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>
84 #include <linux/ramfs.h>
85 #include <linux/pagemap.h>
87 #include <asm/uaccess.h>
89 #define EFIVARS_VERSION "0.08"
90 #define EFIVARS_DATE "2004-May-17"
92 MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
93 MODULE_DESCRIPTION("sysfs interface to EFI Variables");
94 MODULE_LICENSE("GPL");
95 MODULE_VERSION(EFIVARS_VERSION
);
97 #define DUMP_NAME_LEN 52
101 * The maximum size of VariableName + Data = 1024
102 * Therefore, it's reasonable to save that much
103 * space in each part of the structure,
104 * and we use a page for reading/writing.
107 struct efi_variable
{
108 efi_char16_t VariableName
[1024/sizeof(efi_char16_t
)];
109 efi_guid_t VendorGuid
;
110 unsigned long DataSize
;
114 } __attribute__((packed
));
116 struct efivar_entry
{
117 struct efivars
*efivars
;
118 struct efi_variable var
;
119 struct list_head list
;
123 struct efivar_attribute
{
124 struct attribute attr
;
125 ssize_t (*show
) (struct efivar_entry
*entry
, char *buf
);
126 ssize_t (*store
)(struct efivar_entry
*entry
, const char *buf
, size_t count
);
129 static struct efivars __efivars
;
130 static struct efivar_operations ops
;
132 #define PSTORE_EFI_ATTRIBUTES \
133 (EFI_VARIABLE_NON_VOLATILE | \
134 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
135 EFI_VARIABLE_RUNTIME_ACCESS)
137 #define EFIVAR_ATTR(_name, _mode, _show, _store) \
138 struct efivar_attribute efivar_attr_##_name = { \
139 .attr = {.name = __stringify(_name), .mode = _mode}, \
144 #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
145 #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
148 * Prototype for sysfs creation function
151 efivar_create_sysfs_entry(struct efivars
*efivars
,
152 unsigned long variable_name_size
,
153 efi_char16_t
*variable_name
,
154 efi_guid_t
*vendor_guid
);
156 /* Return the number of unicode characters in data */
158 utf16_strnlen(efi_char16_t
*s
, size_t maxlength
)
160 unsigned long length
= 0;
162 while (*s
++ != 0 && length
< maxlength
)
167 static inline unsigned long
168 utf16_strlen(efi_char16_t
*s
)
170 return utf16_strnlen(s
, ~0UL);
174 * Return the number of bytes is the length of this string
175 * Note: this is NOT the same as the number of unicode characters
177 static inline unsigned long
178 utf16_strsize(efi_char16_t
*data
, unsigned long maxlength
)
180 return utf16_strnlen(data
, maxlength
/sizeof(efi_char16_t
)) * sizeof(efi_char16_t
);
184 utf16_strncmp(const efi_char16_t
*a
, const efi_char16_t
*b
, size_t len
)
193 if (*a
== 0) /* implies *b == 0 */
202 validate_device_path(struct efi_variable
*var
, int match
, u8
*buffer
,
205 struct efi_generic_dev_path
*node
;
208 node
= (struct efi_generic_dev_path
*)buffer
;
210 if (len
< sizeof(*node
))
213 while (offset
<= len
- sizeof(*node
) &&
214 node
->length
>= sizeof(*node
) &&
215 node
->length
<= len
- offset
) {
216 offset
+= node
->length
;
218 if ((node
->type
== EFI_DEV_END_PATH
||
219 node
->type
== EFI_DEV_END_PATH2
) &&
220 node
->sub_type
== EFI_DEV_END_ENTIRE
)
223 node
= (struct efi_generic_dev_path
*)(buffer
+ offset
);
227 * If we're here then either node->length pointed past the end
228 * of the buffer or we reached the end of the buffer without
229 * finding a device path end node.
235 validate_boot_order(struct efi_variable
*var
, int match
, u8
*buffer
,
238 /* An array of 16-bit integers */
246 validate_load_option(struct efi_variable
*var
, int match
, u8
*buffer
,
250 int i
, desclength
= 0, namelen
;
252 namelen
= utf16_strnlen(var
->VariableName
, sizeof(var
->VariableName
));
254 /* Either "Boot" or "Driver" followed by four digits of hex */
255 for (i
= match
; i
< match
+4; i
++) {
256 if (var
->VariableName
[i
] > 127 ||
257 hex_to_bin(var
->VariableName
[i
] & 0xff) < 0)
261 /* Reject it if there's 4 digits of hex and then further content */
262 if (namelen
> match
+ 4)
265 /* A valid entry must be at least 8 bytes */
269 filepathlength
= buffer
[4] | buffer
[5] << 8;
272 * There's no stored length for the description, so it has to be
275 desclength
= utf16_strsize((efi_char16_t
*)(buffer
+ 6), len
- 6) + 2;
277 /* Each boot entry must have a descriptor */
282 * If the sum of the length of the description, the claimed filepath
283 * length and the original header are greater than the length of the
284 * variable, it's malformed
286 if ((desclength
+ filepathlength
+ 6) > len
)
290 * And, finally, check the filepath
292 return validate_device_path(var
, match
, buffer
+ desclength
+ 6,
297 validate_uint16(struct efi_variable
*var
, int match
, u8
*buffer
,
300 /* A single 16-bit integer */
308 validate_ascii_string(struct efi_variable
*var
, int match
, u8
*buffer
,
313 for (i
= 0; i
< len
; i
++) {
324 struct variable_validate
{
326 bool (*validate
)(struct efi_variable
*var
, int match
, u8
*data
,
330 static const struct variable_validate variable_validate
[] = {
331 { "BootNext", validate_uint16
},
332 { "BootOrder", validate_boot_order
},
333 { "DriverOrder", validate_boot_order
},
334 { "Boot*", validate_load_option
},
335 { "Driver*", validate_load_option
},
336 { "ConIn", validate_device_path
},
337 { "ConInDev", validate_device_path
},
338 { "ConOut", validate_device_path
},
339 { "ConOutDev", validate_device_path
},
340 { "ErrOut", validate_device_path
},
341 { "ErrOutDev", validate_device_path
},
342 { "Timeout", validate_uint16
},
343 { "Lang", validate_ascii_string
},
344 { "PlatformLang", validate_ascii_string
},
349 validate_var(struct efi_variable
*var
, u8
*data
, unsigned long len
)
352 u16
*unicode_name
= var
->VariableName
;
354 for (i
= 0; variable_validate
[i
].validate
!= NULL
; i
++) {
355 const char *name
= variable_validate
[i
].name
;
358 for (match
= 0; ; match
++) {
359 char c
= name
[match
];
360 u16 u
= unicode_name
[match
];
362 /* All special variables are plain ascii */
366 /* Wildcard in the matching name means we've matched */
368 return variable_validate
[i
].validate(var
,
371 /* Case sensitive match */
375 /* Reached the end of the string while matching */
377 return variable_validate
[i
].validate(var
,
386 get_var_data_locked(struct efivars
*efivars
, struct efi_variable
*var
)
390 var
->DataSize
= 1024;
391 status
= efivars
->ops
->get_variable(var
->VariableName
,
400 get_var_data(struct efivars
*efivars
, struct efi_variable
*var
)
404 spin_lock(&efivars
->lock
);
405 status
= get_var_data_locked(efivars
, var
);
406 spin_unlock(&efivars
->lock
);
408 if (status
!= EFI_SUCCESS
) {
409 printk(KERN_WARNING
"efivars: get_variable() failed 0x%lx!\n",
416 efivar_guid_read(struct efivar_entry
*entry
, char *buf
)
418 struct efi_variable
*var
= &entry
->var
;
424 efi_guid_unparse(&var
->VendorGuid
, str
);
426 str
+= sprintf(str
, "\n");
432 efivar_attr_read(struct efivar_entry
*entry
, char *buf
)
434 struct efi_variable
*var
= &entry
->var
;
441 status
= get_var_data(entry
->efivars
, var
);
442 if (status
!= EFI_SUCCESS
)
445 if (var
->Attributes
& EFI_VARIABLE_NON_VOLATILE
)
446 str
+= sprintf(str
, "EFI_VARIABLE_NON_VOLATILE\n");
447 if (var
->Attributes
& EFI_VARIABLE_BOOTSERVICE_ACCESS
)
448 str
+= sprintf(str
, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
449 if (var
->Attributes
& EFI_VARIABLE_RUNTIME_ACCESS
)
450 str
+= sprintf(str
, "EFI_VARIABLE_RUNTIME_ACCESS\n");
451 if (var
->Attributes
& EFI_VARIABLE_HARDWARE_ERROR_RECORD
)
452 str
+= sprintf(str
, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
453 if (var
->Attributes
& EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
)
455 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
456 if (var
->Attributes
&
457 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
)
459 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
460 if (var
->Attributes
& EFI_VARIABLE_APPEND_WRITE
)
461 str
+= sprintf(str
, "EFI_VARIABLE_APPEND_WRITE\n");
466 efivar_size_read(struct efivar_entry
*entry
, char *buf
)
468 struct efi_variable
*var
= &entry
->var
;
475 status
= get_var_data(entry
->efivars
, var
);
476 if (status
!= EFI_SUCCESS
)
479 str
+= sprintf(str
, "0x%lx\n", var
->DataSize
);
484 efivar_data_read(struct efivar_entry
*entry
, char *buf
)
486 struct efi_variable
*var
= &entry
->var
;
492 status
= get_var_data(entry
->efivars
, var
);
493 if (status
!= EFI_SUCCESS
)
496 memcpy(buf
, var
->Data
, var
->DataSize
);
497 return var
->DataSize
;
500 * We allow each variable to be edited via rewriting the
501 * entire efi variable structure.
504 efivar_store_raw(struct efivar_entry
*entry
, const char *buf
, size_t count
)
506 struct efi_variable
*new_var
, *var
= &entry
->var
;
507 struct efivars
*efivars
= entry
->efivars
;
508 efi_status_t status
= EFI_NOT_FOUND
;
510 if (count
!= sizeof(struct efi_variable
))
513 new_var
= (struct efi_variable
*)buf
;
515 * If only updating the variable data, then the name
516 * and guid should remain the same
518 if (memcmp(new_var
->VariableName
, var
->VariableName
, sizeof(var
->VariableName
)) ||
519 efi_guidcmp(new_var
->VendorGuid
, var
->VendorGuid
)) {
520 printk(KERN_ERR
"efivars: Cannot edit the wrong variable!\n");
524 if ((new_var
->DataSize
<= 0) || (new_var
->Attributes
== 0)){
525 printk(KERN_ERR
"efivars: DataSize & Attributes must be valid!\n");
529 if ((new_var
->Attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
530 validate_var(new_var
, new_var
->Data
, new_var
->DataSize
) == false) {
531 printk(KERN_ERR
"efivars: Malformed variable content\n");
535 spin_lock(&efivars
->lock
);
536 status
= efivars
->ops
->set_variable(new_var
->VariableName
,
537 &new_var
->VendorGuid
,
542 spin_unlock(&efivars
->lock
);
544 if (status
!= EFI_SUCCESS
) {
545 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
550 memcpy(&entry
->var
, new_var
, count
);
555 efivar_show_raw(struct efivar_entry
*entry
, char *buf
)
557 struct efi_variable
*var
= &entry
->var
;
563 status
= get_var_data(entry
->efivars
, var
);
564 if (status
!= EFI_SUCCESS
)
567 memcpy(buf
, var
, sizeof(*var
));
572 * Generic read/write functions that call the specific functions of
575 static ssize_t
efivar_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
578 struct efivar_entry
*var
= to_efivar_entry(kobj
);
579 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
582 if (!capable(CAP_SYS_ADMIN
))
585 if (efivar_attr
->show
) {
586 ret
= efivar_attr
->show(var
, buf
);
591 static ssize_t
efivar_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
592 const char *buf
, size_t count
)
594 struct efivar_entry
*var
= to_efivar_entry(kobj
);
595 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
598 if (!capable(CAP_SYS_ADMIN
))
601 if (efivar_attr
->store
)
602 ret
= efivar_attr
->store(var
, buf
, count
);
607 static const struct sysfs_ops efivar_attr_ops
= {
608 .show
= efivar_attr_show
,
609 .store
= efivar_attr_store
,
612 static void efivar_release(struct kobject
*kobj
)
614 struct efivar_entry
*var
= container_of(kobj
, struct efivar_entry
, kobj
);
618 static EFIVAR_ATTR(guid
, 0400, efivar_guid_read
, NULL
);
619 static EFIVAR_ATTR(attributes
, 0400, efivar_attr_read
, NULL
);
620 static EFIVAR_ATTR(size
, 0400, efivar_size_read
, NULL
);
621 static EFIVAR_ATTR(data
, 0400, efivar_data_read
, NULL
);
622 static EFIVAR_ATTR(raw_var
, 0600, efivar_show_raw
, efivar_store_raw
);
624 static struct attribute
*def_attrs
[] = {
625 &efivar_attr_guid
.attr
,
626 &efivar_attr_size
.attr
,
627 &efivar_attr_attributes
.attr
,
628 &efivar_attr_data
.attr
,
629 &efivar_attr_raw_var
.attr
,
633 static struct kobj_type efivar_ktype
= {
634 .release
= efivar_release
,
635 .sysfs_ops
= &efivar_attr_ops
,
636 .default_attrs
= def_attrs
,
640 efivar_unregister(struct efivar_entry
*var
)
642 kobject_put(&var
->kobj
);
645 static int efivarfs_file_open(struct inode
*inode
, struct file
*file
)
647 file
->private_data
= inode
->i_private
;
651 static ssize_t
efivarfs_file_write(struct file
*file
,
652 const char __user
*userbuf
, size_t count
, loff_t
*ppos
)
654 struct efivar_entry
*var
= file
->private_data
;
655 struct efivars
*efivars
;
659 struct inode
*inode
= file
->f_mapping
->host
;
660 int datasize
= count
- sizeof(attributes
);
661 unsigned long newdatasize
;
663 if (count
< sizeof(attributes
))
666 data
= kmalloc(datasize
, GFP_KERNEL
);
671 efivars
= var
->efivars
;
673 if (copy_from_user(&attributes
, userbuf
, sizeof(attributes
))) {
678 if (attributes
& ~(EFI_VARIABLE_MASK
)) {
683 if (copy_from_user(data
, userbuf
+ sizeof(attributes
), datasize
)) {
688 if (validate_var(&var
->var
, data
, datasize
) == false) {
693 status
= efivars
->ops
->set_variable(var
->var
.VariableName
,
694 &var
->var
.VendorGuid
,
695 attributes
, datasize
,
701 case EFI_INVALID_PARAMETER
:
704 case EFI_OUT_OF_RESOURCES
:
707 case EFI_DEVICE_ERROR
:
710 case EFI_WRITE_PROTECTED
:
713 case EFI_SECURITY_VIOLATION
:
725 * Writing to the variable may have caused a change in size (which
726 * could either be an append or an overwrite), or the variable to be
727 * deleted. Perform a GetVariable() so we can tell what actually
731 status
= efivars
->ops
->get_variable(var
->var
.VariableName
,
732 &var
->var
.VendorGuid
,
736 if (status
== EFI_BUFFER_TOO_SMALL
) {
737 mutex_lock(&inode
->i_mutex
);
738 i_size_write(inode
, newdatasize
+ sizeof(attributes
));
739 mutex_unlock(&inode
->i_mutex
);
741 } else if (status
== EFI_NOT_FOUND
) {
742 spin_lock(&efivars
->lock
);
743 list_del(&var
->list
);
744 spin_unlock(&efivars
->lock
);
745 efivar_unregister(var
);
747 dput(file
->f_dentry
);
750 pr_warn("efivarfs: inconsistent EFI variable implementation? "
751 "status = %lx\n", status
);
760 static ssize_t
efivarfs_file_read(struct file
*file
, char __user
*userbuf
,
761 size_t count
, loff_t
*ppos
)
763 struct efivar_entry
*var
= file
->private_data
;
764 struct efivars
*efivars
= var
->efivars
;
766 unsigned long datasize
= 0;
771 status
= efivars
->ops
->get_variable(var
->var
.VariableName
,
772 &var
->var
.VendorGuid
,
773 &attributes
, &datasize
, NULL
);
775 if (status
!= EFI_BUFFER_TOO_SMALL
)
778 data
= kmalloc(datasize
+ 4, GFP_KERNEL
);
783 status
= efivars
->ops
->get_variable(var
->var
.VariableName
,
784 &var
->var
.VendorGuid
,
785 &attributes
, &datasize
,
787 if (status
!= EFI_SUCCESS
)
790 memcpy(data
, &attributes
, 4);
791 size
= simple_read_from_buffer(userbuf
, count
, ppos
,
799 static void efivarfs_evict_inode(struct inode
*inode
)
804 static const struct super_operations efivarfs_ops
= {
805 .statfs
= simple_statfs
,
806 .drop_inode
= generic_delete_inode
,
807 .evict_inode
= efivarfs_evict_inode
,
808 .show_options
= generic_show_options
,
811 static struct super_block
*efivarfs_sb
;
813 static const struct inode_operations efivarfs_dir_inode_operations
;
815 static const struct file_operations efivarfs_file_operations
= {
816 .open
= efivarfs_file_open
,
817 .read
= efivarfs_file_read
,
818 .write
= efivarfs_file_write
,
822 static struct inode
*efivarfs_get_inode(struct super_block
*sb
,
823 const struct inode
*dir
, int mode
, dev_t dev
)
825 struct inode
*inode
= new_inode(sb
);
828 inode
->i_ino
= get_next_ino();
829 inode
->i_uid
= inode
->i_gid
= 0;
830 inode
->i_mode
= mode
;
831 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
832 switch (mode
& S_IFMT
) {
834 inode
->i_fop
= &efivarfs_file_operations
;
837 inode
->i_op
= &efivarfs_dir_inode_operations
;
838 inode
->i_fop
= &simple_dir_operations
;
846 static void efivarfs_hex_to_guid(const char *str
, efi_guid_t
*guid
)
848 guid
->b
[0] = hex_to_bin(str
[6]) << 4 | hex_to_bin(str
[7]);
849 guid
->b
[1] = hex_to_bin(str
[4]) << 4 | hex_to_bin(str
[5]);
850 guid
->b
[2] = hex_to_bin(str
[2]) << 4 | hex_to_bin(str
[3]);
851 guid
->b
[3] = hex_to_bin(str
[0]) << 4 | hex_to_bin(str
[1]);
852 guid
->b
[4] = hex_to_bin(str
[11]) << 4 | hex_to_bin(str
[12]);
853 guid
->b
[5] = hex_to_bin(str
[9]) << 4 | hex_to_bin(str
[10]);
854 guid
->b
[6] = hex_to_bin(str
[16]) << 4 | hex_to_bin(str
[17]);
855 guid
->b
[7] = hex_to_bin(str
[14]) << 4 | hex_to_bin(str
[15]);
856 guid
->b
[8] = hex_to_bin(str
[19]) << 4 | hex_to_bin(str
[20]);
857 guid
->b
[9] = hex_to_bin(str
[21]) << 4 | hex_to_bin(str
[22]);
858 guid
->b
[10] = hex_to_bin(str
[24]) << 4 | hex_to_bin(str
[25]);
859 guid
->b
[11] = hex_to_bin(str
[26]) << 4 | hex_to_bin(str
[27]);
860 guid
->b
[12] = hex_to_bin(str
[28]) << 4 | hex_to_bin(str
[29]);
861 guid
->b
[13] = hex_to_bin(str
[30]) << 4 | hex_to_bin(str
[31]);
862 guid
->b
[14] = hex_to_bin(str
[32]) << 4 | hex_to_bin(str
[33]);
863 guid
->b
[15] = hex_to_bin(str
[34]) << 4 | hex_to_bin(str
[35]);
866 static int efivarfs_create(struct inode
*dir
, struct dentry
*dentry
,
867 umode_t mode
, bool excl
)
870 struct efivars
*efivars
= &__efivars
;
871 struct efivar_entry
*var
;
872 int namelen
, i
= 0, err
= 0;
874 if (dentry
->d_name
.len
< 38)
877 inode
= efivarfs_get_inode(dir
->i_sb
, dir
, mode
, 0);
881 var
= kzalloc(sizeof(struct efivar_entry
), GFP_KERNEL
);
887 namelen
= dentry
->d_name
.len
- GUID_LEN
;
889 efivarfs_hex_to_guid(dentry
->d_name
.name
+ namelen
+ 1,
890 &var
->var
.VendorGuid
);
892 for (i
= 0; i
< namelen
; i
++)
893 var
->var
.VariableName
[i
] = dentry
->d_name
.name
[i
];
895 var
->var
.VariableName
[i
] = '\0';
897 inode
->i_private
= var
;
898 var
->efivars
= efivars
;
899 var
->kobj
.kset
= efivars
->kset
;
901 err
= kobject_init_and_add(&var
->kobj
, &efivar_ktype
, NULL
, "%s",
902 dentry
->d_name
.name
);
906 kobject_uevent(&var
->kobj
, KOBJ_ADD
);
907 spin_lock(&efivars
->lock
);
908 list_add(&var
->list
, &efivars
->list
);
909 spin_unlock(&efivars
->lock
);
910 d_instantiate(dentry
, inode
);
920 static int efivarfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
922 struct efivar_entry
*var
= dentry
->d_inode
->i_private
;
923 struct efivars
*efivars
= var
->efivars
;
926 spin_lock(&efivars
->lock
);
928 status
= efivars
->ops
->set_variable(var
->var
.VariableName
,
929 &var
->var
.VendorGuid
,
932 if (status
== EFI_SUCCESS
|| status
== EFI_NOT_FOUND
) {
933 list_del(&var
->list
);
934 spin_unlock(&efivars
->lock
);
935 efivar_unregister(var
);
941 spin_unlock(&efivars
->lock
);
945 int efivarfs_fill_super(struct super_block
*sb
, void *data
, int silent
)
947 struct inode
*inode
= NULL
;
949 struct efivar_entry
*entry
, *n
;
950 struct efivars
*efivars
= &__efivars
;
955 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
956 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
957 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
958 sb
->s_magic
= PSTOREFS_MAGIC
;
959 sb
->s_op
= &efivarfs_ops
;
962 inode
= efivarfs_get_inode(sb
, NULL
, S_IFDIR
| 0755, 0);
965 inode
->i_op
= &efivarfs_dir_inode_operations
;
967 root
= d_make_root(inode
);
972 list_for_each_entry_safe(entry
, n
, &efivars
->list
, list
) {
973 struct dentry
*dentry
, *root
= efivarfs_sb
->s_root
;
974 unsigned long size
= 0;
979 len
= utf16_strlen(entry
->var
.VariableName
);
981 /* GUID plus trailing NULL */
982 name
= kmalloc(len
+ 38, GFP_ATOMIC
);
986 for (i
= 0; i
< len
; i
++)
987 name
[i
] = entry
->var
.VariableName
[i
] & 0xFF;
991 efi_guid_unparse(&entry
->var
.VendorGuid
, name
+ len
+ 1);
993 name
[len
+GUID_LEN
] = '\0';
995 inode
= efivarfs_get_inode(efivarfs_sb
, root
->d_inode
,
1000 dentry
= d_alloc_name(root
, name
);
1004 /* copied by the above to local storage in the dentry. */
1007 efivars
->ops
->get_variable(entry
->var
.VariableName
,
1008 &entry
->var
.VendorGuid
,
1009 &entry
->var
.Attributes
,
1013 mutex_lock(&inode
->i_mutex
);
1014 inode
->i_private
= entry
;
1015 i_size_write(inode
, size
+4);
1016 mutex_unlock(&inode
->i_mutex
);
1017 d_add(dentry
, inode
);
1030 static struct dentry
*efivarfs_mount(struct file_system_type
*fs_type
,
1031 int flags
, const char *dev_name
, void *data
)
1033 return mount_single(fs_type
, flags
, data
, efivarfs_fill_super
);
1036 static void efivarfs_kill_sb(struct super_block
*sb
)
1038 kill_litter_super(sb
);
1042 static struct file_system_type efivarfs_type
= {
1044 .mount
= efivarfs_mount
,
1045 .kill_sb
= efivarfs_kill_sb
,
1048 static const struct inode_operations efivarfs_dir_inode_operations
= {
1049 .lookup
= simple_lookup
,
1050 .unlink
= efivarfs_unlink
,
1051 .create
= efivarfs_create
,
1054 static struct pstore_info efi_pstore_info
;
1056 #ifdef CONFIG_PSTORE
1058 static int efi_pstore_open(struct pstore_info
*psi
)
1060 struct efivars
*efivars
= psi
->data
;
1062 spin_lock(&efivars
->lock
);
1063 efivars
->walk_entry
= list_first_entry(&efivars
->list
,
1064 struct efivar_entry
, list
);
1068 static int efi_pstore_close(struct pstore_info
*psi
)
1070 struct efivars
*efivars
= psi
->data
;
1072 spin_unlock(&efivars
->lock
);
1076 static ssize_t
efi_pstore_read(u64
*id
, enum pstore_type_id
*type
,
1077 struct timespec
*timespec
,
1078 char **buf
, struct pstore_info
*psi
)
1080 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
1081 struct efivars
*efivars
= psi
->data
;
1082 char name
[DUMP_NAME_LEN
];
1084 unsigned int part
, size
;
1087 while (&efivars
->walk_entry
->list
!= &efivars
->list
) {
1088 if (!efi_guidcmp(efivars
->walk_entry
->var
.VendorGuid
,
1090 for (i
= 0; i
< DUMP_NAME_LEN
; i
++) {
1091 name
[i
] = efivars
->walk_entry
->var
.VariableName
[i
];
1093 if (sscanf(name
, "dump-type%u-%u-%lu", type
, &part
, &time
) == 3) {
1095 timespec
->tv_sec
= time
;
1096 timespec
->tv_nsec
= 0;
1097 get_var_data_locked(efivars
, &efivars
->walk_entry
->var
);
1098 size
= efivars
->walk_entry
->var
.DataSize
;
1099 *buf
= kmalloc(size
, GFP_KERNEL
);
1102 memcpy(*buf
, efivars
->walk_entry
->var
.Data
,
1104 efivars
->walk_entry
= list_entry(efivars
->walk_entry
->list
.next
,
1105 struct efivar_entry
, list
);
1109 efivars
->walk_entry
= list_entry(efivars
->walk_entry
->list
.next
,
1110 struct efivar_entry
, list
);
1115 static int efi_pstore_write(enum pstore_type_id type
,
1116 enum kmsg_dump_reason reason
, u64
*id
,
1117 unsigned int part
, size_t size
, struct pstore_info
*psi
)
1119 char name
[DUMP_NAME_LEN
];
1120 char stub_name
[DUMP_NAME_LEN
];
1121 efi_char16_t efi_name
[DUMP_NAME_LEN
];
1122 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
1123 struct efivars
*efivars
= psi
->data
;
1124 struct efivar_entry
*entry
, *found
= NULL
;
1127 sprintf(stub_name
, "dump-type%u-%u-", type
, part
);
1128 sprintf(name
, "%s%lu", stub_name
, get_seconds());
1130 spin_lock(&efivars
->lock
);
1132 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
1133 efi_name
[i
] = stub_name
[i
];
1136 * Clean up any entries with the same name
1139 list_for_each_entry(entry
, &efivars
->list
, list
) {
1140 get_var_data_locked(efivars
, &entry
->var
);
1142 if (efi_guidcmp(entry
->var
.VendorGuid
, vendor
))
1144 if (utf16_strncmp(entry
->var
.VariableName
, efi_name
,
1145 utf16_strlen(efi_name
)))
1147 /* Needs to be a prefix */
1148 if (entry
->var
.VariableName
[utf16_strlen(efi_name
)] == 0)
1153 efivars
->ops
->set_variable(entry
->var
.VariableName
,
1154 &entry
->var
.VendorGuid
,
1155 PSTORE_EFI_ATTRIBUTES
,
1160 list_del(&found
->list
);
1162 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
1163 efi_name
[i
] = name
[i
];
1165 efivars
->ops
->set_variable(efi_name
, &vendor
, PSTORE_EFI_ATTRIBUTES
,
1168 spin_unlock(&efivars
->lock
);
1171 efivar_unregister(found
);
1174 ret
= efivar_create_sysfs_entry(efivars
,
1175 utf16_strsize(efi_name
,
1183 static int efi_pstore_erase(enum pstore_type_id type
, u64 id
,
1184 struct pstore_info
*psi
)
1186 efi_pstore_write(type
, 0, &id
, (unsigned int)id
, 0, psi
);
1191 static int efi_pstore_open(struct pstore_info
*psi
)
1196 static int efi_pstore_close(struct pstore_info
*psi
)
1201 static ssize_t
efi_pstore_read(u64
*id
, enum pstore_type_id
*type
,
1202 struct timespec
*timespec
,
1203 char **buf
, struct pstore_info
*psi
)
1208 static int efi_pstore_write(enum pstore_type_id type
,
1209 enum kmsg_dump_reason reason
, u64
*id
,
1210 unsigned int part
, size_t size
, struct pstore_info
*psi
)
1215 static int efi_pstore_erase(enum pstore_type_id type
, u64 id
,
1216 struct pstore_info
*psi
)
1222 static struct pstore_info efi_pstore_info
= {
1223 .owner
= THIS_MODULE
,
1225 .open
= efi_pstore_open
,
1226 .close
= efi_pstore_close
,
1227 .read
= efi_pstore_read
,
1228 .write
= efi_pstore_write
,
1229 .erase
= efi_pstore_erase
,
1232 static ssize_t
efivar_create(struct file
*filp
, struct kobject
*kobj
,
1233 struct bin_attribute
*bin_attr
,
1234 char *buf
, loff_t pos
, size_t count
)
1236 struct efi_variable
*new_var
= (struct efi_variable
*)buf
;
1237 struct efivars
*efivars
= bin_attr
->private;
1238 struct efivar_entry
*search_efivar
, *n
;
1239 unsigned long strsize1
, strsize2
;
1240 efi_status_t status
= EFI_NOT_FOUND
;
1243 if (!capable(CAP_SYS_ADMIN
))
1246 if ((new_var
->Attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
1247 validate_var(new_var
, new_var
->Data
, new_var
->DataSize
) == false) {
1248 printk(KERN_ERR
"efivars: Malformed variable content\n");
1252 spin_lock(&efivars
->lock
);
1255 * Does this variable already exist?
1257 list_for_each_entry_safe(search_efivar
, n
, &efivars
->list
, list
) {
1258 strsize1
= utf16_strsize(search_efivar
->var
.VariableName
, 1024);
1259 strsize2
= utf16_strsize(new_var
->VariableName
, 1024);
1260 if (strsize1
== strsize2
&&
1261 !memcmp(&(search_efivar
->var
.VariableName
),
1262 new_var
->VariableName
, strsize1
) &&
1263 !efi_guidcmp(search_efivar
->var
.VendorGuid
,
1264 new_var
->VendorGuid
)) {
1270 spin_unlock(&efivars
->lock
);
1274 /* now *really* create the variable via EFI */
1275 status
= efivars
->ops
->set_variable(new_var
->VariableName
,
1276 &new_var
->VendorGuid
,
1277 new_var
->Attributes
,
1281 if (status
!= EFI_SUCCESS
) {
1282 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
1284 spin_unlock(&efivars
->lock
);
1287 spin_unlock(&efivars
->lock
);
1289 /* Create the entry in sysfs. Locking is not required here */
1290 status
= efivar_create_sysfs_entry(efivars
,
1291 utf16_strsize(new_var
->VariableName
,
1293 new_var
->VariableName
,
1294 &new_var
->VendorGuid
);
1296 printk(KERN_WARNING
"efivars: variable created, but sysfs entry wasn't.\n");
1301 static ssize_t
efivar_delete(struct file
*filp
, struct kobject
*kobj
,
1302 struct bin_attribute
*bin_attr
,
1303 char *buf
, loff_t pos
, size_t count
)
1305 struct efi_variable
*del_var
= (struct efi_variable
*)buf
;
1306 struct efivars
*efivars
= bin_attr
->private;
1307 struct efivar_entry
*search_efivar
, *n
;
1308 unsigned long strsize1
, strsize2
;
1309 efi_status_t status
= EFI_NOT_FOUND
;
1312 if (!capable(CAP_SYS_ADMIN
))
1315 spin_lock(&efivars
->lock
);
1318 * Does this variable already exist?
1320 list_for_each_entry_safe(search_efivar
, n
, &efivars
->list
, list
) {
1321 strsize1
= utf16_strsize(search_efivar
->var
.VariableName
, 1024);
1322 strsize2
= utf16_strsize(del_var
->VariableName
, 1024);
1323 if (strsize1
== strsize2
&&
1324 !memcmp(&(search_efivar
->var
.VariableName
),
1325 del_var
->VariableName
, strsize1
) &&
1326 !efi_guidcmp(search_efivar
->var
.VendorGuid
,
1327 del_var
->VendorGuid
)) {
1333 spin_unlock(&efivars
->lock
);
1336 /* force the Attributes/DataSize to 0 to ensure deletion */
1337 del_var
->Attributes
= 0;
1338 del_var
->DataSize
= 0;
1340 status
= efivars
->ops
->set_variable(del_var
->VariableName
,
1341 &del_var
->VendorGuid
,
1342 del_var
->Attributes
,
1346 if (status
!= EFI_SUCCESS
) {
1347 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
1349 spin_unlock(&efivars
->lock
);
1352 list_del(&search_efivar
->list
);
1353 /* We need to release this lock before unregistering. */
1354 spin_unlock(&efivars
->lock
);
1355 efivar_unregister(search_efivar
);
1357 /* It's dead Jim.... */
1362 * Let's not leave out systab information that snuck into
1363 * the efivars driver
1365 static ssize_t
systab_show(struct kobject
*kobj
,
1366 struct kobj_attribute
*attr
, char *buf
)
1373 if (efi
.mps
!= EFI_INVALID_TABLE_ADDR
)
1374 str
+= sprintf(str
, "MPS=0x%lx\n", efi
.mps
);
1375 if (efi
.acpi20
!= EFI_INVALID_TABLE_ADDR
)
1376 str
+= sprintf(str
, "ACPI20=0x%lx\n", efi
.acpi20
);
1377 if (efi
.acpi
!= EFI_INVALID_TABLE_ADDR
)
1378 str
+= sprintf(str
, "ACPI=0x%lx\n", efi
.acpi
);
1379 if (efi
.smbios
!= EFI_INVALID_TABLE_ADDR
)
1380 str
+= sprintf(str
, "SMBIOS=0x%lx\n", efi
.smbios
);
1381 if (efi
.hcdp
!= EFI_INVALID_TABLE_ADDR
)
1382 str
+= sprintf(str
, "HCDP=0x%lx\n", efi
.hcdp
);
1383 if (efi
.boot_info
!= EFI_INVALID_TABLE_ADDR
)
1384 str
+= sprintf(str
, "BOOTINFO=0x%lx\n", efi
.boot_info
);
1385 if (efi
.uga
!= EFI_INVALID_TABLE_ADDR
)
1386 str
+= sprintf(str
, "UGA=0x%lx\n", efi
.uga
);
1391 static struct kobj_attribute efi_attr_systab
=
1392 __ATTR(systab
, 0400, systab_show
, NULL
);
1394 static struct attribute
*efi_subsys_attrs
[] = {
1395 &efi_attr_systab
.attr
,
1396 NULL
, /* maybe more in the future? */
1399 static struct attribute_group efi_subsys_attr_group
= {
1400 .attrs
= efi_subsys_attrs
,
1403 static struct kobject
*efi_kobj
;
1406 * efivar_create_sysfs_entry()
1408 * variable_name_size = number of bytes required to hold
1409 * variable_name (not counting the NULL
1410 * character at the end.
1411 * efivars->lock is not held on entry or exit.
1412 * Returns 1 on failure, 0 on success
1415 efivar_create_sysfs_entry(struct efivars
*efivars
,
1416 unsigned long variable_name_size
,
1417 efi_char16_t
*variable_name
,
1418 efi_guid_t
*vendor_guid
)
1420 int i
, short_name_size
= variable_name_size
/ sizeof(efi_char16_t
) + 38;
1422 struct efivar_entry
*new_efivar
;
1424 short_name
= kzalloc(short_name_size
+ 1, GFP_KERNEL
);
1425 new_efivar
= kzalloc(sizeof(struct efivar_entry
), GFP_KERNEL
);
1427 if (!short_name
|| !new_efivar
) {
1433 new_efivar
->efivars
= efivars
;
1434 memcpy(new_efivar
->var
.VariableName
, variable_name
,
1435 variable_name_size
);
1436 memcpy(&(new_efivar
->var
.VendorGuid
), vendor_guid
, sizeof(efi_guid_t
));
1438 /* Convert Unicode to normal chars (assume top bits are 0),
1440 for (i
=0; i
< (int)(variable_name_size
/ sizeof(efi_char16_t
)); i
++) {
1441 short_name
[i
] = variable_name
[i
] & 0xFF;
1443 /* This is ugly, but necessary to separate one vendor's
1444 private variables from another's. */
1446 *(short_name
+ strlen(short_name
)) = '-';
1447 efi_guid_unparse(vendor_guid
, short_name
+ strlen(short_name
));
1449 new_efivar
->kobj
.kset
= efivars
->kset
;
1450 i
= kobject_init_and_add(&new_efivar
->kobj
, &efivar_ktype
, NULL
,
1458 kobject_uevent(&new_efivar
->kobj
, KOBJ_ADD
);
1462 spin_lock(&efivars
->lock
);
1463 list_add(&new_efivar
->list
, &efivars
->list
);
1464 spin_unlock(&efivars
->lock
);
1470 create_efivars_bin_attributes(struct efivars
*efivars
)
1472 struct bin_attribute
*attr
;
1476 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
1480 attr
->attr
.name
= "new_var";
1481 attr
->attr
.mode
= 0200;
1482 attr
->write
= efivar_create
;
1483 attr
->private = efivars
;
1484 efivars
->new_var
= attr
;
1487 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
1492 attr
->attr
.name
= "del_var";
1493 attr
->attr
.mode
= 0200;
1494 attr
->write
= efivar_delete
;
1495 attr
->private = efivars
;
1496 efivars
->del_var
= attr
;
1498 sysfs_bin_attr_init(efivars
->new_var
);
1499 sysfs_bin_attr_init(efivars
->del_var
);
1502 error
= sysfs_create_bin_file(&efivars
->kset
->kobj
,
1505 printk(KERN_ERR
"efivars: unable to create new_var sysfs file"
1506 " due to error %d\n", error
);
1509 error
= sysfs_create_bin_file(&efivars
->kset
->kobj
,
1512 printk(KERN_ERR
"efivars: unable to create del_var sysfs file"
1513 " due to error %d\n", error
);
1514 sysfs_remove_bin_file(&efivars
->kset
->kobj
,
1521 kfree(efivars
->del_var
);
1522 efivars
->del_var
= NULL
;
1523 kfree(efivars
->new_var
);
1524 efivars
->new_var
= NULL
;
1528 void unregister_efivars(struct efivars
*efivars
)
1530 struct efivar_entry
*entry
, *n
;
1532 list_for_each_entry_safe(entry
, n
, &efivars
->list
, list
) {
1533 spin_lock(&efivars
->lock
);
1534 list_del(&entry
->list
);
1535 spin_unlock(&efivars
->lock
);
1536 efivar_unregister(entry
);
1538 if (efivars
->new_var
)
1539 sysfs_remove_bin_file(&efivars
->kset
->kobj
, efivars
->new_var
);
1540 if (efivars
->del_var
)
1541 sysfs_remove_bin_file(&efivars
->kset
->kobj
, efivars
->del_var
);
1542 kfree(efivars
->new_var
);
1543 kfree(efivars
->del_var
);
1544 kobject_put(efivars
->kobject
);
1545 kset_unregister(efivars
->kset
);
1547 EXPORT_SYMBOL_GPL(unregister_efivars
);
1549 int register_efivars(struct efivars
*efivars
,
1550 const struct efivar_operations
*ops
,
1551 struct kobject
*parent_kobj
)
1553 efi_status_t status
= EFI_NOT_FOUND
;
1554 efi_guid_t vendor_guid
;
1555 efi_char16_t
*variable_name
;
1556 unsigned long variable_name_size
= 1024;
1559 variable_name
= kzalloc(variable_name_size
, GFP_KERNEL
);
1560 if (!variable_name
) {
1561 printk(KERN_ERR
"efivars: Memory allocation failed.\n");
1565 spin_lock_init(&efivars
->lock
);
1566 INIT_LIST_HEAD(&efivars
->list
);
1569 efivars
->kset
= kset_create_and_add("vars", NULL
, parent_kobj
);
1570 if (!efivars
->kset
) {
1571 printk(KERN_ERR
"efivars: Subsystem registration failed.\n");
1576 efivars
->kobject
= kobject_create_and_add("efivars", parent_kobj
);
1577 if (!efivars
->kobject
) {
1578 pr_err("efivars: Subsystem registration failed.\n");
1580 kset_unregister(efivars
->kset
);
1585 * Per EFI spec, the maximum storage allocated for both
1586 * the variable name and variable data is 1024 bytes.
1590 variable_name_size
= 1024;
1592 status
= ops
->get_next_variable(&variable_name_size
,
1597 efivar_create_sysfs_entry(efivars
,
1605 printk(KERN_WARNING
"efivars: get_next_variable: status=%lx\n",
1607 status
= EFI_NOT_FOUND
;
1610 } while (status
!= EFI_NOT_FOUND
);
1612 error
= create_efivars_bin_attributes(efivars
);
1614 unregister_efivars(efivars
);
1616 efivars
->efi_pstore_info
= efi_pstore_info
;
1618 efivars
->efi_pstore_info
.buf
= kmalloc(4096, GFP_KERNEL
);
1619 if (efivars
->efi_pstore_info
.buf
) {
1620 efivars
->efi_pstore_info
.bufsize
= 1024;
1621 efivars
->efi_pstore_info
.data
= efivars
;
1622 spin_lock_init(&efivars
->efi_pstore_info
.buf_lock
);
1623 pstore_register(&efivars
->efi_pstore_info
);
1626 register_filesystem(&efivarfs_type
);
1629 kfree(variable_name
);
1633 EXPORT_SYMBOL_GPL(register_efivars
);
1636 * For now we register the efi subsystem with the firmware subsystem
1637 * and the vars subsystem with the efi subsystem. In the future, it
1638 * might make sense to split off the efi subsystem into its own
1639 * driver, but for now only efivars will register with it, so just
1648 printk(KERN_INFO
"EFI Variables Facility v%s %s\n", EFIVARS_VERSION
,
1654 /* For now we'll register the efi directory at /sys/firmware/efi */
1655 efi_kobj
= kobject_create_and_add("efi", firmware_kobj
);
1657 printk(KERN_ERR
"efivars: Firmware registration failed.\n");
1661 ops
.get_variable
= efi
.get_variable
;
1662 ops
.set_variable
= efi
.set_variable
;
1663 ops
.get_next_variable
= efi
.get_next_variable
;
1664 error
= register_efivars(&__efivars
, &ops
, efi_kobj
);
1668 /* Don't forget the systab entry */
1669 error
= sysfs_create_group(efi_kobj
, &efi_subsys_attr_group
);
1672 "efivars: Sysfs attribute export failed with error %d.\n",
1674 goto err_unregister
;
1680 unregister_efivars(&__efivars
);
1682 kobject_put(efi_kobj
);
1690 unregister_efivars(&__efivars
);
1691 kobject_put(efi_kobj
);
1695 module_init(efivars_init
);
1696 module_exit(efivars_exit
);