2 * EFI Variables - 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_unparse()
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/capability.h>
69 #include <linux/types.h>
70 #include <linux/errno.h>
71 #include <linux/init.h>
73 #include <linux/module.h>
74 #include <linux/string.h>
75 #include <linux/smp.h>
76 #include <linux/efi.h>
77 #include <linux/sysfs.h>
78 #include <linux/kobject.h>
79 #include <linux/device.h>
80 #include <linux/slab.h>
81 #include <linux/pstore.h>
82 #include <linux/ctype.h>
85 #include <linux/ramfs.h>
86 #include <linux/pagemap.h>
88 #include <asm/uaccess.h>
90 #define EFIVARS_VERSION "0.08"
91 #define EFIVARS_DATE "2004-May-17"
93 MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
94 MODULE_DESCRIPTION("sysfs interface to EFI Variables");
95 MODULE_LICENSE("GPL");
96 MODULE_VERSION(EFIVARS_VERSION
);
98 #define DUMP_NAME_LEN 52
101 * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"))
102 * not including trailing NUL
107 * The maximum size of VariableName + Data = 1024
108 * Therefore, it's reasonable to save that much
109 * space in each part of the structure,
110 * and we use a page for reading/writing.
113 struct efi_variable
{
114 efi_char16_t VariableName
[1024/sizeof(efi_char16_t
)];
115 efi_guid_t VendorGuid
;
116 unsigned long DataSize
;
120 } __attribute__((packed
));
122 struct efivar_entry
{
123 struct efivars
*efivars
;
124 struct efi_variable var
;
125 struct list_head list
;
129 struct efivar_attribute
{
130 struct attribute attr
;
131 ssize_t (*show
) (struct efivar_entry
*entry
, char *buf
);
132 ssize_t (*store
)(struct efivar_entry
*entry
, const char *buf
, size_t count
);
135 static struct efivars __efivars
;
136 static struct efivar_operations ops
;
138 #define PSTORE_EFI_ATTRIBUTES \
139 (EFI_VARIABLE_NON_VOLATILE | \
140 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
141 EFI_VARIABLE_RUNTIME_ACCESS)
143 #define EFIVAR_ATTR(_name, _mode, _show, _store) \
144 struct efivar_attribute efivar_attr_##_name = { \
145 .attr = {.name = __stringify(_name), .mode = _mode}, \
150 #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
151 #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
154 * Prototype for sysfs creation function
157 efivar_create_sysfs_entry(struct efivars
*efivars
,
158 unsigned long variable_name_size
,
159 efi_char16_t
*variable_name
,
160 efi_guid_t
*vendor_guid
);
163 * Prototype for workqueue functions updating sysfs entry
166 static void efivar_update_sysfs_entries(struct work_struct
*);
167 static DECLARE_WORK(efivar_work
, efivar_update_sysfs_entries
);
169 /* Return the number of unicode characters in data */
171 utf16_strnlen(efi_char16_t
*s
, size_t maxlength
)
173 unsigned long length
= 0;
175 while (*s
++ != 0 && length
< maxlength
)
180 static inline unsigned long
181 utf16_strlen(efi_char16_t
*s
)
183 return utf16_strnlen(s
, ~0UL);
187 * Return the number of bytes is the length of this string
188 * Note: this is NOT the same as the number of unicode characters
190 static inline unsigned long
191 utf16_strsize(efi_char16_t
*data
, unsigned long maxlength
)
193 return utf16_strnlen(data
, maxlength
/sizeof(efi_char16_t
)) * sizeof(efi_char16_t
);
197 utf16_strncmp(const efi_char16_t
*a
, const efi_char16_t
*b
, size_t len
)
206 if (*a
== 0) /* implies *b == 0 */
215 validate_device_path(struct efi_variable
*var
, int match
, u8
*buffer
,
218 struct efi_generic_dev_path
*node
;
221 node
= (struct efi_generic_dev_path
*)buffer
;
223 if (len
< sizeof(*node
))
226 while (offset
<= len
- sizeof(*node
) &&
227 node
->length
>= sizeof(*node
) &&
228 node
->length
<= len
- offset
) {
229 offset
+= node
->length
;
231 if ((node
->type
== EFI_DEV_END_PATH
||
232 node
->type
== EFI_DEV_END_PATH2
) &&
233 node
->sub_type
== EFI_DEV_END_ENTIRE
)
236 node
= (struct efi_generic_dev_path
*)(buffer
+ offset
);
240 * If we're here then either node->length pointed past the end
241 * of the buffer or we reached the end of the buffer without
242 * finding a device path end node.
248 validate_boot_order(struct efi_variable
*var
, int match
, u8
*buffer
,
251 /* An array of 16-bit integers */
259 validate_load_option(struct efi_variable
*var
, int match
, u8
*buffer
,
263 int i
, desclength
= 0, namelen
;
265 namelen
= utf16_strnlen(var
->VariableName
, sizeof(var
->VariableName
));
267 /* Either "Boot" or "Driver" followed by four digits of hex */
268 for (i
= match
; i
< match
+4; i
++) {
269 if (var
->VariableName
[i
] > 127 ||
270 hex_to_bin(var
->VariableName
[i
] & 0xff) < 0)
274 /* Reject it if there's 4 digits of hex and then further content */
275 if (namelen
> match
+ 4)
278 /* A valid entry must be at least 8 bytes */
282 filepathlength
= buffer
[4] | buffer
[5] << 8;
285 * There's no stored length for the description, so it has to be
288 desclength
= utf16_strsize((efi_char16_t
*)(buffer
+ 6), len
- 6) + 2;
290 /* Each boot entry must have a descriptor */
295 * If the sum of the length of the description, the claimed filepath
296 * length and the original header are greater than the length of the
297 * variable, it's malformed
299 if ((desclength
+ filepathlength
+ 6) > len
)
303 * And, finally, check the filepath
305 return validate_device_path(var
, match
, buffer
+ desclength
+ 6,
310 validate_uint16(struct efi_variable
*var
, int match
, u8
*buffer
,
313 /* A single 16-bit integer */
321 validate_ascii_string(struct efi_variable
*var
, int match
, u8
*buffer
,
326 for (i
= 0; i
< len
; i
++) {
337 struct variable_validate
{
339 bool (*validate
)(struct efi_variable
*var
, int match
, u8
*data
,
343 static const struct variable_validate variable_validate
[] = {
344 { "BootNext", validate_uint16
},
345 { "BootOrder", validate_boot_order
},
346 { "DriverOrder", validate_boot_order
},
347 { "Boot*", validate_load_option
},
348 { "Driver*", validate_load_option
},
349 { "ConIn", validate_device_path
},
350 { "ConInDev", validate_device_path
},
351 { "ConOut", validate_device_path
},
352 { "ConOutDev", validate_device_path
},
353 { "ErrOut", validate_device_path
},
354 { "ErrOutDev", validate_device_path
},
355 { "Timeout", validate_uint16
},
356 { "Lang", validate_ascii_string
},
357 { "PlatformLang", validate_ascii_string
},
362 validate_var(struct efi_variable
*var
, u8
*data
, unsigned long len
)
365 u16
*unicode_name
= var
->VariableName
;
367 for (i
= 0; variable_validate
[i
].validate
!= NULL
; i
++) {
368 const char *name
= variable_validate
[i
].name
;
371 for (match
= 0; ; match
++) {
372 char c
= name
[match
];
373 u16 u
= unicode_name
[match
];
375 /* All special variables are plain ascii */
379 /* Wildcard in the matching name means we've matched */
381 return variable_validate
[i
].validate(var
,
384 /* Case sensitive match */
388 /* Reached the end of the string while matching */
390 return variable_validate
[i
].validate(var
,
399 get_var_data_locked(struct efivars
*efivars
, struct efi_variable
*var
)
403 var
->DataSize
= 1024;
404 status
= efivars
->ops
->get_variable(var
->VariableName
,
413 get_var_data(struct efivars
*efivars
, struct efi_variable
*var
)
418 spin_lock_irqsave(&efivars
->lock
, flags
);
419 status
= get_var_data_locked(efivars
, var
);
420 spin_unlock_irqrestore(&efivars
->lock
, flags
);
422 if (status
!= EFI_SUCCESS
) {
423 printk(KERN_WARNING
"efivars: get_variable() failed 0x%lx!\n",
430 efivar_guid_read(struct efivar_entry
*entry
, char *buf
)
432 struct efi_variable
*var
= &entry
->var
;
438 efi_guid_unparse(&var
->VendorGuid
, str
);
440 str
+= sprintf(str
, "\n");
446 efivar_attr_read(struct efivar_entry
*entry
, char *buf
)
448 struct efi_variable
*var
= &entry
->var
;
455 status
= get_var_data(entry
->efivars
, var
);
456 if (status
!= EFI_SUCCESS
)
459 if (var
->Attributes
& EFI_VARIABLE_NON_VOLATILE
)
460 str
+= sprintf(str
, "EFI_VARIABLE_NON_VOLATILE\n");
461 if (var
->Attributes
& EFI_VARIABLE_BOOTSERVICE_ACCESS
)
462 str
+= sprintf(str
, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
463 if (var
->Attributes
& EFI_VARIABLE_RUNTIME_ACCESS
)
464 str
+= sprintf(str
, "EFI_VARIABLE_RUNTIME_ACCESS\n");
465 if (var
->Attributes
& EFI_VARIABLE_HARDWARE_ERROR_RECORD
)
466 str
+= sprintf(str
, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
467 if (var
->Attributes
& EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
)
469 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
470 if (var
->Attributes
&
471 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
)
473 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
474 if (var
->Attributes
& EFI_VARIABLE_APPEND_WRITE
)
475 str
+= sprintf(str
, "EFI_VARIABLE_APPEND_WRITE\n");
480 efivar_size_read(struct efivar_entry
*entry
, char *buf
)
482 struct efi_variable
*var
= &entry
->var
;
489 status
= get_var_data(entry
->efivars
, var
);
490 if (status
!= EFI_SUCCESS
)
493 str
+= sprintf(str
, "0x%lx\n", var
->DataSize
);
498 efivar_data_read(struct efivar_entry
*entry
, char *buf
)
500 struct efi_variable
*var
= &entry
->var
;
506 status
= get_var_data(entry
->efivars
, var
);
507 if (status
!= EFI_SUCCESS
)
510 memcpy(buf
, var
->Data
, var
->DataSize
);
511 return var
->DataSize
;
514 * We allow each variable to be edited via rewriting the
515 * entire efi variable structure.
518 efivar_store_raw(struct efivar_entry
*entry
, const char *buf
, size_t count
)
520 struct efi_variable
*new_var
, *var
= &entry
->var
;
521 struct efivars
*efivars
= entry
->efivars
;
522 efi_status_t status
= EFI_NOT_FOUND
;
524 if (count
!= sizeof(struct efi_variable
))
527 new_var
= (struct efi_variable
*)buf
;
529 * If only updating the variable data, then the name
530 * and guid should remain the same
532 if (memcmp(new_var
->VariableName
, var
->VariableName
, sizeof(var
->VariableName
)) ||
533 efi_guidcmp(new_var
->VendorGuid
, var
->VendorGuid
)) {
534 printk(KERN_ERR
"efivars: Cannot edit the wrong variable!\n");
538 if ((new_var
->DataSize
<= 0) || (new_var
->Attributes
== 0)){
539 printk(KERN_ERR
"efivars: DataSize & Attributes must be valid!\n");
543 if ((new_var
->Attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
544 validate_var(new_var
, new_var
->Data
, new_var
->DataSize
) == false) {
545 printk(KERN_ERR
"efivars: Malformed variable content\n");
549 spin_lock_irq(&efivars
->lock
);
550 status
= efivars
->ops
->set_variable(new_var
->VariableName
,
551 &new_var
->VendorGuid
,
556 spin_unlock_irq(&efivars
->lock
);
558 if (status
!= EFI_SUCCESS
) {
559 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
564 memcpy(&entry
->var
, new_var
, count
);
569 efivar_show_raw(struct efivar_entry
*entry
, char *buf
)
571 struct efi_variable
*var
= &entry
->var
;
577 status
= get_var_data(entry
->efivars
, var
);
578 if (status
!= EFI_SUCCESS
)
581 memcpy(buf
, var
, sizeof(*var
));
586 * Generic read/write functions that call the specific functions of
589 static ssize_t
efivar_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
592 struct efivar_entry
*var
= to_efivar_entry(kobj
);
593 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
596 if (!capable(CAP_SYS_ADMIN
))
599 if (efivar_attr
->show
) {
600 ret
= efivar_attr
->show(var
, buf
);
605 static ssize_t
efivar_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
606 const char *buf
, size_t count
)
608 struct efivar_entry
*var
= to_efivar_entry(kobj
);
609 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
612 if (!capable(CAP_SYS_ADMIN
))
615 if (efivar_attr
->store
)
616 ret
= efivar_attr
->store(var
, buf
, count
);
621 static const struct sysfs_ops efivar_attr_ops
= {
622 .show
= efivar_attr_show
,
623 .store
= efivar_attr_store
,
626 static void efivar_release(struct kobject
*kobj
)
628 struct efivar_entry
*var
= container_of(kobj
, struct efivar_entry
, kobj
);
632 static EFIVAR_ATTR(guid
, 0400, efivar_guid_read
, NULL
);
633 static EFIVAR_ATTR(attributes
, 0400, efivar_attr_read
, NULL
);
634 static EFIVAR_ATTR(size
, 0400, efivar_size_read
, NULL
);
635 static EFIVAR_ATTR(data
, 0400, efivar_data_read
, NULL
);
636 static EFIVAR_ATTR(raw_var
, 0600, efivar_show_raw
, efivar_store_raw
);
638 static struct attribute
*def_attrs
[] = {
639 &efivar_attr_guid
.attr
,
640 &efivar_attr_size
.attr
,
641 &efivar_attr_attributes
.attr
,
642 &efivar_attr_data
.attr
,
643 &efivar_attr_raw_var
.attr
,
647 static struct kobj_type efivar_ktype
= {
648 .release
= efivar_release
,
649 .sysfs_ops
= &efivar_attr_ops
,
650 .default_attrs
= def_attrs
,
654 efivar_unregister(struct efivar_entry
*var
)
656 kobject_put(&var
->kobj
);
659 static int efivarfs_file_open(struct inode
*inode
, struct file
*file
)
661 file
->private_data
= inode
->i_private
;
665 static int efi_status_to_err(efi_status_t status
)
670 case EFI_INVALID_PARAMETER
:
673 case EFI_OUT_OF_RESOURCES
:
676 case EFI_DEVICE_ERROR
:
679 case EFI_WRITE_PROTECTED
:
682 case EFI_SECURITY_VIOLATION
:
695 static ssize_t
efivarfs_file_write(struct file
*file
,
696 const char __user
*userbuf
, size_t count
, loff_t
*ppos
)
698 struct efivar_entry
*var
= file
->private_data
;
699 struct efivars
*efivars
;
703 struct inode
*inode
= file
->f_mapping
->host
;
704 unsigned long datasize
= count
- sizeof(attributes
);
705 unsigned long newdatasize
;
706 u64 storage_size
, remaining_size
, max_size
;
709 if (count
< sizeof(attributes
))
712 if (copy_from_user(&attributes
, userbuf
, sizeof(attributes
)))
715 if (attributes
& ~(EFI_VARIABLE_MASK
))
718 efivars
= var
->efivars
;
721 * Ensure that the user can't allocate arbitrarily large
722 * amounts of memory. Pick a default size of 64K if
723 * QueryVariableInfo() isn't supported by the firmware.
725 spin_lock_irq(&efivars
->lock
);
727 if (!efivars
->ops
->query_variable_info
)
728 status
= EFI_UNSUPPORTED
;
730 const struct efivar_operations
*fops
= efivars
->ops
;
731 status
= fops
->query_variable_info(attributes
, &storage_size
,
732 &remaining_size
, &max_size
);
735 spin_unlock_irq(&efivars
->lock
);
737 if (status
!= EFI_SUCCESS
) {
738 if (status
!= EFI_UNSUPPORTED
)
739 return efi_status_to_err(status
);
741 remaining_size
= 65536;
744 if (datasize
> remaining_size
)
747 data
= kmalloc(datasize
, GFP_KERNEL
);
751 if (copy_from_user(data
, userbuf
+ sizeof(attributes
), datasize
)) {
756 if (validate_var(&var
->var
, data
, datasize
) == false) {
762 * The lock here protects the get_variable call, the conditional
763 * set_variable call, and removal of the variable from the efivars
764 * list (in the case of an authenticated delete).
766 spin_lock_irq(&efivars
->lock
);
768 status
= efivars
->ops
->set_variable(var
->var
.VariableName
,
769 &var
->var
.VendorGuid
,
770 attributes
, datasize
,
773 if (status
!= EFI_SUCCESS
) {
774 spin_unlock_irq(&efivars
->lock
);
777 return efi_status_to_err(status
);
783 * Writing to the variable may have caused a change in size (which
784 * could either be an append or an overwrite), or the variable to be
785 * deleted. Perform a GetVariable() so we can tell what actually
789 status
= efivars
->ops
->get_variable(var
->var
.VariableName
,
790 &var
->var
.VendorGuid
,
794 if (status
== EFI_BUFFER_TOO_SMALL
) {
795 spin_unlock_irq(&efivars
->lock
);
796 mutex_lock(&inode
->i_mutex
);
797 i_size_write(inode
, newdatasize
+ sizeof(attributes
));
798 mutex_unlock(&inode
->i_mutex
);
800 } else if (status
== EFI_NOT_FOUND
) {
801 list_del(&var
->list
);
802 spin_unlock_irq(&efivars
->lock
);
803 efivar_unregister(var
);
805 d_delete(file
->f_dentry
);
806 dput(file
->f_dentry
);
809 spin_unlock_irq(&efivars
->lock
);
810 pr_warn("efivarfs: inconsistent EFI variable implementation? "
811 "status = %lx\n", status
);
820 static ssize_t
efivarfs_file_read(struct file
*file
, char __user
*userbuf
,
821 size_t count
, loff_t
*ppos
)
823 struct efivar_entry
*var
= file
->private_data
;
824 struct efivars
*efivars
= var
->efivars
;
826 unsigned long datasize
= 0;
831 spin_lock_irq(&efivars
->lock
);
832 status
= efivars
->ops
->get_variable(var
->var
.VariableName
,
833 &var
->var
.VendorGuid
,
834 &attributes
, &datasize
, NULL
);
835 spin_unlock_irq(&efivars
->lock
);
837 if (status
!= EFI_BUFFER_TOO_SMALL
)
838 return efi_status_to_err(status
);
840 data
= kmalloc(datasize
+ sizeof(attributes
), GFP_KERNEL
);
845 spin_lock_irq(&efivars
->lock
);
846 status
= efivars
->ops
->get_variable(var
->var
.VariableName
,
847 &var
->var
.VendorGuid
,
848 &attributes
, &datasize
,
849 (data
+ sizeof(attributes
)));
850 spin_unlock_irq(&efivars
->lock
);
852 if (status
!= EFI_SUCCESS
) {
853 size
= efi_status_to_err(status
);
857 memcpy(data
, &attributes
, sizeof(attributes
));
858 size
= simple_read_from_buffer(userbuf
, count
, ppos
,
859 data
, datasize
+ sizeof(attributes
));
866 static void efivarfs_evict_inode(struct inode
*inode
)
871 static const struct super_operations efivarfs_ops
= {
872 .statfs
= simple_statfs
,
873 .drop_inode
= generic_delete_inode
,
874 .evict_inode
= efivarfs_evict_inode
,
875 .show_options
= generic_show_options
,
878 static struct super_block
*efivarfs_sb
;
880 static const struct inode_operations efivarfs_dir_inode_operations
;
882 static const struct file_operations efivarfs_file_operations
= {
883 .open
= efivarfs_file_open
,
884 .read
= efivarfs_file_read
,
885 .write
= efivarfs_file_write
,
889 static struct inode
*efivarfs_get_inode(struct super_block
*sb
,
890 const struct inode
*dir
, int mode
, dev_t dev
)
892 struct inode
*inode
= new_inode(sb
);
895 inode
->i_ino
= get_next_ino();
896 inode
->i_mode
= mode
;
897 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
898 switch (mode
& S_IFMT
) {
900 inode
->i_fop
= &efivarfs_file_operations
;
903 inode
->i_op
= &efivarfs_dir_inode_operations
;
904 inode
->i_fop
= &simple_dir_operations
;
913 * Return true if 'str' is a valid efivarfs filename of the form,
915 * VariableName-12345678-1234-1234-1234-1234567891bc
917 static bool efivarfs_valid_name(const char *str
, int len
)
919 static const char dashes
[GUID_LEN
] = {
920 [8] = 1, [13] = 1, [18] = 1, [23] = 1
922 const char *s
= str
+ len
- GUID_LEN
;
926 * We need a GUID, plus at least one letter for the variable name,
927 * plus the '-' separator
929 if (len
< GUID_LEN
+ 2)
932 /* GUID should be right after the first '-' */
933 if (s
- 1 != strchr(str
, '-'))
937 * Validate that 's' is of the correct format, e.g.
939 * 12345678-1234-1234-1234-123456789abc
941 for (i
= 0; i
< GUID_LEN
; i
++) {
954 static void efivarfs_hex_to_guid(const char *str
, efi_guid_t
*guid
)
956 guid
->b
[0] = hex_to_bin(str
[6]) << 4 | hex_to_bin(str
[7]);
957 guid
->b
[1] = hex_to_bin(str
[4]) << 4 | hex_to_bin(str
[5]);
958 guid
->b
[2] = hex_to_bin(str
[2]) << 4 | hex_to_bin(str
[3]);
959 guid
->b
[3] = hex_to_bin(str
[0]) << 4 | hex_to_bin(str
[1]);
960 guid
->b
[4] = hex_to_bin(str
[11]) << 4 | hex_to_bin(str
[12]);
961 guid
->b
[5] = hex_to_bin(str
[9]) << 4 | hex_to_bin(str
[10]);
962 guid
->b
[6] = hex_to_bin(str
[16]) << 4 | hex_to_bin(str
[17]);
963 guid
->b
[7] = hex_to_bin(str
[14]) << 4 | hex_to_bin(str
[15]);
964 guid
->b
[8] = hex_to_bin(str
[19]) << 4 | hex_to_bin(str
[20]);
965 guid
->b
[9] = hex_to_bin(str
[21]) << 4 | hex_to_bin(str
[22]);
966 guid
->b
[10] = hex_to_bin(str
[24]) << 4 | hex_to_bin(str
[25]);
967 guid
->b
[11] = hex_to_bin(str
[26]) << 4 | hex_to_bin(str
[27]);
968 guid
->b
[12] = hex_to_bin(str
[28]) << 4 | hex_to_bin(str
[29]);
969 guid
->b
[13] = hex_to_bin(str
[30]) << 4 | hex_to_bin(str
[31]);
970 guid
->b
[14] = hex_to_bin(str
[32]) << 4 | hex_to_bin(str
[33]);
971 guid
->b
[15] = hex_to_bin(str
[34]) << 4 | hex_to_bin(str
[35]);
974 static int efivarfs_create(struct inode
*dir
, struct dentry
*dentry
,
975 umode_t mode
, bool excl
)
978 struct efivars
*efivars
= &__efivars
;
979 struct efivar_entry
*var
;
980 int namelen
, i
= 0, err
= 0;
982 if (!efivarfs_valid_name(dentry
->d_name
.name
, dentry
->d_name
.len
))
985 inode
= efivarfs_get_inode(dir
->i_sb
, dir
, mode
, 0);
989 var
= kzalloc(sizeof(struct efivar_entry
), GFP_KERNEL
);
995 /* length of the variable name itself: remove GUID and separator */
996 namelen
= dentry
->d_name
.len
- GUID_LEN
- 1;
998 efivarfs_hex_to_guid(dentry
->d_name
.name
+ namelen
+ 1,
999 &var
->var
.VendorGuid
);
1001 for (i
= 0; i
< namelen
; i
++)
1002 var
->var
.VariableName
[i
] = dentry
->d_name
.name
[i
];
1004 var
->var
.VariableName
[i
] = '\0';
1006 inode
->i_private
= var
;
1007 var
->efivars
= efivars
;
1008 var
->kobj
.kset
= efivars
->kset
;
1010 err
= kobject_init_and_add(&var
->kobj
, &efivar_ktype
, NULL
, "%s",
1011 dentry
->d_name
.name
);
1015 kobject_uevent(&var
->kobj
, KOBJ_ADD
);
1016 spin_lock_irq(&efivars
->lock
);
1017 list_add(&var
->list
, &efivars
->list
);
1018 spin_unlock_irq(&efivars
->lock
);
1019 d_instantiate(dentry
, inode
);
1029 static int efivarfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
1031 struct efivar_entry
*var
= dentry
->d_inode
->i_private
;
1032 struct efivars
*efivars
= var
->efivars
;
1033 efi_status_t status
;
1035 spin_lock_irq(&efivars
->lock
);
1037 status
= efivars
->ops
->set_variable(var
->var
.VariableName
,
1038 &var
->var
.VendorGuid
,
1041 if (status
== EFI_SUCCESS
|| status
== EFI_NOT_FOUND
) {
1042 list_del(&var
->list
);
1043 spin_unlock_irq(&efivars
->lock
);
1044 efivar_unregister(var
);
1045 drop_nlink(dentry
->d_inode
);
1050 spin_unlock_irq(&efivars
->lock
);
1055 * Compare two efivarfs file names.
1057 * An efivarfs filename is composed of two parts,
1059 * 1. A case-sensitive variable name
1060 * 2. A case-insensitive GUID
1062 * So we need to perform a case-sensitive match on part 1 and a
1063 * case-insensitive match on part 2.
1065 static int efivarfs_d_compare(const struct dentry
*parent
, const struct inode
*pinode
,
1066 const struct dentry
*dentry
, const struct inode
*inode
,
1067 unsigned int len
, const char *str
,
1068 const struct qstr
*name
)
1070 int guid
= len
- GUID_LEN
;
1072 if (name
->len
!= len
)
1075 /* Case-sensitive compare for the variable name */
1076 if (memcmp(str
, name
->name
, guid
))
1079 /* Case-insensitive compare for the GUID */
1080 return strncasecmp(name
->name
+ guid
, str
+ guid
, GUID_LEN
);
1083 static int efivarfs_d_hash(const struct dentry
*dentry
,
1084 const struct inode
*inode
, struct qstr
*qstr
)
1086 unsigned long hash
= init_name_hash();
1087 const unsigned char *s
= qstr
->name
;
1088 unsigned int len
= qstr
->len
;
1090 if (!efivarfs_valid_name(s
, len
))
1093 while (len
-- > GUID_LEN
)
1094 hash
= partial_name_hash(*s
++, hash
);
1096 /* GUID is case-insensitive. */
1098 hash
= partial_name_hash(tolower(*s
++), hash
);
1100 qstr
->hash
= end_name_hash(hash
);
1105 * Retaining negative dentries for an in-memory filesystem just wastes
1106 * memory and lookup time: arrange for them to be deleted immediately.
1108 static int efivarfs_delete_dentry(const struct dentry
*dentry
)
1113 static struct dentry_operations efivarfs_d_ops
= {
1114 .d_compare
= efivarfs_d_compare
,
1115 .d_hash
= efivarfs_d_hash
,
1116 .d_delete
= efivarfs_delete_dentry
,
1119 static struct dentry
*efivarfs_alloc_dentry(struct dentry
*parent
, char *name
)
1124 q
.len
= strlen(name
);
1126 if (efivarfs_d_hash(NULL
, NULL
, &q
))
1129 return d_alloc(parent
, &q
);
1132 static int efivarfs_fill_super(struct super_block
*sb
, void *data
, int silent
)
1134 struct inode
*inode
= NULL
;
1135 struct dentry
*root
;
1136 struct efivar_entry
*entry
, *n
;
1137 struct efivars
*efivars
= &__efivars
;
1142 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
1143 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
1144 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
1145 sb
->s_magic
= EFIVARFS_MAGIC
;
1146 sb
->s_op
= &efivarfs_ops
;
1147 sb
->s_d_op
= &efivarfs_d_ops
;
1148 sb
->s_time_gran
= 1;
1150 inode
= efivarfs_get_inode(sb
, NULL
, S_IFDIR
| 0755, 0);
1153 inode
->i_op
= &efivarfs_dir_inode_operations
;
1155 root
= d_make_root(inode
);
1160 list_for_each_entry_safe(entry
, n
, &efivars
->list
, list
) {
1161 struct dentry
*dentry
, *root
= efivarfs_sb
->s_root
;
1162 unsigned long size
= 0;
1167 len
= utf16_strlen(entry
->var
.VariableName
);
1169 /* name, plus '-', plus GUID, plus NUL*/
1170 name
= kmalloc(len
+ 1 + GUID_LEN
+ 1, GFP_ATOMIC
);
1174 for (i
= 0; i
< len
; i
++)
1175 name
[i
] = entry
->var
.VariableName
[i
] & 0xFF;
1179 efi_guid_unparse(&entry
->var
.VendorGuid
, name
+ len
+ 1);
1181 name
[len
+GUID_LEN
+1] = '\0';
1183 inode
= efivarfs_get_inode(efivarfs_sb
, root
->d_inode
,
1188 dentry
= efivarfs_alloc_dentry(root
, name
);
1192 /* copied by the above to local storage in the dentry. */
1195 spin_lock_irq(&efivars
->lock
);
1196 efivars
->ops
->get_variable(entry
->var
.VariableName
,
1197 &entry
->var
.VendorGuid
,
1198 &entry
->var
.Attributes
,
1201 spin_unlock_irq(&efivars
->lock
);
1203 mutex_lock(&inode
->i_mutex
);
1204 inode
->i_private
= entry
;
1205 i_size_write(inode
, size
+ sizeof(entry
->var
.Attributes
));
1206 mutex_unlock(&inode
->i_mutex
);
1207 d_add(dentry
, inode
);
1220 static struct dentry
*efivarfs_mount(struct file_system_type
*fs_type
,
1221 int flags
, const char *dev_name
, void *data
)
1223 return mount_single(fs_type
, flags
, data
, efivarfs_fill_super
);
1226 static void efivarfs_kill_sb(struct super_block
*sb
)
1228 kill_litter_super(sb
);
1232 static struct file_system_type efivarfs_type
= {
1234 .mount
= efivarfs_mount
,
1235 .kill_sb
= efivarfs_kill_sb
,
1239 * Handle negative dentry.
1241 static struct dentry
*efivarfs_lookup(struct inode
*dir
, struct dentry
*dentry
,
1244 if (dentry
->d_name
.len
> NAME_MAX
)
1245 return ERR_PTR(-ENAMETOOLONG
);
1246 d_add(dentry
, NULL
);
1250 static const struct inode_operations efivarfs_dir_inode_operations
= {
1251 .lookup
= efivarfs_lookup
,
1252 .unlink
= efivarfs_unlink
,
1253 .create
= efivarfs_create
,
1256 static struct pstore_info efi_pstore_info
;
1258 #ifdef CONFIG_PSTORE
1260 static int efi_pstore_open(struct pstore_info
*psi
)
1262 struct efivars
*efivars
= psi
->data
;
1264 spin_lock_irq(&efivars
->lock
);
1265 efivars
->walk_entry
= list_first_entry(&efivars
->list
,
1266 struct efivar_entry
, list
);
1270 static int efi_pstore_close(struct pstore_info
*psi
)
1272 struct efivars
*efivars
= psi
->data
;
1274 spin_unlock_irq(&efivars
->lock
);
1278 static ssize_t
efi_pstore_read(u64
*id
, enum pstore_type_id
*type
,
1279 int *count
, struct timespec
*timespec
,
1280 char **buf
, struct pstore_info
*psi
)
1282 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
1283 struct efivars
*efivars
= psi
->data
;
1284 char name
[DUMP_NAME_LEN
];
1287 unsigned int part
, size
;
1290 while (&efivars
->walk_entry
->list
!= &efivars
->list
) {
1291 if (!efi_guidcmp(efivars
->walk_entry
->var
.VendorGuid
,
1293 for (i
= 0; i
< DUMP_NAME_LEN
; i
++) {
1294 name
[i
] = efivars
->walk_entry
->var
.VariableName
[i
];
1296 if (sscanf(name
, "dump-type%u-%u-%d-%lu",
1297 type
, &part
, &cnt
, &time
) == 4) {
1300 timespec
->tv_sec
= time
;
1301 timespec
->tv_nsec
= 0;
1302 } else if (sscanf(name
, "dump-type%u-%u-%lu",
1303 type
, &part
, &time
) == 3) {
1305 * Check if an old format,
1306 * which doesn't support holding
1307 * multiple logs, remains.
1311 timespec
->tv_sec
= time
;
1312 timespec
->tv_nsec
= 0;
1314 efivars
->walk_entry
= list_entry(
1315 efivars
->walk_entry
->list
.next
,
1316 struct efivar_entry
, list
);
1320 get_var_data_locked(efivars
, &efivars
->walk_entry
->var
);
1321 size
= efivars
->walk_entry
->var
.DataSize
;
1322 *buf
= kmalloc(size
, GFP_KERNEL
);
1325 memcpy(*buf
, efivars
->walk_entry
->var
.Data
,
1327 efivars
->walk_entry
= list_entry(
1328 efivars
->walk_entry
->list
.next
,
1329 struct efivar_entry
, list
);
1332 efivars
->walk_entry
= list_entry(efivars
->walk_entry
->list
.next
,
1333 struct efivar_entry
, list
);
1338 static int efi_pstore_write(enum pstore_type_id type
,
1339 enum kmsg_dump_reason reason
, u64
*id
,
1340 unsigned int part
, int count
, size_t size
,
1341 struct pstore_info
*psi
)
1343 char name
[DUMP_NAME_LEN
];
1344 efi_char16_t efi_name
[DUMP_NAME_LEN
];
1345 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
1346 struct efivars
*efivars
= psi
->data
;
1348 u64 storage_space
, remaining_space
, max_variable_size
;
1349 efi_status_t status
= EFI_NOT_FOUND
;
1350 unsigned long flags
;
1352 if (pstore_cannot_block_path(reason
)) {
1354 * If the lock is taken by another cpu in non-blocking path,
1355 * this driver returns without entering firmware to avoid
1358 if (!spin_trylock_irqsave(&efivars
->lock
, flags
))
1361 spin_lock_irqsave(&efivars
->lock
, flags
);
1364 * Check if there is a space enough to log.
1365 * size: a size of logging data
1366 * DUMP_NAME_LEN * 2: a maximum size of variable name
1368 status
= efivars
->ops
->query_variable_info(PSTORE_EFI_ATTRIBUTES
,
1371 &max_variable_size
);
1372 if (status
|| remaining_space
< size
+ DUMP_NAME_LEN
* 2) {
1373 spin_unlock_irqrestore(&efivars
->lock
, flags
);
1378 sprintf(name
, "dump-type%u-%u-%d-%lu", type
, part
, count
,
1381 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
1382 efi_name
[i
] = name
[i
];
1384 efivars
->ops
->set_variable(efi_name
, &vendor
, PSTORE_EFI_ATTRIBUTES
,
1387 spin_unlock_irqrestore(&efivars
->lock
, flags
);
1389 if (reason
== KMSG_DUMP_OOPS
)
1390 schedule_work(&efivar_work
);
1396 static int efi_pstore_erase(enum pstore_type_id type
, u64 id
, int count
,
1397 struct timespec time
, struct pstore_info
*psi
)
1399 char name
[DUMP_NAME_LEN
];
1400 efi_char16_t efi_name
[DUMP_NAME_LEN
];
1401 char name_old
[DUMP_NAME_LEN
];
1402 efi_char16_t efi_name_old
[DUMP_NAME_LEN
];
1403 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
1404 struct efivars
*efivars
= psi
->data
;
1405 struct efivar_entry
*entry
, *found
= NULL
;
1408 sprintf(name
, "dump-type%u-%u-%d-%lu", type
, (unsigned int)id
, count
,
1411 spin_lock_irq(&efivars
->lock
);
1413 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
1414 efi_name
[i
] = name
[i
];
1417 * Clean up an entry with the same name
1420 list_for_each_entry(entry
, &efivars
->list
, list
) {
1421 get_var_data_locked(efivars
, &entry
->var
);
1423 if (efi_guidcmp(entry
->var
.VendorGuid
, vendor
))
1425 if (utf16_strncmp(entry
->var
.VariableName
, efi_name
,
1426 utf16_strlen(efi_name
))) {
1428 * Check if an old format,
1429 * which doesn't support holding
1430 * multiple logs, remains.
1432 sprintf(name_old
, "dump-type%u-%u-%lu", type
,
1433 (unsigned int)id
, time
.tv_sec
);
1435 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
1436 efi_name_old
[i
] = name_old
[i
];
1438 if (utf16_strncmp(entry
->var
.VariableName
, efi_name_old
,
1439 utf16_strlen(efi_name_old
)))
1445 efivars
->ops
->set_variable(entry
->var
.VariableName
,
1446 &entry
->var
.VendorGuid
,
1447 PSTORE_EFI_ATTRIBUTES
,
1453 list_del(&found
->list
);
1455 spin_unlock_irq(&efivars
->lock
);
1458 efivar_unregister(found
);
1463 static int efi_pstore_open(struct pstore_info
*psi
)
1468 static int efi_pstore_close(struct pstore_info
*psi
)
1473 static ssize_t
efi_pstore_read(u64
*id
, enum pstore_type_id
*type
, int *count
,
1474 struct timespec
*timespec
,
1475 char **buf
, struct pstore_info
*psi
)
1480 static int efi_pstore_write(enum pstore_type_id type
,
1481 enum kmsg_dump_reason reason
, u64
*id
,
1482 unsigned int part
, int count
, size_t size
,
1483 struct pstore_info
*psi
)
1488 static int efi_pstore_erase(enum pstore_type_id type
, u64 id
, int count
,
1489 struct timespec time
, struct pstore_info
*psi
)
1495 static struct pstore_info efi_pstore_info
= {
1496 .owner
= THIS_MODULE
,
1498 .open
= efi_pstore_open
,
1499 .close
= efi_pstore_close
,
1500 .read
= efi_pstore_read
,
1501 .write
= efi_pstore_write
,
1502 .erase
= efi_pstore_erase
,
1505 static ssize_t
efivar_create(struct file
*filp
, struct kobject
*kobj
,
1506 struct bin_attribute
*bin_attr
,
1507 char *buf
, loff_t pos
, size_t count
)
1509 struct efi_variable
*new_var
= (struct efi_variable
*)buf
;
1510 struct efivars
*efivars
= bin_attr
->private;
1511 struct efivar_entry
*search_efivar
, *n
;
1512 unsigned long strsize1
, strsize2
;
1513 efi_status_t status
= EFI_NOT_FOUND
;
1516 if (!capable(CAP_SYS_ADMIN
))
1519 if ((new_var
->Attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
1520 validate_var(new_var
, new_var
->Data
, new_var
->DataSize
) == false) {
1521 printk(KERN_ERR
"efivars: Malformed variable content\n");
1525 spin_lock_irq(&efivars
->lock
);
1528 * Does this variable already exist?
1530 list_for_each_entry_safe(search_efivar
, n
, &efivars
->list
, list
) {
1531 strsize1
= utf16_strsize(search_efivar
->var
.VariableName
, 1024);
1532 strsize2
= utf16_strsize(new_var
->VariableName
, 1024);
1533 if (strsize1
== strsize2
&&
1534 !memcmp(&(search_efivar
->var
.VariableName
),
1535 new_var
->VariableName
, strsize1
) &&
1536 !efi_guidcmp(search_efivar
->var
.VendorGuid
,
1537 new_var
->VendorGuid
)) {
1543 spin_unlock_irq(&efivars
->lock
);
1547 /* now *really* create the variable via EFI */
1548 status
= efivars
->ops
->set_variable(new_var
->VariableName
,
1549 &new_var
->VendorGuid
,
1550 new_var
->Attributes
,
1554 if (status
!= EFI_SUCCESS
) {
1555 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
1557 spin_unlock_irq(&efivars
->lock
);
1560 spin_unlock_irq(&efivars
->lock
);
1562 /* Create the entry in sysfs. Locking is not required here */
1563 status
= efivar_create_sysfs_entry(efivars
,
1564 utf16_strsize(new_var
->VariableName
,
1566 new_var
->VariableName
,
1567 &new_var
->VendorGuid
);
1569 printk(KERN_WARNING
"efivars: variable created, but sysfs entry wasn't.\n");
1574 static ssize_t
efivar_delete(struct file
*filp
, struct kobject
*kobj
,
1575 struct bin_attribute
*bin_attr
,
1576 char *buf
, loff_t pos
, size_t count
)
1578 struct efi_variable
*del_var
= (struct efi_variable
*)buf
;
1579 struct efivars
*efivars
= bin_attr
->private;
1580 struct efivar_entry
*search_efivar
, *n
;
1581 unsigned long strsize1
, strsize2
;
1582 efi_status_t status
= EFI_NOT_FOUND
;
1585 if (!capable(CAP_SYS_ADMIN
))
1588 spin_lock_irq(&efivars
->lock
);
1591 * Does this variable already exist?
1593 list_for_each_entry_safe(search_efivar
, n
, &efivars
->list
, list
) {
1594 strsize1
= utf16_strsize(search_efivar
->var
.VariableName
, 1024);
1595 strsize2
= utf16_strsize(del_var
->VariableName
, 1024);
1596 if (strsize1
== strsize2
&&
1597 !memcmp(&(search_efivar
->var
.VariableName
),
1598 del_var
->VariableName
, strsize1
) &&
1599 !efi_guidcmp(search_efivar
->var
.VendorGuid
,
1600 del_var
->VendorGuid
)) {
1606 spin_unlock_irq(&efivars
->lock
);
1609 /* force the Attributes/DataSize to 0 to ensure deletion */
1610 del_var
->Attributes
= 0;
1611 del_var
->DataSize
= 0;
1613 status
= efivars
->ops
->set_variable(del_var
->VariableName
,
1614 &del_var
->VendorGuid
,
1615 del_var
->Attributes
,
1619 if (status
!= EFI_SUCCESS
) {
1620 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
1622 spin_unlock_irq(&efivars
->lock
);
1625 list_del(&search_efivar
->list
);
1626 /* We need to release this lock before unregistering. */
1627 spin_unlock_irq(&efivars
->lock
);
1628 efivar_unregister(search_efivar
);
1630 /* It's dead Jim.... */
1634 static bool variable_is_present(efi_char16_t
*variable_name
, efi_guid_t
*vendor
)
1636 struct efivar_entry
*entry
, *n
;
1637 struct efivars
*efivars
= &__efivars
;
1638 unsigned long strsize1
, strsize2
;
1641 strsize1
= utf16_strsize(variable_name
, 1024);
1642 list_for_each_entry_safe(entry
, n
, &efivars
->list
, list
) {
1643 strsize2
= utf16_strsize(entry
->var
.VariableName
, 1024);
1644 if (strsize1
== strsize2
&&
1645 !memcmp(variable_name
, &(entry
->var
.VariableName
),
1647 !efi_guidcmp(entry
->var
.VendorGuid
,
1656 static void efivar_update_sysfs_entries(struct work_struct
*work
)
1658 struct efivars
*efivars
= &__efivars
;
1660 efi_char16_t
*variable_name
;
1661 unsigned long variable_name_size
= 1024;
1662 efi_status_t status
= EFI_NOT_FOUND
;
1665 /* Add new sysfs entries */
1667 variable_name
= kzalloc(variable_name_size
, GFP_KERNEL
);
1668 if (!variable_name
) {
1669 pr_err("efivars: Memory allocation failed.\n");
1673 spin_lock_irq(&efivars
->lock
);
1676 variable_name_size
= 1024;
1677 status
= efivars
->ops
->get_next_variable(
1678 &variable_name_size
,
1681 if (status
!= EFI_SUCCESS
) {
1684 if (!variable_is_present(variable_name
,
1691 spin_unlock_irq(&efivars
->lock
);
1694 kfree(variable_name
);
1697 efivar_create_sysfs_entry(efivars
,
1699 variable_name
, &vendor
);
1704 * Let's not leave out systab information that snuck into
1705 * the efivars driver
1707 static ssize_t
systab_show(struct kobject
*kobj
,
1708 struct kobj_attribute
*attr
, char *buf
)
1715 if (efi
.mps
!= EFI_INVALID_TABLE_ADDR
)
1716 str
+= sprintf(str
, "MPS=0x%lx\n", efi
.mps
);
1717 if (efi
.acpi20
!= EFI_INVALID_TABLE_ADDR
)
1718 str
+= sprintf(str
, "ACPI20=0x%lx\n", efi
.acpi20
);
1719 if (efi
.acpi
!= EFI_INVALID_TABLE_ADDR
)
1720 str
+= sprintf(str
, "ACPI=0x%lx\n", efi
.acpi
);
1721 if (efi
.smbios
!= EFI_INVALID_TABLE_ADDR
)
1722 str
+= sprintf(str
, "SMBIOS=0x%lx\n", efi
.smbios
);
1723 if (efi
.hcdp
!= EFI_INVALID_TABLE_ADDR
)
1724 str
+= sprintf(str
, "HCDP=0x%lx\n", efi
.hcdp
);
1725 if (efi
.boot_info
!= EFI_INVALID_TABLE_ADDR
)
1726 str
+= sprintf(str
, "BOOTINFO=0x%lx\n", efi
.boot_info
);
1727 if (efi
.uga
!= EFI_INVALID_TABLE_ADDR
)
1728 str
+= sprintf(str
, "UGA=0x%lx\n", efi
.uga
);
1733 static struct kobj_attribute efi_attr_systab
=
1734 __ATTR(systab
, 0400, systab_show
, NULL
);
1736 static struct attribute
*efi_subsys_attrs
[] = {
1737 &efi_attr_systab
.attr
,
1738 NULL
, /* maybe more in the future? */
1741 static struct attribute_group efi_subsys_attr_group
= {
1742 .attrs
= efi_subsys_attrs
,
1745 static struct kobject
*efi_kobj
;
1748 * efivar_create_sysfs_entry()
1750 * variable_name_size = number of bytes required to hold
1751 * variable_name (not counting the NULL
1752 * character at the end.
1753 * efivars->lock is not held on entry or exit.
1754 * Returns 1 on failure, 0 on success
1757 efivar_create_sysfs_entry(struct efivars
*efivars
,
1758 unsigned long variable_name_size
,
1759 efi_char16_t
*variable_name
,
1760 efi_guid_t
*vendor_guid
)
1762 int i
, short_name_size
;
1764 struct efivar_entry
*new_efivar
;
1767 * Length of the variable bytes in ASCII, plus the '-' separator,
1768 * plus the GUID, plus trailing NUL
1770 short_name_size
= variable_name_size
/ sizeof(efi_char16_t
)
1773 short_name
= kzalloc(short_name_size
, GFP_KERNEL
);
1774 new_efivar
= kzalloc(sizeof(struct efivar_entry
), GFP_KERNEL
);
1776 if (!short_name
|| !new_efivar
) {
1782 new_efivar
->efivars
= efivars
;
1783 memcpy(new_efivar
->var
.VariableName
, variable_name
,
1784 variable_name_size
);
1785 memcpy(&(new_efivar
->var
.VendorGuid
), vendor_guid
, sizeof(efi_guid_t
));
1787 /* Convert Unicode to normal chars (assume top bits are 0),
1789 for (i
=0; i
< (int)(variable_name_size
/ sizeof(efi_char16_t
)); i
++) {
1790 short_name
[i
] = variable_name
[i
] & 0xFF;
1792 /* This is ugly, but necessary to separate one vendor's
1793 private variables from another's. */
1795 *(short_name
+ strlen(short_name
)) = '-';
1796 efi_guid_unparse(vendor_guid
, short_name
+ strlen(short_name
));
1798 new_efivar
->kobj
.kset
= efivars
->kset
;
1799 i
= kobject_init_and_add(&new_efivar
->kobj
, &efivar_ktype
, NULL
,
1807 kobject_uevent(&new_efivar
->kobj
, KOBJ_ADD
);
1811 spin_lock_irq(&efivars
->lock
);
1812 list_add(&new_efivar
->list
, &efivars
->list
);
1813 spin_unlock_irq(&efivars
->lock
);
1819 create_efivars_bin_attributes(struct efivars
*efivars
)
1821 struct bin_attribute
*attr
;
1825 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
1829 attr
->attr
.name
= "new_var";
1830 attr
->attr
.mode
= 0200;
1831 attr
->write
= efivar_create
;
1832 attr
->private = efivars
;
1833 efivars
->new_var
= attr
;
1836 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
1841 attr
->attr
.name
= "del_var";
1842 attr
->attr
.mode
= 0200;
1843 attr
->write
= efivar_delete
;
1844 attr
->private = efivars
;
1845 efivars
->del_var
= attr
;
1847 sysfs_bin_attr_init(efivars
->new_var
);
1848 sysfs_bin_attr_init(efivars
->del_var
);
1851 error
= sysfs_create_bin_file(&efivars
->kset
->kobj
,
1854 printk(KERN_ERR
"efivars: unable to create new_var sysfs file"
1855 " due to error %d\n", error
);
1858 error
= sysfs_create_bin_file(&efivars
->kset
->kobj
,
1861 printk(KERN_ERR
"efivars: unable to create del_var sysfs file"
1862 " due to error %d\n", error
);
1863 sysfs_remove_bin_file(&efivars
->kset
->kobj
,
1870 kfree(efivars
->del_var
);
1871 efivars
->del_var
= NULL
;
1872 kfree(efivars
->new_var
);
1873 efivars
->new_var
= NULL
;
1877 void unregister_efivars(struct efivars
*efivars
)
1879 struct efivar_entry
*entry
, *n
;
1881 list_for_each_entry_safe(entry
, n
, &efivars
->list
, list
) {
1882 spin_lock_irq(&efivars
->lock
);
1883 list_del(&entry
->list
);
1884 spin_unlock_irq(&efivars
->lock
);
1885 efivar_unregister(entry
);
1887 if (efivars
->new_var
)
1888 sysfs_remove_bin_file(&efivars
->kset
->kobj
, efivars
->new_var
);
1889 if (efivars
->del_var
)
1890 sysfs_remove_bin_file(&efivars
->kset
->kobj
, efivars
->del_var
);
1891 kfree(efivars
->new_var
);
1892 kfree(efivars
->del_var
);
1893 kobject_put(efivars
->kobject
);
1894 kset_unregister(efivars
->kset
);
1896 EXPORT_SYMBOL_GPL(unregister_efivars
);
1898 int register_efivars(struct efivars
*efivars
,
1899 const struct efivar_operations
*ops
,
1900 struct kobject
*parent_kobj
)
1902 efi_status_t status
= EFI_NOT_FOUND
;
1903 efi_guid_t vendor_guid
;
1904 efi_char16_t
*variable_name
;
1905 unsigned long variable_name_size
= 1024;
1908 variable_name
= kzalloc(variable_name_size
, GFP_KERNEL
);
1909 if (!variable_name
) {
1910 printk(KERN_ERR
"efivars: Memory allocation failed.\n");
1914 spin_lock_init(&efivars
->lock
);
1915 INIT_LIST_HEAD(&efivars
->list
);
1918 efivars
->kset
= kset_create_and_add("vars", NULL
, parent_kobj
);
1919 if (!efivars
->kset
) {
1920 printk(KERN_ERR
"efivars: Subsystem registration failed.\n");
1925 efivars
->kobject
= kobject_create_and_add("efivars", parent_kobj
);
1926 if (!efivars
->kobject
) {
1927 pr_err("efivars: Subsystem registration failed.\n");
1929 kset_unregister(efivars
->kset
);
1934 * Per EFI spec, the maximum storage allocated for both
1935 * the variable name and variable data is 1024 bytes.
1939 variable_name_size
= 1024;
1941 status
= ops
->get_next_variable(&variable_name_size
,
1946 efivar_create_sysfs_entry(efivars
,
1954 printk(KERN_WARNING
"efivars: get_next_variable: status=%lx\n",
1956 status
= EFI_NOT_FOUND
;
1959 } while (status
!= EFI_NOT_FOUND
);
1961 error
= create_efivars_bin_attributes(efivars
);
1963 unregister_efivars(efivars
);
1965 efivars
->efi_pstore_info
= efi_pstore_info
;
1967 efivars
->efi_pstore_info
.buf
= kmalloc(4096, GFP_KERNEL
);
1968 if (efivars
->efi_pstore_info
.buf
) {
1969 efivars
->efi_pstore_info
.bufsize
= 1024;
1970 efivars
->efi_pstore_info
.data
= efivars
;
1971 spin_lock_init(&efivars
->efi_pstore_info
.buf_lock
);
1972 pstore_register(&efivars
->efi_pstore_info
);
1975 register_filesystem(&efivarfs_type
);
1978 kfree(variable_name
);
1982 EXPORT_SYMBOL_GPL(register_efivars
);
1985 * For now we register the efi subsystem with the firmware subsystem
1986 * and the vars subsystem with the efi subsystem. In the future, it
1987 * might make sense to split off the efi subsystem into its own
1988 * driver, but for now only efivars will register with it, so just
1997 printk(KERN_INFO
"EFI Variables Facility v%s %s\n", EFIVARS_VERSION
,
2000 if (!efi_enabled(EFI_RUNTIME_SERVICES
))
2003 /* For now we'll register the efi directory at /sys/firmware/efi */
2004 efi_kobj
= kobject_create_and_add("efi", firmware_kobj
);
2006 printk(KERN_ERR
"efivars: Firmware registration failed.\n");
2010 ops
.get_variable
= efi
.get_variable
;
2011 ops
.set_variable
= efi
.set_variable
;
2012 ops
.get_next_variable
= efi
.get_next_variable
;
2013 ops
.query_variable_info
= efi
.query_variable_info
;
2015 error
= register_efivars(&__efivars
, &ops
, efi_kobj
);
2019 /* Don't forget the systab entry */
2020 error
= sysfs_create_group(efi_kobj
, &efi_subsys_attr_group
);
2023 "efivars: Sysfs attribute export failed with error %d.\n",
2025 goto err_unregister
;
2031 unregister_efivars(&__efivars
);
2033 kobject_put(efi_kobj
);
2040 cancel_work_sync(&efivar_work
);
2042 if (efi_enabled(EFI_RUNTIME_SERVICES
)) {
2043 unregister_efivars(&__efivars
);
2044 kobject_put(efi_kobj
);
2048 module_init(efivars_init
);
2049 module_exit(efivars_exit
);