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
  83 #include <asm/uaccess.h>
  84
  85 #define EFIVARS_VERSION "0.08"
  86 #define EFIVARS_DATE "2004-May-17"
  87
  88 MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
  89 MODULE_DESCRIPTION("sysfs interface to EFI Variables");
  90 MODULE_LICENSE("GPL");
  91 MODULE_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
 102 struct 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
 112 struct efivar_entry {
 113         struct efivars *efivars;
 114         struct efi_variable var;
 115         struct list_head list;
 116         struct kobject kobj;
 117 };
 118
 119 struct 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) \
 131 struct 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  */
 143 static int
 144 efivar_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 */
 150 static unsigned long
 151 utf16_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
 160 static inline unsigned long
 161 utf16_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  */
 170 static inline unsigned long
 171 utf16_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
 176 static inline int
 177 utf16_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
 194 static bool
 195 validate_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
 227 static bool
 228 validate_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
 238 static bool
 239 validate_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
 289 static bool
 290 validate_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
 300 static bool
 301 validate_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
 317 struct variable_validate {
 318         char *name;
 319         bool (*validate)(struct efi_variable *var, int match, u8 *data,
 320                          unsigned long len);
 321 };
 322
 323 static 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
 341 static bool
 342 validate_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
 378 static efi_status_t
 379 get_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
 392 static efi_status_t
 393 get_var_data(struct efivars *efivars, struct efi_variable *var)
 394 {
 395         efi_status_t status;
 396         unsigned long flags;
 397
 398         spin_lock_irqsave(&efivars->lock, flags);
 399         status = get_var_data_locked(efivars, var);
 400         spin_unlock_irqrestore(&efivars->lock, flags);
 401
 402         if (status != EFI_SUCCESS) {
 403                 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
 404                         status);
 405         }
 406         return status;
 407 }
 408
 409 static efi_status_t
 410 check_var_size_locked(struct efivars *efivars, u32 attributes,
 411                         unsigned long size)
 412 {
 413         u64 storage_size, remaining_size, max_size;
 414         efi_status_t status;
 415         const struct efivar_operations *fops = efivars->ops;
 416
 417         if (!efivars->ops->query_variable_info)
 418                 return EFI_UNSUPPORTED;
 419
 420         status = fops->query_variable_info(attributes, &storage_size,
 421                                            &remaining_size, &max_size);
 422
 423         if (status != EFI_SUCCESS)
 424                 return status;
 425
 426         if (!storage_size || size > remaining_size || size > max_size ||
 427             (remaining_size - size) < (storage_size / 2))
 428                 return EFI_OUT_OF_RESOURCES;
 429
 430         return status;
 431 }
 432
 433 static ssize_t
 434 efivar_guid_read(struct efivar_entry *entry, char *buf)
 435 {
 436         struct efi_variable *var = &entry->var;
 437         char *str = buf;
 438
 439         if (!entry || !buf)
 440                 return 0;
 441
 442         efi_guid_unparse(&var->VendorGuid, str);
 443         str += strlen(str);
 444         str += sprintf(str, "\n");
 445
 446         return str - buf;
 447 }
 448
 449 static ssize_t
 450 efivar_attr_read(struct efivar_entry *entry, char *buf)
 451 {
 452         struct efi_variable *var = &entry->var;
 453         char *str = buf;
 454         efi_status_t status;
 455
 456         if (!entry || !buf)
 457                 return -EINVAL;
 458
 459         status = get_var_data(entry->efivars, var);
 460         if (status != EFI_SUCCESS)
 461                 return -EIO;
 462
 463         if (var->Attributes & EFI_VARIABLE_NON_VOLATILE)
 464                 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
 465         if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)
 466                 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
 467         if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)
 468                 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
 469         if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD)
 470                 str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
 471         if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
 472                 str += sprintf(str,
 473                         "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
 474         if (var->Attributes &
 475                         EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
 476                 str += sprintf(str,
 477                         "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
 478         if (var->Attributes & EFI_VARIABLE_APPEND_WRITE)
 479                 str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n");
 480         return str - buf;
 481 }
 482
 483 static ssize_t
 484 efivar_size_read(struct efivar_entry *entry, char *buf)
 485 {
 486         struct efi_variable *var = &entry->var;
 487         char *str = buf;
 488         efi_status_t status;
 489
 490         if (!entry || !buf)
 491                 return -EINVAL;
 492
 493         status = get_var_data(entry->efivars, var);
 494         if (status != EFI_SUCCESS)
 495                 return -EIO;
 496
 497         str += sprintf(str, "0x%lx\n", var->DataSize);
 498         return str - buf;
 499 }
 500
 501 static ssize_t
 502 efivar_data_read(struct efivar_entry *entry, char *buf)
 503 {
 504         struct efi_variable *var = &entry->var;
 505         efi_status_t status;
 506
 507         if (!entry || !buf)
 508                 return -EINVAL;
 509
 510         status = get_var_data(entry->efivars, var);
 511         if (status != EFI_SUCCESS)
 512                 return -EIO;
 513
 514         memcpy(buf, var->Data, var->DataSize);
 515         return var->DataSize;
 516 }
 517 /*
 518  * We allow each variable to be edited via rewriting the
 519  * entire efi variable structure.
 520  */
 521 static ssize_t
 522 efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
 523 {
 524         struct efi_variable *new_var, *var = &entry->var;
 525         struct efivars *efivars = entry->efivars;
 526         efi_status_t status = EFI_NOT_FOUND;
 527
 528         if (count != sizeof(struct efi_variable))
 529                 return -EINVAL;
 530
 531         new_var = (struct efi_variable *)buf;
 532         /*
 533          * If only updating the variable data, then the name
 534          * and guid should remain the same
 535          */
 536         if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
 537                 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
 538                 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
 539                 return -EINVAL;
 540         }
 541
 542         if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
 543                 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
 544                 return -EINVAL;
 545         }
 546
 547         if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
 548             validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
 549                 printk(KERN_ERR "efivars: Malformed variable content\n");
 550                 return -EINVAL;
 551         }
 552
 553         spin_lock_irq(&efivars->lock);
 554
 555         status = check_var_size_locked(efivars, new_var->Attributes,
 556                new_var->DataSize + utf16_strsize(new_var->VariableName, 1024));
 557
 558         if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
 559                 status = efivars->ops->set_variable(new_var->VariableName,
 560                                                     &new_var->VendorGuid,
 561                                                     new_var->Attributes,
 562                                                     new_var->DataSize,
 563                                                     new_var->Data);
 564
 565         spin_unlock_irq(&efivars->lock);
 566
 567         if (status != EFI_SUCCESS) {
 568                 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
 569                         status);
 570                 return -EIO;
 571         }
 572
 573         memcpy(&entry->var, new_var, count);
 574         return count;
 575 }
 576
 577 static ssize_t
 578 efivar_show_raw(struct efivar_entry *entry, char *buf)
 579 {
 580         struct efi_variable *var = &entry->var;
 581         efi_status_t status;
 582
 583         if (!entry || !buf)
 584                 return 0;
 585
 586         status = get_var_data(entry->efivars, var);
 587         if (status != EFI_SUCCESS)
 588                 return -EIO;
 589
 590         memcpy(buf, var, sizeof(*var));
 591         return sizeof(*var);
 592 }
 593
 594 /*
 595  * Generic read/write functions that call the specific functions of
 596  * the attributes...
 597  */
 598 static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
 599                                 char *buf)
 600 {
 601         struct efivar_entry *var = to_efivar_entry(kobj);
 602         struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
 603         ssize_t ret = -EIO;
 604
 605         if (!capable(CAP_SYS_ADMIN))
 606                 return -EACCES;
 607
 608         if (efivar_attr->show) {
 609                 ret = efivar_attr->show(var, buf);
 610         }
 611         return ret;
 612 }
 613
 614 static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
 615                                 const char *buf, size_t count)
 616 {
 617         struct efivar_entry *var = to_efivar_entry(kobj);
 618         struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
 619         ssize_t ret = -EIO;
 620
 621         if (!capable(CAP_SYS_ADMIN))
 622                 return -EACCES;
 623
 624         if (efivar_attr->store)
 625                 ret = efivar_attr->store(var, buf, count);
 626
 627         return ret;
 628 }
 629
 630 static const struct sysfs_ops efivar_attr_ops = {
 631         .show = efivar_attr_show,
 632         .store = efivar_attr_store,
 633 };
 634
 635 static void efivar_release(struct kobject *kobj)
 636 {
 637         struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
 638         kfree(var);
 639 }
 640
 641 static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
 642 static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
 643 static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
 644 static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
 645 static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
 646
 647 static struct attribute *def_attrs[] = {
 648         &efivar_attr_guid.attr,
 649         &efivar_attr_size.attr,
 650         &efivar_attr_attributes.attr,
 651         &efivar_attr_data.attr,
 652         &efivar_attr_raw_var.attr,
 653         NULL,
 654 };
 655
 656 static struct kobj_type efivar_ktype = {
 657         .release = efivar_release,
 658         .sysfs_ops = &efivar_attr_ops,
 659         .default_attrs = def_attrs,
 660 };
 661
 662 static struct pstore_info efi_pstore_info;
 663
 664 static inline void
 665 efivar_unregister(struct efivar_entry *var)
 666 {
 667         kobject_put(&var->kobj);
 668 }
 669
 670 static int efi_status_to_err(efi_status_t status)
 671 {
 672         int err;
 673
 674         switch (status) {
 675         case EFI_INVALID_PARAMETER:
 676                 err = -EINVAL;
 677                 break;
 678         case EFI_OUT_OF_RESOURCES:
 679                 err = -ENOSPC;
 680                 break;
 681         case EFI_DEVICE_ERROR:
 682                 err = -EIO;
 683                 break;
 684         case EFI_WRITE_PROTECTED:
 685                 err = -EROFS;
 686                 break;
 687         case EFI_SECURITY_VIOLATION:
 688                 err = -EACCES;
 689                 break;
 690         case EFI_NOT_FOUND:
 691                 err = -ENOENT;
 692                 break;
 693         default:
 694                 err = -EINVAL;
 695         }
 696
 697         return err;
 698 }
 699
 700 #ifdef CONFIG_PSTORE
 701
 702 static int efi_pstore_open(struct pstore_info *psi)
 703 {
 704         struct efivars *efivars = psi->data;
 705
 706         spin_lock_irq(&efivars->lock);
 707         efivars->walk_entry = list_first_entry(&efivars->list,
 708                                                struct efivar_entry, list);
 709         return 0;
 710 }
 711
 712 static int efi_pstore_close(struct pstore_info *psi)
 713 {
 714         struct efivars *efivars = psi->data;
 715
 716         spin_unlock_irq(&efivars->lock);
 717         return 0;
 718 }
 719
 720 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
 721                                struct timespec *timespec,
 722                                char **buf, struct pstore_info *psi)
 723 {
 724         efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
 725         struct efivars *efivars = psi->data;
 726         char name[DUMP_NAME_LEN];
 727         int i;
 728         unsigned int part, size;
 729         unsigned long time;
 730
 731         while (&efivars->walk_entry->list != &efivars->list) {
 732                 if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid,
 733                                  vendor)) {
 734                         for (i = 0; i < DUMP_NAME_LEN; i++) {
 735                                 name[i] = efivars->walk_entry->var.VariableName[i];
 736                         }
 737                         if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {
 738                                 *id = part;
 739                                 timespec->tv_sec = time;
 740                                 timespec->tv_nsec = 0;
 741                                 get_var_data_locked(efivars, &efivars->walk_entry->var);
 742                                 size = efivars->walk_entry->var.DataSize;
 743                                 *buf = kmalloc(size, GFP_KERNEL);
 744                                 if (*buf == NULL)
 745                                         return -ENOMEM;
 746                                 memcpy(*buf, efivars->walk_entry->var.Data,
 747                                        size);
 748                                 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
 749                                                    struct efivar_entry, list);
 750                                 return size;
 751                         }
 752                 }
 753                 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
 754                                                  struct efivar_entry, list);
 755         }
 756         return 0;
 757 }
 758
 759 static int efi_pstore_write(enum pstore_type_id type, u64 *id,
 760                 unsigned int part, size_t size, struct pstore_info *psi)
 761 {
 762         char name[DUMP_NAME_LEN];
 763         char stub_name[DUMP_NAME_LEN];
 764         efi_char16_t efi_name[DUMP_NAME_LEN];
 765         efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
 766         struct efivars *efivars = psi->data;
 767         struct efivar_entry *entry, *found = NULL;
 768         int i, ret = 0;
 769         efi_status_t status = EFI_NOT_FOUND;
 770         unsigned long flags;
 771
 772         sprintf(stub_name, "dump-type%u-%u-", type, part);
 773         sprintf(name, "%s%lu", stub_name, get_seconds());
 774
 775         spin_lock_irqsave(&efivars->lock, flags);
 776
 777         /*
 778          * Check if there is a space enough to log.
 779          * size: a size of logging data
 780          * DUMP_NAME_LEN * 2: a maximum size of variable name
 781          */
 782
 783         status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES,
 784                                          size + DUMP_NAME_LEN * 2);
 785
 786         if (status) {
 787                 spin_unlock_irqrestore(&efivars->lock, flags);
 788                 *id = part;
 789                 return -ENOSPC;
 790         }
 791
 792         for (i = 0; i < DUMP_NAME_LEN; i++)
 793                 efi_name[i] = stub_name[i];
 794
 795         /*
 796          * Clean up any entries with the same name
 797          */
 798
 799         list_for_each_entry(entry, &efivars->list, list) {
 800                 get_var_data_locked(efivars, &entry->var);
 801
 802                 if (efi_guidcmp(entry->var.VendorGuid, vendor))
 803                         continue;
 804                 if (utf16_strncmp(entry->var.VariableName, efi_name,
 805                                   utf16_strlen(efi_name)))
 806                         continue;
 807                 /* Needs to be a prefix */
 808                 if (entry->var.VariableName[utf16_strlen(efi_name)] == 0)
 809                         continue;
 810
 811                 /* found */
 812                 found = entry;
 813                 efivars->ops->set_variable(entry->var.VariableName,
 814                                            &entry->var.VendorGuid,
 815                                            PSTORE_EFI_ATTRIBUTES,
 816                                            0, NULL);
 817         }
 818
 819         if (found)
 820                 list_del(&found->list);
 821
 822         for (i = 0; i < DUMP_NAME_LEN; i++)
 823                 efi_name[i] = name[i];
 824
 825         efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
 826                                    size, psi->buf);
 827
 828         spin_unlock_irqrestore(&efivars->lock, flags);
 829
 830         if (found)
 831                 efivar_unregister(found);
 832
 833         if (size)
 834                 ret = efivar_create_sysfs_entry(efivars,
 835                                           utf16_strsize(efi_name,
 836                                                         DUMP_NAME_LEN * 2),
 837                                           efi_name, &vendor);
 838
 839         *id = part;
 840         return ret;
 841 };
 842
 843 static int efi_pstore_erase(enum pstore_type_id type, u64 id,
 844                             struct pstore_info *psi)
 845 {
 846         efi_pstore_write(type, &id, (unsigned int)id, 0, psi);
 847
 848         return 0;
 849 }
 850 #else
 851 static int efi_pstore_open(struct pstore_info *psi)
 852 {
 853         return 0;
 854 }
 855
 856 static int efi_pstore_close(struct pstore_info *psi)
 857 {
 858         return 0;
 859 }
 860
 861 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
 862                                struct timespec *timespec,
 863                                char **buf, struct pstore_info *psi)
 864 {
 865         return -1;
 866 }
 867
 868 static int efi_pstore_write(enum pstore_type_id type, u64 *id,
 869                 unsigned int part, size_t size, struct pstore_info *psi)
 870 {
 871         return 0;
 872 }
 873
 874 static int efi_pstore_erase(enum pstore_type_id type, u64 id,
 875                             struct pstore_info *psi)
 876 {
 877         return 0;
 878 }
 879 #endif
 880
 881 static struct pstore_info efi_pstore_info = {
 882         .owner          = THIS_MODULE,
 883         .name           = "efi",
 884         .open           = efi_pstore_open,
 885         .close          = efi_pstore_close,
 886         .read           = efi_pstore_read,
 887         .write          = efi_pstore_write,
 888         .erase          = efi_pstore_erase,
 889 };
 890
 891 static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
 892                              struct bin_attribute *bin_attr,
 893                              char *buf, loff_t pos, size_t count)
 894 {
 895         struct efi_variable *new_var = (struct efi_variable *)buf;
 896         struct efivars *efivars = bin_attr->private;
 897         struct efivar_entry *search_efivar, *n;
 898         unsigned long strsize1, strsize2;
 899         efi_status_t status = EFI_NOT_FOUND;
 900         int found = 0;
 901
 902         if (!capable(CAP_SYS_ADMIN))
 903                 return -EACCES;
 904
 905         if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
 906             validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
 907                 printk(KERN_ERR "efivars: Malformed variable content\n");
 908                 return -EINVAL;
 909         }
 910
 911         spin_lock_irq(&efivars->lock);
 912
 913         /*
 914          * Does this variable already exist?
 915          */
 916         list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
 917                 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
 918                 strsize2 = utf16_strsize(new_var->VariableName, 1024);
 919                 if (strsize1 == strsize2 &&
 920                         !memcmp(&(search_efivar->var.VariableName),
 921                                 new_var->VariableName, strsize1) &&
 922                         !efi_guidcmp(search_efivar->var.VendorGuid,
 923                                 new_var->VendorGuid)) {
 924                         found = 1;
 925                         break;
 926                 }
 927         }
 928         if (found) {
 929                 spin_unlock_irq(&efivars->lock);
 930                 return -EINVAL;
 931         }
 932
 933         status = check_var_size_locked(efivars, new_var->Attributes,
 934                new_var->DataSize + utf16_strsize(new_var->VariableName, 1024));
 935
 936         if (status && status != EFI_UNSUPPORTED) {
 937                 spin_unlock_irq(&efivars->lock);
 938                 return efi_status_to_err(status);
 939         }
 940
 941         /* now *really* create the variable via EFI */
 942         status = efivars->ops->set_variable(new_var->VariableName,
 943                                             &new_var->VendorGuid,
 944                                             new_var->Attributes,
 945                                             new_var->DataSize,
 946                                             new_var->Data);
 947
 948         if (status != EFI_SUCCESS) {
 949                 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
 950                         status);
 951                 spin_unlock_irq(&efivars->lock);
 952                 return -EIO;
 953         }
 954         spin_unlock_irq(&efivars->lock);
 955
 956         /* Create the entry in sysfs.  Locking is not required here */
 957         status = efivar_create_sysfs_entry(efivars,
 958                                            utf16_strsize(new_var->VariableName,
 959                                                          1024),
 960                                            new_var->VariableName,
 961                                            &new_var->VendorGuid);
 962         if (status) {
 963                 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
 964         }
 965         return count;
 966 }
 967
 968 static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
 969                              struct bin_attribute *bin_attr,
 970                              char *buf, loff_t pos, size_t count)
 971 {
 972         struct efi_variable *del_var = (struct efi_variable *)buf;
 973         struct efivars *efivars = bin_attr->private;
 974         struct efivar_entry *search_efivar, *n;
 975         unsigned long strsize1, strsize2;
 976         efi_status_t status = EFI_NOT_FOUND;
 977         int found = 0;
 978
 979         if (!capable(CAP_SYS_ADMIN))
 980                 return -EACCES;
 981
 982         spin_lock_irq(&efivars->lock);
 983
 984         /*
 985          * Does this variable already exist?
 986          */
 987         list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
 988                 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
 989                 strsize2 = utf16_strsize(del_var->VariableName, 1024);
 990                 if (strsize1 == strsize2 &&
 991                         !memcmp(&(search_efivar->var.VariableName),
 992                                 del_var->VariableName, strsize1) &&
 993                         !efi_guidcmp(search_efivar->var.VendorGuid,
 994                                 del_var->VendorGuid)) {
 995                         found = 1;
 996                         break;
 997                 }
 998         }
 999         if (!found) {
1000                 spin_unlock_irq(&efivars->lock);
1001                 return -EINVAL;
1002         }
1003         /* force the Attributes/DataSize to 0 to ensure deletion */
1004         del_var->Attributes = 0;
1005         del_var->DataSize = 0;
1006
1007         status = efivars->ops->set_variable(del_var->VariableName,
1008                                             &del_var->VendorGuid,
1009                                             del_var->Attributes,
1010                                             del_var->DataSize,
1011                                             del_var->Data);
1012
1013         if (status != EFI_SUCCESS) {
1014                 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
1015                         status);
1016                 spin_unlock_irq(&efivars->lock);
1017                 return -EIO;
1018         }
1019         list_del(&search_efivar->list);
1020         /* We need to release this lock before unregistering. */
1021         spin_unlock_irq(&efivars->lock);
1022         efivar_unregister(search_efivar);
1023
1024         /* It's dead Jim.... */
1025         return count;
1026 }
1027
1028 /*
1029  * Let's not leave out systab information that snuck into
1030  * the efivars driver
1031  */
1032 static ssize_t systab_show(struct kobject *kobj,
1033                            struct kobj_attribute *attr, char *buf)
1034 {
1035         char *str = buf;
1036
1037         if (!kobj || !buf)
1038                 return -EINVAL;
1039
1040         if (efi.mps != EFI_INVALID_TABLE_ADDR)
1041                 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
1042         if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
1043                 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
1044         if (efi.acpi != EFI_INVALID_TABLE_ADDR)
1045                 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
1046         if (efi.smbios != EFI_INVALID_TABLE_ADDR)
1047                 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
1048         if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
1049                 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
1050         if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
1051                 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
1052         if (efi.uga != EFI_INVALID_TABLE_ADDR)
1053                 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
1054
1055         return str - buf;
1056 }
1057
1058 static struct kobj_attribute efi_attr_systab =
1059                         __ATTR(systab, 0400, systab_show, NULL);
1060
1061 static struct attribute *efi_subsys_attrs[] = {
1062         &efi_attr_systab.attr,
1063         NULL,   /* maybe more in the future? */
1064 };
1065
1066 static struct attribute_group efi_subsys_attr_group = {
1067         .attrs = efi_subsys_attrs,
1068 };
1069
1070 static struct kobject *efi_kobj;
1071
1072 /*
1073  * efivar_create_sysfs_entry()
1074  * Requires:
1075  *    variable_name_size = number of bytes required to hold
1076  *                         variable_name (not counting the NULL
1077  *                         character at the end.
1078  *    efivars->lock is not held on entry or exit.
1079  * Returns 1 on failure, 0 on success
1080  */
1081 static int
1082 efivar_create_sysfs_entry(struct efivars *efivars,
1083                           unsigned long variable_name_size,
1084                           efi_char16_t *variable_name,
1085                           efi_guid_t *vendor_guid)
1086 {
1087         int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
1088         char *short_name;
1089         struct efivar_entry *new_efivar;
1090
1091         short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
1092         new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
1093
1094         if (!short_name || !new_efivar)  {
1095                 kfree(short_name);
1096                 kfree(new_efivar);
1097                 return 1;
1098         }
1099
1100         new_efivar->efivars = efivars;
1101         memcpy(new_efivar->var.VariableName, variable_name,
1102                 variable_name_size);
1103         memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
1104
1105         /* Convert Unicode to normal chars (assume top bits are 0),
1106            ala UTF-8 */
1107         for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
1108                 short_name[i] = variable_name[i] & 0xFF;
1109         }
1110         /* This is ugly, but necessary to separate one vendor's
1111            private variables from another's.         */
1112
1113         *(short_name + strlen(short_name)) = '-';
1114         efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
1115
1116         new_efivar->kobj.kset = efivars->kset;
1117         i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
1118                                  "%s", short_name);
1119         if (i) {
1120                 kfree(short_name);
1121                 kfree(new_efivar);
1122                 return 1;
1123         }
1124
1125         kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
1126         kfree(short_name);
1127         short_name = NULL;
1128
1129         spin_lock_irq(&efivars->lock);
1130         list_add(&new_efivar->list, &efivars->list);
1131         spin_unlock_irq(&efivars->lock);
1132
1133         return 0;
1134 }
1135
1136 static int
1137 create_efivars_bin_attributes(struct efivars *efivars)
1138 {
1139         struct bin_attribute *attr;
1140         int error;
1141
1142         /* new_var */
1143         attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1144         if (!attr)
1145                 return -ENOMEM;
1146
1147         attr->attr.name = "new_var";
1148         attr->attr.mode = 0200;
1149         attr->write = efivar_create;
1150         attr->private = efivars;
1151         efivars->new_var = attr;
1152
1153         /* del_var */
1154         attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1155         if (!attr) {
1156                 error = -ENOMEM;
1157                 goto out_free;
1158         }
1159         attr->attr.name = "del_var";
1160         attr->attr.mode = 0200;
1161         attr->write = efivar_delete;
1162         attr->private = efivars;
1163         efivars->del_var = attr;
1164
1165         sysfs_bin_attr_init(efivars->new_var);
1166         sysfs_bin_attr_init(efivars->del_var);
1167
1168         /* Register */
1169         error = sysfs_create_bin_file(&efivars->kset->kobj,
1170                                       efivars->new_var);
1171         if (error) {
1172                 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
1173                         " due to error %d\n", error);
1174                 goto out_free;
1175         }
1176         error = sysfs_create_bin_file(&efivars->kset->kobj,
1177                                       efivars->del_var);
1178         if (error) {
1179                 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
1180                         " due to error %d\n", error);
1181                 sysfs_remove_bin_file(&efivars->kset->kobj,
1182                                       efivars->new_var);
1183                 goto out_free;
1184         }
1185
1186         return 0;
1187 out_free:
1188         kfree(efivars->del_var);
1189         efivars->del_var = NULL;
1190         kfree(efivars->new_var);
1191         efivars->new_var = NULL;
1192         return error;
1193 }
1194
1195 void unregister_efivars(struct efivars *efivars)
1196 {
1197         struct efivar_entry *entry, *n;
1198
1199         list_for_each_entry_safe(entry, n, &efivars->list, list) {
1200                 spin_lock_irq(&efivars->lock);
1201                 list_del(&entry->list);
1202                 spin_unlock_irq(&efivars->lock);
1203                 efivar_unregister(entry);
1204         }
1205         if (efivars->new_var)
1206                 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
1207         if (efivars->del_var)
1208                 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
1209         kfree(efivars->new_var);
1210         kfree(efivars->del_var);
1211         kset_unregister(efivars->kset);
1212 }
1213 EXPORT_SYMBOL_GPL(unregister_efivars);
1214
1215 int register_efivars(struct efivars *efivars,
1216                      const struct efivar_operations *ops,
1217                      struct kobject *parent_kobj)
1218 {
1219         efi_status_t status = EFI_NOT_FOUND;
1220         efi_guid_t vendor_guid;
1221         efi_char16_t *variable_name;
1222         unsigned long variable_name_size = 1024;
1223         int error = 0;
1224
1225         variable_name = kzalloc(variable_name_size, GFP_KERNEL);
1226         if (!variable_name) {
1227                 printk(KERN_ERR "efivars: Memory allocation failed.\n");
1228                 return -ENOMEM;
1229         }
1230
1231         spin_lock_init(&efivars->lock);
1232         INIT_LIST_HEAD(&efivars->list);
1233         efivars->ops = ops;
1234
1235         efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
1236         if (!efivars->kset) {
1237                 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
1238                 error = -ENOMEM;
1239                 goto out;
1240         }
1241
1242         /*
1243          * Per EFI spec, the maximum storage allocated for both
1244          * the variable name and variable data is 1024 bytes.
1245          */
1246
1247         do {
1248                 variable_name_size = 1024;
1249
1250                 status = ops->get_next_variable(&variable_name_size,
1251                                                 variable_name,
1252                                                 &vendor_guid);
1253                 switch (status) {
1254                 case EFI_SUCCESS:
1255                         efivar_create_sysfs_entry(efivars,
1256                                                   variable_name_size,
1257                                                   variable_name,
1258                                                   &vendor_guid);
1259                         break;
1260                 case EFI_NOT_FOUND:
1261                         break;
1262                 default:
1263                         printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
1264                                 status);
1265                         status = EFI_NOT_FOUND;
1266                         break;
1267                 }
1268         } while (status != EFI_NOT_FOUND);
1269
1270         error = create_efivars_bin_attributes(efivars);
1271         if (error)
1272                 unregister_efivars(efivars);
1273
1274         efivars->efi_pstore_info = efi_pstore_info;
1275
1276         efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
1277         if (efivars->efi_pstore_info.buf) {
1278                 efivars->efi_pstore_info.bufsize = 1024;
1279                 efivars->efi_pstore_info.data = efivars;
1280                 spin_lock_init(&efivars->efi_pstore_info.buf_lock);
1281                 pstore_register(&efivars->efi_pstore_info);
1282         }
1283
1284 out:
1285         kfree(variable_name);
1286
1287         return error;
1288 }
1289 EXPORT_SYMBOL_GPL(register_efivars);
1290
1291 static struct efivars __efivars;
1292 static struct efivar_operations ops;
1293
1294 /*
1295  * For now we register the efi subsystem with the firmware subsystem
1296  * and the vars subsystem with the efi subsystem.  In the future, it
1297  * might make sense to split off the efi subsystem into its own
1298  * driver, but for now only efivars will register with it, so just
1299  * include it here.
1300  */
1301
1302 static int __init
1303 efivars_init(void)
1304 {
1305         int error = 0;
1306
1307         printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
1308                EFIVARS_DATE);
1309
1310         if (!efi_enabled(EFI_RUNTIME_SERVICES))
1311                 return 0;
1312
1313         /* For now we'll register the efi directory at /sys/firmware/efi */
1314         efi_kobj = kobject_create_and_add("efi", firmware_kobj);
1315         if (!efi_kobj) {
1316                 printk(KERN_ERR "efivars: Firmware registration failed.\n");
1317                 return -ENOMEM;
1318         }
1319
1320         ops.get_variable = efi.get_variable;
1321         ops.set_variable = efi.set_variable;
1322         ops.get_next_variable = efi.get_next_variable;
1323         ops.query_variable_info = efi.query_variable_info;
1324         error = register_efivars(&__efivars, &ops, efi_kobj);
1325         if (error)
1326                 goto err_put;
1327
1328         /* Don't forget the systab entry */
1329         error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
1330         if (error) {
1331                 printk(KERN_ERR
1332                        "efivars: Sysfs attribute export failed with error %d.\n",
1333                        error);
1334                 goto err_unregister;
1335         }
1336
1337         return 0;
1338
1339 err_unregister:
1340         unregister_efivars(&__efivars);
1341 err_put:
1342         kobject_put(efi_kobj);
1343         return error;
1344 }
1345
1346 static void __exit
1347 efivars_exit(void)
1348 {
1349         if (efi_enabled(EFI_RUNTIME_SERVICES)) {
1350                 unregister_efivars(&__efivars);
1351                 kobject_put(efi_kobj);
1352         }
1353 }
1354
1355 module_init(efivars_init);
1356 module_exit(efivars_exit);
1357