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 &&
107                !(params[i].ops->flags & KERNEL_PARAM_FL_NOARG))
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, strtolfn) \
231    int param_set_##name(const char *val, const struct kernel_param *kp) \
232    { \
233        return strtolfn(val, 0, (type *)kp->arg); \
234    } \
235    int param_get_##name(char *buffer, const struct kernel_param *kp) \
236    { \
237        return scnprintf(buffer, PAGE_SIZE, format, \
238                *((type *)kp->arg)); \
239    } \
240    struct kernel_param_ops param_ops_##name = { \
241        .set = param_set_##name, \
242        .get = param_get_##name, \
243    }; \
244    EXPORT_SYMBOL(param_set_##name); \
245    EXPORT_SYMBOL(param_get_##name); \
246    EXPORT_SYMBOL(param_ops_##name)
247
248
249STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8);
250STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16);
251STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16);
252STANDARD_PARAM_DEF(int, int, "%i", kstrtoint);
253STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint);
254STANDARD_PARAM_DEF(long, long, "%li", kstrtol);
255STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul);
256
257int param_set_charp(const char *val, const struct kernel_param *kp)
258{
259    if (strlen(val) > 1024) {
260        pr_err("%s: string parameter too long\n", kp->name);
261        return -ENOSPC;
262    }
263
264    maybe_kfree_parameter(*(char **)kp->arg);
265
266    /* This is a hack. We can't kmalloc in early boot, and we
267     * don't need to; this mangled commandline is preserved. */
268    if (slab_is_available()) {
269        *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
270        if (!*(char **)kp->arg)
271            return -ENOMEM;
272        strcpy(*(char **)kp->arg, val);
273    } else
274        *(const char **)kp->arg = val;
275
276    return 0;
277}
278EXPORT_SYMBOL(param_set_charp);
279
280int param_get_charp(char *buffer, const struct kernel_param *kp)
281{
282    return scnprintf(buffer, PAGE_SIZE, "%s", *((char **)kp->arg));
283}
284EXPORT_SYMBOL(param_get_charp);
285
286static void param_free_charp(void *arg)
287{
288    maybe_kfree_parameter(*((char **)arg));
289}
290
291struct kernel_param_ops param_ops_charp = {
292    .set = param_set_charp,
293    .get = param_get_charp,
294    .free = param_free_charp,
295};
296EXPORT_SYMBOL(param_ops_charp);
297
298/* Actually could be a bool or an int, for historical reasons. */
299int param_set_bool(const char *val, const struct kernel_param *kp)
300{
301    /* No equals means "set"... */
302    if (!val) val = "1";
303
304    /* One of =[yYnN01] */
305    return strtobool(val, kp->arg);
306}
307EXPORT_SYMBOL(param_set_bool);
308
309int param_get_bool(char *buffer, const struct kernel_param *kp)
310{
311    /* Y and N chosen as being relatively non-coder friendly */
312    return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N');
313}
314EXPORT_SYMBOL(param_get_bool);
315
316struct kernel_param_ops param_ops_bool = {
317    .flags = KERNEL_PARAM_FL_NOARG,
318    .set = param_set_bool,
319    .get = param_get_bool,
320};
321EXPORT_SYMBOL(param_ops_bool);
322
323/* This one must be bool. */
324int param_set_invbool(const char *val, const struct kernel_param *kp)
325{
326    int ret;
327    bool boolval;
328    struct kernel_param dummy;
329
330    dummy.arg = &boolval;
331    ret = param_set_bool(val, &dummy);
332    if (ret == 0)
333        *(bool *)kp->arg = !boolval;
334    return ret;
335}
336EXPORT_SYMBOL(param_set_invbool);
337
338int param_get_invbool(char *buffer, const struct kernel_param *kp)
339{
340    return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
341}
342EXPORT_SYMBOL(param_get_invbool);
343
344struct kernel_param_ops param_ops_invbool = {
345    .set = param_set_invbool,
346    .get = param_get_invbool,
347};
348EXPORT_SYMBOL(param_ops_invbool);
349
350int param_set_bint(const char *val, const struct kernel_param *kp)
351{
352    struct kernel_param boolkp;
353    bool v;
354    int ret;
355
356    /* Match bool exactly, by re-using it. */
357    boolkp = *kp;
358    boolkp.arg = &v;
359
360    ret = param_set_bool(val, &boolkp);
361    if (ret == 0)
362        *(int *)kp->arg = v;
363    return ret;
364}
365EXPORT_SYMBOL(param_set_bint);
366
367struct kernel_param_ops param_ops_bint = {
368    .flags = KERNEL_PARAM_FL_NOARG,
369    .set = param_set_bint,
370    .get = param_get_int,
371};
372EXPORT_SYMBOL(param_ops_bint);
373
374/* We break the rule and mangle the string. */
375static int param_array(const char *name,
376               const char *val,
377               unsigned int min, unsigned int max,
378               void *elem, int elemsize,
379               int (*set)(const char *, const struct kernel_param *kp),
380               s16 level,
381               unsigned int *num)
382{
383    int ret;
384    struct kernel_param kp;
385    char save;
386
387    /* Get the name right for errors. */
388    kp.name = name;
389    kp.arg = elem;
390    kp.level = level;
391
392    *num = 0;
393    /* We expect a comma-separated list of values. */
394    do {
395        int len;
396
397        if (*num == max) {
398            pr_err("%s: can only take %i arguments\n", name, max);
399            return -EINVAL;
400        }
401        len = strcspn(val, ",");
402
403        /* nul-terminate and parse */
404        save = val[len];
405        ((char *)val)[len] = '\0';
406        BUG_ON(!mutex_is_locked(&param_lock));
407        ret = set(val, &kp);
408
409        if (ret != 0)
410            return ret;
411        kp.arg += elemsize;
412        val += len+1;
413        (*num)++;
414    } while (save == ',');
415
416    if (*num < min) {
417        pr_err("%s: needs at least %i arguments\n", name, min);
418        return -EINVAL;
419    }
420    return 0;
421}
422
423static int param_array_set(const char *val, const struct kernel_param *kp)
424{
425    const struct kparam_array *arr = kp->arr;
426    unsigned int temp_num;
427
428    return param_array(kp->name, val, 1, arr->max, arr->elem,
429               arr->elemsize, arr->ops->set, kp->level,
430               arr->num ?: &temp_num);
431}
432
433static int param_array_get(char *buffer, const struct kernel_param *kp)
434{
435    int i, off, ret;
436    const struct kparam_array *arr = kp->arr;
437    struct kernel_param p;
438
439    p = *kp;
440    for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
441        if (i)
442            buffer[off++] = ',';
443        p.arg = arr->elem + arr->elemsize * i;
444        BUG_ON(!mutex_is_locked(&param_lock));
445        ret = arr->ops->get(buffer + off, &p);
446        if (ret < 0)
447            return ret;
448        off += ret;
449    }
450    buffer[off] = '\0';
451    return off;
452}
453
454static void param_array_free(void *arg)
455{
456    unsigned int i;
457    const struct kparam_array *arr = arg;
458
459    if (arr->ops->free)
460        for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
461            arr->ops->free(arr->elem + arr->elemsize * i);
462}
463
464struct kernel_param_ops param_array_ops = {
465    .set = param_array_set,
466    .get = param_array_get,
467    .free = param_array_free,
468};
469EXPORT_SYMBOL(param_array_ops);
470
471int param_set_copystring(const char *val, const struct kernel_param *kp)
472{
473    const struct kparam_string *kps = kp->str;
474
475    if (strlen(val)+1 > kps->maxlen) {
476        pr_err("%s: string doesn't fit in %u chars.\n",
477               kp->name, kps->maxlen-1);
478        return -ENOSPC;
479    }
480    strcpy(kps->string, val);
481    return 0;
482}
483EXPORT_SYMBOL(param_set_copystring);
484
485int param_get_string(char *buffer, const struct kernel_param *kp)
486{
487    const struct kparam_string *kps = kp->str;
488    return strlcpy(buffer, kps->string, kps->maxlen);
489}
490EXPORT_SYMBOL(param_get_string);
491
492struct kernel_param_ops param_ops_string = {
493    .set = param_set_copystring,
494    .get = param_get_string,
495};
496EXPORT_SYMBOL(param_ops_string);
497
498/* sysfs output in /sys/modules/XYZ/parameters/ */
499#define to_module_attr(n) container_of(n, struct module_attribute, attr)
500#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)
501
502extern struct kernel_param __start___param[], __stop___param[];
503
504struct param_attribute
505{
506    struct module_attribute mattr;
507    const struct kernel_param *param;
508};
509
510struct module_param_attrs
511{
512    unsigned int num;
513    struct attribute_group grp;
514    struct param_attribute attrs[0];
515};
516
517#ifdef CONFIG_SYSFS
518#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
519
520static ssize_t param_attr_show(struct module_attribute *mattr,
521                   struct module_kobject *mk, char *buf)
522{
523    int count;
524    struct param_attribute *attribute = to_param_attr(mattr);
525
526    if (!attribute->param->ops->get)
527        return -EPERM;
528
529    mutex_lock(&param_lock);
530    count = attribute->param->ops->get(buf, attribute->param);
531    mutex_unlock(&param_lock);
532    if (count > 0) {
533        strcat(buf, "\n");
534        ++count;
535    }
536    return count;
537}
538
539/* sysfs always hands a nul-terminated string in buf. We rely on that. */
540static ssize_t param_attr_store(struct module_attribute *mattr,
541                struct module_kobject *km,
542                const char *buf, size_t len)
543{
544     int err;
545    struct param_attribute *attribute = to_param_attr(mattr);
546
547    if (!attribute->param->ops->set)
548        return -EPERM;
549
550    mutex_lock(&param_lock);
551    err = attribute->param->ops->set(buf, attribute->param);
552    mutex_unlock(&param_lock);
553    if (!err)
554        return len;
555    return err;
556}
557#endif
558
559#ifdef CONFIG_MODULES
560#define __modinit
561#else
562#define __modinit __init
563#endif
564
565#ifdef CONFIG_SYSFS
566void __kernel_param_lock(void)
567{
568    mutex_lock(&param_lock);
569}
570EXPORT_SYMBOL(__kernel_param_lock);
571
572void __kernel_param_unlock(void)
573{
574    mutex_unlock(&param_lock);
575}
576EXPORT_SYMBOL(__kernel_param_unlock);
577
578/*
579 * add_sysfs_param - add a parameter to sysfs
580 * @mk: struct module_kobject
581 * @kparam: the actual parameter definition to add to sysfs
582 * @name: name of parameter
583 *
584 * Create a kobject if for a (per-module) parameter if mp NULL, and
585 * create file in sysfs. Returns an error on out of memory. Always cleans up
586 * if there's an error.
587 */
588static __modinit int add_sysfs_param(struct module_kobject *mk,
589                     const struct kernel_param *kp,
590                     const char *name)
591{
592    struct module_param_attrs *new;
593    struct attribute **attrs;
594    int err, num;
595
596    /* We don't bother calling this with invisible parameters. */
597    BUG_ON(!kp->perm);
598
599    if (!mk->mp) {
600        num = 0;
601        attrs = NULL;
602    } else {
603        num = mk->mp->num;
604        attrs = mk->mp->grp.attrs;
605    }
606
607    /* Enlarge. */
608    new = krealloc(mk->mp,
609               sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
610               GFP_KERNEL);
611    if (!new) {
612        kfree(attrs);
613        err = -ENOMEM;
614        goto fail;
615    }
616    /* Despite looking like the typical realloc() bug, this is safe.
617     * We *want* the old 'attrs' to be freed either way, and we'll store
618     * the new one in the success case. */
619    attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
620    if (!attrs) {
621        err = -ENOMEM;
622        goto fail_free_new;
623    }
624
625    /* Sysfs wants everything zeroed. */
626    memset(new, 0, sizeof(*new));
627    memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
628    memset(&attrs[num], 0, sizeof(attrs[num]));
629    new->grp.name = "parameters";
630    new->grp.attrs = attrs;
631
632    /* Tack new one on the end. */
633    sysfs_attr_init(&new->attrs[num].mattr.attr);
634    new->attrs[num].param = kp;
635    new->attrs[num].mattr.show = param_attr_show;
636    new->attrs[num].mattr.store = param_attr_store;
637    new->attrs[num].mattr.attr.name = (char *)name;
638    new->attrs[num].mattr.attr.mode = kp->perm;
639    new->num = num+1;
640
641    /* Fix up all the pointers, since krealloc can move us */
642    for (num = 0; num < new->num; num++)
643        new->grp.attrs[num] = &new->attrs[num].mattr.attr;
644    new->grp.attrs[num] = NULL;
645
646    mk->mp = new;
647    return 0;
648
649fail_free_new:
650    kfree(new);
651fail:
652    mk->mp = NULL;
653    return err;
654}
655
656#ifdef CONFIG_MODULES
657static void free_module_param_attrs(struct module_kobject *mk)
658{
659    kfree(mk->mp->grp.attrs);
660    kfree(mk->mp);
661    mk->mp = NULL;
662}
663
664/*
665 * module_param_sysfs_setup - setup sysfs support for one module
666 * @mod: module
667 * @kparam: module parameters (array)
668 * @num_params: number of module parameters
669 *
670 * Adds sysfs entries for module parameters under
671 * /sys/module/[mod->name]/parameters/
672 */
673int module_param_sysfs_setup(struct module *mod,
674                 const struct kernel_param *kparam,
675                 unsigned int num_params)
676{
677    int i, err;
678    bool params = false;
679
680    for (i = 0; i < num_params; i++) {
681        if (kparam[i].perm == 0)
682            continue;
683        err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
684        if (err)
685            return err;
686        params = true;
687    }
688
689    if (!params)
690        return 0;
691
692    /* Create the param group. */
693    err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
694    if (err)
695        free_module_param_attrs(&mod->mkobj);
696    return err;
697}
698
699/*
700 * module_param_sysfs_remove - remove sysfs support for one module
701 * @mod: module
702 *
703 * Remove sysfs entries for module parameters and the corresponding
704 * kobject.
705 */
706void module_param_sysfs_remove(struct module *mod)
707{
708    if (mod->mkobj.mp) {
709        sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
710        /* We are positive that no one is using any param
711         * attrs at this point. Deallocate immediately. */
712        free_module_param_attrs(&mod->mkobj);
713    }
714}
715#endif
716
717void destroy_params(const struct kernel_param *params, unsigned num)
718{
719    unsigned int i;
720
721    for (i = 0; i < num; i++)
722        if (params[i].ops->free)
723            params[i].ops->free(params[i].arg);
724}
725
726static struct module_kobject * __init locate_module_kobject(const char *name)
727{
728    struct module_kobject *mk;
729    struct kobject *kobj;
730    int err;
731
732    kobj = kset_find_obj(module_kset, name);
733    if (kobj) {
734        mk = to_module_kobject(kobj);
735    } else {
736        mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
737        BUG_ON(!mk);
738
739        mk->mod = THIS_MODULE;
740        mk->kobj.kset = module_kset;
741        err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
742                       "%s", name);
743#ifdef CONFIG_MODULES
744        if (!err)
745            err = sysfs_create_file(&mk->kobj, &module_uevent.attr);
746#endif
747        if (err) {
748            kobject_put(&mk->kobj);
749            pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n",
750                name, err);
751            return NULL;
752        }
753
754        /* So that we hold reference in both cases. */
755        kobject_get(&mk->kobj);
756    }
757
758    return mk;
759}
760
761static void __init kernel_add_sysfs_param(const char *name,
762                      struct kernel_param *kparam,
763                      unsigned int name_skip)
764{
765    struct module_kobject *mk;
766    int err;
767
768    mk = locate_module_kobject(name);
769    if (!mk)
770        return;
771
772    /* We need to remove old parameters before adding more. */
773    if (mk->mp)
774        sysfs_remove_group(&mk->kobj, &mk->mp->grp);
775
776    /* These should not fail at boot. */
777    err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
778    BUG_ON(err);
779    err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
780    BUG_ON(err);
781    kobject_uevent(&mk->kobj, KOBJ_ADD);
782    kobject_put(&mk->kobj);
783}
784
785/*
786 * param_sysfs_builtin - add sysfs parameters for built-in modules
787 *
788 * Add module_parameters to sysfs for "modules" built into the kernel.
789 *
790 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
791 * "parameter" name is stored behind a dot in kernel_param->name. So,
792 * extract the "module" name for all built-in kernel_param-eters,
793 * and for all who have the same, call kernel_add_sysfs_param.
794 */
795static void __init param_sysfs_builtin(void)
796{
797    struct kernel_param *kp;
798    unsigned int name_len;
799    char modname[MODULE_NAME_LEN];
800
801    for (kp = __start___param; kp < __stop___param; kp++) {
802        char *dot;
803
804        if (kp->perm == 0)
805            continue;
806
807        dot = strchr(kp->name, '.');
808        if (!dot) {
809            /* This happens for core_param() */
810            strcpy(modname, "kernel");
811            name_len = 0;
812        } else {
813            name_len = dot - kp->name + 1;
814            strlcpy(modname, kp->name, name_len);
815        }
816        kernel_add_sysfs_param(modname, kp, name_len);
817    }
818}
819
820ssize_t __modver_version_show(struct module_attribute *mattr,
821                  struct module_kobject *mk, char *buf)
822{
823    struct module_version_attribute *vattr =
824        container_of(mattr, struct module_version_attribute, mattr);
825
826    return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
827}
828
829extern const struct module_version_attribute *__start___modver[];
830extern const struct module_version_attribute *__stop___modver[];
831
832static void __init version_sysfs_builtin(void)
833{
834    const struct module_version_attribute **p;
835    struct module_kobject *mk;
836    int err;
837
838    for (p = __start___modver; p < __stop___modver; p++) {
839        const struct module_version_attribute *vattr = *p;
840
841        mk = locate_module_kobject(vattr->module_name);
842        if (mk) {
843            err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
844            kobject_uevent(&mk->kobj, KOBJ_ADD);
845            kobject_put(&mk->kobj);
846        }
847    }
848}
849
850/* module-related sysfs stuff */
851
852static ssize_t module_attr_show(struct kobject *kobj,
853                struct attribute *attr,
854                char *buf)
855{
856    struct module_attribute *attribute;
857    struct module_kobject *mk;
858    int ret;
859
860    attribute = to_module_attr(attr);
861    mk = to_module_kobject(kobj);
862
863    if (!attribute->show)
864        return -EIO;
865
866    ret = attribute->show(attribute, mk, buf);
867
868    return ret;
869}
870
871static ssize_t module_attr_store(struct kobject *kobj,
872                struct attribute *attr,
873                const char *buf, size_t len)
874{
875    struct module_attribute *attribute;
876    struct module_kobject *mk;
877    int ret;
878
879    attribute = to_module_attr(attr);
880    mk = to_module_kobject(kobj);
881
882    if (!attribute->store)
883        return -EIO;
884
885    ret = attribute->store(attribute, mk, buf, len);
886
887    return ret;
888}
889
890static const struct sysfs_ops module_sysfs_ops = {
891    .show = module_attr_show,
892    .store = module_attr_store,
893};
894
895static int uevent_filter(struct kset *kset, struct kobject *kobj)
896{
897    struct kobj_type *ktype = get_ktype(kobj);
898
899    if (ktype == &module_ktype)
900        return 1;
901    return 0;
902}
903
904static const struct kset_uevent_ops module_uevent_ops = {
905    .filter = uevent_filter,
906};
907
908struct kset *module_kset;
909int module_sysfs_initialized;
910
911static void module_kobj_release(struct kobject *kobj)
912{
913    struct module_kobject *mk = to_module_kobject(kobj);
914    complete(mk->kobj_completion);
915}
916
917struct kobj_type module_ktype = {
918    .release = module_kobj_release,
919    .sysfs_ops = &module_sysfs_ops,
920};
921
922/*
923 * param_sysfs_init - wrapper for built-in params support
924 */
925static int __init param_sysfs_init(void)
926{
927    module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
928    if (!module_kset) {
929        printk(KERN_WARNING "%s (%d): error creating kset\n",
930            __FILE__, __LINE__);
931        return -ENOMEM;
932    }
933    module_sysfs_initialized = 1;
934
935    version_sysfs_builtin();
936    param_sysfs_builtin();
937
938    return 0;
939}
940subsys_initcall(param_sysfs_init);
941
942#endif /* CONFIG_SYSFS */
943

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