terminated string in buf. We rely on that. */
533static ssize_t param_attr_store(struct module_attribute *mattr,
534                struct module *owner,
535                const char *buf, size_t len)
536{
537     int err;
538    struct param_attribute *attribute = to_param_attr(mattr);
539
540    if (!attribute->param->ops->set)
541        return -EPERM;
542
543    mutex_lock(&param_lock);
544    err = attribute->param->ops->set(buf, attribute->param);
545    mutex_unlock(&param_lock);
546    if (!err)
547        return len;
548    return err;
549}
550#endif
551
552#ifdef CONFIG_MODULES
553#define __modinit
554#else
555#define __modinit __init
556#endif
557
558#ifdef CONFIG_SYSFS
559void __kernel_param_lock(void)
560{
561    mutex_lock(&param_lock);
562}
563EXPORT_SYMBOL(__kernel_param_lock);
564
565void __kernel_param_unlock(void)
566{
567    mutex_unlock(&param_lock);
568}
569EXPORT_SYMBOL(__kernel_param_unlock);
570
571/*
572 * add_sysfs_param - add a parameter to sysfs
573 * @mk: struct module_kobject
574 * @kparam: the actual parameter definition to add to sysfs
575 * @name: name of parameter
576 *
577 * Create a kobject if for a (per-module) parameter if mp NULL, and
578 * create file in sysfs. Returns an error on out of memory. Always cleans up
579 * if there's an error.
580 */
581static __modinit int add_sysfs_param(struct module_kobject *mk,
582                     const struct kernel_param *kp,
583                     const char *name)
584{
585    struct module_param_attrs *new;
586    struct attribute **attrs;
587    int err, num;
588
589    /* We don't bother calling this with invisible parameters. */
590    BUG_ON(!kp->perm);
591
592    if (!mk->mp) {
593        num = 0;
594        attrs = NULL;
595    } else {
596        num = mk->mp->num;
597        attrs = mk->mp->grp.attrs;
598    }
599
600    /* Enlarge. */
601    new = krealloc(mk->mp,
602               sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
603               GFP_KERNEL);
604    if (!new) {
605        kfree(mk->mp);
606        err = -ENOMEM;
607        goto fail;
608    }
609    attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
610    if (!attrs) {
611        err = -ENOMEM;
612        goto fail_free_new;
613    }
614
615    /* Sysfs wants everything zeroed. */
616    memset(new, 0, sizeof(*new));
617    memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
618    memset(&attrs[num], 0, sizeof(attrs[num]));
619    new->grp.name = "parameters";
620    new->grp.attrs = attrs;
621
622    /* Tack new one on the end. */
623    sysfs_attr_init(&new->attrs[num].mattr.attr);
624    new->attrs[num].param = kp;
625    new->attrs[num].mattr.show = param_attr_show;
626    new->attrs[num].mattr.store = param_attr_store;
627    new->attrs[num].mattr.attr.name = (char *)name;
628    new->attrs[num].mattr.attr.mode = kp->perm;
629    new->num = num+1;
630
631    /* Fix up all the pointers, since krealloc can move us */
632    for (num = 0; num < new->num; num++)
633        new->grp.attrs[num] = &new->attrs[num].mattr.attr;
634    new->grp.attrs[num] = NULL;
635
636    mk->mp = new;
637    return 0;
638
639fail_free_new:
640    kfree(new);
641fail:
642    mk->mp = NULL;
643    return err;
644}
645
646#ifdef CONFIG_MODULES
647static void free_module_param_attrs(struct module_kobject *mk)
648{
649    kfree(mk->mp->grp.attrs);
650    kfree(mk->mp);
651    mk->mp = NULL;
652}
653
654/*
655 * module_param_sysfs_setup - setup sysfs support for one module
656 * @mod: module
657 * @kparam: module parameters (array)
658 * @num_params: number of module parameters
659 *
660 * Adds sysfs entries for module parameters under
661 * /sys/module/[mod->name]/parameters/
662 */
663int module_param_sysfs_setup(struct module *mod,
664                 const struct kernel_param *kparam,
665                 unsigned int num_params)
666{
667    int i, err;
668    bool params = false;
669
670    for (i = 0; i < num_params; i++) {
671        if (kparam[i].perm == 0)
672            continue;
673        err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
674        if (err)
675            return err;
676        params = true;
677    }
678
679    if (!params)
680        return 0;
681
682    /* Create the param group. */
683    err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
684    if (err)
685        free_module_param_attrs(&mod->mkobj);
686    return err;
687}
688
689/*
690 * module_param_sysfs_remove - remove sysfs support for one module
691 * @mod: module
692 *
693 * Remove sysfs entries for module parameters and the corresponding
694 * kobject.
695 */
696void module_param_sysfs_remove(struct module *mod)
697{
698    if (mod->mkobj.mp) {
699        sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
700        /* We are positive that no one is using any param
701         * attrs at this point. Deallocate immediately. */
702        free_module_param_attrs(&mod->mkobj);
703    }
704}
705#endif
706
707void destroy_params(const struct kernel_param *params, unsigned num)
708{
709    unsigned int i;
710
711    for (i = 0; i < num; i++)
712        if (params[i].ops->free)
713            params[i].ops->free(params[i].arg);
714}
715
716static struct module_kobject * __init locate_module_kobject(const char *name)
717{
718    struct module_kobject *mk;
719    struct kobject *kobj;
720    int err;
721
722    kobj = kset_find_obj(module_kset, name);
723    if (kobj) {
724        mk = to_module_kobject(kobj);
725    } else {
726        mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
727        BUG_ON(!mk);
728
729        mk->mod = THIS_MODULE;
730        mk->kobj.kset = module_kset;
731        err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
732                       "%s", name);
733        if (err) {
734            kobject_put(&mk->kobj);
735            printk(KERN_ERR
736                "Module '%s' failed add to sysfs, error number %d\n",
737                name, err);
738            printk(KERN_ERR
739                "The system will be unstable now.\n");
740            return NULL;
741        }
742
743        /* So that we hold reference in both cases. */
744        kobject_get(&mk->kobj);
745    }
746
747    return mk;
748}
749
750static void __init kernel_add_sysfs_param(const char *name,
751                      struct kernel_param *kparam,
752                      unsigned int name_skip)
753{
754    struct module_kobject *mk;
755    int err;
756
757    mk = locate_module_kobject(name);
758    if (!mk)
759        return;
760
761    /* We need to remove old parameters before adding more. */
762    if (mk->mp)
763        sysfs_remove_group(&mk->kobj, &mk->mp->grp);
764
765    /* These should not fail at boot. */
766    err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
767    BUG_ON(err);
768    err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
769    BUG_ON(err);
770    kobject_uevent(&mk->kobj, KOBJ_ADD);
771    kobject_put(&mk->kobj);
772}
773
774/*
775 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
776 *
777 * Add module_parameters to sysfs for "modules" built into the kernel.
778 *
779 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
780 * "parameter" name is stored behind a dot in kernel_param->name. So,
781 * extract the "module" name for all built-in kernel_param-eters,
782 * and for all who have the same, call kernel_add_sysfs_param.
783 */
784static void __init param_sysfs_builtin(void)
785{
786    struct kernel_param *kp;
787    unsigned int name_len;
788    char modname[MODULE_NAME_LEN];
789
790    for (kp = __start___param; kp < __stop___param; kp++) {
791        char *dot;
792
793        if (kp->perm == 0)
794            continue;
795
796        dot = strchr(kp->name, '.');
797        if (!dot) {
798            /* This happens for core_param() */
799            strcpy(modname, "kernel");
800            name_len = 0;
801        } else {
802            name_len = dot - kp->name + 1;
803            strlcpy(modname, kp->name, name_len);
804        }
805        kernel_add_sysfs_param(modname, kp, name_len);
806    }
807}
808
809ssize_t __modver_version_show(struct module_attribute *mattr,
810                  struct module *mod, char *buf)
811{
812    struct module_version_attribute *vattr =
813        container_of(mattr, struct module_version_attribute, mattr);
814
815    return sprintf(buf, "%s\n", vattr->version);
816}
817
818extern const struct module_version_attribute *__start___modver[];
819extern const struct module_version_attribute *__stop___modver[];
820
821static void __init version_sysfs_builtin(void)
822{
823    const struct module_version_attribute **p;
824    struct module_kobject *mk;
825    int err;
826
827    for (p = __start___modver; p < __stop___modver; p++) {
828        const struct module_version_attribute *vattr = *p;
829
830        mk = locate_module_kobject(vattr->module_name);
831        if (mk) {
832            err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
833            kobject_uevent(&mk->kobj, KOBJ_ADD);
834            kobject_put(&mk->kobj);
835        }
836    }
837}
838
839/* module-related sysfs stuff */
840
841static ssize_t module_attr_show(struct kobject *kobj,
842                struct attribute *attr,
843                char *buf)
844{
845    struct module_attribute *attribute;
846    struct module_kobject *mk;
847    int ret;
848
849    attribute = to_module_attr(attr);
850    mk = to_module_kobject(kobj);
851
852    if (!attribute->show)
853        return -EIO;
854
855    ret = attribute->show(attribute, mk->mod, buf);
856
857    return ret;
858}
859
860static ssize_t module_attr_store(struct kobject *kobj,
861                struct attribute *attr,
862                const char *buf, size_t len)
863{
864    struct module_attribute *attribute;
865    struct module_kobject *mk;
866    int ret;
867
868    attribute = to_module_attr(attr);
869    mk = to_module_kobject(kobj);
870
871    if (!attribute->store)
872        return -EIO;
873
874    ret = attribute->store(attribute, mk->mod, buf, len);
875
876    return ret;
877}
878
879static const struct sysfs_ops module_sysfs_ops = {
880    .show = module_attr_show,
881    .store = module_attr_store,
882};
883
884static int uevent_filter(struct kset *kset, struct kobject *kobj)
885{
886    struct kobj_type *ktype = get_ktype(kobj);
887
888    if (ktype == &module_ktype)
889        return 1;
890    return 0;
891}
892
893static const struct kset_uevent_ops module_uevent_ops = {
894    .filter = uevent_filter,
895};
896
897struct kset *module_kset;
898int module_sysfs_initialized;
899
900struct kobj_type module_ktype = {
901    .sysfs_ops = &module_sysfs_ops,
902};
903
904/*
905 * param_sysfs_init - wrapper for built-in params support
906 */
907static int __init param_sysfs_init(void)
908{
909    module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
910    if (!module_kset) {
911        printk(KERN_WARNING "%s (%d): error creating kset\n",
912            __FILE__, __LINE__);
913        return -ENOMEM;
914    }
915    module_sysfs_initialized = 1;
916
917    version_sysfs_builtin();
918    param_sysfs_builtin();
919
920    return 0;
921}
922subsys_initcall(param_sysfs_init);
923
924#endif /* CONFIG_SYSFS */
925

Archive Download this file



interactive