blob: 7b1c37497c9a2683569f8a1ac9c959e8d5bc7636 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * EFI Variables - efivars.c
3 *
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
6 *
7 * This code takes all variables accessible from EFI runtime and
8 * exports them via sysfs
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 * Changelog:
25 *
26 * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
27 * remove check for efi_enabled in exit
28 * add MODULE_VERSION
29 *
30 * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
31 * minor bug fixes
32 *
33 * 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
34 * converted driver to export variable information via sysfs
35 * and moved to drivers/firmware directory
36 * bumped revision number to v0.07 to reflect conversion & move
37 *
38 * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
39 * fix locking per Peter Chubb's findings
40 *
41 * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
42 * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
43 *
44 * 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
45 * use list_for_each_safe when deleting vars.
46 * remove ifdef CONFIG_SMP around include <linux/smp.h>
47 * v0.04 release to linux-ia64@linuxia64.org
48 *
49 * 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
50 * Moved vars from /proc/efi to /proc/efi/vars, and made
51 * efi.c own the /proc/efi directory.
52 * v0.03 release to linux-ia64@linuxia64.org
53 *
54 * 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
55 * At the request of Stephane, moved ownership of /proc/efi
56 * to efi.c, and now efivars lives under /proc/efi/vars.
57 *
58 * 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
59 * Feedback received from Stephane Eranian incorporated.
60 * efivar_write() checks copy_from_user() return value.
61 * efivar_read/write() returns proper errno.
62 * v0.02 release to linux-ia64@linuxia64.org
63 *
64 * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
65 * v0.01 release to linux-ia64@linuxia64.org
66 */
67
Randy.Dunlapc59ede72006-01-11 12:17:46 -080068#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070069#include <linux/types.h>
70#include <linux/errno.h>
71#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070072#include <linux/mm.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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090080#include <linux/slab.h>
Matthew Garrett5ee9c192011-07-21 16:57:56 -040081#include <linux/pstore.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Matthew Garrett5d9db882012-10-05 13:54:56 +080083#include <linux/fs.h>
84#include <linux/ramfs.h>
85#include <linux/pagemap.h>
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087#include <asm/uaccess.h>
88
89#define EFIVARS_VERSION "0.08"
90#define EFIVARS_DATE "2004-May-17"
91
92MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
93MODULE_DESCRIPTION("sysfs interface to EFI Variables");
94MODULE_LICENSE("GPL");
95MODULE_VERSION(EFIVARS_VERSION);
96
Matthew Garrett5ee9c192011-07-21 16:57:56 -040097#define DUMP_NAME_LEN 52
98
Linus Torvalds1da177e2005-04-16 15:20:36 -070099/*
Jeremy Kerr310ad752012-10-19 15:16:45 +0800100 * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"))
101 * not including trailing NUL
102 */
103#define GUID_LEN 36
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
105/*
106 * The maximum size of VariableName + Data = 1024
107 * Therefore, it's reasonable to save that much
108 * space in each part of the structure,
109 * and we use a page for reading/writing.
110 */
111
112struct efi_variable {
113 efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
114 efi_guid_t VendorGuid;
115 unsigned long DataSize;
116 __u8 Data[1024];
117 efi_status_t Status;
118 __u32 Attributes;
119} __attribute__((packed));
120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121struct efivar_entry {
Mike Waychison4142ef12011-03-11 17:43:11 -0800122 struct efivars *efivars;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 struct efi_variable var;
124 struct list_head list;
125 struct kobject kobj;
126};
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128struct efivar_attribute {
129 struct attribute attr;
130 ssize_t (*show) (struct efivar_entry *entry, char *buf);
131 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
132};
133
Matthew Garrett5d9db882012-10-05 13:54:56 +0800134static struct efivars __efivars;
135static struct efivar_operations ops;
136
Mike Waychison7644c162011-07-21 16:58:00 -0400137#define PSTORE_EFI_ATTRIBUTES \
138 (EFI_VARIABLE_NON_VOLATILE | \
139 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
140 EFI_VARIABLE_RUNTIME_ACCESS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142#define EFIVAR_ATTR(_name, _mode, _show, _store) \
143struct efivar_attribute efivar_attr_##_name = { \
Tejun Heo7b595752007-06-14 03:45:17 +0900144 .attr = {.name = __stringify(_name), .mode = _mode}, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 .show = _show, \
146 .store = _store, \
147};
148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
150#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
151
152/*
153 * Prototype for sysfs creation function
154 */
155static int
Mike Waychison4142ef12011-03-11 17:43:11 -0800156efivar_create_sysfs_entry(struct efivars *efivars,
157 unsigned long variable_name_size,
158 efi_char16_t *variable_name,
159 efi_guid_t *vendor_guid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160
161/* Return the number of unicode characters in data */
162static unsigned long
Mike Waychisona2940902011-07-21 16:57:57 -0400163utf16_strnlen(efi_char16_t *s, size_t maxlength)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164{
165 unsigned long length = 0;
166
Mike Waychisona2940902011-07-21 16:57:57 -0400167 while (*s++ != 0 && length < maxlength)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 length++;
169 return length;
170}
171
Tony Luckb728a5c2011-08-02 15:08:30 -0700172static inline unsigned long
Mike Waychisona2940902011-07-21 16:57:57 -0400173utf16_strlen(efi_char16_t *s)
174{
175 return utf16_strnlen(s, ~0UL);
176}
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178/*
179 * Return the number of bytes is the length of this string
180 * Note: this is NOT the same as the number of unicode characters
181 */
182static inline unsigned long
Mike Waychisona2940902011-07-21 16:57:57 -0400183utf16_strsize(efi_char16_t *data, unsigned long maxlength)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184{
Mike Waychisona2940902011-07-21 16:57:57 -0400185 return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186}
187
Mike Waychison828aa1f2011-07-21 16:57:58 -0400188static inline int
189utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len)
190{
191 while (1) {
192 if (len == 0)
193 return 0;
194 if (*a < *b)
195 return -1;
196 if (*a > *b)
197 return 1;
198 if (*a == 0) /* implies *b == 0 */
199 return 0;
200 a++;
201 b++;
202 len--;
203 }
204}
205
Matthew Garrettfec6c202012-04-30 16:11:30 -0400206static bool
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400207validate_device_path(struct efi_variable *var, int match, u8 *buffer,
208 unsigned long len)
Matthew Garrettfec6c202012-04-30 16:11:30 -0400209{
210 struct efi_generic_dev_path *node;
211 int offset = 0;
212
213 node = (struct efi_generic_dev_path *)buffer;
214
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400215 if (len < sizeof(*node))
216 return false;
Matthew Garrettfec6c202012-04-30 16:11:30 -0400217
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400218 while (offset <= len - sizeof(*node) &&
219 node->length >= sizeof(*node) &&
220 node->length <= len - offset) {
221 offset += node->length;
Matthew Garrettfec6c202012-04-30 16:11:30 -0400222
223 if ((node->type == EFI_DEV_END_PATH ||
224 node->type == EFI_DEV_END_PATH2) &&
225 node->sub_type == EFI_DEV_END_ENTIRE)
226 return true;
227
228 node = (struct efi_generic_dev_path *)(buffer + offset);
229 }
230
231 /*
232 * If we're here then either node->length pointed past the end
233 * of the buffer or we reached the end of the buffer without
234 * finding a device path end node.
235 */
236 return false;
237}
238
239static bool
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400240validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
241 unsigned long len)
Matthew Garrettfec6c202012-04-30 16:11:30 -0400242{
243 /* An array of 16-bit integers */
244 if ((len % 2) != 0)
245 return false;
246
247 return true;
248}
249
250static bool
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400251validate_load_option(struct efi_variable *var, int match, u8 *buffer,
252 unsigned long len)
Matthew Garrettfec6c202012-04-30 16:11:30 -0400253{
254 u16 filepathlength;
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400255 int i, desclength = 0, namelen;
256
257 namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
Matthew Garrettfec6c202012-04-30 16:11:30 -0400258
259 /* Either "Boot" or "Driver" followed by four digits of hex */
260 for (i = match; i < match+4; i++) {
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400261 if (var->VariableName[i] > 127 ||
262 hex_to_bin(var->VariableName[i] & 0xff) < 0)
Matthew Garrettfec6c202012-04-30 16:11:30 -0400263 return true;
264 }
265
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400266 /* Reject it if there's 4 digits of hex and then further content */
267 if (namelen > match + 4)
268 return false;
269
270 /* A valid entry must be at least 8 bytes */
271 if (len < 8)
Matthew Garrettfec6c202012-04-30 16:11:30 -0400272 return false;
273
274 filepathlength = buffer[4] | buffer[5] << 8;
275
276 /*
277 * There's no stored length for the description, so it has to be
278 * found by hand
279 */
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400280 desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
Matthew Garrettfec6c202012-04-30 16:11:30 -0400281
282 /* Each boot entry must have a descriptor */
283 if (!desclength)
284 return false;
285
286 /*
287 * If the sum of the length of the description, the claimed filepath
288 * length and the original header are greater than the length of the
289 * variable, it's malformed
290 */
291 if ((desclength + filepathlength + 6) > len)
292 return false;
293
294 /*
295 * And, finally, check the filepath
296 */
297 return validate_device_path(var, match, buffer + desclength + 6,
298 filepathlength);
299}
300
301static bool
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400302validate_uint16(struct efi_variable *var, int match, u8 *buffer,
303 unsigned long len)
Matthew Garrettfec6c202012-04-30 16:11:30 -0400304{
305 /* A single 16-bit integer */
306 if (len != 2)
307 return false;
308
309 return true;
310}
311
312static bool
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400313validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
314 unsigned long len)
Matthew Garrettfec6c202012-04-30 16:11:30 -0400315{
316 int i;
317
318 for (i = 0; i < len; i++) {
319 if (buffer[i] > 127)
320 return false;
321
322 if (buffer[i] == 0)
323 return true;
324 }
325
326 return false;
327}
328
329struct variable_validate {
330 char *name;
331 bool (*validate)(struct efi_variable *var, int match, u8 *data,
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400332 unsigned long len);
Matthew Garrettfec6c202012-04-30 16:11:30 -0400333};
334
335static const struct variable_validate variable_validate[] = {
336 { "BootNext", validate_uint16 },
337 { "BootOrder", validate_boot_order },
338 { "DriverOrder", validate_boot_order },
339 { "Boot*", validate_load_option },
340 { "Driver*", validate_load_option },
341 { "ConIn", validate_device_path },
342 { "ConInDev", validate_device_path },
343 { "ConOut", validate_device_path },
344 { "ConOutDev", validate_device_path },
345 { "ErrOut", validate_device_path },
346 { "ErrOutDev", validate_device_path },
347 { "Timeout", validate_uint16 },
348 { "Lang", validate_ascii_string },
349 { "PlatformLang", validate_ascii_string },
350 { "", NULL },
351};
352
353static bool
Matthew Garrett54b3a4d2012-05-03 16:50:46 -0400354validate_var(struct efi_variable *var, u8 *data, unsigned long len)
Matthew Garrettfec6c202012-04-30 16:11:30 -0400355{
356 int i;
357 u16 *unicode_name = var->VariableName;
358
359 for (i = 0; variable_validate[i].validate != NULL; i++) {
360 const char *name = variable_validate[i].name;
361 int match;
362
363 for (match = 0; ; match++) {
364 char c = name[match];
365 u16 u = unicode_name[match];
366
367 /* All special variables are plain ascii */
368 if (u > 127)
369 return true;
370
371 /* Wildcard in the matching name means we've matched */
372 if (c == '*')
373 return variable_validate[i].validate(var,
374 match, data, len);
375
376 /* Case sensitive match */
377 if (c != u)
378 break;
379
380 /* Reached the end of the string while matching */
381 if (!c)
382 return variable_validate[i].validate(var,
383 match, data, len);
384 }
385 }
386
387 return true;
388}
389
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390static efi_status_t
Matthew Garrett5ee9c192011-07-21 16:57:56 -0400391get_var_data_locked(struct efivars *efivars, struct efi_variable *var)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392{
393 efi_status_t status;
394
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 var->DataSize = 1024;
Mike Waychison32958142011-03-11 17:43:21 -0800396 status = efivars->ops->get_variable(var->VariableName,
397 &var->VendorGuid,
398 &var->Attributes,
399 &var->DataSize,
400 var->Data);
Matthew Garrett5ee9c192011-07-21 16:57:56 -0400401 return status;
402}
403
404static efi_status_t
405get_var_data(struct efivars *efivars, struct efi_variable *var)
406{
407 efi_status_t status;
408
409 spin_lock(&efivars->lock);
410 status = get_var_data_locked(efivars, var);
Mike Waychison29422692011-03-11 17:43:00 -0800411 spin_unlock(&efivars->lock);
Matthew Garrett5ee9c192011-07-21 16:57:56 -0400412
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 if (status != EFI_SUCCESS) {
414 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
415 status);
416 }
417 return status;
418}
419
420static ssize_t
421efivar_guid_read(struct efivar_entry *entry, char *buf)
422{
423 struct efi_variable *var = &entry->var;
424 char *str = buf;
425
426 if (!entry || !buf)
427 return 0;
428
429 efi_guid_unparse(&var->VendorGuid, str);
430 str += strlen(str);
431 str += sprintf(str, "\n");
432
433 return str - buf;
434}
435
436static ssize_t
437efivar_attr_read(struct efivar_entry *entry, char *buf)
438{
439 struct efi_variable *var = &entry->var;
440 char *str = buf;
441 efi_status_t status;
442
443 if (!entry || !buf)
444 return -EINVAL;
445
Mike Waychison4142ef12011-03-11 17:43:11 -0800446 status = get_var_data(entry->efivars, var);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 if (status != EFI_SUCCESS)
448 return -EIO;
449
Khalid Aziz70839092012-09-10 12:52:42 -0600450 if (var->Attributes & EFI_VARIABLE_NON_VOLATILE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
Khalid Aziz70839092012-09-10 12:52:42 -0600452 if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
Khalid Aziz70839092012-09-10 12:52:42 -0600454 if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
Khalid Aziz70839092012-09-10 12:52:42 -0600456 if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD)
457 str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
458 if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
459 str += sprintf(str,
460 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
461 if (var->Attributes &
462 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
463 str += sprintf(str,
464 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
465 if (var->Attributes & EFI_VARIABLE_APPEND_WRITE)
466 str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 return str - buf;
468}
469
470static ssize_t
471efivar_size_read(struct efivar_entry *entry, char *buf)
472{
473 struct efi_variable *var = &entry->var;
474 char *str = buf;
475 efi_status_t status;
476
477 if (!entry || !buf)
478 return -EINVAL;
479
Mike Waychison4142ef12011-03-11 17:43:11 -0800480 status = get_var_data(entry->efivars, var);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 if (status != EFI_SUCCESS)
482 return -EIO;
483
484 str += sprintf(str, "0x%lx\n", var->DataSize);
485 return str - buf;
486}
487
488static ssize_t
489efivar_data_read(struct efivar_entry *entry, char *buf)
490{
491 struct efi_variable *var = &entry->var;
492 efi_status_t status;
493
494 if (!entry || !buf)
495 return -EINVAL;
496
Mike Waychison4142ef12011-03-11 17:43:11 -0800497 status = get_var_data(entry->efivars, var);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 if (status != EFI_SUCCESS)
499 return -EIO;
500
501 memcpy(buf, var->Data, var->DataSize);
502 return var->DataSize;
503}
504/*
505 * We allow each variable to be edited via rewriting the
506 * entire efi variable structure.
507 */
508static ssize_t
509efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
510{
511 struct efi_variable *new_var, *var = &entry->var;
Mike Waychison4142ef12011-03-11 17:43:11 -0800512 struct efivars *efivars = entry->efivars;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 efi_status_t status = EFI_NOT_FOUND;
514
515 if (count != sizeof(struct efi_variable))
516 return -EINVAL;
517
518 new_var = (struct efi_variable *)buf;
519 /*
520 * If only updating the variable data, then the name
521 * and guid should remain the same
522 */
523 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
524 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
525 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
526 return -EINVAL;
527 }
528
529 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
530 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
531 return -EINVAL;
532 }
533
Matthew Garrettfec6c202012-04-30 16:11:30 -0400534 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
535 validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
536 printk(KERN_ERR "efivars: Malformed variable content\n");
537 return -EINVAL;
538 }
539
Mike Waychison29422692011-03-11 17:43:00 -0800540 spin_lock(&efivars->lock);
Mike Waychison32958142011-03-11 17:43:21 -0800541 status = efivars->ops->set_variable(new_var->VariableName,
542 &new_var->VendorGuid,
543 new_var->Attributes,
544 new_var->DataSize,
545 new_var->Data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
Mike Waychison29422692011-03-11 17:43:00 -0800547 spin_unlock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
549 if (status != EFI_SUCCESS) {
550 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
551 status);
552 return -EIO;
553 }
554
555 memcpy(&entry->var, new_var, count);
556 return count;
557}
558
559static ssize_t
560efivar_show_raw(struct efivar_entry *entry, char *buf)
561{
562 struct efi_variable *var = &entry->var;
563 efi_status_t status;
564
565 if (!entry || !buf)
566 return 0;
567
Mike Waychison4142ef12011-03-11 17:43:11 -0800568 status = get_var_data(entry->efivars, var);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 if (status != EFI_SUCCESS)
570 return -EIO;
571
572 memcpy(buf, var, sizeof(*var));
573 return sizeof(*var);
574}
575
576/*
577 * Generic read/write functions that call the specific functions of
Justin P. Mattock70f23fd2011-05-10 10:16:21 +0200578 * the attributes...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 */
580static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
581 char *buf)
582{
583 struct efivar_entry *var = to_efivar_entry(kobj);
584 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500585 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586
587 if (!capable(CAP_SYS_ADMIN))
588 return -EACCES;
589
590 if (efivar_attr->show) {
591 ret = efivar_attr->show(var, buf);
592 }
593 return ret;
594}
595
596static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
597 const char *buf, size_t count)
598{
599 struct efivar_entry *var = to_efivar_entry(kobj);
600 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500601 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
603 if (!capable(CAP_SYS_ADMIN))
604 return -EACCES;
605
606 if (efivar_attr->store)
607 ret = efivar_attr->store(var, buf, count);
608
609 return ret;
610}
611
Emese Revfy52cf25d2010-01-19 02:58:23 +0100612static const struct sysfs_ops efivar_attr_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 .show = efivar_attr_show,
614 .store = efivar_attr_store,
615};
616
617static void efivar_release(struct kobject *kobj)
618{
619 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 kfree(var);
621}
622
623static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
624static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
625static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
626static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
627static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
628
629static struct attribute *def_attrs[] = {
630 &efivar_attr_guid.attr,
631 &efivar_attr_size.attr,
632 &efivar_attr_attributes.attr,
633 &efivar_attr_data.attr,
634 &efivar_attr_raw_var.attr,
635 NULL,
636};
637
Greg Kroah-Hartmane89a4112007-10-11 10:47:49 -0600638static struct kobj_type efivar_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 .release = efivar_release,
640 .sysfs_ops = &efivar_attr_ops,
641 .default_attrs = def_attrs,
642};
643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644static inline void
645efivar_unregister(struct efivar_entry *var)
646{
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800647 kobject_put(&var->kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648}
649
Matthew Garrett5d9db882012-10-05 13:54:56 +0800650static int efivarfs_file_open(struct inode *inode, struct file *file)
651{
652 file->private_data = inode->i_private;
653 return 0;
654}
655
Matt Fleming7253eab2012-10-16 15:58:07 +0100656static int efi_status_to_err(efi_status_t status)
657{
658 int err;
659
660 switch (status) {
661 case EFI_INVALID_PARAMETER:
662 err = -EINVAL;
663 break;
664 case EFI_OUT_OF_RESOURCES:
665 err = -ENOSPC;
666 break;
667 case EFI_DEVICE_ERROR:
668 err = -EIO;
669 break;
670 case EFI_WRITE_PROTECTED:
671 err = -EROFS;
672 break;
673 case EFI_SECURITY_VIOLATION:
674 err = -EACCES;
675 break;
676 case EFI_NOT_FOUND:
677 err = -ENOENT;
678 break;
679 default:
680 err = -EINVAL;
681 }
682
683 return err;
684}
685
Matthew Garrett5d9db882012-10-05 13:54:56 +0800686static ssize_t efivarfs_file_write(struct file *file,
687 const char __user *userbuf, size_t count, loff_t *ppos)
688{
689 struct efivar_entry *var = file->private_data;
690 struct efivars *efivars;
691 efi_status_t status;
692 void *data;
693 u32 attributes;
694 struct inode *inode = file->f_mapping->host;
Matt Fleming07b1c5b2012-10-23 12:35:43 +0100695 unsigned long datasize = count - sizeof(attributes);
Jeremy Kerr0c542ed2012-10-05 13:54:56 +0800696 unsigned long newdatasize;
Matt Fleming89d16662012-11-09 21:02:56 +0000697 u64 storage_size, remaining_size, max_size;
Matt Flemingcfcf2f12012-10-26 12:18:53 +0100698 ssize_t bytes = 0;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800699
700 if (count < sizeof(attributes))
701 return -EINVAL;
702
Matt Fleming89d16662012-11-09 21:02:56 +0000703 if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
704 return -EFAULT;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800705
Matt Fleming89d16662012-11-09 21:02:56 +0000706 if (attributes & ~(EFI_VARIABLE_MASK))
707 return -EINVAL;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800708
709 efivars = var->efivars;
710
Matt Fleming89d16662012-11-09 21:02:56 +0000711 /*
712 * Ensure that the user can't allocate arbitrarily large
713 * amounts of memory. Pick a default size of 64K if
714 * QueryVariableInfo() isn't supported by the firmware.
715 */
716 spin_lock(&efivars->lock);
717
718 if (!efivars->ops->query_variable_info)
719 status = EFI_UNSUPPORTED;
720 else {
721 const struct efivar_operations *fops = efivars->ops;
722 status = fops->query_variable_info(attributes, &storage_size,
723 &remaining_size, &max_size);
Matthew Garrett5d9db882012-10-05 13:54:56 +0800724 }
725
Matt Fleming89d16662012-11-09 21:02:56 +0000726 spin_unlock(&efivars->lock);
727
728 if (status != EFI_SUCCESS) {
729 if (status != EFI_UNSUPPORTED)
730 return efi_status_to_err(status);
731
732 remaining_size = 65536;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800733 }
734
Matt Fleming89d16662012-11-09 21:02:56 +0000735 if (datasize > remaining_size)
736 return -ENOSPC;
737
738 data = kmalloc(datasize, GFP_KERNEL);
739 if (!data)
740 return -ENOMEM;
741
Matthew Garrett5d9db882012-10-05 13:54:56 +0800742 if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
Matt Flemingcfcf2f12012-10-26 12:18:53 +0100743 bytes = -EFAULT;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800744 goto out;
745 }
746
747 if (validate_var(&var->var, data, datasize) == false) {
Matt Flemingcfcf2f12012-10-26 12:18:53 +0100748 bytes = -EINVAL;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800749 goto out;
750 }
751
Jeremy Kerrf5f6a602012-10-11 21:19:11 +0800752 /*
753 * The lock here protects the get_variable call, the conditional
754 * set_variable call, and removal of the variable from the efivars
755 * list (in the case of an authenticated delete).
756 */
757 spin_lock(&efivars->lock);
758
Matthew Garrett5d9db882012-10-05 13:54:56 +0800759 status = efivars->ops->set_variable(var->var.VariableName,
760 &var->var.VendorGuid,
761 attributes, datasize,
762 data);
763
Jeremy Kerrf5f6a602012-10-11 21:19:11 +0800764 if (status != EFI_SUCCESS) {
765 spin_unlock(&efivars->lock);
766 kfree(data);
767
Matt Fleming7253eab2012-10-16 15:58:07 +0100768 return efi_status_to_err(status);
Matthew Garrett5d9db882012-10-05 13:54:56 +0800769 }
Jeremy Kerr0c542ed2012-10-05 13:54:56 +0800770
Matt Flemingcfcf2f12012-10-26 12:18:53 +0100771 bytes = count;
772
Jeremy Kerr0c542ed2012-10-05 13:54:56 +0800773 /*
774 * Writing to the variable may have caused a change in size (which
775 * could either be an append or an overwrite), or the variable to be
776 * deleted. Perform a GetVariable() so we can tell what actually
777 * happened.
778 */
779 newdatasize = 0;
780 status = efivars->ops->get_variable(var->var.VariableName,
781 &var->var.VendorGuid,
782 NULL, &newdatasize,
783 NULL);
784
785 if (status == EFI_BUFFER_TOO_SMALL) {
Jeremy Kerrf5f6a602012-10-11 21:19:11 +0800786 spin_unlock(&efivars->lock);
Jeremy Kerr0c542ed2012-10-05 13:54:56 +0800787 mutex_lock(&inode->i_mutex);
788 i_size_write(inode, newdatasize + sizeof(attributes));
789 mutex_unlock(&inode->i_mutex);
790
791 } else if (status == EFI_NOT_FOUND) {
Jeremy Kerr0c542ed2012-10-05 13:54:56 +0800792 list_del(&var->list);
793 spin_unlock(&efivars->lock);
794 efivar_unregister(var);
795 drop_nlink(inode);
796 dput(file->f_dentry);
797
798 } else {
Jeremy Kerrf5f6a602012-10-11 21:19:11 +0800799 spin_unlock(&efivars->lock);
Jeremy Kerr0c542ed2012-10-05 13:54:56 +0800800 pr_warn("efivarfs: inconsistent EFI variable implementation? "
801 "status = %lx\n", status);
802 }
803
Matthew Garrett5d9db882012-10-05 13:54:56 +0800804out:
805 kfree(data);
806
Matt Flemingcfcf2f12012-10-26 12:18:53 +0100807 return bytes;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800808}
809
810static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
811 size_t count, loff_t *ppos)
812{
813 struct efivar_entry *var = file->private_data;
814 struct efivars *efivars = var->efivars;
815 efi_status_t status;
816 unsigned long datasize = 0;
817 u32 attributes;
818 void *data;
Andy Whitcroftd142df02012-10-11 11:32:17 +0100819 ssize_t size = 0;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800820
Jeremy Kerrf5f6a602012-10-11 21:19:11 +0800821 spin_lock(&efivars->lock);
Matthew Garrett5d9db882012-10-05 13:54:56 +0800822 status = efivars->ops->get_variable(var->var.VariableName,
823 &var->var.VendorGuid,
824 &attributes, &datasize, NULL);
Jeremy Kerrf5f6a602012-10-11 21:19:11 +0800825 spin_unlock(&efivars->lock);
Matthew Garrett5d9db882012-10-05 13:54:56 +0800826
827 if (status != EFI_BUFFER_TOO_SMALL)
Matt Fleming7253eab2012-10-16 15:58:07 +0100828 return efi_status_to_err(status);
Matthew Garrett5d9db882012-10-05 13:54:56 +0800829
Matt Flemingd2923842012-10-22 15:23:29 +0100830 data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
Matthew Garrett5d9db882012-10-05 13:54:56 +0800831
832 if (!data)
Matt Fleming7253eab2012-10-16 15:58:07 +0100833 return -ENOMEM;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800834
Jeremy Kerrf5f6a602012-10-11 21:19:11 +0800835 spin_lock(&efivars->lock);
Matthew Garrett5d9db882012-10-05 13:54:56 +0800836 status = efivars->ops->get_variable(var->var.VariableName,
837 &var->var.VendorGuid,
838 &attributes, &datasize,
Matt Flemingd2923842012-10-22 15:23:29 +0100839 (data + sizeof(attributes)));
Jeremy Kerrf5f6a602012-10-11 21:19:11 +0800840 spin_unlock(&efivars->lock);
841
Matt Fleming7253eab2012-10-16 15:58:07 +0100842 if (status != EFI_SUCCESS) {
843 size = efi_status_to_err(status);
Andy Whitcroftd142df02012-10-11 11:32:17 +0100844 goto out_free;
Matt Fleming7253eab2012-10-16 15:58:07 +0100845 }
Matthew Garrett5d9db882012-10-05 13:54:56 +0800846
Matt Flemingd2923842012-10-22 15:23:29 +0100847 memcpy(data, &attributes, sizeof(attributes));
Matthew Garrett5d9db882012-10-05 13:54:56 +0800848 size = simple_read_from_buffer(userbuf, count, ppos,
Matt Flemingd2923842012-10-22 15:23:29 +0100849 data, datasize + sizeof(attributes));
Andy Whitcroftd142df02012-10-11 11:32:17 +0100850out_free:
Matthew Garrett5d9db882012-10-05 13:54:56 +0800851 kfree(data);
852
853 return size;
854}
855
856static void efivarfs_evict_inode(struct inode *inode)
857{
858 clear_inode(inode);
859}
860
861static const struct super_operations efivarfs_ops = {
862 .statfs = simple_statfs,
863 .drop_inode = generic_delete_inode,
864 .evict_inode = efivarfs_evict_inode,
865 .show_options = generic_show_options,
866};
867
868static struct super_block *efivarfs_sb;
869
870static const struct inode_operations efivarfs_dir_inode_operations;
871
872static const struct file_operations efivarfs_file_operations = {
873 .open = efivarfs_file_open,
874 .read = efivarfs_file_read,
875 .write = efivarfs_file_write,
876 .llseek = no_llseek,
877};
878
879static struct inode *efivarfs_get_inode(struct super_block *sb,
880 const struct inode *dir, int mode, dev_t dev)
881{
882 struct inode *inode = new_inode(sb);
883
884 if (inode) {
885 inode->i_ino = get_next_ino();
Matthew Garrett5d9db882012-10-05 13:54:56 +0800886 inode->i_mode = mode;
887 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
888 switch (mode & S_IFMT) {
889 case S_IFREG:
890 inode->i_fop = &efivarfs_file_operations;
891 break;
892 case S_IFDIR:
893 inode->i_op = &efivarfs_dir_inode_operations;
894 inode->i_fop = &simple_dir_operations;
895 inc_nlink(inode);
896 break;
897 }
898 }
899 return inode;
900}
901
902static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid)
903{
904 guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]);
905 guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]);
906 guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]);
907 guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]);
908 guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]);
909 guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]);
910 guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]);
911 guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]);
912 guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]);
913 guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]);
914 guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]);
915 guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]);
916 guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]);
917 guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]);
918 guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]);
919 guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]);
920}
921
922static int efivarfs_create(struct inode *dir, struct dentry *dentry,
923 umode_t mode, bool excl)
924{
Andy Whitcroft45a937a2012-10-11 11:32:18 +0100925 struct inode *inode;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800926 struct efivars *efivars = &__efivars;
927 struct efivar_entry *var;
928 int namelen, i = 0, err = 0;
929
Jeremy Kerr310ad752012-10-19 15:16:45 +0800930 /*
931 * We need a GUID, plus at least one letter for the variable name,
932 * plus the '-' separator
933 */
934 if (dentry->d_name.len < GUID_LEN + 2)
Matthew Garrett5d9db882012-10-05 13:54:56 +0800935 return -EINVAL;
936
Andy Whitcroft45a937a2012-10-11 11:32:18 +0100937 inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
Matthew Garrett5d9db882012-10-05 13:54:56 +0800938 if (!inode)
Matt Flemingaeeaa8d2012-10-23 12:41:03 +0100939 return -ENOMEM;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800940
941 var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
Andy Whitcroft45a937a2012-10-11 11:32:18 +0100942 if (!var) {
943 err = -ENOMEM;
944 goto out;
945 }
Matthew Garrett5d9db882012-10-05 13:54:56 +0800946
Jeremy Kerr310ad752012-10-19 15:16:45 +0800947 /* length of the variable name itself: remove GUID and separator */
948 namelen = dentry->d_name.len - GUID_LEN - 1;
Matthew Garrett5d9db882012-10-05 13:54:56 +0800949
950 efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1,
951 &var->var.VendorGuid);
952
953 for (i = 0; i < namelen; i++)
954 var->var.VariableName[i] = dentry->d_name.name[i];
955
956 var->var.VariableName[i] = '\0';
957
958 inode->i_private = var;
959 var->efivars = efivars;
960 var->kobj.kset = efivars->kset;
961
962 err = kobject_init_and_add(&var->kobj, &efivar_ktype, NULL, "%s",
963 dentry->d_name.name);
964 if (err)
965 goto out;
966
967 kobject_uevent(&var->kobj, KOBJ_ADD);
968 spin_lock(&efivars->lock);
969 list_add(&var->list, &efivars->list);
970 spin_unlock(&efivars->lock);
971 d_instantiate(dentry, inode);
972 dget(dentry);
973out:
Andy Whitcroft45a937a2012-10-11 11:32:18 +0100974 if (err) {
Matthew Garrett5d9db882012-10-05 13:54:56 +0800975 kfree(var);
Andy Whitcroft45a937a2012-10-11 11:32:18 +0100976 iput(inode);
977 }
Matthew Garrett5d9db882012-10-05 13:54:56 +0800978 return err;
979}
980
981static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
982{
983 struct efivar_entry *var = dentry->d_inode->i_private;
984 struct efivars *efivars = var->efivars;
985 efi_status_t status;
986
987 spin_lock(&efivars->lock);
988
989 status = efivars->ops->set_variable(var->var.VariableName,
990 &var->var.VendorGuid,
991 0, 0, NULL);
992
993 if (status == EFI_SUCCESS || status == EFI_NOT_FOUND) {
994 list_del(&var->list);
995 spin_unlock(&efivars->lock);
996 efivar_unregister(var);
997 drop_nlink(dir);
998 dput(dentry);
999 return 0;
1000 }
1001
1002 spin_unlock(&efivars->lock);
1003 return -EINVAL;
1004};
1005
Matt Fleminge83af1f2012-11-15 20:03:16 +00001006static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
Matthew Garrett5d9db882012-10-05 13:54:56 +08001007{
1008 struct inode *inode = NULL;
1009 struct dentry *root;
1010 struct efivar_entry *entry, *n;
1011 struct efivars *efivars = &__efivars;
Andy Whitcroft5ba6e292012-10-11 11:32:21 +01001012 char *name;
Matthew Garrett5d9db882012-10-05 13:54:56 +08001013
1014 efivarfs_sb = sb;
1015
1016 sb->s_maxbytes = MAX_LFS_FILESIZE;
1017 sb->s_blocksize = PAGE_CACHE_SIZE;
1018 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
Matt Fleming91716322012-10-22 15:51:45 +01001019 sb->s_magic = EFIVARFS_MAGIC;
Matthew Garrett5d9db882012-10-05 13:54:56 +08001020 sb->s_op = &efivarfs_ops;
1021 sb->s_time_gran = 1;
1022
1023 inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0);
Andy Whitcroft5c9b50a2012-10-11 11:32:19 +01001024 if (!inode)
1025 return -ENOMEM;
Matthew Garrett5d9db882012-10-05 13:54:56 +08001026 inode->i_op = &efivarfs_dir_inode_operations;
1027
1028 root = d_make_root(inode);
1029 sb->s_root = root;
Andy Whitcroft5c9b50a2012-10-11 11:32:19 +01001030 if (!root)
1031 return -ENOMEM;
Matthew Garrett5d9db882012-10-05 13:54:56 +08001032
1033 list_for_each_entry_safe(entry, n, &efivars->list, list) {
Matthew Garrett5d9db882012-10-05 13:54:56 +08001034 struct dentry *dentry, *root = efivarfs_sb->s_root;
Matthew Garrett5d9db882012-10-05 13:54:56 +08001035 unsigned long size = 0;
1036 int len, i;
1037
Andy Whitcroft5ba6e292012-10-11 11:32:21 +01001038 inode = NULL;
1039
Matthew Garrett5d9db882012-10-05 13:54:56 +08001040 len = utf16_strlen(entry->var.VariableName);
1041
Jeremy Kerr310ad752012-10-19 15:16:45 +08001042 /* name, plus '-', plus GUID, plus NUL*/
1043 name = kmalloc(len + 1 + GUID_LEN + 1, GFP_ATOMIC);
Andy Whitcroft5ba6e292012-10-11 11:32:21 +01001044 if (!name)
1045 goto fail;
Matthew Garrett5d9db882012-10-05 13:54:56 +08001046
1047 for (i = 0; i < len; i++)
1048 name[i] = entry->var.VariableName[i] & 0xFF;
1049
1050 name[len] = '-';
1051
1052 efi_guid_unparse(&entry->var.VendorGuid, name + len + 1);
1053
Jeremy Kerr310ad752012-10-19 15:16:45 +08001054 name[len+GUID_LEN+1] = '\0';
Matthew Garrett5d9db882012-10-05 13:54:56 +08001055
1056 inode = efivarfs_get_inode(efivarfs_sb, root->d_inode,
1057 S_IFREG | 0644, 0);
Andy Whitcroft5ba6e292012-10-11 11:32:21 +01001058 if (!inode)
1059 goto fail_name;
1060
Matthew Garrett5d9db882012-10-05 13:54:56 +08001061 dentry = d_alloc_name(root, name);
Andy Whitcroft5ba6e292012-10-11 11:32:21 +01001062 if (!dentry)
1063 goto fail_inode;
1064
Andy Whitcroftc0359db2012-10-11 11:32:20 +01001065 /* copied by the above to local storage in the dentry. */
1066 kfree(name);
Matthew Garrett5d9db882012-10-05 13:54:56 +08001067
Jeremy Kerrf5f6a602012-10-11 21:19:11 +08001068 spin_lock(&efivars->lock);
Matthew Garrett5d9db882012-10-05 13:54:56 +08001069 efivars->ops->get_variable(entry->var.VariableName,
1070 &entry->var.VendorGuid,
1071 &entry->var.Attributes,
1072 &size,
1073 NULL);
Jeremy Kerrf5f6a602012-10-11 21:19:11 +08001074 spin_unlock(&efivars->lock);
Matthew Garrett5d9db882012-10-05 13:54:56 +08001075
1076 mutex_lock(&inode->i_mutex);
1077 inode->i_private = entry;
1078 i_size_write(inode, size+4);
1079 mutex_unlock(&inode->i_mutex);
1080 d_add(dentry, inode);
1081 }
1082
1083 return 0;
Andy Whitcroft5ba6e292012-10-11 11:32:21 +01001084
1085fail_inode:
1086 iput(inode);
1087fail_name:
1088 kfree(name);
1089fail:
1090 return -ENOMEM;
Matthew Garrett5d9db882012-10-05 13:54:56 +08001091}
1092
1093static struct dentry *efivarfs_mount(struct file_system_type *fs_type,
1094 int flags, const char *dev_name, void *data)
1095{
1096 return mount_single(fs_type, flags, data, efivarfs_fill_super);
1097}
1098
1099static void efivarfs_kill_sb(struct super_block *sb)
1100{
1101 kill_litter_super(sb);
1102 efivarfs_sb = NULL;
1103}
1104
1105static struct file_system_type efivarfs_type = {
1106 .name = "efivarfs",
1107 .mount = efivarfs_mount,
1108 .kill_sb = efivarfs_kill_sb,
1109};
1110
1111static const struct inode_operations efivarfs_dir_inode_operations = {
1112 .lookup = simple_lookup,
1113 .unlink = efivarfs_unlink,
1114 .create = efivarfs_create,
1115};
1116
1117static struct pstore_info efi_pstore_info;
1118
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001119#ifdef CONFIG_PSTORE
1120
1121static int efi_pstore_open(struct pstore_info *psi)
1122{
1123 struct efivars *efivars = psi->data;
1124
1125 spin_lock(&efivars->lock);
1126 efivars->walk_entry = list_first_entry(&efivars->list,
1127 struct efivar_entry, list);
1128 return 0;
1129}
1130
1131static int efi_pstore_close(struct pstore_info *psi)
1132{
1133 struct efivars *efivars = psi->data;
1134
1135 spin_unlock(&efivars->lock);
1136 return 0;
1137}
1138
1139static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001140 int *count, struct timespec *timespec,
Kees Cookf6f82852011-11-17 12:58:07 -08001141 char **buf, struct pstore_info *psi)
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001142{
1143 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
1144 struct efivars *efivars = psi->data;
1145 char name[DUMP_NAME_LEN];
1146 int i;
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001147 int cnt;
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001148 unsigned int part, size;
1149 unsigned long time;
1150
1151 while (&efivars->walk_entry->list != &efivars->list) {
1152 if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid,
1153 vendor)) {
1154 for (i = 0; i < DUMP_NAME_LEN; i++) {
1155 name[i] = efivars->walk_entry->var.VariableName[i];
1156 }
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001157 if (sscanf(name, "dump-type%u-%u-%d-%lu",
1158 type, &part, &cnt, &time) == 4) {
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001159 *id = part;
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001160 *count = cnt;
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001161 timespec->tv_sec = time;
1162 timespec->tv_nsec = 0;
Seiji Aguchi0f7de852012-11-14 20:28:50 +00001163 } else if (sscanf(name, "dump-type%u-%u-%lu",
1164 type, &part, &time) == 3) {
1165 /*
1166 * Check if an old format,
1167 * which doesn't support holding
1168 * multiple logs, remains.
1169 */
1170 *id = part;
1171 *count = 0;
1172 timespec->tv_sec = time;
1173 timespec->tv_nsec = 0;
1174 } else {
1175 efivars->walk_entry = list_entry(
1176 efivars->walk_entry->list.next,
1177 struct efivar_entry, list);
1178 continue;
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001179 }
Seiji Aguchi0f7de852012-11-14 20:28:50 +00001180
1181 get_var_data_locked(efivars, &efivars->walk_entry->var);
1182 size = efivars->walk_entry->var.DataSize;
1183 *buf = kmalloc(size, GFP_KERNEL);
1184 if (*buf == NULL)
1185 return -ENOMEM;
1186 memcpy(*buf, efivars->walk_entry->var.Data,
1187 size);
1188 efivars->walk_entry = list_entry(
1189 efivars->walk_entry->list.next,
1190 struct efivar_entry, list);
1191 return size;
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001192 }
1193 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
1194 struct efivar_entry, list);
1195 }
1196 return 0;
1197}
1198
Kees Cook3d6d8d22011-11-17 13:13:29 -08001199static int efi_pstore_write(enum pstore_type_id type,
1200 enum kmsg_dump_reason reason, u64 *id,
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001201 unsigned int part, int count, size_t size,
1202 struct pstore_info *psi)
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001203{
1204 char name[DUMP_NAME_LEN];
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001205 efi_char16_t efi_name[DUMP_NAME_LEN];
1206 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
1207 struct efivars *efivars = psi->data;
Chen Gongb238b8f2011-10-12 09:17:24 -07001208 int i, ret = 0;
Seiji Aguchid80a3612012-11-14 20:25:37 +00001209 u64 storage_space, remaining_space, max_variable_size;
1210 efi_status_t status = EFI_NOT_FOUND;
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001211
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001212 spin_lock(&efivars->lock);
1213
Seiji Aguchid80a3612012-11-14 20:25:37 +00001214 /*
1215 * Check if there is a space enough to log.
1216 * size: a size of logging data
1217 * DUMP_NAME_LEN * 2: a maximum size of variable name
1218 */
1219 status = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES,
1220 &storage_space,
1221 &remaining_space,
1222 &max_variable_size);
1223 if (status || remaining_space < size + DUMP_NAME_LEN * 2) {
1224 spin_unlock(&efivars->lock);
1225 *id = part;
1226 return -ENOSPC;
1227 }
1228
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001229 sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
Seiji Aguchi96480d92012-11-14 20:26:46 +00001230 get_seconds());
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001231
1232 for (i = 0; i < DUMP_NAME_LEN; i++)
1233 efi_name[i] = name[i];
1234
Mike Waychison7644c162011-07-21 16:58:00 -04001235 efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001236 size, psi->buf);
1237
1238 spin_unlock(&efivars->lock);
1239
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001240 if (size)
Chen Gongb238b8f2011-10-12 09:17:24 -07001241 ret = efivar_create_sysfs_entry(efivars,
Mike Waychisona2940902011-07-21 16:57:57 -04001242 utf16_strsize(efi_name,
1243 DUMP_NAME_LEN * 2),
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001244 efi_name, &vendor);
1245
Chen Gongb238b8f2011-10-12 09:17:24 -07001246 *id = part;
1247 return ret;
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001248};
1249
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001250static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
Seiji Aguchia9efd392012-11-14 20:27:28 +00001251 struct timespec time, struct pstore_info *psi)
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001252{
Seiji Aguchia9efd392012-11-14 20:27:28 +00001253 char name[DUMP_NAME_LEN];
Seiji Aguchidd230fe2012-11-14 20:26:21 +00001254 efi_char16_t efi_name[DUMP_NAME_LEN];
Seiji Aguchif94ec0c2012-11-14 20:29:21 +00001255 char name_old[DUMP_NAME_LEN];
1256 efi_char16_t efi_name_old[DUMP_NAME_LEN];
Seiji Aguchidd230fe2012-11-14 20:26:21 +00001257 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
1258 struct efivars *efivars = psi->data;
1259 struct efivar_entry *entry, *found = NULL;
1260 int i;
1261
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001262 sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
Seiji Aguchia9efd392012-11-14 20:27:28 +00001263 time.tv_sec);
Seiji Aguchidd230fe2012-11-14 20:26:21 +00001264
1265 spin_lock(&efivars->lock);
1266
1267 for (i = 0; i < DUMP_NAME_LEN; i++)
Seiji Aguchia9efd392012-11-14 20:27:28 +00001268 efi_name[i] = name[i];
Seiji Aguchidd230fe2012-11-14 20:26:21 +00001269
1270 /*
Seiji Aguchia9efd392012-11-14 20:27:28 +00001271 * Clean up an entry with the same name
Seiji Aguchidd230fe2012-11-14 20:26:21 +00001272 */
1273
1274 list_for_each_entry(entry, &efivars->list, list) {
1275 get_var_data_locked(efivars, &entry->var);
1276
1277 if (efi_guidcmp(entry->var.VendorGuid, vendor))
1278 continue;
1279 if (utf16_strncmp(entry->var.VariableName, efi_name,
Seiji Aguchif94ec0c2012-11-14 20:29:21 +00001280 utf16_strlen(efi_name))) {
1281 /*
1282 * Check if an old format,
1283 * which doesn't support holding
1284 * multiple logs, remains.
1285 */
1286 sprintf(name_old, "dump-type%u-%u-%lu", type,
1287 (unsigned int)id, time.tv_sec);
1288
1289 for (i = 0; i < DUMP_NAME_LEN; i++)
1290 efi_name_old[i] = name_old[i];
1291
1292 if (utf16_strncmp(entry->var.VariableName, efi_name_old,
1293 utf16_strlen(efi_name_old)))
1294 continue;
1295 }
Seiji Aguchidd230fe2012-11-14 20:26:21 +00001296
1297 /* found */
1298 found = entry;
1299 efivars->ops->set_variable(entry->var.VariableName,
1300 &entry->var.VendorGuid,
1301 PSTORE_EFI_ATTRIBUTES,
1302 0, NULL);
Seiji Aguchia9efd392012-11-14 20:27:28 +00001303 break;
Seiji Aguchidd230fe2012-11-14 20:26:21 +00001304 }
1305
1306 if (found)
1307 list_del(&found->list);
1308
1309 spin_unlock(&efivars->lock);
1310
1311 if (found)
1312 efivar_unregister(found);
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001313
1314 return 0;
1315}
1316#else
1317static int efi_pstore_open(struct pstore_info *psi)
1318{
1319 return 0;
1320}
1321
1322static int efi_pstore_close(struct pstore_info *psi)
1323{
1324 return 0;
1325}
1326
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001327static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, int *count,
Christoph Fritzeee628d2011-11-28 23:49:33 +01001328 struct timespec *timespec,
1329 char **buf, struct pstore_info *psi)
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001330{
1331 return -1;
1332}
1333
Kees Cook3d6d8d22011-11-17 13:13:29 -08001334static int efi_pstore_write(enum pstore_type_id type,
1335 enum kmsg_dump_reason reason, u64 *id,
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001336 unsigned int part, int count, size_t size,
1337 struct pstore_info *psi)
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001338{
1339 return 0;
1340}
1341
Seiji Aguchi755d4fe2012-11-26 16:07:44 -08001342static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
Seiji Aguchia9efd392012-11-14 20:27:28 +00001343 struct timespec time, struct pstore_info *psi)
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001344{
1345 return 0;
1346}
1347#endif
1348
1349static struct pstore_info efi_pstore_info = {
1350 .owner = THIS_MODULE,
1351 .name = "efi",
1352 .open = efi_pstore_open,
1353 .close = efi_pstore_close,
1354 .read = efi_pstore_read,
1355 .write = efi_pstore_write,
1356 .erase = efi_pstore_erase,
1357};
Linus Torvalds1da177e2005-04-16 15:20:36 -07001358
Chris Wright2c3c8be2010-05-12 18:28:57 -07001359static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -08001360 struct bin_attribute *bin_attr,
1361 char *buf, loff_t pos, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362{
1363 struct efi_variable *new_var = (struct efi_variable *)buf;
Mike Waychison4142ef12011-03-11 17:43:11 -08001364 struct efivars *efivars = bin_attr->private;
Matt Domsch496a0fc2007-01-26 00:57:18 -08001365 struct efivar_entry *search_efivar, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366 unsigned long strsize1, strsize2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 efi_status_t status = EFI_NOT_FOUND;
1368 int found = 0;
1369
1370 if (!capable(CAP_SYS_ADMIN))
1371 return -EACCES;
1372
Matthew Garrettfec6c202012-04-30 16:11:30 -04001373 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
1374 validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
1375 printk(KERN_ERR "efivars: Malformed variable content\n");
1376 return -EINVAL;
1377 }
1378
Mike Waychison29422692011-03-11 17:43:00 -08001379 spin_lock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380
1381 /*
1382 * Does this variable already exist?
1383 */
Mike Waychison29422692011-03-11 17:43:00 -08001384 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
Mike Waychisona2940902011-07-21 16:57:57 -04001385 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
1386 strsize2 = utf16_strsize(new_var->VariableName, 1024);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387 if (strsize1 == strsize2 &&
1388 !memcmp(&(search_efivar->var.VariableName),
1389 new_var->VariableName, strsize1) &&
1390 !efi_guidcmp(search_efivar->var.VendorGuid,
1391 new_var->VendorGuid)) {
1392 found = 1;
1393 break;
1394 }
1395 }
1396 if (found) {
Mike Waychison29422692011-03-11 17:43:00 -08001397 spin_unlock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 return -EINVAL;
1399 }
1400
1401 /* now *really* create the variable via EFI */
Mike Waychison32958142011-03-11 17:43:21 -08001402 status = efivars->ops->set_variable(new_var->VariableName,
1403 &new_var->VendorGuid,
1404 new_var->Attributes,
1405 new_var->DataSize,
1406 new_var->Data);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407
1408 if (status != EFI_SUCCESS) {
1409 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
1410 status);
Mike Waychison29422692011-03-11 17:43:00 -08001411 spin_unlock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 return -EIO;
1413 }
Mike Waychison29422692011-03-11 17:43:00 -08001414 spin_unlock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415
1416 /* Create the entry in sysfs. Locking is not required here */
Mike Waychison4142ef12011-03-11 17:43:11 -08001417 status = efivar_create_sysfs_entry(efivars,
Mike Waychisona2940902011-07-21 16:57:57 -04001418 utf16_strsize(new_var->VariableName,
1419 1024),
Mike Waychison4142ef12011-03-11 17:43:11 -08001420 new_var->VariableName,
1421 &new_var->VendorGuid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422 if (status) {
1423 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
1424 }
1425 return count;
1426}
1427
Chris Wright2c3c8be2010-05-12 18:28:57 -07001428static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -08001429 struct bin_attribute *bin_attr,
1430 char *buf, loff_t pos, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431{
1432 struct efi_variable *del_var = (struct efi_variable *)buf;
Mike Waychison4142ef12011-03-11 17:43:11 -08001433 struct efivars *efivars = bin_attr->private;
Matt Domsch496a0fc2007-01-26 00:57:18 -08001434 struct efivar_entry *search_efivar, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435 unsigned long strsize1, strsize2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 efi_status_t status = EFI_NOT_FOUND;
1437 int found = 0;
1438
1439 if (!capable(CAP_SYS_ADMIN))
1440 return -EACCES;
1441
Mike Waychison29422692011-03-11 17:43:00 -08001442 spin_lock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443
1444 /*
1445 * Does this variable already exist?
1446 */
Mike Waychison29422692011-03-11 17:43:00 -08001447 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
Mike Waychisona2940902011-07-21 16:57:57 -04001448 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
1449 strsize2 = utf16_strsize(del_var->VariableName, 1024);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450 if (strsize1 == strsize2 &&
1451 !memcmp(&(search_efivar->var.VariableName),
1452 del_var->VariableName, strsize1) &&
1453 !efi_guidcmp(search_efivar->var.VendorGuid,
1454 del_var->VendorGuid)) {
1455 found = 1;
1456 break;
1457 }
1458 }
1459 if (!found) {
Mike Waychison29422692011-03-11 17:43:00 -08001460 spin_unlock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 return -EINVAL;
1462 }
1463 /* force the Attributes/DataSize to 0 to ensure deletion */
1464 del_var->Attributes = 0;
1465 del_var->DataSize = 0;
1466
Mike Waychison32958142011-03-11 17:43:21 -08001467 status = efivars->ops->set_variable(del_var->VariableName,
1468 &del_var->VendorGuid,
1469 del_var->Attributes,
1470 del_var->DataSize,
1471 del_var->Data);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472
1473 if (status != EFI_SUCCESS) {
1474 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
1475 status);
Mike Waychison29422692011-03-11 17:43:00 -08001476 spin_unlock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001477 return -EIO;
1478 }
Matt Domsch496a0fc2007-01-26 00:57:18 -08001479 list_del(&search_efivar->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480 /* We need to release this lock before unregistering. */
Mike Waychison29422692011-03-11 17:43:00 -08001481 spin_unlock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001482 efivar_unregister(search_efivar);
1483
1484 /* It's dead Jim.... */
1485 return count;
1486}
1487
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488/*
1489 * Let's not leave out systab information that snuck into
1490 * the efivars driver
1491 */
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -07001492static ssize_t systab_show(struct kobject *kobj,
1493 struct kobj_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494{
1495 char *str = buf;
1496
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -07001497 if (!kobj || !buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001498 return -EINVAL;
1499
Bjorn Helgaasb2c99e32006-03-26 01:37:08 -08001500 if (efi.mps != EFI_INVALID_TABLE_ADDR)
1501 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
1502 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
1503 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
1504 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
1505 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
1506 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
1507 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
1508 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
1509 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
1510 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
1511 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
1512 if (efi.uga != EFI_INVALID_TABLE_ADDR)
1513 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001514
1515 return str - buf;
1516}
1517
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -07001518static struct kobj_attribute efi_attr_systab =
1519 __ATTR(systab, 0400, systab_show, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -07001521static struct attribute *efi_subsys_attrs[] = {
1522 &efi_attr_systab.attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523 NULL, /* maybe more in the future? */
1524};
1525
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -07001526static struct attribute_group efi_subsys_attr_group = {
1527 .attrs = efi_subsys_attrs,
1528};
1529
Greg Kroah-Hartmanbc87d2f2007-11-07 13:56:19 -08001530static struct kobject *efi_kobj;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531
1532/*
1533 * efivar_create_sysfs_entry()
1534 * Requires:
1535 * variable_name_size = number of bytes required to hold
1536 * variable_name (not counting the NULL
1537 * character at the end.
Mike Waychison29422692011-03-11 17:43:00 -08001538 * efivars->lock is not held on entry or exit.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001539 * Returns 1 on failure, 0 on success
1540 */
1541static int
Mike Waychison4142ef12011-03-11 17:43:11 -08001542efivar_create_sysfs_entry(struct efivars *efivars,
1543 unsigned long variable_name_size,
1544 efi_char16_t *variable_name,
1545 efi_guid_t *vendor_guid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546{
Jeremy Kerr310ad752012-10-19 15:16:45 +08001547 int i, short_name_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548 char *short_name;
1549 struct efivar_entry *new_efivar;
1550
Jeremy Kerr310ad752012-10-19 15:16:45 +08001551 /*
1552 * Length of the variable bytes in ASCII, plus the '-' separator,
1553 * plus the GUID, plus trailing NUL
1554 */
1555 short_name_size = variable_name_size / sizeof(efi_char16_t)
1556 + 1 + GUID_LEN + 1;
1557
1558 short_name = kzalloc(short_name_size, GFP_KERNEL);
Deepak Saxena9c215382005-11-07 01:01:24 -08001559 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001560
1561 if (!short_name || !new_efivar) {
Jesper Juhl0933ad92005-06-25 14:59:15 -07001562 kfree(short_name);
1563 kfree(new_efivar);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564 return 1;
1565 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566
Mike Waychison4142ef12011-03-11 17:43:11 -08001567 new_efivar->efivars = efivars;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001568 memcpy(new_efivar->var.VariableName, variable_name,
1569 variable_name_size);
1570 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
1571
1572 /* Convert Unicode to normal chars (assume top bits are 0),
1573 ala UTF-8 */
1574 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
1575 short_name[i] = variable_name[i] & 0xFF;
1576 }
1577 /* This is ugly, but necessary to separate one vendor's
1578 private variables from another's. */
1579
1580 *(short_name + strlen(short_name)) = '-';
1581 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
1582
Mike Waychison29422692011-03-11 17:43:00 -08001583 new_efivar->kobj.kset = efivars->kset;
Greg Kroah-Hartmand6d292c2007-12-17 15:54:39 -04001584 i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
1585 "%s", short_name);
Jeff Garzik69b21862006-10-11 01:22:23 -07001586 if (i) {
1587 kfree(short_name);
1588 kfree(new_efivar);
1589 return 1;
1590 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591
Greg Kroah-Hartmand6d292c2007-12-17 15:54:39 -04001592 kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
Jesper Juhl0933ad92005-06-25 14:59:15 -07001593 kfree(short_name);
1594 short_name = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595
Mike Waychison29422692011-03-11 17:43:00 -08001596 spin_lock(&efivars->lock);
1597 list_add(&new_efivar->list, &efivars->list);
1598 spin_unlock(&efivars->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599
1600 return 0;
1601}
Mike Waychisond502fbb2011-03-11 17:43:06 -08001602
1603static int
1604create_efivars_bin_attributes(struct efivars *efivars)
1605{
1606 struct bin_attribute *attr;
1607 int error;
1608
1609 /* new_var */
1610 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1611 if (!attr)
1612 return -ENOMEM;
1613
1614 attr->attr.name = "new_var";
1615 attr->attr.mode = 0200;
1616 attr->write = efivar_create;
1617 attr->private = efivars;
1618 efivars->new_var = attr;
1619
1620 /* del_var */
1621 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1622 if (!attr) {
1623 error = -ENOMEM;
1624 goto out_free;
1625 }
1626 attr->attr.name = "del_var";
1627 attr->attr.mode = 0200;
1628 attr->write = efivar_delete;
1629 attr->private = efivars;
1630 efivars->del_var = attr;
1631
1632 sysfs_bin_attr_init(efivars->new_var);
1633 sysfs_bin_attr_init(efivars->del_var);
1634
1635 /* Register */
1636 error = sysfs_create_bin_file(&efivars->kset->kobj,
1637 efivars->new_var);
1638 if (error) {
1639 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
1640 " due to error %d\n", error);
1641 goto out_free;
1642 }
1643 error = sysfs_create_bin_file(&efivars->kset->kobj,
1644 efivars->del_var);
1645 if (error) {
1646 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
1647 " due to error %d\n", error);
1648 sysfs_remove_bin_file(&efivars->kset->kobj,
1649 efivars->new_var);
1650 goto out_free;
1651 }
1652
1653 return 0;
1654out_free:
Dan Carpenter051d51b2011-03-18 10:12:14 +03001655 kfree(efivars->del_var);
1656 efivars->del_var = NULL;
Mike Waychisond502fbb2011-03-11 17:43:06 -08001657 kfree(efivars->new_var);
1658 efivars->new_var = NULL;
1659 return error;
1660}
1661
Mike Waychison4fc756b2011-03-11 17:43:27 -08001662void unregister_efivars(struct efivars *efivars)
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001663{
1664 struct efivar_entry *entry, *n;
Mike Waychison4142ef12011-03-11 17:43:11 -08001665
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001666 list_for_each_entry_safe(entry, n, &efivars->list, list) {
1667 spin_lock(&efivars->lock);
1668 list_del(&entry->list);
1669 spin_unlock(&efivars->lock);
1670 efivar_unregister(entry);
1671 }
1672 if (efivars->new_var)
1673 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
1674 if (efivars->del_var)
1675 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
1676 kfree(efivars->new_var);
1677 kfree(efivars->del_var);
Lee, Chun-Yi605e70c2012-10-05 13:54:56 +08001678 kobject_put(efivars->kobject);
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001679 kset_unregister(efivars->kset);
1680}
Mike Waychison4fc756b2011-03-11 17:43:27 -08001681EXPORT_SYMBOL_GPL(unregister_efivars);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682
Mike Waychison4fc756b2011-03-11 17:43:27 -08001683int register_efivars(struct efivars *efivars,
1684 const struct efivar_operations *ops,
1685 struct kobject *parent_kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686{
1687 efi_status_t status = EFI_NOT_FOUND;
1688 efi_guid_t vendor_guid;
1689 efi_char16_t *variable_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 unsigned long variable_name_size = 1024;
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -07001691 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001692
Deepak Saxena9c215382005-11-07 01:01:24 -08001693 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 if (!variable_name) {
1695 printk(KERN_ERR "efivars: Memory allocation failed.\n");
1696 return -ENOMEM;
1697 }
1698
Mike Waychison29422692011-03-11 17:43:00 -08001699 spin_lock_init(&efivars->lock);
1700 INIT_LIST_HEAD(&efivars->list);
Mike Waychison32958142011-03-11 17:43:21 -08001701 efivars->ops = ops;
Mike Waychison29422692011-03-11 17:43:00 -08001702
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001703 efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
Mike Waychison29422692011-03-11 17:43:00 -08001704 if (!efivars->kset) {
Greg Kroah-Hartman66ac8312007-11-02 13:20:40 -07001705 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
1706 error = -ENOMEM;
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001707 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708 }
1709
Lee, Chun-Yi605e70c2012-10-05 13:54:56 +08001710 efivars->kobject = kobject_create_and_add("efivars", parent_kobj);
1711 if (!efivars->kobject) {
1712 pr_err("efivars: Subsystem registration failed.\n");
1713 error = -ENOMEM;
1714 kset_unregister(efivars->kset);
1715 goto out;
1716 }
1717
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718 /*
1719 * Per EFI spec, the maximum storage allocated for both
1720 * the variable name and variable data is 1024 bytes.
1721 */
1722
1723 do {
1724 variable_name_size = 1024;
1725
Mike Waychison32958142011-03-11 17:43:21 -08001726 status = ops->get_next_variable(&variable_name_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001727 variable_name,
1728 &vendor_guid);
1729 switch (status) {
1730 case EFI_SUCCESS:
Mike Waychison4142ef12011-03-11 17:43:11 -08001731 efivar_create_sysfs_entry(efivars,
1732 variable_name_size,
1733 variable_name,
1734 &vendor_guid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 break;
1736 case EFI_NOT_FOUND:
1737 break;
1738 default:
1739 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
1740 status);
1741 status = EFI_NOT_FOUND;
1742 break;
1743 }
1744 } while (status != EFI_NOT_FOUND);
1745
Mike Waychisond502fbb2011-03-11 17:43:06 -08001746 error = create_efivars_bin_attributes(efivars);
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001747 if (error)
1748 unregister_efivars(efivars);
1749
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001750 efivars->efi_pstore_info = efi_pstore_info;
1751
1752 efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
1753 if (efivars->efi_pstore_info.buf) {
1754 efivars->efi_pstore_info.bufsize = 1024;
1755 efivars->efi_pstore_info.data = efivars;
Don Zickusabd4d552011-08-12 10:54:51 -07001756 spin_lock_init(&efivars->efi_pstore_info.buf_lock);
Matthew Garrett5ee9c192011-07-21 16:57:56 -04001757 pstore_register(&efivars->efi_pstore_info);
1758 }
1759
Matthew Garrett5d9db882012-10-05 13:54:56 +08001760 register_filesystem(&efivarfs_type);
1761
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001762out:
1763 kfree(variable_name);
1764
1765 return error;
1766}
Mike Waychison4fc756b2011-03-11 17:43:27 -08001767EXPORT_SYMBOL_GPL(register_efivars);
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001768
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001769/*
1770 * For now we register the efi subsystem with the firmware subsystem
1771 * and the vars subsystem with the efi subsystem. In the future, it
1772 * might make sense to split off the efi subsystem into its own
1773 * driver, but for now only efivars will register with it, so just
1774 * include it here.
1775 */
1776
1777static int __init
1778efivars_init(void)
1779{
1780 int error = 0;
1781
1782 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
1783 EFIVARS_DATE);
1784
1785 if (!efi_enabled)
Mike Waychison4fc756b2011-03-11 17:43:27 -08001786 return 0;
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001787
1788 /* For now we'll register the efi directory at /sys/firmware/efi */
1789 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
1790 if (!efi_kobj) {
1791 printk(KERN_ERR "efivars: Firmware registration failed.\n");
1792 return -ENOMEM;
1793 }
1794
Mike Waychison32958142011-03-11 17:43:21 -08001795 ops.get_variable = efi.get_variable;
1796 ops.set_variable = efi.set_variable;
1797 ops.get_next_variable = efi.get_next_variable;
Seiji Aguchid80a3612012-11-14 20:25:37 +00001798 ops.query_variable_info = efi.query_variable_info;
Matt Fleming89d16662012-11-09 21:02:56 +00001799
Mike Waychison32958142011-03-11 17:43:21 -08001800 error = register_efivars(&__efivars, &ops, efi_kobj);
Dan Carpenter3116aab2011-03-18 10:12:38 +03001801 if (error)
1802 goto err_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001803
1804 /* Don't forget the systab entry */
Greg Kroah-Hartmanbc87d2f2007-11-07 13:56:19 -08001805 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001806 if (error) {
1807 printk(KERN_ERR
1808 "efivars: Sysfs attribute export failed with error %d.\n",
1809 error);
Dan Carpenter3116aab2011-03-18 10:12:38 +03001810 goto err_unregister;
Mike Waychison76b53f7c2011-03-11 17:43:16 -08001811 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812
Dan Carpenter3116aab2011-03-18 10:12:38 +03001813 return 0;
1814
1815err_unregister:
1816 unregister_efivars(&__efivars);
1817err_put:
1818 kobject_put(efi_kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001819 return error;
1820}
1821
1822static void __exit
1823efivars_exit(void)
1824{
Randy Dunlapaabb6e12011-05-06 13:27:41 -07001825 if (efi_enabled) {
1826 unregister_efivars(&__efivars);
1827 kobject_put(efi_kobj);
1828 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001829}
1830
1831module_init(efivars_init);
1832module_exit(efivars_exit);
1833