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Merge tag 'late-omap' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[deliverable/linux.git] / drivers / firmware / efivars.c
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 #include <linux/ctype.h>
83
84 #include <linux/fs.h>
85 #include <linux/ramfs.h>
86 #include <linux/pagemap.h>
87
88 #include <asm/uaccess.h>
89
90 #define EFIVARS_VERSION "0.08"
91 #define EFIVARS_DATE "2004-May-17"
92
93 MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
94 MODULE_DESCRIPTION("sysfs interface to EFI Variables");
95 MODULE_LICENSE("GPL");
96 MODULE_VERSION(EFIVARS_VERSION);
97
98 #define DUMP_NAME_LEN 52
99
100 /*
101 * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"))
102 * not including trailing NUL
103 */
104 #define GUID_LEN 36
105
106 /*
107 * The maximum size of VariableName + Data = 1024
108 * Therefore, it's reasonable to save that much
109 * space in each part of the structure,
110 * and we use a page for reading/writing.
111 */
112
113 struct efi_variable {
114 efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
115 efi_guid_t VendorGuid;
116 unsigned long DataSize;
117 __u8 Data[1024];
118 efi_status_t Status;
119 __u32 Attributes;
120 } __attribute__((packed));
121
122 struct efivar_entry {
123 struct efivars *efivars;
124 struct efi_variable var;
125 struct list_head list;
126 struct kobject kobj;
127 };
128
129 struct efivar_attribute {
130 struct attribute attr;
131 ssize_t (*show) (struct efivar_entry *entry, char *buf);
132 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
133 };
134
135 static struct efivars __efivars;
136 static struct efivar_operations ops;
137
138 #define PSTORE_EFI_ATTRIBUTES \
139 (EFI_VARIABLE_NON_VOLATILE | \
140 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
141 EFI_VARIABLE_RUNTIME_ACCESS)
142
143 #define EFIVAR_ATTR(_name, _mode, _show, _store) \
144 struct efivar_attribute efivar_attr_##_name = { \
145 .attr = {.name = __stringify(_name), .mode = _mode}, \
146 .show = _show, \
147 .store = _store, \
148 };
149
150 #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
151 #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
152
153 /*
154 * Prototype for sysfs creation function
155 */
156 static int
157 efivar_create_sysfs_entry(struct efivars *efivars,
158 unsigned long variable_name_size,
159 efi_char16_t *variable_name,
160 efi_guid_t *vendor_guid);
161
162 /*
163 * Prototype for workqueue functions updating sysfs entry
164 */
165
166 static void efivar_update_sysfs_entries(struct work_struct *);
167 static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries);
168
169 /* Return the number of unicode characters in data */
170 static unsigned long
171 utf16_strnlen(efi_char16_t *s, size_t maxlength)
172 {
173 unsigned long length = 0;
174
175 while (*s++ != 0 && length < maxlength)
176 length++;
177 return length;
178 }
179
180 static inline unsigned long
181 utf16_strlen(efi_char16_t *s)
182 {
183 return utf16_strnlen(s, ~0UL);
184 }
185
186 /*
187 * Return the number of bytes is the length of this string
188 * Note: this is NOT the same as the number of unicode characters
189 */
190 static inline unsigned long
191 utf16_strsize(efi_char16_t *data, unsigned long maxlength)
192 {
193 return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
194 }
195
196 static inline int
197 utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len)
198 {
199 while (1) {
200 if (len == 0)
201 return 0;
202 if (*a < *b)
203 return -1;
204 if (*a > *b)
205 return 1;
206 if (*a == 0) /* implies *b == 0 */
207 return 0;
208 a++;
209 b++;
210 len--;
211 }
212 }
213
214 static bool
215 validate_device_path(struct efi_variable *var, int match, u8 *buffer,
216 unsigned long len)
217 {
218 struct efi_generic_dev_path *node;
219 int offset = 0;
220
221 node = (struct efi_generic_dev_path *)buffer;
222
223 if (len < sizeof(*node))
224 return false;
225
226 while (offset <= len - sizeof(*node) &&
227 node->length >= sizeof(*node) &&
228 node->length <= len - offset) {
229 offset += node->length;
230
231 if ((node->type == EFI_DEV_END_PATH ||
232 node->type == EFI_DEV_END_PATH2) &&
233 node->sub_type == EFI_DEV_END_ENTIRE)
234 return true;
235
236 node = (struct efi_generic_dev_path *)(buffer + offset);
237 }
238
239 /*
240 * If we're here then either node->length pointed past the end
241 * of the buffer or we reached the end of the buffer without
242 * finding a device path end node.
243 */
244 return false;
245 }
246
247 static bool
248 validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
249 unsigned long len)
250 {
251 /* An array of 16-bit integers */
252 if ((len % 2) != 0)
253 return false;
254
255 return true;
256 }
257
258 static bool
259 validate_load_option(struct efi_variable *var, int match, u8 *buffer,
260 unsigned long len)
261 {
262 u16 filepathlength;
263 int i, desclength = 0, namelen;
264
265 namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
266
267 /* Either "Boot" or "Driver" followed by four digits of hex */
268 for (i = match; i < match+4; i++) {
269 if (var->VariableName[i] > 127 ||
270 hex_to_bin(var->VariableName[i] & 0xff) < 0)
271 return true;
272 }
273
274 /* Reject it if there's 4 digits of hex and then further content */
275 if (namelen > match + 4)
276 return false;
277
278 /* A valid entry must be at least 8 bytes */
279 if (len < 8)
280 return false;
281
282 filepathlength = buffer[4] | buffer[5] << 8;
283
284 /*
285 * There's no stored length for the description, so it has to be
286 * found by hand
287 */
288 desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
289
290 /* Each boot entry must have a descriptor */
291 if (!desclength)
292 return false;
293
294 /*
295 * If the sum of the length of the description, the claimed filepath
296 * length and the original header are greater than the length of the
297 * variable, it's malformed
298 */
299 if ((desclength + filepathlength + 6) > len)
300 return false;
301
302 /*
303 * And, finally, check the filepath
304 */
305 return validate_device_path(var, match, buffer + desclength + 6,
306 filepathlength);
307 }
308
309 static bool
310 validate_uint16(struct efi_variable *var, int match, u8 *buffer,
311 unsigned long len)
312 {
313 /* A single 16-bit integer */
314 if (len != 2)
315 return false;
316
317 return true;
318 }
319
320 static bool
321 validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
322 unsigned long len)
323 {
324 int i;
325
326 for (i = 0; i < len; i++) {
327 if (buffer[i] > 127)
328 return false;
329
330 if (buffer[i] == 0)
331 return true;
332 }
333
334 return false;
335 }
336
337 struct variable_validate {
338 char *name;
339 bool (*validate)(struct efi_variable *var, int match, u8 *data,
340 unsigned long len);
341 };
342
343 static const struct variable_validate variable_validate[] = {
344 { "BootNext", validate_uint16 },
345 { "BootOrder", validate_boot_order },
346 { "DriverOrder", validate_boot_order },
347 { "Boot*", validate_load_option },
348 { "Driver*", validate_load_option },
349 { "ConIn", validate_device_path },
350 { "ConInDev", validate_device_path },
351 { "ConOut", validate_device_path },
352 { "ConOutDev", validate_device_path },
353 { "ErrOut", validate_device_path },
354 { "ErrOutDev", validate_device_path },
355 { "Timeout", validate_uint16 },
356 { "Lang", validate_ascii_string },
357 { "PlatformLang", validate_ascii_string },
358 { "", NULL },
359 };
360
361 static bool
362 validate_var(struct efi_variable *var, u8 *data, unsigned long len)
363 {
364 int i;
365 u16 *unicode_name = var->VariableName;
366
367 for (i = 0; variable_validate[i].validate != NULL; i++) {
368 const char *name = variable_validate[i].name;
369 int match;
370
371 for (match = 0; ; match++) {
372 char c = name[match];
373 u16 u = unicode_name[match];
374
375 /* All special variables are plain ascii */
376 if (u > 127)
377 return true;
378
379 /* Wildcard in the matching name means we've matched */
380 if (c == '*')
381 return variable_validate[i].validate(var,
382 match, data, len);
383
384 /* Case sensitive match */
385 if (c != u)
386 break;
387
388 /* Reached the end of the string while matching */
389 if (!c)
390 return variable_validate[i].validate(var,
391 match, data, len);
392 }
393 }
394
395 return true;
396 }
397
398 static efi_status_t
399 get_var_data_locked(struct efivars *efivars, struct efi_variable *var)
400 {
401 efi_status_t status;
402
403 var->DataSize = 1024;
404 status = efivars->ops->get_variable(var->VariableName,
405 &var->VendorGuid,
406 &var->Attributes,
407 &var->DataSize,
408 var->Data);
409 return status;
410 }
411
412 static efi_status_t
413 get_var_data(struct efivars *efivars, struct efi_variable *var)
414 {
415 efi_status_t status;
416 unsigned long flags;
417
418 spin_lock_irqsave(&efivars->lock, flags);
419 status = get_var_data_locked(efivars, var);
420 spin_unlock_irqrestore(&efivars->lock, flags);
421
422 if (status != EFI_SUCCESS) {
423 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
424 status);
425 }
426 return status;
427 }
428
429 static ssize_t
430 efivar_guid_read(struct efivar_entry *entry, char *buf)
431 {
432 struct efi_variable *var = &entry->var;
433 char *str = buf;
434
435 if (!entry || !buf)
436 return 0;
437
438 efi_guid_unparse(&var->VendorGuid, str);
439 str += strlen(str);
440 str += sprintf(str, "\n");
441
442 return str - buf;
443 }
444
445 static ssize_t
446 efivar_attr_read(struct efivar_entry *entry, char *buf)
447 {
448 struct efi_variable *var = &entry->var;
449 char *str = buf;
450 efi_status_t status;
451
452 if (!entry || !buf)
453 return -EINVAL;
454
455 status = get_var_data(entry->efivars, var);
456 if (status != EFI_SUCCESS)
457 return -EIO;
458
459 if (var->Attributes & EFI_VARIABLE_NON_VOLATILE)
460 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
461 if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)
462 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
463 if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)
464 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
465 if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD)
466 str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
467 if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
468 str += sprintf(str,
469 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
470 if (var->Attributes &
471 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
472 str += sprintf(str,
473 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
474 if (var->Attributes & EFI_VARIABLE_APPEND_WRITE)
475 str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n");
476 return str - buf;
477 }
478
479 static ssize_t
480 efivar_size_read(struct efivar_entry *entry, char *buf)
481 {
482 struct efi_variable *var = &entry->var;
483 char *str = buf;
484 efi_status_t status;
485
486 if (!entry || !buf)
487 return -EINVAL;
488
489 status = get_var_data(entry->efivars, var);
490 if (status != EFI_SUCCESS)
491 return -EIO;
492
493 str += sprintf(str, "0x%lx\n", var->DataSize);
494 return str - buf;
495 }
496
497 static ssize_t
498 efivar_data_read(struct efivar_entry *entry, char *buf)
499 {
500 struct efi_variable *var = &entry->var;
501 efi_status_t status;
502
503 if (!entry || !buf)
504 return -EINVAL;
505
506 status = get_var_data(entry->efivars, var);
507 if (status != EFI_SUCCESS)
508 return -EIO;
509
510 memcpy(buf, var->Data, var->DataSize);
511 return var->DataSize;
512 }
513 /*
514 * We allow each variable to be edited via rewriting the
515 * entire efi variable structure.
516 */
517 static ssize_t
518 efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
519 {
520 struct efi_variable *new_var, *var = &entry->var;
521 struct efivars *efivars = entry->efivars;
522 efi_status_t status = EFI_NOT_FOUND;
523
524 if (count != sizeof(struct efi_variable))
525 return -EINVAL;
526
527 new_var = (struct efi_variable *)buf;
528 /*
529 * If only updating the variable data, then the name
530 * and guid should remain the same
531 */
532 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
533 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
534 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
535 return -EINVAL;
536 }
537
538 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
539 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
540 return -EINVAL;
541 }
542
543 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
544 validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
545 printk(KERN_ERR "efivars: Malformed variable content\n");
546 return -EINVAL;
547 }
548
549 spin_lock_irq(&efivars->lock);
550 status = efivars->ops->set_variable(new_var->VariableName,
551 &new_var->VendorGuid,
552 new_var->Attributes,
553 new_var->DataSize,
554 new_var->Data);
555
556 spin_unlock_irq(&efivars->lock);
557
558 if (status != EFI_SUCCESS) {
559 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
560 status);
561 return -EIO;
562 }
563
564 memcpy(&entry->var, new_var, count);
565 return count;
566 }
567
568 static ssize_t
569 efivar_show_raw(struct efivar_entry *entry, char *buf)
570 {
571 struct efi_variable *var = &entry->var;
572 efi_status_t status;
573
574 if (!entry || !buf)
575 return 0;
576
577 status = get_var_data(entry->efivars, var);
578 if (status != EFI_SUCCESS)
579 return -EIO;
580
581 memcpy(buf, var, sizeof(*var));
582 return sizeof(*var);
583 }
584
585 /*
586 * Generic read/write functions that call the specific functions of
587 * the attributes...
588 */
589 static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
590 char *buf)
591 {
592 struct efivar_entry *var = to_efivar_entry(kobj);
593 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
594 ssize_t ret = -EIO;
595
596 if (!capable(CAP_SYS_ADMIN))
597 return -EACCES;
598
599 if (efivar_attr->show) {
600 ret = efivar_attr->show(var, buf);
601 }
602 return ret;
603 }
604
605 static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
606 const char *buf, size_t count)
607 {
608 struct efivar_entry *var = to_efivar_entry(kobj);
609 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
610 ssize_t ret = -EIO;
611
612 if (!capable(CAP_SYS_ADMIN))
613 return -EACCES;
614
615 if (efivar_attr->store)
616 ret = efivar_attr->store(var, buf, count);
617
618 return ret;
619 }
620
621 static const struct sysfs_ops efivar_attr_ops = {
622 .show = efivar_attr_show,
623 .store = efivar_attr_store,
624 };
625
626 static void efivar_release(struct kobject *kobj)
627 {
628 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
629 kfree(var);
630 }
631
632 static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
633 static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
634 static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
635 static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
636 static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
637
638 static struct attribute *def_attrs[] = {
639 &efivar_attr_guid.attr,
640 &efivar_attr_size.attr,
641 &efivar_attr_attributes.attr,
642 &efivar_attr_data.attr,
643 &efivar_attr_raw_var.attr,
644 NULL,
645 };
646
647 static struct kobj_type efivar_ktype = {
648 .release = efivar_release,
649 .sysfs_ops = &efivar_attr_ops,
650 .default_attrs = def_attrs,
651 };
652
653 static inline void
654 efivar_unregister(struct efivar_entry *var)
655 {
656 kobject_put(&var->kobj);
657 }
658
659 static int efivarfs_file_open(struct inode *inode, struct file *file)
660 {
661 file->private_data = inode->i_private;
662 return 0;
663 }
664
665 static int efi_status_to_err(efi_status_t status)
666 {
667 int err;
668
669 switch (status) {
670 case EFI_INVALID_PARAMETER:
671 err = -EINVAL;
672 break;
673 case EFI_OUT_OF_RESOURCES:
674 err = -ENOSPC;
675 break;
676 case EFI_DEVICE_ERROR:
677 err = -EIO;
678 break;
679 case EFI_WRITE_PROTECTED:
680 err = -EROFS;
681 break;
682 case EFI_SECURITY_VIOLATION:
683 err = -EACCES;
684 break;
685 case EFI_NOT_FOUND:
686 err = -EIO;
687 break;
688 default:
689 err = -EINVAL;
690 }
691
692 return err;
693 }
694
695 static ssize_t efivarfs_file_write(struct file *file,
696 const char __user *userbuf, size_t count, loff_t *ppos)
697 {
698 struct efivar_entry *var = file->private_data;
699 struct efivars *efivars;
700 efi_status_t status;
701 void *data;
702 u32 attributes;
703 struct inode *inode = file->f_mapping->host;
704 unsigned long datasize = count - sizeof(attributes);
705 unsigned long newdatasize;
706 u64 storage_size, remaining_size, max_size;
707 ssize_t bytes = 0;
708
709 if (count < sizeof(attributes))
710 return -EINVAL;
711
712 if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
713 return -EFAULT;
714
715 if (attributes & ~(EFI_VARIABLE_MASK))
716 return -EINVAL;
717
718 efivars = var->efivars;
719
720 /*
721 * Ensure that the user can't allocate arbitrarily large
722 * amounts of memory. Pick a default size of 64K if
723 * QueryVariableInfo() isn't supported by the firmware.
724 */
725 spin_lock_irq(&efivars->lock);
726
727 if (!efivars->ops->query_variable_info)
728 status = EFI_UNSUPPORTED;
729 else {
730 const struct efivar_operations *fops = efivars->ops;
731 status = fops->query_variable_info(attributes, &storage_size,
732 &remaining_size, &max_size);
733 }
734
735 spin_unlock_irq(&efivars->lock);
736
737 if (status != EFI_SUCCESS) {
738 if (status != EFI_UNSUPPORTED)
739 return efi_status_to_err(status);
740
741 remaining_size = 65536;
742 }
743
744 if (datasize > remaining_size)
745 return -ENOSPC;
746
747 data = kmalloc(datasize, GFP_KERNEL);
748 if (!data)
749 return -ENOMEM;
750
751 if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
752 bytes = -EFAULT;
753 goto out;
754 }
755
756 if (validate_var(&var->var, data, datasize) == false) {
757 bytes = -EINVAL;
758 goto out;
759 }
760
761 /*
762 * The lock here protects the get_variable call, the conditional
763 * set_variable call, and removal of the variable from the efivars
764 * list (in the case of an authenticated delete).
765 */
766 spin_lock_irq(&efivars->lock);
767
768 status = efivars->ops->set_variable(var->var.VariableName,
769 &var->var.VendorGuid,
770 attributes, datasize,
771 data);
772
773 if (status != EFI_SUCCESS) {
774 spin_unlock_irq(&efivars->lock);
775 kfree(data);
776
777 return efi_status_to_err(status);
778 }
779
780 bytes = count;
781
782 /*
783 * Writing to the variable may have caused a change in size (which
784 * could either be an append or an overwrite), or the variable to be
785 * deleted. Perform a GetVariable() so we can tell what actually
786 * happened.
787 */
788 newdatasize = 0;
789 status = efivars->ops->get_variable(var->var.VariableName,
790 &var->var.VendorGuid,
791 NULL, &newdatasize,
792 NULL);
793
794 if (status == EFI_BUFFER_TOO_SMALL) {
795 spin_unlock_irq(&efivars->lock);
796 mutex_lock(&inode->i_mutex);
797 i_size_write(inode, newdatasize + sizeof(attributes));
798 mutex_unlock(&inode->i_mutex);
799
800 } else if (status == EFI_NOT_FOUND) {
801 list_del(&var->list);
802 spin_unlock_irq(&efivars->lock);
803 efivar_unregister(var);
804 drop_nlink(inode);
805 d_delete(file->f_dentry);
806 dput(file->f_dentry);
807
808 } else {
809 spin_unlock_irq(&efivars->lock);
810 pr_warn("efivarfs: inconsistent EFI variable implementation? "
811 "status = %lx\n", status);
812 }
813
814 out:
815 kfree(data);
816
817 return bytes;
818 }
819
820 static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
821 size_t count, loff_t *ppos)
822 {
823 struct efivar_entry *var = file->private_data;
824 struct efivars *efivars = var->efivars;
825 efi_status_t status;
826 unsigned long datasize = 0;
827 u32 attributes;
828 void *data;
829 ssize_t size = 0;
830
831 spin_lock_irq(&efivars->lock);
832 status = efivars->ops->get_variable(var->var.VariableName,
833 &var->var.VendorGuid,
834 &attributes, &datasize, NULL);
835 spin_unlock_irq(&efivars->lock);
836
837 if (status != EFI_BUFFER_TOO_SMALL)
838 return efi_status_to_err(status);
839
840 data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
841
842 if (!data)
843 return -ENOMEM;
844
845 spin_lock_irq(&efivars->lock);
846 status = efivars->ops->get_variable(var->var.VariableName,
847 &var->var.VendorGuid,
848 &attributes, &datasize,
849 (data + sizeof(attributes)));
850 spin_unlock_irq(&efivars->lock);
851
852 if (status != EFI_SUCCESS) {
853 size = efi_status_to_err(status);
854 goto out_free;
855 }
856
857 memcpy(data, &attributes, sizeof(attributes));
858 size = simple_read_from_buffer(userbuf, count, ppos,
859 data, datasize + sizeof(attributes));
860 out_free:
861 kfree(data);
862
863 return size;
864 }
865
866 static void efivarfs_evict_inode(struct inode *inode)
867 {
868 clear_inode(inode);
869 }
870
871 static const struct super_operations efivarfs_ops = {
872 .statfs = simple_statfs,
873 .drop_inode = generic_delete_inode,
874 .evict_inode = efivarfs_evict_inode,
875 .show_options = generic_show_options,
876 };
877
878 static struct super_block *efivarfs_sb;
879
880 static const struct inode_operations efivarfs_dir_inode_operations;
881
882 static const struct file_operations efivarfs_file_operations = {
883 .open = efivarfs_file_open,
884 .read = efivarfs_file_read,
885 .write = efivarfs_file_write,
886 .llseek = no_llseek,
887 };
888
889 static struct inode *efivarfs_get_inode(struct super_block *sb,
890 const struct inode *dir, int mode, dev_t dev)
891 {
892 struct inode *inode = new_inode(sb);
893
894 if (inode) {
895 inode->i_ino = get_next_ino();
896 inode->i_mode = mode;
897 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
898 switch (mode & S_IFMT) {
899 case S_IFREG:
900 inode->i_fop = &efivarfs_file_operations;
901 break;
902 case S_IFDIR:
903 inode->i_op = &efivarfs_dir_inode_operations;
904 inode->i_fop = &simple_dir_operations;
905 inc_nlink(inode);
906 break;
907 }
908 }
909 return inode;
910 }
911
912 /*
913 * Return true if 'str' is a valid efivarfs filename of the form,
914 *
915 * VariableName-12345678-1234-1234-1234-1234567891bc
916 */
917 static bool efivarfs_valid_name(const char *str, int len)
918 {
919 static const char dashes[GUID_LEN] = {
920 [8] = 1, [13] = 1, [18] = 1, [23] = 1
921 };
922 const char *s = str + len - GUID_LEN;
923 int i;
924
925 /*
926 * We need a GUID, plus at least one letter for the variable name,
927 * plus the '-' separator
928 */
929 if (len < GUID_LEN + 2)
930 return false;
931
932 /* GUID should be right after the first '-' */
933 if (s - 1 != strchr(str, '-'))
934 return false;
935
936 /*
937 * Validate that 's' is of the correct format, e.g.
938 *
939 * 12345678-1234-1234-1234-123456789abc
940 */
941 for (i = 0; i < GUID_LEN; i++) {
942 if (dashes[i]) {
943 if (*s++ != '-')
944 return false;
945 } else {
946 if (!isxdigit(*s++))
947 return false;
948 }
949 }
950
951 return true;
952 }
953
954 static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid)
955 {
956 guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]);
957 guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]);
958 guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]);
959 guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]);
960 guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]);
961 guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]);
962 guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]);
963 guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]);
964 guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]);
965 guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]);
966 guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]);
967 guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]);
968 guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]);
969 guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]);
970 guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]);
971 guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]);
972 }
973
974 static int efivarfs_create(struct inode *dir, struct dentry *dentry,
975 umode_t mode, bool excl)
976 {
977 struct inode *inode;
978 struct efivars *efivars = &__efivars;
979 struct efivar_entry *var;
980 int namelen, i = 0, err = 0;
981
982 if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
983 return -EINVAL;
984
985 inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
986 if (!inode)
987 return -ENOMEM;
988
989 var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
990 if (!var) {
991 err = -ENOMEM;
992 goto out;
993 }
994
995 /* length of the variable name itself: remove GUID and separator */
996 namelen = dentry->d_name.len - GUID_LEN - 1;
997
998 efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1,
999 &var->var.VendorGuid);
1000
1001 for (i = 0; i < namelen; i++)
1002 var->var.VariableName[i] = dentry->d_name.name[i];
1003
1004 var->var.VariableName[i] = '\0';
1005
1006 inode->i_private = var;
1007 var->efivars = efivars;
1008 var->kobj.kset = efivars->kset;
1009
1010 err = kobject_init_and_add(&var->kobj, &efivar_ktype, NULL, "%s",
1011 dentry->d_name.name);
1012 if (err)
1013 goto out;
1014
1015 kobject_uevent(&var->kobj, KOBJ_ADD);
1016 spin_lock_irq(&efivars->lock);
1017 list_add(&var->list, &efivars->list);
1018 spin_unlock_irq(&efivars->lock);
1019 d_instantiate(dentry, inode);
1020 dget(dentry);
1021 out:
1022 if (err) {
1023 kfree(var);
1024 iput(inode);
1025 }
1026 return err;
1027 }
1028
1029 static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
1030 {
1031 struct efivar_entry *var = dentry->d_inode->i_private;
1032 struct efivars *efivars = var->efivars;
1033 efi_status_t status;
1034
1035 spin_lock_irq(&efivars->lock);
1036
1037 status = efivars->ops->set_variable(var->var.VariableName,
1038 &var->var.VendorGuid,
1039 0, 0, NULL);
1040
1041 if (status == EFI_SUCCESS || status == EFI_NOT_FOUND) {
1042 list_del(&var->list);
1043 spin_unlock_irq(&efivars->lock);
1044 efivar_unregister(var);
1045 drop_nlink(dentry->d_inode);
1046 dput(dentry);
1047 return 0;
1048 }
1049
1050 spin_unlock_irq(&efivars->lock);
1051 return -EINVAL;
1052 };
1053
1054 /*
1055 * Compare two efivarfs file names.
1056 *
1057 * An efivarfs filename is composed of two parts,
1058 *
1059 * 1. A case-sensitive variable name
1060 * 2. A case-insensitive GUID
1061 *
1062 * So we need to perform a case-sensitive match on part 1 and a
1063 * case-insensitive match on part 2.
1064 */
1065 static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode,
1066 const struct dentry *dentry, const struct inode *inode,
1067 unsigned int len, const char *str,
1068 const struct qstr *name)
1069 {
1070 int guid = len - GUID_LEN;
1071
1072 if (name->len != len)
1073 return 1;
1074
1075 /* Case-sensitive compare for the variable name */
1076 if (memcmp(str, name->name, guid))
1077 return 1;
1078
1079 /* Case-insensitive compare for the GUID */
1080 return strncasecmp(name->name + guid, str + guid, GUID_LEN);
1081 }
1082
1083 static int efivarfs_d_hash(const struct dentry *dentry,
1084 const struct inode *inode, struct qstr *qstr)
1085 {
1086 unsigned long hash = init_name_hash();
1087 const unsigned char *s = qstr->name;
1088 unsigned int len = qstr->len;
1089
1090 if (!efivarfs_valid_name(s, len))
1091 return -EINVAL;
1092
1093 while (len-- > GUID_LEN)
1094 hash = partial_name_hash(*s++, hash);
1095
1096 /* GUID is case-insensitive. */
1097 while (len--)
1098 hash = partial_name_hash(tolower(*s++), hash);
1099
1100 qstr->hash = end_name_hash(hash);
1101 return 0;
1102 }
1103
1104 /*
1105 * Retaining negative dentries for an in-memory filesystem just wastes
1106 * memory and lookup time: arrange for them to be deleted immediately.
1107 */
1108 static int efivarfs_delete_dentry(const struct dentry *dentry)
1109 {
1110 return 1;
1111 }
1112
1113 static struct dentry_operations efivarfs_d_ops = {
1114 .d_compare = efivarfs_d_compare,
1115 .d_hash = efivarfs_d_hash,
1116 .d_delete = efivarfs_delete_dentry,
1117 };
1118
1119 static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name)
1120 {
1121 struct qstr q;
1122
1123 q.name = name;
1124 q.len = strlen(name);
1125
1126 if (efivarfs_d_hash(NULL, NULL, &q))
1127 return NULL;
1128
1129 return d_alloc(parent, &q);
1130 }
1131
1132 static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
1133 {
1134 struct inode *inode = NULL;
1135 struct dentry *root;
1136 struct efivar_entry *entry, *n;
1137 struct efivars *efivars = &__efivars;
1138 char *name;
1139
1140 efivarfs_sb = sb;
1141
1142 sb->s_maxbytes = MAX_LFS_FILESIZE;
1143 sb->s_blocksize = PAGE_CACHE_SIZE;
1144 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1145 sb->s_magic = EFIVARFS_MAGIC;
1146 sb->s_op = &efivarfs_ops;
1147 sb->s_d_op = &efivarfs_d_ops;
1148 sb->s_time_gran = 1;
1149
1150 inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0);
1151 if (!inode)
1152 return -ENOMEM;
1153 inode->i_op = &efivarfs_dir_inode_operations;
1154
1155 root = d_make_root(inode);
1156 sb->s_root = root;
1157 if (!root)
1158 return -ENOMEM;
1159
1160 list_for_each_entry_safe(entry, n, &efivars->list, list) {
1161 struct dentry *dentry, *root = efivarfs_sb->s_root;
1162 unsigned long size = 0;
1163 int len, i;
1164
1165 inode = NULL;
1166
1167 len = utf16_strlen(entry->var.VariableName);
1168
1169 /* name, plus '-', plus GUID, plus NUL*/
1170 name = kmalloc(len + 1 + GUID_LEN + 1, GFP_ATOMIC);
1171 if (!name)
1172 goto fail;
1173
1174 for (i = 0; i < len; i++)
1175 name[i] = entry->var.VariableName[i] & 0xFF;
1176
1177 name[len] = '-';
1178
1179 efi_guid_unparse(&entry->var.VendorGuid, name + len + 1);
1180
1181 name[len+GUID_LEN+1] = '\0';
1182
1183 inode = efivarfs_get_inode(efivarfs_sb, root->d_inode,
1184 S_IFREG | 0644, 0);
1185 if (!inode)
1186 goto fail_name;
1187
1188 dentry = efivarfs_alloc_dentry(root, name);
1189 if (!dentry)
1190 goto fail_inode;
1191
1192 /* copied by the above to local storage in the dentry. */
1193 kfree(name);
1194
1195 spin_lock_irq(&efivars->lock);
1196 efivars->ops->get_variable(entry->var.VariableName,
1197 &entry->var.VendorGuid,
1198 &entry->var.Attributes,
1199 &size,
1200 NULL);
1201 spin_unlock_irq(&efivars->lock);
1202
1203 mutex_lock(&inode->i_mutex);
1204 inode->i_private = entry;
1205 i_size_write(inode, size + sizeof(entry->var.Attributes));
1206 mutex_unlock(&inode->i_mutex);
1207 d_add(dentry, inode);
1208 }
1209
1210 return 0;
1211
1212 fail_inode:
1213 iput(inode);
1214 fail_name:
1215 kfree(name);
1216 fail:
1217 return -ENOMEM;
1218 }
1219
1220 static struct dentry *efivarfs_mount(struct file_system_type *fs_type,
1221 int flags, const char *dev_name, void *data)
1222 {
1223 return mount_single(fs_type, flags, data, efivarfs_fill_super);
1224 }
1225
1226 static void efivarfs_kill_sb(struct super_block *sb)
1227 {
1228 kill_litter_super(sb);
1229 efivarfs_sb = NULL;
1230 }
1231
1232 static struct file_system_type efivarfs_type = {
1233 .name = "efivarfs",
1234 .mount = efivarfs_mount,
1235 .kill_sb = efivarfs_kill_sb,
1236 };
1237
1238 /*
1239 * Handle negative dentry.
1240 */
1241 static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry,
1242 unsigned int flags)
1243 {
1244 if (dentry->d_name.len > NAME_MAX)
1245 return ERR_PTR(-ENAMETOOLONG);
1246 d_add(dentry, NULL);
1247 return NULL;
1248 }
1249
1250 static const struct inode_operations efivarfs_dir_inode_operations = {
1251 .lookup = efivarfs_lookup,
1252 .unlink = efivarfs_unlink,
1253 .create = efivarfs_create,
1254 };
1255
1256 static struct pstore_info efi_pstore_info;
1257
1258 #ifdef CONFIG_PSTORE
1259
1260 static int efi_pstore_open(struct pstore_info *psi)
1261 {
1262 struct efivars *efivars = psi->data;
1263
1264 spin_lock_irq(&efivars->lock);
1265 efivars->walk_entry = list_first_entry(&efivars->list,
1266 struct efivar_entry, list);
1267 return 0;
1268 }
1269
1270 static int efi_pstore_close(struct pstore_info *psi)
1271 {
1272 struct efivars *efivars = psi->data;
1273
1274 spin_unlock_irq(&efivars->lock);
1275 return 0;
1276 }
1277
1278 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
1279 int *count, struct timespec *timespec,
1280 char **buf, struct pstore_info *psi)
1281 {
1282 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
1283 struct efivars *efivars = psi->data;
1284 char name[DUMP_NAME_LEN];
1285 int i;
1286 int cnt;
1287 unsigned int part, size;
1288 unsigned long time;
1289
1290 while (&efivars->walk_entry->list != &efivars->list) {
1291 if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid,
1292 vendor)) {
1293 for (i = 0; i < DUMP_NAME_LEN; i++) {
1294 name[i] = efivars->walk_entry->var.VariableName[i];
1295 }
1296 if (sscanf(name, "dump-type%u-%u-%d-%lu",
1297 type, &part, &cnt, &time) == 4) {
1298 *id = part;
1299 *count = cnt;
1300 timespec->tv_sec = time;
1301 timespec->tv_nsec = 0;
1302 } else if (sscanf(name, "dump-type%u-%u-%lu",
1303 type, &part, &time) == 3) {
1304 /*
1305 * Check if an old format,
1306 * which doesn't support holding
1307 * multiple logs, remains.
1308 */
1309 *id = part;
1310 *count = 0;
1311 timespec->tv_sec = time;
1312 timespec->tv_nsec = 0;
1313 } else {
1314 efivars->walk_entry = list_entry(
1315 efivars->walk_entry->list.next,
1316 struct efivar_entry, list);
1317 continue;
1318 }
1319
1320 get_var_data_locked(efivars, &efivars->walk_entry->var);
1321 size = efivars->walk_entry->var.DataSize;
1322 *buf = kmalloc(size, GFP_KERNEL);
1323 if (*buf == NULL)
1324 return -ENOMEM;
1325 memcpy(*buf, efivars->walk_entry->var.Data,
1326 size);
1327 efivars->walk_entry = list_entry(
1328 efivars->walk_entry->list.next,
1329 struct efivar_entry, list);
1330 return size;
1331 }
1332 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
1333 struct efivar_entry, list);
1334 }
1335 return 0;
1336 }
1337
1338 static int efi_pstore_write(enum pstore_type_id type,
1339 enum kmsg_dump_reason reason, u64 *id,
1340 unsigned int part, int count, size_t size,
1341 struct pstore_info *psi)
1342 {
1343 char name[DUMP_NAME_LEN];
1344 efi_char16_t efi_name[DUMP_NAME_LEN];
1345 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
1346 struct efivars *efivars = psi->data;
1347 int i, ret = 0;
1348 u64 storage_space, remaining_space, max_variable_size;
1349 efi_status_t status = EFI_NOT_FOUND;
1350 unsigned long flags;
1351
1352 if (pstore_cannot_block_path(reason)) {
1353 /*
1354 * If the lock is taken by another cpu in non-blocking path,
1355 * this driver returns without entering firmware to avoid
1356 * hanging up.
1357 */
1358 if (!spin_trylock_irqsave(&efivars->lock, flags))
1359 return -EBUSY;
1360 } else
1361 spin_lock_irqsave(&efivars->lock, flags);
1362
1363 /*
1364 * Check if there is a space enough to log.
1365 * size: a size of logging data
1366 * DUMP_NAME_LEN * 2: a maximum size of variable name
1367 */
1368 status = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES,
1369 &storage_space,
1370 &remaining_space,
1371 &max_variable_size);
1372 if (status || remaining_space < size + DUMP_NAME_LEN * 2) {
1373 spin_unlock_irqrestore(&efivars->lock, flags);
1374 *id = part;
1375 return -ENOSPC;
1376 }
1377
1378 sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
1379 get_seconds());
1380
1381 for (i = 0; i < DUMP_NAME_LEN; i++)
1382 efi_name[i] = name[i];
1383
1384 efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
1385 size, psi->buf);
1386
1387 spin_unlock_irqrestore(&efivars->lock, flags);
1388
1389 if (reason == KMSG_DUMP_OOPS)
1390 schedule_work(&efivar_work);
1391
1392 *id = part;
1393 return ret;
1394 };
1395
1396 static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
1397 struct timespec time, struct pstore_info *psi)
1398 {
1399 char name[DUMP_NAME_LEN];
1400 efi_char16_t efi_name[DUMP_NAME_LEN];
1401 char name_old[DUMP_NAME_LEN];
1402 efi_char16_t efi_name_old[DUMP_NAME_LEN];
1403 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
1404 struct efivars *efivars = psi->data;
1405 struct efivar_entry *entry, *found = NULL;
1406 int i;
1407
1408 sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
1409 time.tv_sec);
1410
1411 spin_lock_irq(&efivars->lock);
1412
1413 for (i = 0; i < DUMP_NAME_LEN; i++)
1414 efi_name[i] = name[i];
1415
1416 /*
1417 * Clean up an entry with the same name
1418 */
1419
1420 list_for_each_entry(entry, &efivars->list, list) {
1421 get_var_data_locked(efivars, &entry->var);
1422
1423 if (efi_guidcmp(entry->var.VendorGuid, vendor))
1424 continue;
1425 if (utf16_strncmp(entry->var.VariableName, efi_name,
1426 utf16_strlen(efi_name))) {
1427 /*
1428 * Check if an old format,
1429 * which doesn't support holding
1430 * multiple logs, remains.
1431 */
1432 sprintf(name_old, "dump-type%u-%u-%lu", type,
1433 (unsigned int)id, time.tv_sec);
1434
1435 for (i = 0; i < DUMP_NAME_LEN; i++)
1436 efi_name_old[i] = name_old[i];
1437
1438 if (utf16_strncmp(entry->var.VariableName, efi_name_old,
1439 utf16_strlen(efi_name_old)))
1440 continue;
1441 }
1442
1443 /* found */
1444 found = entry;
1445 efivars->ops->set_variable(entry->var.VariableName,
1446 &entry->var.VendorGuid,
1447 PSTORE_EFI_ATTRIBUTES,
1448 0, NULL);
1449 break;
1450 }
1451
1452 if (found)
1453 list_del(&found->list);
1454
1455 spin_unlock_irq(&efivars->lock);
1456
1457 if (found)
1458 efivar_unregister(found);
1459
1460 return 0;
1461 }
1462 #else
1463 static int efi_pstore_open(struct pstore_info *psi)
1464 {
1465 return 0;
1466 }
1467
1468 static int efi_pstore_close(struct pstore_info *psi)
1469 {
1470 return 0;
1471 }
1472
1473 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, int *count,
1474 struct timespec *timespec,
1475 char **buf, struct pstore_info *psi)
1476 {
1477 return -1;
1478 }
1479
1480 static int efi_pstore_write(enum pstore_type_id type,
1481 enum kmsg_dump_reason reason, u64 *id,
1482 unsigned int part, int count, size_t size,
1483 struct pstore_info *psi)
1484 {
1485 return 0;
1486 }
1487
1488 static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
1489 struct timespec time, struct pstore_info *psi)
1490 {
1491 return 0;
1492 }
1493 #endif
1494
1495 static struct pstore_info efi_pstore_info = {
1496 .owner = THIS_MODULE,
1497 .name = "efi",
1498 .open = efi_pstore_open,
1499 .close = efi_pstore_close,
1500 .read = efi_pstore_read,
1501 .write = efi_pstore_write,
1502 .erase = efi_pstore_erase,
1503 };
1504
1505 static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
1506 struct bin_attribute *bin_attr,
1507 char *buf, loff_t pos, size_t count)
1508 {
1509 struct efi_variable *new_var = (struct efi_variable *)buf;
1510 struct efivars *efivars = bin_attr->private;
1511 struct efivar_entry *search_efivar, *n;
1512 unsigned long strsize1, strsize2;
1513 efi_status_t status = EFI_NOT_FOUND;
1514 int found = 0;
1515
1516 if (!capable(CAP_SYS_ADMIN))
1517 return -EACCES;
1518
1519 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
1520 validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
1521 printk(KERN_ERR "efivars: Malformed variable content\n");
1522 return -EINVAL;
1523 }
1524
1525 spin_lock_irq(&efivars->lock);
1526
1527 /*
1528 * Does this variable already exist?
1529 */
1530 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
1531 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
1532 strsize2 = utf16_strsize(new_var->VariableName, 1024);
1533 if (strsize1 == strsize2 &&
1534 !memcmp(&(search_efivar->var.VariableName),
1535 new_var->VariableName, strsize1) &&
1536 !efi_guidcmp(search_efivar->var.VendorGuid,
1537 new_var->VendorGuid)) {
1538 found = 1;
1539 break;
1540 }
1541 }
1542 if (found) {
1543 spin_unlock_irq(&efivars->lock);
1544 return -EINVAL;
1545 }
1546
1547 /* now *really* create the variable via EFI */
1548 status = efivars->ops->set_variable(new_var->VariableName,
1549 &new_var->VendorGuid,
1550 new_var->Attributes,
1551 new_var->DataSize,
1552 new_var->Data);
1553
1554 if (status != EFI_SUCCESS) {
1555 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
1556 status);
1557 spin_unlock_irq(&efivars->lock);
1558 return -EIO;
1559 }
1560 spin_unlock_irq(&efivars->lock);
1561
1562 /* Create the entry in sysfs. Locking is not required here */
1563 status = efivar_create_sysfs_entry(efivars,
1564 utf16_strsize(new_var->VariableName,
1565 1024),
1566 new_var->VariableName,
1567 &new_var->VendorGuid);
1568 if (status) {
1569 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
1570 }
1571 return count;
1572 }
1573
1574 static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
1575 struct bin_attribute *bin_attr,
1576 char *buf, loff_t pos, size_t count)
1577 {
1578 struct efi_variable *del_var = (struct efi_variable *)buf;
1579 struct efivars *efivars = bin_attr->private;
1580 struct efivar_entry *search_efivar, *n;
1581 unsigned long strsize1, strsize2;
1582 efi_status_t status = EFI_NOT_FOUND;
1583 int found = 0;
1584
1585 if (!capable(CAP_SYS_ADMIN))
1586 return -EACCES;
1587
1588 spin_lock_irq(&efivars->lock);
1589
1590 /*
1591 * Does this variable already exist?
1592 */
1593 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
1594 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
1595 strsize2 = utf16_strsize(del_var->VariableName, 1024);
1596 if (strsize1 == strsize2 &&
1597 !memcmp(&(search_efivar->var.VariableName),
1598 del_var->VariableName, strsize1) &&
1599 !efi_guidcmp(search_efivar->var.VendorGuid,
1600 del_var->VendorGuid)) {
1601 found = 1;
1602 break;
1603 }
1604 }
1605 if (!found) {
1606 spin_unlock_irq(&efivars->lock);
1607 return -EINVAL;
1608 }
1609 /* force the Attributes/DataSize to 0 to ensure deletion */
1610 del_var->Attributes = 0;
1611 del_var->DataSize = 0;
1612
1613 status = efivars->ops->set_variable(del_var->VariableName,
1614 &del_var->VendorGuid,
1615 del_var->Attributes,
1616 del_var->DataSize,
1617 del_var->Data);
1618
1619 if (status != EFI_SUCCESS) {
1620 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
1621 status);
1622 spin_unlock_irq(&efivars->lock);
1623 return -EIO;
1624 }
1625 list_del(&search_efivar->list);
1626 /* We need to release this lock before unregistering. */
1627 spin_unlock_irq(&efivars->lock);
1628 efivar_unregister(search_efivar);
1629
1630 /* It's dead Jim.... */
1631 return count;
1632 }
1633
1634 static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor)
1635 {
1636 struct efivar_entry *entry, *n;
1637 struct efivars *efivars = &__efivars;
1638 unsigned long strsize1, strsize2;
1639 bool found = false;
1640
1641 strsize1 = utf16_strsize(variable_name, 1024);
1642 list_for_each_entry_safe(entry, n, &efivars->list, list) {
1643 strsize2 = utf16_strsize(entry->var.VariableName, 1024);
1644 if (strsize1 == strsize2 &&
1645 !memcmp(variable_name, &(entry->var.VariableName),
1646 strsize2) &&
1647 !efi_guidcmp(entry->var.VendorGuid,
1648 *vendor)) {
1649 found = true;
1650 break;
1651 }
1652 }
1653 return found;
1654 }
1655
1656 static void efivar_update_sysfs_entries(struct work_struct *work)
1657 {
1658 struct efivars *efivars = &__efivars;
1659 efi_guid_t vendor;
1660 efi_char16_t *variable_name;
1661 unsigned long variable_name_size = 1024;
1662 efi_status_t status = EFI_NOT_FOUND;
1663 bool found;
1664
1665 /* Add new sysfs entries */
1666 while (1) {
1667 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
1668 if (!variable_name) {
1669 pr_err("efivars: Memory allocation failed.\n");
1670 return;
1671 }
1672
1673 spin_lock_irq(&efivars->lock);
1674 found = false;
1675 while (1) {
1676 variable_name_size = 1024;
1677 status = efivars->ops->get_next_variable(
1678 &variable_name_size,
1679 variable_name,
1680 &vendor);
1681 if (status != EFI_SUCCESS) {
1682 break;
1683 } else {
1684 if (!variable_is_present(variable_name,
1685 &vendor)) {
1686 found = true;
1687 break;
1688 }
1689 }
1690 }
1691 spin_unlock_irq(&efivars->lock);
1692
1693 if (!found) {
1694 kfree(variable_name);
1695 break;
1696 } else
1697 efivar_create_sysfs_entry(efivars,
1698 variable_name_size,
1699 variable_name, &vendor);
1700 }
1701 }
1702
1703 /*
1704 * Let's not leave out systab information that snuck into
1705 * the efivars driver
1706 */
1707 static ssize_t systab_show(struct kobject *kobj,
1708 struct kobj_attribute *attr, char *buf)
1709 {
1710 char *str = buf;
1711
1712 if (!kobj || !buf)
1713 return -EINVAL;
1714
1715 if (efi.mps != EFI_INVALID_TABLE_ADDR)
1716 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
1717 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
1718 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
1719 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
1720 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
1721 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
1722 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
1723 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
1724 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
1725 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
1726 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
1727 if (efi.uga != EFI_INVALID_TABLE_ADDR)
1728 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
1729
1730 return str - buf;
1731 }
1732
1733 static struct kobj_attribute efi_attr_systab =
1734 __ATTR(systab, 0400, systab_show, NULL);
1735
1736 static struct attribute *efi_subsys_attrs[] = {
1737 &efi_attr_systab.attr,
1738 NULL, /* maybe more in the future? */
1739 };
1740
1741 static struct attribute_group efi_subsys_attr_group = {
1742 .attrs = efi_subsys_attrs,
1743 };
1744
1745 static struct kobject *efi_kobj;
1746
1747 /*
1748 * efivar_create_sysfs_entry()
1749 * Requires:
1750 * variable_name_size = number of bytes required to hold
1751 * variable_name (not counting the NULL
1752 * character at the end.
1753 * efivars->lock is not held on entry or exit.
1754 * Returns 1 on failure, 0 on success
1755 */
1756 static int
1757 efivar_create_sysfs_entry(struct efivars *efivars,
1758 unsigned long variable_name_size,
1759 efi_char16_t *variable_name,
1760 efi_guid_t *vendor_guid)
1761 {
1762 int i, short_name_size;
1763 char *short_name;
1764 struct efivar_entry *new_efivar;
1765
1766 /*
1767 * Length of the variable bytes in ASCII, plus the '-' separator,
1768 * plus the GUID, plus trailing NUL
1769 */
1770 short_name_size = variable_name_size / sizeof(efi_char16_t)
1771 + 1 + GUID_LEN + 1;
1772
1773 short_name = kzalloc(short_name_size, GFP_KERNEL);
1774 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
1775
1776 if (!short_name || !new_efivar) {
1777 kfree(short_name);
1778 kfree(new_efivar);
1779 return 1;
1780 }
1781
1782 new_efivar->efivars = efivars;
1783 memcpy(new_efivar->var.VariableName, variable_name,
1784 variable_name_size);
1785 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
1786
1787 /* Convert Unicode to normal chars (assume top bits are 0),
1788 ala UTF-8 */
1789 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
1790 short_name[i] = variable_name[i] & 0xFF;
1791 }
1792 /* This is ugly, but necessary to separate one vendor's
1793 private variables from another's. */
1794
1795 *(short_name + strlen(short_name)) = '-';
1796 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
1797
1798 new_efivar->kobj.kset = efivars->kset;
1799 i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
1800 "%s", short_name);
1801 if (i) {
1802 kfree(short_name);
1803 kfree(new_efivar);
1804 return 1;
1805 }
1806
1807 kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
1808 kfree(short_name);
1809 short_name = NULL;
1810
1811 spin_lock_irq(&efivars->lock);
1812 list_add(&new_efivar->list, &efivars->list);
1813 spin_unlock_irq(&efivars->lock);
1814
1815 return 0;
1816 }
1817
1818 static int
1819 create_efivars_bin_attributes(struct efivars *efivars)
1820 {
1821 struct bin_attribute *attr;
1822 int error;
1823
1824 /* new_var */
1825 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1826 if (!attr)
1827 return -ENOMEM;
1828
1829 attr->attr.name = "new_var";
1830 attr->attr.mode = 0200;
1831 attr->write = efivar_create;
1832 attr->private = efivars;
1833 efivars->new_var = attr;
1834
1835 /* del_var */
1836 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1837 if (!attr) {
1838 error = -ENOMEM;
1839 goto out_free;
1840 }
1841 attr->attr.name = "del_var";
1842 attr->attr.mode = 0200;
1843 attr->write = efivar_delete;
1844 attr->private = efivars;
1845 efivars->del_var = attr;
1846
1847 sysfs_bin_attr_init(efivars->new_var);
1848 sysfs_bin_attr_init(efivars->del_var);
1849
1850 /* Register */
1851 error = sysfs_create_bin_file(&efivars->kset->kobj,
1852 efivars->new_var);
1853 if (error) {
1854 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
1855 " due to error %d\n", error);
1856 goto out_free;
1857 }
1858 error = sysfs_create_bin_file(&efivars->kset->kobj,
1859 efivars->del_var);
1860 if (error) {
1861 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
1862 " due to error %d\n", error);
1863 sysfs_remove_bin_file(&efivars->kset->kobj,
1864 efivars->new_var);
1865 goto out_free;
1866 }
1867
1868 return 0;
1869 out_free:
1870 kfree(efivars->del_var);
1871 efivars->del_var = NULL;
1872 kfree(efivars->new_var);
1873 efivars->new_var = NULL;
1874 return error;
1875 }
1876
1877 void unregister_efivars(struct efivars *efivars)
1878 {
1879 struct efivar_entry *entry, *n;
1880
1881 list_for_each_entry_safe(entry, n, &efivars->list, list) {
1882 spin_lock_irq(&efivars->lock);
1883 list_del(&entry->list);
1884 spin_unlock_irq(&efivars->lock);
1885 efivar_unregister(entry);
1886 }
1887 if (efivars->new_var)
1888 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
1889 if (efivars->del_var)
1890 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
1891 kfree(efivars->new_var);
1892 kfree(efivars->del_var);
1893 kobject_put(efivars->kobject);
1894 kset_unregister(efivars->kset);
1895 }
1896 EXPORT_SYMBOL_GPL(unregister_efivars);
1897
1898 int register_efivars(struct efivars *efivars,
1899 const struct efivar_operations *ops,
1900 struct kobject *parent_kobj)
1901 {
1902 efi_status_t status = EFI_NOT_FOUND;
1903 efi_guid_t vendor_guid;
1904 efi_char16_t *variable_name;
1905 unsigned long variable_name_size = 1024;
1906 int error = 0;
1907
1908 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
1909 if (!variable_name) {
1910 printk(KERN_ERR "efivars: Memory allocation failed.\n");
1911 return -ENOMEM;
1912 }
1913
1914 spin_lock_init(&efivars->lock);
1915 INIT_LIST_HEAD(&efivars->list);
1916 efivars->ops = ops;
1917
1918 efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
1919 if (!efivars->kset) {
1920 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
1921 error = -ENOMEM;
1922 goto out;
1923 }
1924
1925 efivars->kobject = kobject_create_and_add("efivars", parent_kobj);
1926 if (!efivars->kobject) {
1927 pr_err("efivars: Subsystem registration failed.\n");
1928 error = -ENOMEM;
1929 kset_unregister(efivars->kset);
1930 goto out;
1931 }
1932
1933 /*
1934 * Per EFI spec, the maximum storage allocated for both
1935 * the variable name and variable data is 1024 bytes.
1936 */
1937
1938 do {
1939 variable_name_size = 1024;
1940
1941 status = ops->get_next_variable(&variable_name_size,
1942 variable_name,
1943 &vendor_guid);
1944 switch (status) {
1945 case EFI_SUCCESS:
1946 efivar_create_sysfs_entry(efivars,
1947 variable_name_size,
1948 variable_name,
1949 &vendor_guid);
1950 break;
1951 case EFI_NOT_FOUND:
1952 break;
1953 default:
1954 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
1955 status);
1956 status = EFI_NOT_FOUND;
1957 break;
1958 }
1959 } while (status != EFI_NOT_FOUND);
1960
1961 error = create_efivars_bin_attributes(efivars);
1962 if (error)
1963 unregister_efivars(efivars);
1964
1965 efivars->efi_pstore_info = efi_pstore_info;
1966
1967 efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
1968 if (efivars->efi_pstore_info.buf) {
1969 efivars->efi_pstore_info.bufsize = 1024;
1970 efivars->efi_pstore_info.data = efivars;
1971 spin_lock_init(&efivars->efi_pstore_info.buf_lock);
1972 pstore_register(&efivars->efi_pstore_info);
1973 }
1974
1975 register_filesystem(&efivarfs_type);
1976
1977 out:
1978 kfree(variable_name);
1979
1980 return error;
1981 }
1982 EXPORT_SYMBOL_GPL(register_efivars);
1983
1984 /*
1985 * For now we register the efi subsystem with the firmware subsystem
1986 * and the vars subsystem with the efi subsystem. In the future, it
1987 * might make sense to split off the efi subsystem into its own
1988 * driver, but for now only efivars will register with it, so just
1989 * include it here.
1990 */
1991
1992 static int __init
1993 efivars_init(void)
1994 {
1995 int error = 0;
1996
1997 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
1998 EFIVARS_DATE);
1999
2000 if (!efi_enabled(EFI_RUNTIME_SERVICES))
2001 return 0;
2002
2003 /* For now we'll register the efi directory at /sys/firmware/efi */
2004 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
2005 if (!efi_kobj) {
2006 printk(KERN_ERR "efivars: Firmware registration failed.\n");
2007 return -ENOMEM;
2008 }
2009
2010 ops.get_variable = efi.get_variable;
2011 ops.set_variable = efi.set_variable;
2012 ops.get_next_variable = efi.get_next_variable;
2013 ops.query_variable_info = efi.query_variable_info;
2014
2015 error = register_efivars(&__efivars, &ops, efi_kobj);
2016 if (error)
2017 goto err_put;
2018
2019 /* Don't forget the systab entry */
2020 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
2021 if (error) {
2022 printk(KERN_ERR
2023 "efivars: Sysfs attribute export failed with error %d.\n",
2024 error);
2025 goto err_unregister;
2026 }
2027
2028 return 0;
2029
2030 err_unregister:
2031 unregister_efivars(&__efivars);
2032 err_put:
2033 kobject_put(efi_kobj);
2034 return error;
2035 }
2036
2037 static void __exit
2038 efivars_exit(void)
2039 {
2040 cancel_work_sync(&efivar_work);
2041
2042 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
2043 unregister_efivars(&__efivars);
2044 kobject_put(efi_kobj);
2045 }
2046 }
2047
2048 module_init(efivars_init);
2049 module_exit(efivars_exit);
2050
Linux kernel - Deliverables
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