1 /*
2 * Originally from efivars.c,
3 *
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
6 *
7 * This code takes all variables accessible from EFI runtime and
8 * exports them via sysfs
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 * Changelog:
25 *
26 * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
27 * remove check for efi_enabled in exit
28 * add MODULE_VERSION
29 *
30 * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
31 * minor bug fixes
32 *
33 * 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
34 * converted driver to export variable information via sysfs
35 * and moved to drivers/firmware directory
36 * bumped revision number to v0.07 to reflect conversion & move
37 *
38 * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
39 * fix locking per Peter Chubb's findings
40 *
41 * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
42 * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_to_str()
43 *
44 * 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
45 * use list_for_each_safe when deleting vars.
46 * remove ifdef CONFIG_SMP around include <linux/smp.h>
47 * v0.04 release to linux-ia64@linuxia64.org
48 *
49 * 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
50 * Moved vars from /proc/efi to /proc/efi/vars, and made
51 * efi.c own the /proc/efi directory.
52 * v0.03 release to linux-ia64@linuxia64.org
53 *
54 * 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
55 * At the request of Stephane, moved ownership of /proc/efi
56 * to efi.c, and now efivars lives under /proc/efi/vars.
57 *
58 * 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
59 * Feedback received from Stephane Eranian incorporated.
60 * efivar_write() checks copy_from_user() return value.
61 * efivar_read/write() returns proper errno.
62 * v0.02 release to linux-ia64@linuxia64.org
63 *
64 * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
65 * v0.01 release to linux-ia64@linuxia64.org
66 */
67
68 #include <linux/efi.h>
69 #include <linux/module.h>
70 #include <linux/slab.h>
71 #include <linux/ucs2_string.h>
72 #include <linux/compat.h>
73
74 #define EFIVARS_VERSION "0.08"
75 #define EFIVARS_DATE "2004-May-17"
76
77 MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
78 MODULE_DESCRIPTION("sysfs interface to EFI Variables");
79 MODULE_LICENSE("GPL");
80 MODULE_VERSION(EFIVARS_VERSION);
81 MODULE_ALIAS("platform:efivars");
82
83 LIST_HEAD(efivar_sysfs_list);
84 EXPORT_SYMBOL_GPL(efivar_sysfs_list);
85
86 static struct kset *efivars_kset;
87
88 static struct bin_attribute *efivars_new_var;
89 static struct bin_attribute *efivars_del_var;
90
91 struct compat_efi_variable {
92 efi_char16_t VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)];
93 efi_guid_t VendorGuid;
94 __u32 DataSize;
95 __u8 Data[1024];
96 __u32 Status;
97 __u32 Attributes;
98 } __packed;
99
100 struct efivar_attribute {
101 struct attribute attr;
102 ssize_t (*show) (struct efivar_entry *entry, char *buf);
103 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
104 };
105
106 #define EFIVAR_ATTR(_name, _mode, _show, _store) \
107 struct efivar_attribute efivar_attr_##_name = { \
108 .attr = {.name = __stringify(_name), .mode = _mode}, \
109 .show = _show, \
110 .store = _store, \
111 };
112
113 #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
114 #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
115
116 /*
117 * Prototype for sysfs creation function
118 */
119 static int
120 efivar_create_sysfs_entry(struct efivar_entry *new_var);
121
122 static ssize_t
efivar_guid_read(struct efivar_entry * entry,char * buf)123 efivar_guid_read(struct efivar_entry *entry, char *buf)
124 {
125 struct efi_variable *var = &entry->var;
126 char *str = buf;
127
128 if (!entry || !buf)
129 return 0;
130
131 efi_guid_to_str(&var->VendorGuid, str);
132 str += strlen(str);
133 str += sprintf(str, "\n");
134
135 return str - buf;
136 }
137
138 static ssize_t
efivar_attr_read(struct efivar_entry * entry,char * buf)139 efivar_attr_read(struct efivar_entry *entry, char *buf)
140 {
141 struct efi_variable *var = &entry->var;
142 unsigned long size = sizeof(var->Data);
143 char *str = buf;
144 int ret;
145
146 if (!entry || !buf)
147 return -EINVAL;
148
149 ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data);
150 var->DataSize = size;
151 if (ret)
152 return -EIO;
153
154 if (var->Attributes & EFI_VARIABLE_NON_VOLATILE)
155 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
156 if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)
157 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
158 if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)
159 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
160 if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD)
161 str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
162 if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
163 str += sprintf(str,
164 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
165 if (var->Attributes &
166 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
167 str += sprintf(str,
168 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
169 if (var->Attributes & EFI_VARIABLE_APPEND_WRITE)
170 str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n");
171 return str - buf;
172 }
173
174 static ssize_t
efivar_size_read(struct efivar_entry * entry,char * buf)175 efivar_size_read(struct efivar_entry *entry, char *buf)
176 {
177 struct efi_variable *var = &entry->var;
178 unsigned long size = sizeof(var->Data);
179 char *str = buf;
180 int ret;
181
182 if (!entry || !buf)
183 return -EINVAL;
184
185 ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data);
186 var->DataSize = size;
187 if (ret)
188 return -EIO;
189
190 str += sprintf(str, "0x%lx\n", var->DataSize);
191 return str - buf;
192 }
193
194 static ssize_t
efivar_data_read(struct efivar_entry * entry,char * buf)195 efivar_data_read(struct efivar_entry *entry, char *buf)
196 {
197 struct efi_variable *var = &entry->var;
198 unsigned long size = sizeof(var->Data);
199 int ret;
200
201 if (!entry || !buf)
202 return -EINVAL;
203
204 ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data);
205 var->DataSize = size;
206 if (ret)
207 return -EIO;
208
209 memcpy(buf, var->Data, var->DataSize);
210 return var->DataSize;
211 }
212
213 static inline int
sanity_check(struct efi_variable * var,efi_char16_t * name,efi_guid_t vendor,unsigned long size,u32 attributes,u8 * data)214 sanity_check(struct efi_variable *var, efi_char16_t *name, efi_guid_t vendor,
215 unsigned long size, u32 attributes, u8 *data)
216 {
217 /*
218 * If only updating the variable data, then the name
219 * and guid should remain the same
220 */
221 if (memcmp(name, var->VariableName, sizeof(var->VariableName)) ||
222 efi_guidcmp(vendor, var->VendorGuid)) {
223 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
224 return -EINVAL;
225 }
226
227 if ((size <= 0) || (attributes == 0)){
228 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
229 return -EINVAL;
230 }
231
232 if ((attributes & ~EFI_VARIABLE_MASK) != 0 ||
233 efivar_validate(vendor, name, data, size) == false) {
234 printk(KERN_ERR "efivars: Malformed variable content\n");
235 return -EINVAL;
236 }
237
238 return 0;
239 }
240
is_compat(void)241 static inline bool is_compat(void)
242 {
243 if (IS_ENABLED(CONFIG_COMPAT) && in_compat_syscall())
244 return true;
245
246 return false;
247 }
248
249 static void
copy_out_compat(struct efi_variable * dst,struct compat_efi_variable * src)250 copy_out_compat(struct efi_variable *dst, struct compat_efi_variable *src)
251 {
252 memcpy(dst->VariableName, src->VariableName, EFI_VAR_NAME_LEN);
253 memcpy(dst->Data, src->Data, sizeof(src->Data));
254
255 dst->VendorGuid = src->VendorGuid;
256 dst->DataSize = src->DataSize;
257 dst->Attributes = src->Attributes;
258 }
259
260 /*
261 * We allow each variable to be edited via rewriting the
262 * entire efi variable structure.
263 */
264 static ssize_t
efivar_store_raw(struct efivar_entry * entry,const char * buf,size_t count)265 efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
266 {
267 struct efi_variable *new_var, *var = &entry->var;
268 efi_char16_t *name;
269 unsigned long size;
270 efi_guid_t vendor;
271 u32 attributes;
272 u8 *data;
273 int err;
274
275 if (!entry || !buf)
276 return -EINVAL;
277
278 if (is_compat()) {
279 struct compat_efi_variable *compat;
280
281 if (count != sizeof(*compat))
282 return -EINVAL;
283
284 compat = (struct compat_efi_variable *)buf;
285 attributes = compat->Attributes;
286 vendor = compat->VendorGuid;
287 name = compat->VariableName;
288 size = compat->DataSize;
289 data = compat->Data;
290
291 err = sanity_check(var, name, vendor, size, attributes, data);
292 if (err)
293 return err;
294
295 copy_out_compat(&entry->var, compat);
296 } else {
297 if (count != sizeof(struct efi_variable))
298 return -EINVAL;
299
300 new_var = (struct efi_variable *)buf;
301
302 attributes = new_var->Attributes;
303 vendor = new_var->VendorGuid;
304 name = new_var->VariableName;
305 size = new_var->DataSize;
306 data = new_var->Data;
307
308 err = sanity_check(var, name, vendor, size, attributes, data);
309 if (err)
310 return err;
311
312 memcpy(&entry->var, new_var, count);
313 }
314
315 err = efivar_entry_set(entry, attributes, size, data, NULL);
316 if (err) {
317 printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err);
318 return -EIO;
319 }
320
321 return count;
322 }
323
324 static ssize_t
efivar_show_raw(struct efivar_entry * entry,char * buf)325 efivar_show_raw(struct efivar_entry *entry, char *buf)
326 {
327 struct efi_variable *var = &entry->var;
328 struct compat_efi_variable *compat;
329 unsigned long datasize = sizeof(var->Data);
330 size_t size;
331 int ret;
332
333 if (!entry || !buf)
334 return 0;
335
336 ret = efivar_entry_get(entry, &var->Attributes, &datasize, var->Data);
337 var->DataSize = datasize;
338 if (ret)
339 return -EIO;
340
341 if (is_compat()) {
342 compat = (struct compat_efi_variable *)buf;
343
344 size = sizeof(*compat);
345 memcpy(compat->VariableName, var->VariableName,
346 EFI_VAR_NAME_LEN);
347 memcpy(compat->Data, var->Data, sizeof(compat->Data));
348
349 compat->VendorGuid = var->VendorGuid;
350 compat->DataSize = var->DataSize;
351 compat->Attributes = var->Attributes;
352 } else {
353 size = sizeof(*var);
354 memcpy(buf, var, size);
355 }
356
357 return size;
358 }
359
360 /*
361 * Generic read/write functions that call the specific functions of
362 * the attributes...
363 */
efivar_attr_show(struct kobject * kobj,struct attribute * attr,char * buf)364 static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
365 char *buf)
366 {
367 struct efivar_entry *var = to_efivar_entry(kobj);
368 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
369 ssize_t ret = -EIO;
370
371 if (!capable(CAP_SYS_ADMIN))
372 return -EACCES;
373
374 if (efivar_attr->show) {
375 ret = efivar_attr->show(var, buf);
376 }
377 return ret;
378 }
379
efivar_attr_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t count)380 static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
381 const char *buf, size_t count)
382 {
383 struct efivar_entry *var = to_efivar_entry(kobj);
384 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
385 ssize_t ret = -EIO;
386
387 if (!capable(CAP_SYS_ADMIN))
388 return -EACCES;
389
390 if (efivar_attr->store)
391 ret = efivar_attr->store(var, buf, count);
392
393 return ret;
394 }
395
396 static const struct sysfs_ops efivar_attr_ops = {
397 .show = efivar_attr_show,
398 .store = efivar_attr_store,
399 };
400
efivar_release(struct kobject * kobj)401 static void efivar_release(struct kobject *kobj)
402 {
403 struct efivar_entry *var = to_efivar_entry(kobj);
404 kfree(var);
405 }
406
407 static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
408 static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
409 static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
410 static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
411 static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
412
413 static struct attribute *def_attrs[] = {
414 &efivar_attr_guid.attr,
415 &efivar_attr_size.attr,
416 &efivar_attr_attributes.attr,
417 &efivar_attr_data.attr,
418 &efivar_attr_raw_var.attr,
419 NULL,
420 };
421
422 static struct kobj_type efivar_ktype = {
423 .release = efivar_release,
424 .sysfs_ops = &efivar_attr_ops,
425 .default_attrs = def_attrs,
426 };
427
efivar_create(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)428 static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
429 struct bin_attribute *bin_attr,
430 char *buf, loff_t pos, size_t count)
431 {
432 struct compat_efi_variable *compat = (struct compat_efi_variable *)buf;
433 struct efi_variable *new_var = (struct efi_variable *)buf;
434 struct efivar_entry *new_entry;
435 bool need_compat = is_compat();
436 efi_char16_t *name;
437 unsigned long size;
438 u32 attributes;
439 u8 *data;
440 int err;
441
442 if (!capable(CAP_SYS_ADMIN))
443 return -EACCES;
444
445 if (need_compat) {
446 if (count != sizeof(*compat))
447 return -EINVAL;
448
449 attributes = compat->Attributes;
450 name = compat->VariableName;
451 size = compat->DataSize;
452 data = compat->Data;
453 } else {
454 if (count != sizeof(*new_var))
455 return -EINVAL;
456
457 attributes = new_var->Attributes;
458 name = new_var->VariableName;
459 size = new_var->DataSize;
460 data = new_var->Data;
461 }
462
463 if ((attributes & ~EFI_VARIABLE_MASK) != 0 ||
464 efivar_validate(new_var->VendorGuid, name, data,
465 size) == false) {
466 printk(KERN_ERR "efivars: Malformed variable content\n");
467 return -EINVAL;
468 }
469
470 new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
471 if (!new_entry)
472 return -ENOMEM;
473
474 if (need_compat)
475 copy_out_compat(&new_entry->var, compat);
476 else
477 memcpy(&new_entry->var, new_var, sizeof(*new_var));
478
479 err = efivar_entry_set(new_entry, attributes, size,
480 data, &efivar_sysfs_list);
481 if (err) {
482 if (err == -EEXIST)
483 err = -EINVAL;
484 goto out;
485 }
486
487 if (efivar_create_sysfs_entry(new_entry)) {
488 printk(KERN_WARNING "efivars: failed to create sysfs entry.\n");
489 kfree(new_entry);
490 }
491 return count;
492
493 out:
494 kfree(new_entry);
495 return err;
496 }
497
efivar_delete(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)498 static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
499 struct bin_attribute *bin_attr,
500 char *buf, loff_t pos, size_t count)
501 {
502 struct efi_variable *del_var = (struct efi_variable *)buf;
503 struct compat_efi_variable *compat;
504 struct efivar_entry *entry;
505 efi_char16_t *name;
506 efi_guid_t vendor;
507 int err = 0;
508
509 if (!capable(CAP_SYS_ADMIN))
510 return -EACCES;
511
512 if (is_compat()) {
513 if (count != sizeof(*compat))
514 return -EINVAL;
515
516 compat = (struct compat_efi_variable *)buf;
517 name = compat->VariableName;
518 vendor = compat->VendorGuid;
519 } else {
520 if (count != sizeof(*del_var))
521 return -EINVAL;
522
523 name = del_var->VariableName;
524 vendor = del_var->VendorGuid;
525 }
526
527 if (efivar_entry_iter_begin())
528 return -EINTR;
529 entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true);
530 if (!entry)
531 err = -EINVAL;
532 else if (__efivar_entry_delete(entry))
533 err = -EIO;
534
535 if (err) {
536 efivar_entry_iter_end();
537 return err;
538 }
539
540 if (!entry->scanning) {
541 efivar_entry_iter_end();
542 efivar_unregister(entry);
543 } else
544 efivar_entry_iter_end();
545
546 /* It's dead Jim.... */
547 return count;
548 }
549
550 /**
551 * efivar_create_sysfs_entry - create a new entry in sysfs
552 * @new_var: efivar entry to create
553 *
554 * Returns 0 on success, negative error code on failure
555 */
556 static int
efivar_create_sysfs_entry(struct efivar_entry * new_var)557 efivar_create_sysfs_entry(struct efivar_entry *new_var)
558 {
559 int short_name_size;
560 char *short_name;
561 unsigned long utf8_name_size;
562 efi_char16_t *variable_name = new_var->var.VariableName;
563 int ret;
564
565 /*
566 * Length of the variable bytes in UTF8, plus the '-' separator,
567 * plus the GUID, plus trailing NUL
568 */
569 utf8_name_size = ucs2_utf8size(variable_name);
570 short_name_size = utf8_name_size + 1 + EFI_VARIABLE_GUID_LEN + 1;
571
572 short_name = kmalloc(short_name_size, GFP_KERNEL);
573 if (!short_name)
574 return -ENOMEM;
575
576 ucs2_as_utf8(short_name, variable_name, short_name_size);
577
578 /* This is ugly, but necessary to separate one vendor's
579 private variables from another's. */
580 short_name[utf8_name_size] = '-';
581 efi_guid_to_str(&new_var->var.VendorGuid,
582 short_name + utf8_name_size + 1);
583
584 new_var->kobj.kset = efivars_kset;
585
586 ret = kobject_init_and_add(&new_var->kobj, &efivar_ktype,
587 NULL, "%s", short_name);
588 kfree(short_name);
589 if (ret)
590 return ret;
591
592 kobject_uevent(&new_var->kobj, KOBJ_ADD);
593 if (efivar_entry_add(new_var, &efivar_sysfs_list)) {
594 efivar_unregister(new_var);
595 return -EINTR;
596 }
597
598 return 0;
599 }
600
601 static int
create_efivars_bin_attributes(void)602 create_efivars_bin_attributes(void)
603 {
604 struct bin_attribute *attr;
605 int error;
606
607 /* new_var */
608 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
609 if (!attr)
610 return -ENOMEM;
611
612 attr->attr.name = "new_var";
613 attr->attr.mode = 0200;
614 attr->write = efivar_create;
615 efivars_new_var = attr;
616
617 /* del_var */
618 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
619 if (!attr) {
620 error = -ENOMEM;
621 goto out_free;
622 }
623 attr->attr.name = "del_var";
624 attr->attr.mode = 0200;
625 attr->write = efivar_delete;
626 efivars_del_var = attr;
627
628 sysfs_bin_attr_init(efivars_new_var);
629 sysfs_bin_attr_init(efivars_del_var);
630
631 /* Register */
632 error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var);
633 if (error) {
634 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
635 " due to error %d\n", error);
636 goto out_free;
637 }
638
639 error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var);
640 if (error) {
641 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
642 " due to error %d\n", error);
643 sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var);
644 goto out_free;
645 }
646
647 return 0;
648 out_free:
649 kfree(efivars_del_var);
650 efivars_del_var = NULL;
651 kfree(efivars_new_var);
652 efivars_new_var = NULL;
653 return error;
654 }
655
efivar_update_sysfs_entry(efi_char16_t * name,efi_guid_t vendor,unsigned long name_size,void * data)656 static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor,
657 unsigned long name_size, void *data)
658 {
659 struct efivar_entry *entry = data;
660
661 if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false))
662 return 0;
663
664 memcpy(entry->var.VariableName, name, name_size);
665 memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
666
667 return 1;
668 }
669
efivar_update_sysfs_entries(struct work_struct * work)670 static void efivar_update_sysfs_entries(struct work_struct *work)
671 {
672 struct efivar_entry *entry;
673 int err;
674
675 /* Add new sysfs entries */
676 while (1) {
677 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
678 if (!entry)
679 return;
680
681 err = efivar_init(efivar_update_sysfs_entry, entry,
682 false, &efivar_sysfs_list);
683 if (!err)
684 break;
685
686 efivar_create_sysfs_entry(entry);
687 }
688
689 kfree(entry);
690 }
691
efivars_sysfs_callback(efi_char16_t * name,efi_guid_t vendor,unsigned long name_size,void * data)692 static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor,
693 unsigned long name_size, void *data)
694 {
695 struct efivar_entry *entry;
696
697 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
698 if (!entry)
699 return -ENOMEM;
700
701 memcpy(entry->var.VariableName, name, name_size);
702 memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
703
704 efivar_create_sysfs_entry(entry);
705
706 return 0;
707 }
708
efivar_sysfs_destroy(struct efivar_entry * entry,void * data)709 static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data)
710 {
711 int err = efivar_entry_remove(entry);
712
713 if (err)
714 return err;
715 efivar_unregister(entry);
716 return 0;
717 }
718
efivars_sysfs_exit(void)719 static void efivars_sysfs_exit(void)
720 {
721 /* Remove all entries and destroy */
722 int err;
723
724 err = __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list,
725 NULL, NULL);
726 if (err) {
727 pr_err("efivars: Failed to destroy sysfs entries\n");
728 return;
729 }
730
731 if (efivars_new_var)
732 sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var);
733 if (efivars_del_var)
734 sysfs_remove_bin_file(&efivars_kset->kobj, efivars_del_var);
735 kfree(efivars_new_var);
736 kfree(efivars_del_var);
737 kset_unregister(efivars_kset);
738 }
739
efivars_sysfs_init(void)740 int efivars_sysfs_init(void)
741 {
742 struct kobject *parent_kobj = efivars_kobject();
743 int error = 0;
744
745 if (!efi_enabled(EFI_RUNTIME_SERVICES))
746 return -ENODEV;
747
748 /* No efivars has been registered yet */
749 if (!parent_kobj)
750 return 0;
751
752 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
753 EFIVARS_DATE);
754
755 efivars_kset = kset_create_and_add("vars", NULL, parent_kobj);
756 if (!efivars_kset) {
757 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
758 return -ENOMEM;
759 }
760
761 efivar_init(efivars_sysfs_callback, NULL, true, &efivar_sysfs_list);
762
763 error = create_efivars_bin_attributes();
764 if (error) {
765 efivars_sysfs_exit();
766 return error;
767 }
768
769 INIT_WORK(&efivar_work, efivar_update_sysfs_entries);
770
771 return 0;
772 }
773 EXPORT_SYMBOL_GPL(efivars_sysfs_init);
774
775 module_init(efivars_sysfs_init);
776 module_exit(efivars_sysfs_exit);
777