Loading...
Note: File does not exist in v6.8.
1/*
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
68#include <linux/capability.h>
69#include <linux/types.h>
70#include <linux/errno.h>
71#include <linux/init.h>
72#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>
80#include <linux/slab.h>
81#include <linux/pstore.h>
82
83#include <asm/uaccess.h>
84
85#define EFIVARS_VERSION "0.08"
86#define EFIVARS_DATE "2004-May-17"
87
88MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
89MODULE_DESCRIPTION("sysfs interface to EFI Variables");
90MODULE_LICENSE("GPL");
91MODULE_VERSION(EFIVARS_VERSION);
92
93#define DUMP_NAME_LEN 52
94
95/*
96 * The maximum size of VariableName + Data = 1024
97 * Therefore, it's reasonable to save that much
98 * space in each part of the structure,
99 * and we use a page for reading/writing.
100 */
101
102struct efi_variable {
103 efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
104 efi_guid_t VendorGuid;
105 unsigned long DataSize;
106 __u8 Data[1024];
107 efi_status_t Status;
108 __u32 Attributes;
109} __attribute__((packed));
110
111
112struct efivar_entry {
113 struct efivars *efivars;
114 struct efi_variable var;
115 struct list_head list;
116 struct kobject kobj;
117};
118
119struct efivar_attribute {
120 struct attribute attr;
121 ssize_t (*show) (struct efivar_entry *entry, char *buf);
122 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
123};
124
125#define PSTORE_EFI_ATTRIBUTES \
126 (EFI_VARIABLE_NON_VOLATILE | \
127 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
128 EFI_VARIABLE_RUNTIME_ACCESS)
129
130#define EFIVAR_ATTR(_name, _mode, _show, _store) \
131struct efivar_attribute efivar_attr_##_name = { \
132 .attr = {.name = __stringify(_name), .mode = _mode}, \
133 .show = _show, \
134 .store = _store, \
135};
136
137#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
138#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
139
140/*
141 * Prototype for sysfs creation function
142 */
143static int
144efivar_create_sysfs_entry(struct efivars *efivars,
145 unsigned long variable_name_size,
146 efi_char16_t *variable_name,
147 efi_guid_t *vendor_guid);
148
149/* Return the number of unicode characters in data */
150static unsigned long
151utf16_strnlen(efi_char16_t *s, size_t maxlength)
152{
153 unsigned long length = 0;
154
155 while (*s++ != 0 && length < maxlength)
156 length++;
157 return length;
158}
159
160static inline unsigned long
161utf16_strlen(efi_char16_t *s)
162{
163 return utf16_strnlen(s, ~0UL);
164}
165
166/*
167 * Return the number of bytes is the length of this string
168 * Note: this is NOT the same as the number of unicode characters
169 */
170static inline unsigned long
171utf16_strsize(efi_char16_t *data, unsigned long maxlength)
172{
173 return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
174}
175
176static inline int
177utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len)
178{
179 while (1) {
180 if (len == 0)
181 return 0;
182 if (*a < *b)
183 return -1;
184 if (*a > *b)
185 return 1;
186 if (*a == 0) /* implies *b == 0 */
187 return 0;
188 a++;
189 b++;
190 len--;
191 }
192}
193
194static bool
195validate_device_path(struct efi_variable *var, int match, u8 *buffer,
196 unsigned long len)
197{
198 struct efi_generic_dev_path *node;
199 int offset = 0;
200
201 node = (struct efi_generic_dev_path *)buffer;
202
203 if (len < sizeof(*node))
204 return false;
205
206 while (offset <= len - sizeof(*node) &&
207 node->length >= sizeof(*node) &&
208 node->length <= len - offset) {
209 offset += node->length;
210
211 if ((node->type == EFI_DEV_END_PATH ||
212 node->type == EFI_DEV_END_PATH2) &&
213 node->sub_type == EFI_DEV_END_ENTIRE)
214 return true;
215
216 node = (struct efi_generic_dev_path *)(buffer + offset);
217 }
218
219 /*
220 * If we're here then either node->length pointed past the end
221 * of the buffer or we reached the end of the buffer without
222 * finding a device path end node.
223 */
224 return false;
225}
226
227static bool
228validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
229 unsigned long len)
230{
231 /* An array of 16-bit integers */
232 if ((len % 2) != 0)
233 return false;
234
235 return true;
236}
237
238static bool
239validate_load_option(struct efi_variable *var, int match, u8 *buffer,
240 unsigned long len)
241{
242 u16 filepathlength;
243 int i, desclength = 0, namelen;
244
245 namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
246
247 /* Either "Boot" or "Driver" followed by four digits of hex */
248 for (i = match; i < match+4; i++) {
249 if (var->VariableName[i] > 127 ||
250 hex_to_bin(var->VariableName[i] & 0xff) < 0)
251 return true;
252 }
253
254 /* Reject it if there's 4 digits of hex and then further content */
255 if (namelen > match + 4)
256 return false;
257
258 /* A valid entry must be at least 8 bytes */
259 if (len < 8)
260 return false;
261
262 filepathlength = buffer[4] | buffer[5] << 8;
263
264 /*
265 * There's no stored length for the description, so it has to be
266 * found by hand
267 */
268 desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
269
270 /* Each boot entry must have a descriptor */
271 if (!desclength)
272 return false;
273
274 /*
275 * If the sum of the length of the description, the claimed filepath
276 * length and the original header are greater than the length of the
277 * variable, it's malformed
278 */
279 if ((desclength + filepathlength + 6) > len)
280 return false;
281
282 /*
283 * And, finally, check the filepath
284 */
285 return validate_device_path(var, match, buffer + desclength + 6,
286 filepathlength);
287}
288
289static bool
290validate_uint16(struct efi_variable *var, int match, u8 *buffer,
291 unsigned long len)
292{
293 /* A single 16-bit integer */
294 if (len != 2)
295 return false;
296
297 return true;
298}
299
300static bool
301validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
302 unsigned long len)
303{
304 int i;
305
306 for (i = 0; i < len; i++) {
307 if (buffer[i] > 127)
308 return false;
309
310 if (buffer[i] == 0)
311 return true;
312 }
313
314 return false;
315}
316
317struct variable_validate {
318 char *name;
319 bool (*validate)(struct efi_variable *var, int match, u8 *data,
320 unsigned long len);
321};
322
323static const struct variable_validate variable_validate[] = {
324 { "BootNext", validate_uint16 },
325 { "BootOrder", validate_boot_order },
326 { "DriverOrder", validate_boot_order },
327 { "Boot*", validate_load_option },
328 { "Driver*", validate_load_option },
329 { "ConIn", validate_device_path },
330 { "ConInDev", validate_device_path },
331 { "ConOut", validate_device_path },
332 { "ConOutDev", validate_device_path },
333 { "ErrOut", validate_device_path },
334 { "ErrOutDev", validate_device_path },
335 { "Timeout", validate_uint16 },
336 { "Lang", validate_ascii_string },
337 { "PlatformLang", validate_ascii_string },
338 { "", NULL },
339};
340
341static bool
342validate_var(struct efi_variable *var, u8 *data, unsigned long len)
343{
344 int i;
345 u16 *unicode_name = var->VariableName;
346
347 for (i = 0; variable_validate[i].validate != NULL; i++) {
348 const char *name = variable_validate[i].name;
349 int match;
350
351 for (match = 0; ; match++) {
352 char c = name[match];
353 u16 u = unicode_name[match];
354
355 /* All special variables are plain ascii */
356 if (u > 127)
357 return true;
358
359 /* Wildcard in the matching name means we've matched */
360 if (c == '*')
361 return variable_validate[i].validate(var,
362 match, data, len);
363
364 /* Case sensitive match */
365 if (c != u)
366 break;
367
368 /* Reached the end of the string while matching */
369 if (!c)
370 return variable_validate[i].validate(var,
371 match, data, len);
372 }
373 }
374
375 return true;
376}
377
378static efi_status_t
379get_var_data_locked(struct efivars *efivars, struct efi_variable *var)
380{
381 efi_status_t status;
382
383 var->DataSize = 1024;
384 status = efivars->ops->get_variable(var->VariableName,
385 &var->VendorGuid,
386 &var->Attributes,
387 &var->DataSize,
388 var->Data);
389 return status;
390}
391
392static efi_status_t
393get_var_data(struct efivars *efivars, struct efi_variable *var)
394{
395 efi_status_t status;
396
397 spin_lock(&efivars->lock);
398 status = get_var_data_locked(efivars, var);
399 spin_unlock(&efivars->lock);
400
401 if (status != EFI_SUCCESS) {
402 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
403 status);
404 }
405 return status;
406}
407
408static ssize_t
409efivar_guid_read(struct efivar_entry *entry, char *buf)
410{
411 struct efi_variable *var = &entry->var;
412 char *str = buf;
413
414 if (!entry || !buf)
415 return 0;
416
417 efi_guid_unparse(&var->VendorGuid, str);
418 str += strlen(str);
419 str += sprintf(str, "\n");
420
421 return str - buf;
422}
423
424static ssize_t
425efivar_attr_read(struct efivar_entry *entry, char *buf)
426{
427 struct efi_variable *var = &entry->var;
428 char *str = buf;
429 efi_status_t status;
430
431 if (!entry || !buf)
432 return -EINVAL;
433
434 status = get_var_data(entry->efivars, var);
435 if (status != EFI_SUCCESS)
436 return -EIO;
437
438 if (var->Attributes & EFI_VARIABLE_NON_VOLATILE)
439 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
440 if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)
441 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
442 if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)
443 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
444 if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD)
445 str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
446 if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
447 str += sprintf(str,
448 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
449 if (var->Attributes &
450 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
451 str += sprintf(str,
452 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
453 if (var->Attributes & EFI_VARIABLE_APPEND_WRITE)
454 str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n");
455 return str - buf;
456}
457
458static ssize_t
459efivar_size_read(struct efivar_entry *entry, char *buf)
460{
461 struct efi_variable *var = &entry->var;
462 char *str = buf;
463 efi_status_t status;
464
465 if (!entry || !buf)
466 return -EINVAL;
467
468 status = get_var_data(entry->efivars, var);
469 if (status != EFI_SUCCESS)
470 return -EIO;
471
472 str += sprintf(str, "0x%lx\n", var->DataSize);
473 return str - buf;
474}
475
476static ssize_t
477efivar_data_read(struct efivar_entry *entry, char *buf)
478{
479 struct efi_variable *var = &entry->var;
480 efi_status_t status;
481
482 if (!entry || !buf)
483 return -EINVAL;
484
485 status = get_var_data(entry->efivars, var);
486 if (status != EFI_SUCCESS)
487 return -EIO;
488
489 memcpy(buf, var->Data, var->DataSize);
490 return var->DataSize;
491}
492/*
493 * We allow each variable to be edited via rewriting the
494 * entire efi variable structure.
495 */
496static ssize_t
497efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
498{
499 struct efi_variable *new_var, *var = &entry->var;
500 struct efivars *efivars = entry->efivars;
501 efi_status_t status = EFI_NOT_FOUND;
502
503 if (count != sizeof(struct efi_variable))
504 return -EINVAL;
505
506 new_var = (struct efi_variable *)buf;
507 /*
508 * If only updating the variable data, then the name
509 * and guid should remain the same
510 */
511 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
512 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
513 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
514 return -EINVAL;
515 }
516
517 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
518 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
519 return -EINVAL;
520 }
521
522 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
523 validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
524 printk(KERN_ERR "efivars: Malformed variable content\n");
525 return -EINVAL;
526 }
527
528 spin_lock(&efivars->lock);
529 status = efivars->ops->set_variable(new_var->VariableName,
530 &new_var->VendorGuid,
531 new_var->Attributes,
532 new_var->DataSize,
533 new_var->Data);
534
535 spin_unlock(&efivars->lock);
536
537 if (status != EFI_SUCCESS) {
538 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
539 status);
540 return -EIO;
541 }
542
543 memcpy(&entry->var, new_var, count);
544 return count;
545}
546
547static ssize_t
548efivar_show_raw(struct efivar_entry *entry, char *buf)
549{
550 struct efi_variable *var = &entry->var;
551 efi_status_t status;
552
553 if (!entry || !buf)
554 return 0;
555
556 status = get_var_data(entry->efivars, var);
557 if (status != EFI_SUCCESS)
558 return -EIO;
559
560 memcpy(buf, var, sizeof(*var));
561 return sizeof(*var);
562}
563
564/*
565 * Generic read/write functions that call the specific functions of
566 * the attributes...
567 */
568static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
569 char *buf)
570{
571 struct efivar_entry *var = to_efivar_entry(kobj);
572 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
573 ssize_t ret = -EIO;
574
575 if (!capable(CAP_SYS_ADMIN))
576 return -EACCES;
577
578 if (efivar_attr->show) {
579 ret = efivar_attr->show(var, buf);
580 }
581 return ret;
582}
583
584static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
585 const char *buf, size_t count)
586{
587 struct efivar_entry *var = to_efivar_entry(kobj);
588 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
589 ssize_t ret = -EIO;
590
591 if (!capable(CAP_SYS_ADMIN))
592 return -EACCES;
593
594 if (efivar_attr->store)
595 ret = efivar_attr->store(var, buf, count);
596
597 return ret;
598}
599
600static const struct sysfs_ops efivar_attr_ops = {
601 .show = efivar_attr_show,
602 .store = efivar_attr_store,
603};
604
605static void efivar_release(struct kobject *kobj)
606{
607 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
608 kfree(var);
609}
610
611static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
612static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
613static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
614static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
615static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
616
617static struct attribute *def_attrs[] = {
618 &efivar_attr_guid.attr,
619 &efivar_attr_size.attr,
620 &efivar_attr_attributes.attr,
621 &efivar_attr_data.attr,
622 &efivar_attr_raw_var.attr,
623 NULL,
624};
625
626static struct kobj_type efivar_ktype = {
627 .release = efivar_release,
628 .sysfs_ops = &efivar_attr_ops,
629 .default_attrs = def_attrs,
630};
631
632static struct pstore_info efi_pstore_info;
633
634static inline void
635efivar_unregister(struct efivar_entry *var)
636{
637 kobject_put(&var->kobj);
638}
639
640#ifdef CONFIG_PSTORE
641
642static int efi_pstore_open(struct pstore_info *psi)
643{
644 struct efivars *efivars = psi->data;
645
646 spin_lock(&efivars->lock);
647 efivars->walk_entry = list_first_entry(&efivars->list,
648 struct efivar_entry, list);
649 return 0;
650}
651
652static int efi_pstore_close(struct pstore_info *psi)
653{
654 struct efivars *efivars = psi->data;
655
656 spin_unlock(&efivars->lock);
657 return 0;
658}
659
660static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
661 struct timespec *timespec,
662 char **buf, struct pstore_info *psi)
663{
664 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
665 struct efivars *efivars = psi->data;
666 char name[DUMP_NAME_LEN];
667 int i;
668 unsigned int part, size;
669 unsigned long time;
670
671 while (&efivars->walk_entry->list != &efivars->list) {
672 if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid,
673 vendor)) {
674 for (i = 0; i < DUMP_NAME_LEN; i++) {
675 name[i] = efivars->walk_entry->var.VariableName[i];
676 }
677 if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {
678 *id = part;
679 timespec->tv_sec = time;
680 timespec->tv_nsec = 0;
681 get_var_data_locked(efivars, &efivars->walk_entry->var);
682 size = efivars->walk_entry->var.DataSize;
683 *buf = kmalloc(size, GFP_KERNEL);
684 if (*buf == NULL)
685 return -ENOMEM;
686 memcpy(*buf, efivars->walk_entry->var.Data,
687 size);
688 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
689 struct efivar_entry, list);
690 return size;
691 }
692 }
693 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
694 struct efivar_entry, list);
695 }
696 return 0;
697}
698
699static int efi_pstore_write(enum pstore_type_id type,
700 enum kmsg_dump_reason reason, u64 *id,
701 unsigned int part, size_t size, struct pstore_info *psi)
702{
703 char name[DUMP_NAME_LEN];
704 char stub_name[DUMP_NAME_LEN];
705 efi_char16_t efi_name[DUMP_NAME_LEN];
706 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
707 struct efivars *efivars = psi->data;
708 struct efivar_entry *entry, *found = NULL;
709 int i, ret = 0;
710
711 sprintf(stub_name, "dump-type%u-%u-", type, part);
712 sprintf(name, "%s%lu", stub_name, get_seconds());
713
714 spin_lock(&efivars->lock);
715
716 for (i = 0; i < DUMP_NAME_LEN; i++)
717 efi_name[i] = stub_name[i];
718
719 /*
720 * Clean up any entries with the same name
721 */
722
723 list_for_each_entry(entry, &efivars->list, list) {
724 get_var_data_locked(efivars, &entry->var);
725
726 if (efi_guidcmp(entry->var.VendorGuid, vendor))
727 continue;
728 if (utf16_strncmp(entry->var.VariableName, efi_name,
729 utf16_strlen(efi_name)))
730 continue;
731 /* Needs to be a prefix */
732 if (entry->var.VariableName[utf16_strlen(efi_name)] == 0)
733 continue;
734
735 /* found */
736 found = entry;
737 efivars->ops->set_variable(entry->var.VariableName,
738 &entry->var.VendorGuid,
739 PSTORE_EFI_ATTRIBUTES,
740 0, NULL);
741 }
742
743 if (found)
744 list_del(&found->list);
745
746 for (i = 0; i < DUMP_NAME_LEN; i++)
747 efi_name[i] = name[i];
748
749 efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
750 size, psi->buf);
751
752 spin_unlock(&efivars->lock);
753
754 if (found)
755 efivar_unregister(found);
756
757 if (size)
758 ret = efivar_create_sysfs_entry(efivars,
759 utf16_strsize(efi_name,
760 DUMP_NAME_LEN * 2),
761 efi_name, &vendor);
762
763 *id = part;
764 return ret;
765};
766
767static int efi_pstore_erase(enum pstore_type_id type, u64 id,
768 struct pstore_info *psi)
769{
770 efi_pstore_write(type, 0, &id, (unsigned int)id, 0, psi);
771
772 return 0;
773}
774#else
775static int efi_pstore_open(struct pstore_info *psi)
776{
777 return 0;
778}
779
780static int efi_pstore_close(struct pstore_info *psi)
781{
782 return 0;
783}
784
785static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
786 struct timespec *timespec,
787 char **buf, struct pstore_info *psi)
788{
789 return -1;
790}
791
792static int efi_pstore_write(enum pstore_type_id type,
793 enum kmsg_dump_reason reason, u64 *id,
794 unsigned int part, size_t size, struct pstore_info *psi)
795{
796 return 0;
797}
798
799static int efi_pstore_erase(enum pstore_type_id type, u64 id,
800 struct pstore_info *psi)
801{
802 return 0;
803}
804#endif
805
806static struct pstore_info efi_pstore_info = {
807 .owner = THIS_MODULE,
808 .name = "efi",
809 .open = efi_pstore_open,
810 .close = efi_pstore_close,
811 .read = efi_pstore_read,
812 .write = efi_pstore_write,
813 .erase = efi_pstore_erase,
814};
815
816static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
817 struct bin_attribute *bin_attr,
818 char *buf, loff_t pos, size_t count)
819{
820 struct efi_variable *new_var = (struct efi_variable *)buf;
821 struct efivars *efivars = bin_attr->private;
822 struct efivar_entry *search_efivar, *n;
823 unsigned long strsize1, strsize2;
824 efi_status_t status = EFI_NOT_FOUND;
825 int found = 0;
826
827 if (!capable(CAP_SYS_ADMIN))
828 return -EACCES;
829
830 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
831 validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
832 printk(KERN_ERR "efivars: Malformed variable content\n");
833 return -EINVAL;
834 }
835
836 spin_lock(&efivars->lock);
837
838 /*
839 * Does this variable already exist?
840 */
841 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
842 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
843 strsize2 = utf16_strsize(new_var->VariableName, 1024);
844 if (strsize1 == strsize2 &&
845 !memcmp(&(search_efivar->var.VariableName),
846 new_var->VariableName, strsize1) &&
847 !efi_guidcmp(search_efivar->var.VendorGuid,
848 new_var->VendorGuid)) {
849 found = 1;
850 break;
851 }
852 }
853 if (found) {
854 spin_unlock(&efivars->lock);
855 return -EINVAL;
856 }
857
858 /* now *really* create the variable via EFI */
859 status = efivars->ops->set_variable(new_var->VariableName,
860 &new_var->VendorGuid,
861 new_var->Attributes,
862 new_var->DataSize,
863 new_var->Data);
864
865 if (status != EFI_SUCCESS) {
866 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
867 status);
868 spin_unlock(&efivars->lock);
869 return -EIO;
870 }
871 spin_unlock(&efivars->lock);
872
873 /* Create the entry in sysfs. Locking is not required here */
874 status = efivar_create_sysfs_entry(efivars,
875 utf16_strsize(new_var->VariableName,
876 1024),
877 new_var->VariableName,
878 &new_var->VendorGuid);
879 if (status) {
880 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
881 }
882 return count;
883}
884
885static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
886 struct bin_attribute *bin_attr,
887 char *buf, loff_t pos, size_t count)
888{
889 struct efi_variable *del_var = (struct efi_variable *)buf;
890 struct efivars *efivars = bin_attr->private;
891 struct efivar_entry *search_efivar, *n;
892 unsigned long strsize1, strsize2;
893 efi_status_t status = EFI_NOT_FOUND;
894 int found = 0;
895
896 if (!capable(CAP_SYS_ADMIN))
897 return -EACCES;
898
899 spin_lock(&efivars->lock);
900
901 /*
902 * Does this variable already exist?
903 */
904 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
905 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
906 strsize2 = utf16_strsize(del_var->VariableName, 1024);
907 if (strsize1 == strsize2 &&
908 !memcmp(&(search_efivar->var.VariableName),
909 del_var->VariableName, strsize1) &&
910 !efi_guidcmp(search_efivar->var.VendorGuid,
911 del_var->VendorGuid)) {
912 found = 1;
913 break;
914 }
915 }
916 if (!found) {
917 spin_unlock(&efivars->lock);
918 return -EINVAL;
919 }
920 /* force the Attributes/DataSize to 0 to ensure deletion */
921 del_var->Attributes = 0;
922 del_var->DataSize = 0;
923
924 status = efivars->ops->set_variable(del_var->VariableName,
925 &del_var->VendorGuid,
926 del_var->Attributes,
927 del_var->DataSize,
928 del_var->Data);
929
930 if (status != EFI_SUCCESS) {
931 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
932 status);
933 spin_unlock(&efivars->lock);
934 return -EIO;
935 }
936 list_del(&search_efivar->list);
937 /* We need to release this lock before unregistering. */
938 spin_unlock(&efivars->lock);
939 efivar_unregister(search_efivar);
940
941 /* It's dead Jim.... */
942 return count;
943}
944
945/*
946 * Let's not leave out systab information that snuck into
947 * the efivars driver
948 */
949static ssize_t systab_show(struct kobject *kobj,
950 struct kobj_attribute *attr, char *buf)
951{
952 char *str = buf;
953
954 if (!kobj || !buf)
955 return -EINVAL;
956
957 if (efi.mps != EFI_INVALID_TABLE_ADDR)
958 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
959 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
960 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
961 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
962 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
963 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
964 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
965 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
966 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
967 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
968 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
969 if (efi.uga != EFI_INVALID_TABLE_ADDR)
970 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
971
972 return str - buf;
973}
974
975static struct kobj_attribute efi_attr_systab =
976 __ATTR(systab, 0400, systab_show, NULL);
977
978static struct attribute *efi_subsys_attrs[] = {
979 &efi_attr_systab.attr,
980 NULL, /* maybe more in the future? */
981};
982
983static struct attribute_group efi_subsys_attr_group = {
984 .attrs = efi_subsys_attrs,
985};
986
987static struct kobject *efi_kobj;
988
989/*
990 * efivar_create_sysfs_entry()
991 * Requires:
992 * variable_name_size = number of bytes required to hold
993 * variable_name (not counting the NULL
994 * character at the end.
995 * efivars->lock is not held on entry or exit.
996 * Returns 1 on failure, 0 on success
997 */
998static int
999efivar_create_sysfs_entry(struct efivars *efivars,
1000 unsigned long variable_name_size,
1001 efi_char16_t *variable_name,
1002 efi_guid_t *vendor_guid)
1003{
1004 int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
1005 char *short_name;
1006 struct efivar_entry *new_efivar;
1007
1008 short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
1009 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
1010
1011 if (!short_name || !new_efivar) {
1012 kfree(short_name);
1013 kfree(new_efivar);
1014 return 1;
1015 }
1016
1017 new_efivar->efivars = efivars;
1018 memcpy(new_efivar->var.VariableName, variable_name,
1019 variable_name_size);
1020 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
1021
1022 /* Convert Unicode to normal chars (assume top bits are 0),
1023 ala UTF-8 */
1024 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
1025 short_name[i] = variable_name[i] & 0xFF;
1026 }
1027 /* This is ugly, but necessary to separate one vendor's
1028 private variables from another's. */
1029
1030 *(short_name + strlen(short_name)) = '-';
1031 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
1032
1033 new_efivar->kobj.kset = efivars->kset;
1034 i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
1035 "%s", short_name);
1036 if (i) {
1037 kfree(short_name);
1038 kfree(new_efivar);
1039 return 1;
1040 }
1041
1042 kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
1043 kfree(short_name);
1044 short_name = NULL;
1045
1046 spin_lock(&efivars->lock);
1047 list_add(&new_efivar->list, &efivars->list);
1048 spin_unlock(&efivars->lock);
1049
1050 return 0;
1051}
1052
1053static int
1054create_efivars_bin_attributes(struct efivars *efivars)
1055{
1056 struct bin_attribute *attr;
1057 int error;
1058
1059 /* new_var */
1060 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1061 if (!attr)
1062 return -ENOMEM;
1063
1064 attr->attr.name = "new_var";
1065 attr->attr.mode = 0200;
1066 attr->write = efivar_create;
1067 attr->private = efivars;
1068 efivars->new_var = attr;
1069
1070 /* del_var */
1071 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1072 if (!attr) {
1073 error = -ENOMEM;
1074 goto out_free;
1075 }
1076 attr->attr.name = "del_var";
1077 attr->attr.mode = 0200;
1078 attr->write = efivar_delete;
1079 attr->private = efivars;
1080 efivars->del_var = attr;
1081
1082 sysfs_bin_attr_init(efivars->new_var);
1083 sysfs_bin_attr_init(efivars->del_var);
1084
1085 /* Register */
1086 error = sysfs_create_bin_file(&efivars->kset->kobj,
1087 efivars->new_var);
1088 if (error) {
1089 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
1090 " due to error %d\n", error);
1091 goto out_free;
1092 }
1093 error = sysfs_create_bin_file(&efivars->kset->kobj,
1094 efivars->del_var);
1095 if (error) {
1096 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
1097 " due to error %d\n", error);
1098 sysfs_remove_bin_file(&efivars->kset->kobj,
1099 efivars->new_var);
1100 goto out_free;
1101 }
1102
1103 return 0;
1104out_free:
1105 kfree(efivars->del_var);
1106 efivars->del_var = NULL;
1107 kfree(efivars->new_var);
1108 efivars->new_var = NULL;
1109 return error;
1110}
1111
1112void unregister_efivars(struct efivars *efivars)
1113{
1114 struct efivar_entry *entry, *n;
1115
1116 list_for_each_entry_safe(entry, n, &efivars->list, list) {
1117 spin_lock(&efivars->lock);
1118 list_del(&entry->list);
1119 spin_unlock(&efivars->lock);
1120 efivar_unregister(entry);
1121 }
1122 if (efivars->new_var)
1123 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
1124 if (efivars->del_var)
1125 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
1126 kfree(efivars->new_var);
1127 kfree(efivars->del_var);
1128 kset_unregister(efivars->kset);
1129}
1130EXPORT_SYMBOL_GPL(unregister_efivars);
1131
1132int register_efivars(struct efivars *efivars,
1133 const struct efivar_operations *ops,
1134 struct kobject *parent_kobj)
1135{
1136 efi_status_t status = EFI_NOT_FOUND;
1137 efi_guid_t vendor_guid;
1138 efi_char16_t *variable_name;
1139 unsigned long variable_name_size = 1024;
1140 int error = 0;
1141
1142 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
1143 if (!variable_name) {
1144 printk(KERN_ERR "efivars: Memory allocation failed.\n");
1145 return -ENOMEM;
1146 }
1147
1148 spin_lock_init(&efivars->lock);
1149 INIT_LIST_HEAD(&efivars->list);
1150 efivars->ops = ops;
1151
1152 efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
1153 if (!efivars->kset) {
1154 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
1155 error = -ENOMEM;
1156 goto out;
1157 }
1158
1159 /*
1160 * Per EFI spec, the maximum storage allocated for both
1161 * the variable name and variable data is 1024 bytes.
1162 */
1163
1164 do {
1165 variable_name_size = 1024;
1166
1167 status = ops->get_next_variable(&variable_name_size,
1168 variable_name,
1169 &vendor_guid);
1170 switch (status) {
1171 case EFI_SUCCESS:
1172 efivar_create_sysfs_entry(efivars,
1173 variable_name_size,
1174 variable_name,
1175 &vendor_guid);
1176 break;
1177 case EFI_NOT_FOUND:
1178 break;
1179 default:
1180 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
1181 status);
1182 status = EFI_NOT_FOUND;
1183 break;
1184 }
1185 } while (status != EFI_NOT_FOUND);
1186
1187 error = create_efivars_bin_attributes(efivars);
1188 if (error)
1189 unregister_efivars(efivars);
1190
1191 efivars->efi_pstore_info = efi_pstore_info;
1192
1193 efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
1194 if (efivars->efi_pstore_info.buf) {
1195 efivars->efi_pstore_info.bufsize = 1024;
1196 efivars->efi_pstore_info.data = efivars;
1197 spin_lock_init(&efivars->efi_pstore_info.buf_lock);
1198 pstore_register(&efivars->efi_pstore_info);
1199 }
1200
1201out:
1202 kfree(variable_name);
1203
1204 return error;
1205}
1206EXPORT_SYMBOL_GPL(register_efivars);
1207
1208static struct efivars __efivars;
1209static struct efivar_operations ops;
1210
1211/*
1212 * For now we register the efi subsystem with the firmware subsystem
1213 * and the vars subsystem with the efi subsystem. In the future, it
1214 * might make sense to split off the efi subsystem into its own
1215 * driver, but for now only efivars will register with it, so just
1216 * include it here.
1217 */
1218
1219static int __init
1220efivars_init(void)
1221{
1222 int error = 0;
1223
1224 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
1225 EFIVARS_DATE);
1226
1227 if (!efi_enabled)
1228 return 0;
1229
1230 /* For now we'll register the efi directory at /sys/firmware/efi */
1231 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
1232 if (!efi_kobj) {
1233 printk(KERN_ERR "efivars: Firmware registration failed.\n");
1234 return -ENOMEM;
1235 }
1236
1237 ops.get_variable = efi.get_variable;
1238 ops.set_variable = efi.set_variable;
1239 ops.get_next_variable = efi.get_next_variable;
1240 error = register_efivars(&__efivars, &ops, efi_kobj);
1241 if (error)
1242 goto err_put;
1243
1244 /* Don't forget the systab entry */
1245 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
1246 if (error) {
1247 printk(KERN_ERR
1248 "efivars: Sysfs attribute export failed with error %d.\n",
1249 error);
1250 goto err_unregister;
1251 }
1252
1253 return 0;
1254
1255err_unregister:
1256 unregister_efivars(&__efivars);
1257err_put:
1258 kobject_put(efi_kobj);
1259 return error;
1260}
1261
1262static void __exit
1263efivars_exit(void)
1264{
1265 if (efi_enabled) {
1266 unregister_efivars(&__efivars);
1267 kobject_put(efi_kobj);
1268 }
1269}
1270
1271module_init(efivars_init);
1272module_exit(efivars_exit);
1273