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/kernel.h>
19#include <linux/string.h>
20#include <linux/errno.h>
21#include <linux/module.h>
22#include <linux/device.h>
23#include <linux/err.h>
24#include <linux/slab.h>
25#include <linux/ctype.h>
26
27/* Protects all parameters, and incidentally kmalloced_param list. */
28static DEFINE_MUTEX(param_lock);
29
30/* This just allows us to keep track of which parameters are kmalloced. */
31struct kmalloced_param {
32    struct list_head list;
33    char val[];
34};
35static LIST_HEAD(kmalloced_params);
36
37static void *kmalloc_parameter(unsigned int size)
38{
39    struct kmalloced_param *p;
40
41    p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
42    if (!p)
43        return NULL;
44
45    list_add(&p->list, &kmalloced_params);
46    return p->val;
47}
48
49/* Does nothing if parameter wasn't kmalloced above. */
50static void maybe_kfree_parameter(void *param)
51{
52    struct kmalloced_param *p;
53
54    list_for_each_entry(p, &kmalloced_params, list) {
55        if (p->val == param) {
56            list_del(&p->list);
57            kfree(p);
58            break;
59        }
60    }
61}
62
63static char dash2underscore(char c)
64{
65    if (c == '-')
66        return '_';
67    return c;
68}
69
70bool parameqn(const char *a, const char *b, size_t n)
71{
72    size_t i;
73
74    for (i = 0; i < n; i++) {
75        if (dash2underscore(a[i]) != dash2underscore(b[i]))
76            return false;
77    }
78    return true;
79}
80
81bool parameq(const char *a, const char *b)
82{
83    return parameqn(a, b, strlen(a)+1);
84}
85
86static int parse_one(char *param,
87             char *val,
88             const char *doing,
89             const struct kernel_param *params,
90             unsigned num_params,
91             s16 min_level,
92             s16 max_level,
93             int (*handle_unknown)(char *param, char *val,
94                     const char *doing))
95{
96    unsigned int i;
97    int err;
98
99    /* Find parameter */
100    for (i = 0; i < num_params; i++) {
101        if (parameq(param, params[i].name)) {
102            if (params[i].level < min_level
103                || params[i].level > max_level)
104                return 0;
105            /* No one handled NULL, so do it here. */
106            if (!val && params[i].ops->set != param_set_bool
107                && params[i].ops->set != param_set_bint)
108                return -EINVAL;
109            pr_debug("handling %s with %p\n", param,
110                params[i].ops->set);
111            mutex_lock(&param_lock);
112            err = params[i].ops->set(val, &params[i]);
113            mutex_unlock(&param_lock);
114            return err;
115        }
116    }
117
118    if (handle_unknown) {
119        pr_debug("doing %s: %s='%s'\n", doing, param, val);
120        return handle_unknown(param, val, doing);
121    }
122
123    pr_debug("Unknown argument '%s'\n", param);
124    return -ENOENT;
125}
126
127/* You can use " around spaces, but can't escape ". */
128/* Hyphens and underscores equivalent in parameter names. */
129static char *next_arg(char *args, char **param, char **val)
130{
131    unsigned int i, equals = 0;
132    int in_quote = 0, quoted = 0;
133    char *next;
134
135    if (*args == '"') {
136        args++;
137        in_quote = 1;
138        quoted = 1;
139    }
140
141    for (i = 0; args[i]; i++) {
142        if (isspace(args[i]) && !in_quote)
143            break;
144        if (equals == 0) {
145            if (args[i] == '=')
146                equals = i;
147        }
148        if (args[i] == '"')
149            in_quote = !in_quote;
150    }
151
152    *param = args;
153    if (!equals)
154        *val = NULL;
155    else {
156        args[equals] = '\0';
157        *val = args + equals + 1;
158
159        /* Don't include quotes in value. */
160        if (**val == '"') {
161            (*val)++;
162            if (args[i-1] == '"')
163                args[i-1] = '\0';
164        }
165        if (quoted && args[i-1] == '"')
166            args[i-1] = '\0';
167    }
168
169    if (args[i]) {
170        args[i] = '\0';
171        next = args + i + 1;
172    } else
173        next = args + i;
174
175    /* Chew up trailing spaces. */
176    return skip_spaces(next);
177}
178
179/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
180int parse_args(const char *doing,
181           char *args,
182           const struct kernel_param *params,
183           unsigned num,
184           s16 min_level,
185           s16 max_level,
186           int (*unknown)(char *param, char *val, const char *doing))
187{
188    char *param, *val;
189
190    /* Chew leading spaces */
191    args = skip_spaces(args);
192
193    if (*args)
194        pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);
195
196    while (*args) {
197        int ret;
198        int irq_was_disabled;
199
200        args = next_arg(args, &param, &val);
201        irq_was_disabled = irqs_disabled();
202        ret = parse_one(param, val, doing, params, num,
203                min_level, max_level, unknown);
204        if (irq_was_disabled && !irqs_disabled())
205            pr_warn("%s: option '%s' enabled irq's!\n",
206                doing, param);
207
208        switch (ret) {
209        case -ENOENT:
210            pr_err("%s: Unknown parameter `%s'\n", doing, param);
211            return ret;
212        case -ENOSPC:
213            pr_err("%s: `%s' too large for parameter `%s'\n",
214                   doing, val ?: "", param);
215            return ret;
216        case 0:
217            break;
218        default:
219            pr_err("%s: `%s' invalid for parameter `%s'\n",
220                   doing, val ?: "", param);
221            return ret;
222        }
223    }
224
225    /* All parsed OK. */
226    return 0;
227}
228
229/* Lazy bastard, eh? */
230#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
231    int param_set_##name(const char *val, const struct kernel_param *kp) \
232    { \
233        tmptype l; \
234        int ret; \
235                                    \
236        ret = strtolfn(val, 0, &l); \
237        if (ret < 0 || ((type)l != l)) \
238            return ret < 0 ? ret : -EINVAL; \
239        *((type *)kp->arg) = l; \
240        return 0; \
241    } \
242    int param_get_##name(char *buffer, const struct kernel_param *kp) \
243    { \
244        return sprintf(buffer, format, *((type *)kp->arg)); \
245    } \
246    struct kernel_param_ops param_ops_##name = { \
247        .set = param_set_##name, \
248        .get = param_get_##name, \
249    }; \
250    EXPORT_SYMBOL(param_set_##name); \
251    EXPORT_SYMBOL(param_get_##name); \
252    EXPORT_SYMBOL(param_ops_##name)
253
254
255STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
256STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
257STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
258STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
259STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
260STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
261STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
262
263int param_set_charp(const char *val, const struct kernel_param *kp)
264{
265    if (strlen(val) > 1024) {
266        pr_err("%s: string parameter too long\n", kp->name);
267        return -ENOSPC;
268    }
269
270    maybe_kfree_parameter(*(char **)kp->arg);
271
272    /* This is a hack. We can't kmalloc in early boot, and we
273     * don't need to; this mangled commandline is preserved. */
274    if (slab_is_available()) {
275        *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
276        if (!*(char **)kp->arg)
277            return -ENOMEM;
278        strcpy(*(char **)kp->arg, val);
279    } else
280        *(const char **)kp->arg = val;
281
282    return 0;
283}
284EXPORT_SYMBOL(param_set_charp);
285
286int param_get_charp(char *buffer, const struct kernel_param *kp)
287{
288    return sprintf(buffer, "%s", *((char **)kp->arg));
289}
290EXPORT_SYMBOL(param_get_charp);
291
292static void param_free_charp(void *arg)
293{
294    maybe_kfree_parameter(*((char **)arg));
295}
296
297struct kernel_param_ops param_ops_charp = {
298    .set = param_set_charp,
299    .get = param_get_charp,
300    .free = param_free_charp,
301};
302EXPORT_SYMBOL(param_ops_charp);
303
304/* Actually could be a bool or an int, for historical reasons. */
305int param_set_bool(const char *val, const struct kernel_param *kp)
306{
307    /* No equals means "set"... */
308    if (!val) val = "1";
309
310    /* One of =[yYnN01] */
311    return strtobool(val, kp->arg);
312}
313EXPORT_SYMBOL(param_set_bool);
314
315int param_get_bool(char *buffer, const struct kernel_param *kp)
316{
317    /* Y and N chosen as being relatively non-coder friendly */
318    return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
319}
320EXPORT_SYMBOL(param_get_bool);
321
322struct kernel_param_ops param_ops_bool = {
323    .set = param_set_bool,
324    .get = param_get_bool,
325};
326EXPORT_SYMBOL(param_ops_bool);
327
328/* This one must be bool. */
329int param_set_invbool(const char *val, const struct kernel_param *kp)
330{
331    int ret;
332    bool boolval;
333    struct kernel_param dummy;
334
335    dummy.arg = &boolval;
336    ret = param_set_bool(val, &dummy);
337    if (ret == 0)
338        *(bool *)kp->arg = !boolval;
339    return ret;
340}
341EXPORT_SYMBOL(param_set_invbool);
342
343int param_get_invbool(char *buffer, const struct kernel_param *kp)
344{
345    return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
346}
347EXPORT_SYMBOL(param_get_invbool);
348
349struct kernel_param_ops param_ops_invbool = {
350    .set = param_set_invbool,
351    .get = param_get_invbool,
352};
353EXPORT_SYMBOL(param_ops_invbool);
354
355int param_set_bint(const char *val, const struct kernel_param *kp)
356{
357    struct kernel_param boolkp;
358    bool v;
359    int ret;
360
361    /* Match bool exactly, by re-using it. */
362    boolkp = *kp;
363    boolkp.arg = &v;
364
365    ret = param_set_bool(val, &boolkp);
366    if (ret == 0)
367        *(int *)kp->arg = v;
368    return ret;
369}
370EXPORT_SYMBOL(param_set_bint);
371
372struct kernel_param_ops param_ops_bint = {
373    .set = param_set_bint,
374    .get = param_get_int,
375};
376EXPORT_SYMBOL(param_ops_bint);
377
378/* We break the rule and mangle the string. */
379static int param_array(const char *name,
380               const char *val,
381               unsigned int min, unsigned int max,
382               void *elem, int elemsize,
383               int (*set)(const char *, const struct kernel_param *kp),
384               s16 level,
385               unsigned int *num)
386{
387    int ret;
388    struct kernel_param kp;
389    char save;
390
391    /* Get the name right for errors. */
392    kp.name = name;
393    kp.arg = elem;
394    kp.level = level;
395
396    *num = 0;
397    /* We expect a comma-separated list of values. */
398    do {
399        int len;
400
401        if (*num == max) {
402            pr_err("%s: can only take %i arguments\n", name, max);
403            return -EINVAL;
404        }
405        len = strcspn(val, ",");
406
407        /* nul-terminate and parse */
408        save = val[len];
409        ((char *)val)[len] = '\0';
410        BUG_ON(!mutex_is_locked(&param_lock));
411        ret = set(val, &kp);
412
413        if (ret != 0)
414            return ret;
415        kp.arg += elemsize;
416        val += len+1;
417        (*num)++;
418    } while (save == ',');
419
420    if (*num < min) {
421        pr_err("%s: needs at least %i arguments\n", name, min);
422        return -EINVAL;
423    }
424    return 0;
425}
426
427static int param_array_set(const char *val, const struct kernel_param *kp)
428{
429    const struct kparam_array *arr = kp->arr;
430    unsigned int temp_num;
431
432    return param_array(kp->name, val, 1, arr->max, arr->elem,
433               arr->elemsize, arr->ops->set, kp->level,
434               arr->num ?: &temp_num);
435}
436
437static int param_array_get(char *buffer, const struct kernel_param *kp)
438{
439    int i, off, ret;
440    const struct kparam_array *arr = kp->arr;
441    struct kernel_param p;
442
443    p = *kp;
444    for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
445        if (i)
446            buffer[off++] = ',';
447        p.arg = arr->elem + arr->elemsize * i;
448        BUG_ON(!mutex_is_locked(&param_lock));
449        ret = arr->ops->get(buffer + off, &p);
450        if (ret < 0)
451            return ret;
452        off += ret;
453    }
454    buffer[off] = '\0';
455    return off;
456}
457
458static void param_array_free(void *arg)
459{
460    unsigned int i;
461    const struct kparam_array *arr = arg;
462
463    if (arr->ops->free)
464        for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
465            arr->ops->free(arr->elem + arr->elemsize * i);
466}
467
468struct kernel_param_ops param_array_ops = {
469    .set = param_array_set,
470    .get = param_array_get,
471    .free = param_array_free,
472};
473EXPORT_SYMBOL(param_array_ops);
474
475int param_set_copystring(const char *val, const struct kernel_param *kp)
476{
477    const struct kparam_string *kps = kp->str;
478
479    if (strlen(val)+1 > kps->maxlen) {
480        pr_err("%s: string doesn't fit in %u chars.\n",
481               kp->name, kps->maxlen-1);
482        return -ENOSPC;
483    }
484    strcpy(kps->string, val);
485    return 0;
486}
487EXPORT_SYMBOL(param_set_copystring);
488
489int param_get_string(char *buffer, const struct kernel_param *kp)
490{
491    const struct kparam_string *kps = kp->str;
492    return strlcpy(buffer, kps->string, kps->maxlen);
493}
494EXPORT_SYMBOL(param_get_string);
495
496struct kernel_param_ops param_ops_string = {
497    .set = param_set_copystring,
498    .get = param_get_string,
499};
500EXPORT_SYMBOL(param_ops_string);
501
502/* sysfs output in /sys/modules/XYZ/parameters/ */
503#define to_module_attr(n) container_of(n, struct module_attribute, attr)
504#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
505
506extern struct kernel_param __start___param[], __stop___param[];
507
508struct param_attribute
509{
510    struct module_attribute mattr;
511    const struct kernel_param *param;
512};
513
514struct module_param_attrs
515{
516    unsigned int num;
517    struct attribute_group grp;
518    struct param_attribute attrs[0];
519};
520
521#ifdef CONFIG_SYSFS
522#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
523
524static ssize_t param_attr_show(struct module_attribute *mattr,
525                   struct module_kobject *mk, char *buf)
526{
527    int count;
528    struct param_attribute *attribute = to_param_attr(mattr);
529
530    if (!attribute->param->ops->get)
531        return -EPERM;
532
533    mutex_lock(&param_lock);
534    count = attribute->param->ops->get(buf, attribute->param);
535    mutex_unlock(&param_lock);
536    if (count > 0) {
537        strcat(buf, "\n");
538        ++count;
539    }
540    return count;
541}
542
543/* sysfs always hands a nul-terminated string in buf. We rely on that. */
544static ssize_t param_attr_store(struct module_attribute *mattr,
545                struct module_kobject *km,
546                const char *buf, size_t len)
547{
548     int err;
549    struct param_attribute *attribute = to_param_attr(mattr);
550
551    if (!attribute->param->ops->set)
552        return -EPERM;
553
554    mutex_lock(&param_lock);
555    err = attribute->param->ops->set(buf, attribute->param);
556    mutex_unlock(&param_lock);
557    if (!err)
558        return len;
559    return err;
560}
561#endif
562
563#ifdef CONFIG_MODULES
564#define __modinit
565#else
566#define __modinit __init
567#endif
568
569#ifdef CONFIG_SYSFS
570void __kernel_param_lock(void)
571{
572    mutex_lock(&param_lock);
573}
574EXPORT_SYMBOL(__kernel_param_lock);
575
576void __kernel_param_unlock(void)
577{
578    mutex_unlock(&param_lock);
579}
580EXPORT_SYMBOL(__kernel_param_unlock);
581
582/*
583 * add_sysfs_param - add a parameter to sysfs
584 * @mk: struct module_kobject
585 * @kparam: the actual parameter definition to add to sysfs
586 * @name: name of parameter
587 *
588 * Create a kobject if for a (per-module) parameter if mp NULL, and
589 * create file in sysfs. Returns an error on out of memory. Always cleans up
590 * if there's an error.
591 */
592static __modinit int add_sysfs_param(struct module_kobject *mk,
593                     const struct kernel_param *kp,
594                     const char *name)
595{
596    struct module_param_attrs *new;
597    struct attribute **attrs;
598    int err, num;
599
600    /* We don't bother calling this with invisible parameters. */
601    BUG_ON(!kp->perm);
602
603    if (!mk->mp) {
604        num = 0;
605        attrs = NULL;
606    } else {
607        num = mk->mp->num;
608        attrs = mk->mp->grp.attrs;
609    }
610
611    /* Enlarge. */
612    new = krealloc(mk->mp,
613               sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
614               GFP_KERNEL);
615    if (!new) {
616        kfree(mk->mp);
617        err = -ENOMEM;
618        goto fail;
619    }
620    attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
621    if (!attrs) {
622        err = -ENOMEM;
623        goto fail_free_new;
624    }
625
626    /* Sysfs wants everything zeroed. */
627    memset(new, 0, sizeof(*new));
628    memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
629    memset(&attrs[num], 0, sizeof(attrs[num]));
630    new->grp.name = "parameters";
631    new->grp.attrs = attrs;
632
633    /* Tack new one on the end. */
634    sysfs_attr_init(&new->attrs[num].mattr.attr);
635    new->attrs[num].param = kp;
636    new->attrs[num].mattr.show = param_attr_show;
637    new->attrs[num].mattr.store = param_attr_store;
638    new->attrs[num].mattr.attr.name = (char *)name;
639    new->attrs[num].mattr.attr.mode = kp->perm;
640    new->num = num+1;
641
642    /* Fix up all the pointers, since krealloc can move us */
643    for (num = 0; num < new->num; num++)
644        new->grp.attrs[num] = &new->attrs[num].mattr.attr;
645    new->grp.attrs[num] = NULL;
646
647    mk->mp = new;
648    return 0;
649
650fail_free_new:
651    kfree(new);
652fail:
653    mk->mp = NULL;
654    return err;
655}
656
657#ifdef CONFIG_MODULES
658static void free_module_param_attrs(struct module_kobject *mk)
659{
660    kfree(mk->mp->grp.attrs);
661    kfree(mk->mp);
662    mk->mp = NULL;
663}
664
665/*
666 * module_param_sysfs_setup - setup sysfs support for one module
667 * @mod: module
668 * @kparam: module parameters (array)
669 * @num_params: number of module parameters
670 *
671 * Adds sysfs entries for module parameters under
672 * /sys/module/[mod->name]/parameters/
673 */
674int module_param_sysfs_setup(struct module *mod,
675                 const struct kernel_param *kparam,
676                 unsigned int num_params)
677{
678    int i, err;
679    bool params = false;
680
681    for (i = 0; i < num_params; i++) {
682        if (kparam[i].perm == 0)
683            continue;
684        err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
685        if (err)
686            return err;
687        params = true;
688    }
689
690    if (!params)
691        return 0;
692
693    /* Create the param group. */
694    err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
695    if (err)
696        free_module_param_attrs(&mod->mkobj);
697    return err;
698}
699
700/*
701 * module_param_sysfs_remove - remove sysfs support for one module
702 * @mod: module
703 *
704 * Remove sysfs entries for module parameters and the corresponding
705 * kobject.
706 */
707void module_param_sysfs_remove(struct module *mod)
708{
709    if (mod->mkobj.mp) {
710        sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
711        /* We are positive that no one is using any param
712         * attrs at this point. Deallocate immediately. */
713        free_module_param_attrs(&mod->mkobj);
714    }
715}
716#endif
717
718void destroy_params(const struct kernel_param *params, unsigned num)
719{
720    unsigned int i;
721
722    for (i = 0; i < num; i++)
723        if (params[i].ops->free)
724            params[i].ops->free(params[i].arg);
725}
726
727static struct module_kobject * __init locate_module_kobject(const char *name)
728{
729    struct module_kobject *mk;
730    struct kobject *kobj;
731    int err;
732
733    kobj = kset_find_obj(module_kset, name);
734    if (kobj) {
735        mk = to_module_kobject(kobj);
736    } else {
737        mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
738        BUG_ON(!mk);
739
740        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#ifdef CONFIG_MODULES
745        if (!err)
746            err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
747#endif
748        if (err) {
749            kobject_put(&mk->kobj);
750            pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
751                name, err);
752            return NULL;
753        }
754
755        /* So that we hold reference in both cases. */
756        kobject_get(&mk->kobj);
757    }
758
759    return mk;
760}
761
762static void __init kernel_add_sysfs_param(const char *name,
763                      struct kernel_param *kparam,
764                      unsigned int name_skip)
765{
766    struct module_kobject *mk;
767    int err;
768
769    mk = locate_module_kobject(name);
770    if (!mk)
771        return;
772
773    /* We need to remove old parameters before adding more. */
774    if (mk->mp)
775        sysfs_remove_group(&mk->kobj, &mk->mp->grp);
776
777    /* These should not fail at boot. */
778    err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
779    BUG_ON(err);
780    err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
781    BUG_ON(err);
782    kobject_uevent(&mk->kobj, KOBJ_ADD);
783    kobject_put(&mk->kobj);
784}
785
786/*
787 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
788 *
789 * Add module_parameters to sysfs for "modules" built into the kernel.
790 *
791 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
792 * "parameter" name is stored behind a dot in kernel_param->name. So,
793 * extract the "module" name for all built-in kernel_param-eters,
794 * and for all who have the same, call kernel_add_sysfs_param.
795 */
796static void __init param_sysfs_builtin(void)
797{
798    struct kernel_param *kp;
799    unsigned int name_len;
800    char modname[MODULE_NAME_LEN];
801
802    for (kp = __start___param; kp < __stop___param; kp++) {
803        char *dot;
804
805        if (kp->perm == 0)
806            continue;
807
808        dot = strchr(kp->name, '.');
809        if (!dot) {
810            /* This happens for core_param() */
811            strcpy(modname, "kernel");
812            name_len = 0;
813        } else {
814            name_len = dot - kp->name + 1;
815            strlcpy(modname, kp->name, name_len);
816        }
817        kernel_add_sysfs_param(modname, kp, name_len);
818    }
819}
820
821ssize_t __modver_version_show(struct module_attribute *mattr,
822                  struct module_kobject *mk, char *buf)
823{
824    struct module_version_attribute *vattr =
825        container_of(mattr, struct module_version_attribute, mattr);
826
827    return sprintf(buf, "%s\n", vattr->version);
828}
829
830extern const struct module_version_attribute *__start___modver[];
831extern const struct module_version_attribute *__stop___modver[];
832
833static void __init version_sysfs_builtin(void)
834{
835    const struct module_version_attribute **p;
836    struct module_kobject *mk;
837    int err;
838
839    for (p = __start___modver; p < __stop___modver; p++) {
840        const struct module_version_attribute *vattr = *p;
841
842        mk = locate_module_kobject(vattr->module_name);
843        if (mk) {
844            err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
845            kobject_uevent(&mk->kobj, KOBJ_ADD);
846            kobject_put(&mk->kobj);
847        }
848    }
849}
850
851/* module-related sysfs stuff */
852
853static ssize_t module_attr_show(struct kobject *kobj,
854                struct attribute *attr,
855                char *buf)
856{
857    struct module_attribute *attribute;
858    struct module_kobject *mk;
859    int ret;
860
861    attribute = to_module_attr(attr);
862    mk = to_module_kobject(kobj);
863
864    if (!attribute->show)
865        return -EIO;
866
867    ret = attribute->show(attribute, mk, buf);
868
869    return ret;
870}
871
872static ssize_t module_attr_store(struct kobject *kobj,
873                struct attribute *attr,
874                const char *buf, size_t len)
875{
876    struct module_attribute *attribute;
877    struct module_kobject *mk;
878    int ret;
879
880    attribute = to_module_attr(attr);
881    mk = to_module_kobject(kobj);
882
883    if (!attribute->store)
884        return -EIO;
885
886    ret = attribute->store(attribute, mk, buf, len);
887
888    return ret;
889}
890
891static const struct sysfs_ops module_sysfs_ops = {
892    .show = module_attr_show,
893    .store = module_attr_store,
894};
895
896static int uevent_filter(struct kset *kset, struct kobject *kobj)
897{
898    struct kobj_type *ktype = get_ktype(kobj);
899
900    if (ktype == &module_ktype)
901        return 1;
902    return 0;
903}
904
905static const struct kset_uevent_ops module_uevent_ops = {
906    .filter = uevent_filter,
907};
908
909struct kset *module_kset;
910int module_sysfs_initialized;
911
912struct kobj_type module_ktype = {
913    .sysfs_ops = &module_sysfs_ops,
914};
915
916/*
917 * param_sysfs_init - wrapper for built-in params support
918 */
919static int __init param_sysfs_init(void)
920{
921    module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
922    if (!module_kset) {
923        printk(KERN_WARNING "%s (%d): error creating kset\n",
924            __FILE__, __LINE__);
925        return -ENOMEM;
926    }
927    module_sysfs_initialized = 1;
928
929    version_sysfs_builtin();
930    param_sysfs_builtin();
931
932    return 0;
933}
934subsys_initcall(param_sysfs_init);
935
936#endif /* CONFIG_SYSFS */
937

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