2 * Originally from efivars.c,
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
7 * This code takes all variables accessible from EFI runtime and
8 * exports them via sysfs
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.
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.
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
26 * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
27 * remove check for efi_enabled in exit
30 * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
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
38 * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
39 * fix locking per Peter Chubb's findings
41 * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
42 * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_to_str()
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
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
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.
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
64 * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
65 * v0.01 release to linux-ia64@linuxia64.org
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>
74 #define EFIVARS_VERSION "0.08"
75 #define EFIVARS_DATE "2004-May-17"
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");
83 LIST_HEAD(efivar_sysfs_list
);
84 EXPORT_SYMBOL_GPL(efivar_sysfs_list
);
86 static struct kset
*efivars_kset
;
88 static struct bin_attribute
*efivars_new_var
;
89 static struct bin_attribute
*efivars_del_var
;
91 struct compat_efi_variable
{
92 efi_char16_t VariableName
[EFI_VAR_NAME_LEN
/sizeof(efi_char16_t
)];
93 efi_guid_t VendorGuid
;
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
);
106 #define EFIVAR_ATTR(_name, _mode, _show, _store) \
107 struct efivar_attribute efivar_attr_##_name = { \
108 .attr = {.name = __stringify(_name), .mode = _mode}, \
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)
117 * Prototype for sysfs creation function
120 efivar_create_sysfs_entry(struct efivar_entry
*new_var
);
123 efivar_guid_read(struct efivar_entry
*entry
, char *buf
)
125 struct efi_variable
*var
= &entry
->var
;
131 efi_guid_to_str(&var
->VendorGuid
, str
);
133 str
+= sprintf(str
, "\n");
139 efivar_attr_read(struct efivar_entry
*entry
, char *buf
)
141 struct efi_variable
*var
= &entry
->var
;
147 var
->DataSize
= 1024;
148 if (efivar_entry_get(entry
, &var
->Attributes
, &var
->DataSize
, var
->Data
))
151 if (var
->Attributes
& EFI_VARIABLE_NON_VOLATILE
)
152 str
+= sprintf(str
, "EFI_VARIABLE_NON_VOLATILE\n");
153 if (var
->Attributes
& EFI_VARIABLE_BOOTSERVICE_ACCESS
)
154 str
+= sprintf(str
, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
155 if (var
->Attributes
& EFI_VARIABLE_RUNTIME_ACCESS
)
156 str
+= sprintf(str
, "EFI_VARIABLE_RUNTIME_ACCESS\n");
157 if (var
->Attributes
& EFI_VARIABLE_HARDWARE_ERROR_RECORD
)
158 str
+= sprintf(str
, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
159 if (var
->Attributes
& EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
)
161 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
162 if (var
->Attributes
&
163 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
)
165 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
166 if (var
->Attributes
& EFI_VARIABLE_APPEND_WRITE
)
167 str
+= sprintf(str
, "EFI_VARIABLE_APPEND_WRITE\n");
172 efivar_size_read(struct efivar_entry
*entry
, char *buf
)
174 struct efi_variable
*var
= &entry
->var
;
180 var
->DataSize
= 1024;
181 if (efivar_entry_get(entry
, &var
->Attributes
, &var
->DataSize
, var
->Data
))
184 str
+= sprintf(str
, "0x%lx\n", var
->DataSize
);
189 efivar_data_read(struct efivar_entry
*entry
, char *buf
)
191 struct efi_variable
*var
= &entry
->var
;
196 var
->DataSize
= 1024;
197 if (efivar_entry_get(entry
, &var
->Attributes
, &var
->DataSize
, var
->Data
))
200 memcpy(buf
, var
->Data
, var
->DataSize
);
201 return var
->DataSize
;
205 sanity_check(struct efi_variable
*var
, efi_char16_t
*name
, efi_guid_t vendor
,
206 unsigned long size
, u32 attributes
, u8
*data
)
209 * If only updating the variable data, then the name
210 * and guid should remain the same
212 if (memcmp(name
, var
->VariableName
, sizeof(var
->VariableName
)) ||
213 efi_guidcmp(vendor
, var
->VendorGuid
)) {
214 printk(KERN_ERR
"efivars: Cannot edit the wrong variable!\n");
218 if ((size
<= 0) || (attributes
== 0)){
219 printk(KERN_ERR
"efivars: DataSize & Attributes must be valid!\n");
223 if ((attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
224 efivar_validate(vendor
, name
, data
, size
) == false) {
225 printk(KERN_ERR
"efivars: Malformed variable content\n");
232 static inline bool is_compat(void)
234 if (IS_ENABLED(CONFIG_COMPAT
) && in_compat_syscall())
241 copy_out_compat(struct efi_variable
*dst
, struct compat_efi_variable
*src
)
243 memcpy(dst
->VariableName
, src
->VariableName
, EFI_VAR_NAME_LEN
);
244 memcpy(dst
->Data
, src
->Data
, sizeof(src
->Data
));
246 dst
->VendorGuid
= src
->VendorGuid
;
247 dst
->DataSize
= src
->DataSize
;
248 dst
->Attributes
= src
->Attributes
;
252 * We allow each variable to be edited via rewriting the
253 * entire efi variable structure.
256 efivar_store_raw(struct efivar_entry
*entry
, const char *buf
, size_t count
)
258 struct efi_variable
*new_var
, *var
= &entry
->var
;
267 struct compat_efi_variable
*compat
;
269 if (count
!= sizeof(*compat
))
272 compat
= (struct compat_efi_variable
*)buf
;
273 attributes
= compat
->Attributes
;
274 vendor
= compat
->VendorGuid
;
275 name
= compat
->VariableName
;
276 size
= compat
->DataSize
;
279 err
= sanity_check(var
, name
, vendor
, size
, attributes
, data
);
283 copy_out_compat(&entry
->var
, compat
);
285 if (count
!= sizeof(struct efi_variable
))
288 new_var
= (struct efi_variable
*)buf
;
290 attributes
= new_var
->Attributes
;
291 vendor
= new_var
->VendorGuid
;
292 name
= new_var
->VariableName
;
293 size
= new_var
->DataSize
;
294 data
= new_var
->Data
;
296 err
= sanity_check(var
, name
, vendor
, size
, attributes
, data
);
300 memcpy(&entry
->var
, new_var
, count
);
303 err
= efivar_entry_set(entry
, attributes
, size
, data
, NULL
);
305 printk(KERN_WARNING
"efivars: set_variable() failed: status=%d\n", err
);
313 efivar_show_raw(struct efivar_entry
*entry
, char *buf
)
315 struct efi_variable
*var
= &entry
->var
;
316 struct compat_efi_variable
*compat
;
322 var
->DataSize
= 1024;
323 if (efivar_entry_get(entry
, &entry
->var
.Attributes
,
324 &entry
->var
.DataSize
, entry
->var
.Data
))
328 compat
= (struct compat_efi_variable
*)buf
;
330 size
= sizeof(*compat
);
331 memcpy(compat
->VariableName
, var
->VariableName
,
333 memcpy(compat
->Data
, var
->Data
, sizeof(compat
->Data
));
335 compat
->VendorGuid
= var
->VendorGuid
;
336 compat
->DataSize
= var
->DataSize
;
337 compat
->Attributes
= var
->Attributes
;
340 memcpy(buf
, var
, size
);
347 * Generic read/write functions that call the specific functions of
350 static ssize_t
efivar_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
353 struct efivar_entry
*var
= to_efivar_entry(kobj
);
354 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
357 if (!capable(CAP_SYS_ADMIN
))
360 if (efivar_attr
->show
) {
361 ret
= efivar_attr
->show(var
, buf
);
366 static ssize_t
efivar_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
367 const char *buf
, size_t count
)
369 struct efivar_entry
*var
= to_efivar_entry(kobj
);
370 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
373 if (!capable(CAP_SYS_ADMIN
))
376 if (efivar_attr
->store
)
377 ret
= efivar_attr
->store(var
, buf
, count
);
382 static const struct sysfs_ops efivar_attr_ops
= {
383 .show
= efivar_attr_show
,
384 .store
= efivar_attr_store
,
387 static void efivar_release(struct kobject
*kobj
)
389 struct efivar_entry
*var
= to_efivar_entry(kobj
);
393 static EFIVAR_ATTR(guid
, 0400, efivar_guid_read
, NULL
);
394 static EFIVAR_ATTR(attributes
, 0400, efivar_attr_read
, NULL
);
395 static EFIVAR_ATTR(size
, 0400, efivar_size_read
, NULL
);
396 static EFIVAR_ATTR(data
, 0400, efivar_data_read
, NULL
);
397 static EFIVAR_ATTR(raw_var
, 0600, efivar_show_raw
, efivar_store_raw
);
399 static struct attribute
*def_attrs
[] = {
400 &efivar_attr_guid
.attr
,
401 &efivar_attr_size
.attr
,
402 &efivar_attr_attributes
.attr
,
403 &efivar_attr_data
.attr
,
404 &efivar_attr_raw_var
.attr
,
408 static struct kobj_type efivar_ktype
= {
409 .release
= efivar_release
,
410 .sysfs_ops
= &efivar_attr_ops
,
411 .default_attrs
= def_attrs
,
414 static ssize_t
efivar_create(struct file
*filp
, struct kobject
*kobj
,
415 struct bin_attribute
*bin_attr
,
416 char *buf
, loff_t pos
, size_t count
)
418 struct compat_efi_variable
*compat
= (struct compat_efi_variable
*)buf
;
419 struct efi_variable
*new_var
= (struct efi_variable
*)buf
;
420 struct efivar_entry
*new_entry
;
421 bool need_compat
= is_compat();
428 if (!capable(CAP_SYS_ADMIN
))
432 if (count
!= sizeof(*compat
))
435 attributes
= compat
->Attributes
;
436 name
= compat
->VariableName
;
437 size
= compat
->DataSize
;
440 if (count
!= sizeof(*new_var
))
443 attributes
= new_var
->Attributes
;
444 name
= new_var
->VariableName
;
445 size
= new_var
->DataSize
;
446 data
= new_var
->Data
;
449 if ((attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
450 efivar_validate(new_var
->VendorGuid
, name
, data
,
452 printk(KERN_ERR
"efivars: Malformed variable content\n");
456 new_entry
= kzalloc(sizeof(*new_entry
), GFP_KERNEL
);
461 copy_out_compat(&new_entry
->var
, compat
);
463 memcpy(&new_entry
->var
, new_var
, sizeof(*new_var
));
465 err
= efivar_entry_set(new_entry
, attributes
, size
,
466 data
, &efivar_sysfs_list
);
473 if (efivar_create_sysfs_entry(new_entry
)) {
474 printk(KERN_WARNING
"efivars: failed to create sysfs entry.\n");
484 static ssize_t
efivar_delete(struct file
*filp
, struct kobject
*kobj
,
485 struct bin_attribute
*bin_attr
,
486 char *buf
, loff_t pos
, size_t count
)
488 struct efi_variable
*del_var
= (struct efi_variable
*)buf
;
489 struct compat_efi_variable
*compat
;
490 struct efivar_entry
*entry
;
495 if (!capable(CAP_SYS_ADMIN
))
499 if (count
!= sizeof(*compat
))
502 compat
= (struct compat_efi_variable
*)buf
;
503 name
= compat
->VariableName
;
504 vendor
= compat
->VendorGuid
;
506 if (count
!= sizeof(*del_var
))
509 name
= del_var
->VariableName
;
510 vendor
= del_var
->VendorGuid
;
513 if (efivar_entry_iter_begin())
515 entry
= efivar_entry_find(name
, vendor
, &efivar_sysfs_list
, true);
518 else if (__efivar_entry_delete(entry
))
522 efivar_entry_iter_end();
526 if (!entry
->scanning
) {
527 efivar_entry_iter_end();
528 efivar_unregister(entry
);
530 efivar_entry_iter_end();
532 /* It's dead Jim.... */
537 * efivar_create_sysfs_entry - create a new entry in sysfs
538 * @new_var: efivar entry to create
540 * Returns 0 on success, negative error code on failure
543 efivar_create_sysfs_entry(struct efivar_entry
*new_var
)
547 unsigned long utf8_name_size
;
548 efi_char16_t
*variable_name
= new_var
->var
.VariableName
;
552 * Length of the variable bytes in UTF8, plus the '-' separator,
553 * plus the GUID, plus trailing NUL
555 utf8_name_size
= ucs2_utf8size(variable_name
);
556 short_name_size
= utf8_name_size
+ 1 + EFI_VARIABLE_GUID_LEN
+ 1;
558 short_name
= kmalloc(short_name_size
, GFP_KERNEL
);
562 ucs2_as_utf8(short_name
, variable_name
, short_name_size
);
564 /* This is ugly, but necessary to separate one vendor's
565 private variables from another's. */
566 short_name
[utf8_name_size
] = '-';
567 efi_guid_to_str(&new_var
->var
.VendorGuid
,
568 short_name
+ utf8_name_size
+ 1);
570 new_var
->kobj
.kset
= efivars_kset
;
572 ret
= kobject_init_and_add(&new_var
->kobj
, &efivar_ktype
,
573 NULL
, "%s", short_name
);
578 kobject_uevent(&new_var
->kobj
, KOBJ_ADD
);
579 if (efivar_entry_add(new_var
, &efivar_sysfs_list
)) {
580 efivar_unregister(new_var
);
588 create_efivars_bin_attributes(void)
590 struct bin_attribute
*attr
;
594 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
598 attr
->attr
.name
= "new_var";
599 attr
->attr
.mode
= 0200;
600 attr
->write
= efivar_create
;
601 efivars_new_var
= attr
;
604 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
609 attr
->attr
.name
= "del_var";
610 attr
->attr
.mode
= 0200;
611 attr
->write
= efivar_delete
;
612 efivars_del_var
= attr
;
614 sysfs_bin_attr_init(efivars_new_var
);
615 sysfs_bin_attr_init(efivars_del_var
);
618 error
= sysfs_create_bin_file(&efivars_kset
->kobj
, efivars_new_var
);
620 printk(KERN_ERR
"efivars: unable to create new_var sysfs file"
621 " due to error %d\n", error
);
625 error
= sysfs_create_bin_file(&efivars_kset
->kobj
, efivars_del_var
);
627 printk(KERN_ERR
"efivars: unable to create del_var sysfs file"
628 " due to error %d\n", error
);
629 sysfs_remove_bin_file(&efivars_kset
->kobj
, efivars_new_var
);
635 kfree(efivars_del_var
);
636 efivars_del_var
= NULL
;
637 kfree(efivars_new_var
);
638 efivars_new_var
= NULL
;
642 static int efivar_update_sysfs_entry(efi_char16_t
*name
, efi_guid_t vendor
,
643 unsigned long name_size
, void *data
)
645 struct efivar_entry
*entry
= data
;
647 if (efivar_entry_find(name
, vendor
, &efivar_sysfs_list
, false))
650 memcpy(entry
->var
.VariableName
, name
, name_size
);
651 memcpy(&(entry
->var
.VendorGuid
), &vendor
, sizeof(efi_guid_t
));
656 static void efivar_update_sysfs_entries(struct work_struct
*work
)
658 struct efivar_entry
*entry
;
661 /* Add new sysfs entries */
663 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
667 err
= efivar_init(efivar_update_sysfs_entry
, entry
,
668 false, &efivar_sysfs_list
);
672 efivar_create_sysfs_entry(entry
);
678 static int efivars_sysfs_callback(efi_char16_t
*name
, efi_guid_t vendor
,
679 unsigned long name_size
, void *data
)
681 struct efivar_entry
*entry
;
683 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
687 memcpy(entry
->var
.VariableName
, name
, name_size
);
688 memcpy(&(entry
->var
.VendorGuid
), &vendor
, sizeof(efi_guid_t
));
690 efivar_create_sysfs_entry(entry
);
695 static int efivar_sysfs_destroy(struct efivar_entry
*entry
, void *data
)
697 int err
= efivar_entry_remove(entry
);
701 efivar_unregister(entry
);
705 static void efivars_sysfs_exit(void)
707 /* Remove all entries and destroy */
710 err
= __efivar_entry_iter(efivar_sysfs_destroy
, &efivar_sysfs_list
,
713 pr_err("efivars: Failed to destroy sysfs entries\n");
718 sysfs_remove_bin_file(&efivars_kset
->kobj
, efivars_new_var
);
720 sysfs_remove_bin_file(&efivars_kset
->kobj
, efivars_del_var
);
721 kfree(efivars_new_var
);
722 kfree(efivars_del_var
);
723 kset_unregister(efivars_kset
);
726 int efivars_sysfs_init(void)
728 struct kobject
*parent_kobj
= efivars_kobject();
731 if (!efi_enabled(EFI_RUNTIME_SERVICES
))
734 /* No efivars has been registered yet */
738 printk(KERN_INFO
"EFI Variables Facility v%s %s\n", EFIVARS_VERSION
,
741 efivars_kset
= kset_create_and_add("vars", NULL
, parent_kobj
);
743 printk(KERN_ERR
"efivars: Subsystem registration failed.\n");
747 efivar_init(efivars_sysfs_callback
, NULL
, true, &efivar_sysfs_list
);
749 error
= create_efivars_bin_attributes();
751 efivars_sysfs_exit();
755 INIT_WORK(&efivar_work
, efivar_update_sysfs_entries
);
759 EXPORT_SYMBOL_GPL(efivars_sysfs_init
);
761 module_init(efivars_sysfs_init
);
762 module_exit(efivars_sysfs_exit
);