| 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 | static bool efivars_pstore_disable = |
| 107 | IS_ENABLED(EFI_VARS_PSTORE_DEFAULT_DISABLE); |
| 108 | |
| 109 | module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); |
| 110 | |
| 111 | /* |
| 112 | * The maximum size of VariableName + Data = 1024 |
| 113 | * Therefore, it's reasonable to save that much |
| 114 | * space in each part of the structure, |
| 115 | * and we use a page for reading/writing. |
| 116 | */ |
| 117 | |
| 118 | struct efi_variable { |
| 119 | efi_char16_t VariableName[1024/sizeof(efi_char16_t)]; |
| 120 | efi_guid_t VendorGuid; |
| 121 | unsigned long DataSize; |
| 122 | __u8 Data[1024]; |
| 123 | efi_status_t Status; |
| 124 | __u32 Attributes; |
| 125 | } __attribute__((packed)); |
| 126 | |
| 127 | struct efivar_entry { |
| 128 | struct efivars *efivars; |
| 129 | struct efi_variable var; |
| 130 | struct list_head list; |
| 131 | struct kobject kobj; |
| 132 | }; |
| 133 | |
| 134 | struct efivar_attribute { |
| 135 | struct attribute attr; |
| 136 | ssize_t (*show) (struct efivar_entry *entry, char *buf); |
| 137 | ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); |
| 138 | }; |
| 139 | |
| 140 | static struct efivars __efivars; |
| 141 | static struct efivar_operations ops; |
| 142 | |
| 143 | #define PSTORE_EFI_ATTRIBUTES \ |
| 144 | (EFI_VARIABLE_NON_VOLATILE | \ |
| 145 | EFI_VARIABLE_BOOTSERVICE_ACCESS | \ |
| 146 | EFI_VARIABLE_RUNTIME_ACCESS) |
| 147 | |
| 148 | #define EFIVAR_ATTR(_name, _mode, _show, _store) \ |
| 149 | struct efivar_attribute efivar_attr_##_name = { \ |
| 150 | .attr = {.name = __stringify(_name), .mode = _mode}, \ |
| 151 | .show = _show, \ |
| 152 | .store = _store, \ |
| 153 | }; |
| 154 | |
| 155 | #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr) |
| 156 | #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj) |
| 157 | |
| 158 | /* |
| 159 | * Prototype for sysfs creation function |
| 160 | */ |
| 161 | static int |
| 162 | efivar_create_sysfs_entry(struct efivars *efivars, |
| 163 | unsigned long variable_name_size, |
| 164 | efi_char16_t *variable_name, |
| 165 | efi_guid_t *vendor_guid); |
| 166 | |
| 167 | /* |
| 168 | * Prototype for workqueue functions updating sysfs entry |
| 169 | */ |
| 170 | |
| 171 | static void efivar_update_sysfs_entries(struct work_struct *); |
| 172 | static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries); |
| 173 | |
| 174 | /* Return the number of unicode characters in data */ |
| 175 | static unsigned long |
| 176 | utf16_strnlen(efi_char16_t *s, size_t maxlength) |
| 177 | { |
| 178 | unsigned long length = 0; |
| 179 | |
| 180 | while (*s++ != 0 && length < maxlength) |
| 181 | length++; |
| 182 | return length; |
| 183 | } |
| 184 | |
| 185 | static inline unsigned long |
| 186 | utf16_strlen(efi_char16_t *s) |
| 187 | { |
| 188 | return utf16_strnlen(s, ~0UL); |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Return the number of bytes is the length of this string |
| 193 | * Note: this is NOT the same as the number of unicode characters |
| 194 | */ |
| 195 | static inline unsigned long |
| 196 | utf16_strsize(efi_char16_t *data, unsigned long maxlength) |
| 197 | { |
| 198 | return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t); |
| 199 | } |
| 200 | |
| 201 | static inline int |
| 202 | utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len) |
| 203 | { |
| 204 | while (1) { |
| 205 | if (len == 0) |
| 206 | return 0; |
| 207 | if (*a < *b) |
| 208 | return -1; |
| 209 | if (*a > *b) |
| 210 | return 1; |
| 211 | if (*a == 0) /* implies *b == 0 */ |
| 212 | return 0; |
| 213 | a++; |
| 214 | b++; |
| 215 | len--; |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | static bool |
| 220 | validate_device_path(struct efi_variable *var, int match, u8 *buffer, |
| 221 | unsigned long len) |
| 222 | { |
| 223 | struct efi_generic_dev_path *node; |
| 224 | int offset = 0; |
| 225 | |
| 226 | node = (struct efi_generic_dev_path *)buffer; |
| 227 | |
| 228 | if (len < sizeof(*node)) |
| 229 | return false; |
| 230 | |
| 231 | while (offset <= len - sizeof(*node) && |
| 232 | node->length >= sizeof(*node) && |
| 233 | node->length <= len - offset) { |
| 234 | offset += node->length; |
| 235 | |
| 236 | if ((node->type == EFI_DEV_END_PATH || |
| 237 | node->type == EFI_DEV_END_PATH2) && |
| 238 | node->sub_type == EFI_DEV_END_ENTIRE) |
| 239 | return true; |
| 240 | |
| 241 | node = (struct efi_generic_dev_path *)(buffer + offset); |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * If we're here then either node->length pointed past the end |
| 246 | * of the buffer or we reached the end of the buffer without |
| 247 | * finding a device path end node. |
| 248 | */ |
| 249 | return false; |
| 250 | } |
| 251 | |
| 252 | static bool |
| 253 | validate_boot_order(struct efi_variable *var, int match, u8 *buffer, |
| 254 | unsigned long len) |
| 255 | { |
| 256 | /* An array of 16-bit integers */ |
| 257 | if ((len % 2) != 0) |
| 258 | return false; |
| 259 | |
| 260 | return true; |
| 261 | } |
| 262 | |
| 263 | static bool |
| 264 | validate_load_option(struct efi_variable *var, int match, u8 *buffer, |
| 265 | unsigned long len) |
| 266 | { |
| 267 | u16 filepathlength; |
| 268 | int i, desclength = 0, namelen; |
| 269 | |
| 270 | namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName)); |
| 271 | |
| 272 | /* Either "Boot" or "Driver" followed by four digits of hex */ |
| 273 | for (i = match; i < match+4; i++) { |
| 274 | if (var->VariableName[i] > 127 || |
| 275 | hex_to_bin(var->VariableName[i] & 0xff) < 0) |
| 276 | return true; |
| 277 | } |
| 278 | |
| 279 | /* Reject it if there's 4 digits of hex and then further content */ |
| 280 | if (namelen > match + 4) |
| 281 | return false; |
| 282 | |
| 283 | /* A valid entry must be at least 8 bytes */ |
| 284 | if (len < 8) |
| 285 | return false; |
| 286 | |
| 287 | filepathlength = buffer[4] | buffer[5] << 8; |
| 288 | |
| 289 | /* |
| 290 | * There's no stored length for the description, so it has to be |
| 291 | * found by hand |
| 292 | */ |
| 293 | desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2; |
| 294 | |
| 295 | /* Each boot entry must have a descriptor */ |
| 296 | if (!desclength) |
| 297 | return false; |
| 298 | |
| 299 | /* |
| 300 | * If the sum of the length of the description, the claimed filepath |
| 301 | * length and the original header are greater than the length of the |
| 302 | * variable, it's malformed |
| 303 | */ |
| 304 | if ((desclength + filepathlength + 6) > len) |
| 305 | return false; |
| 306 | |
| 307 | /* |
| 308 | * And, finally, check the filepath |
| 309 | */ |
| 310 | return validate_device_path(var, match, buffer + desclength + 6, |
| 311 | filepathlength); |
| 312 | } |
| 313 | |
| 314 | static bool |
| 315 | validate_uint16(struct efi_variable *var, int match, u8 *buffer, |
| 316 | unsigned long len) |
| 317 | { |
| 318 | /* A single 16-bit integer */ |
| 319 | if (len != 2) |
| 320 | return false; |
| 321 | |
| 322 | return true; |
| 323 | } |
| 324 | |
| 325 | static bool |
| 326 | validate_ascii_string(struct efi_variable *var, int match, u8 *buffer, |
| 327 | unsigned long len) |
| 328 | { |
| 329 | int i; |
| 330 | |
| 331 | for (i = 0; i < len; i++) { |
| 332 | if (buffer[i] > 127) |
| 333 | return false; |
| 334 | |
| 335 | if (buffer[i] == 0) |
| 336 | return true; |
| 337 | } |
| 338 | |
| 339 | return false; |
| 340 | } |
| 341 | |
| 342 | struct variable_validate { |
| 343 | char *name; |
| 344 | bool (*validate)(struct efi_variable *var, int match, u8 *data, |
| 345 | unsigned long len); |
| 346 | }; |
| 347 | |
| 348 | static const struct variable_validate variable_validate[] = { |
| 349 | { "BootNext", validate_uint16 }, |
| 350 | { "BootOrder", validate_boot_order }, |
| 351 | { "DriverOrder", validate_boot_order }, |
| 352 | { "Boot*", validate_load_option }, |
| 353 | { "Driver*", validate_load_option }, |
| 354 | { "ConIn", validate_device_path }, |
| 355 | { "ConInDev", validate_device_path }, |
| 356 | { "ConOut", validate_device_path }, |
| 357 | { "ConOutDev", validate_device_path }, |
| 358 | { "ErrOut", validate_device_path }, |
| 359 | { "ErrOutDev", validate_device_path }, |
| 360 | { "Timeout", validate_uint16 }, |
| 361 | { "Lang", validate_ascii_string }, |
| 362 | { "PlatformLang", validate_ascii_string }, |
| 363 | { "", NULL }, |
| 364 | }; |
| 365 | |
| 366 | static bool |
| 367 | validate_var(struct efi_variable *var, u8 *data, unsigned long len) |
| 368 | { |
| 369 | int i; |
| 370 | u16 *unicode_name = var->VariableName; |
| 371 | |
| 372 | for (i = 0; variable_validate[i].validate != NULL; i++) { |
| 373 | const char *name = variable_validate[i].name; |
| 374 | int match; |
| 375 | |
| 376 | for (match = 0; ; match++) { |
| 377 | char c = name[match]; |
| 378 | u16 u = unicode_name[match]; |
| 379 | |
| 380 | /* All special variables are plain ascii */ |
| 381 | if (u > 127) |
| 382 | return true; |
| 383 | |
| 384 | /* Wildcard in the matching name means we've matched */ |
| 385 | if (c == '*') |
| 386 | return variable_validate[i].validate(var, |
| 387 | match, data, len); |
| 388 | |
| 389 | /* Case sensitive match */ |
| 390 | if (c != u) |
| 391 | break; |
| 392 | |
| 393 | /* Reached the end of the string while matching */ |
| 394 | if (!c) |
| 395 | return variable_validate[i].validate(var, |
| 396 | match, data, len); |
| 397 | } |
| 398 | } |
| 399 | |
| 400 | return true; |
| 401 | } |
| 402 | |
| 403 | static efi_status_t |
| 404 | get_var_data_locked(struct efivars *efivars, struct efi_variable *var) |
| 405 | { |
| 406 | efi_status_t status; |
| 407 | |
| 408 | var->DataSize = 1024; |
| 409 | status = efivars->ops->get_variable(var->VariableName, |
| 410 | &var->VendorGuid, |
| 411 | &var->Attributes, |
| 412 | &var->DataSize, |
| 413 | var->Data); |
| 414 | return status; |
| 415 | } |
| 416 | |
| 417 | static efi_status_t |
| 418 | get_var_data(struct efivars *efivars, struct efi_variable *var) |
| 419 | { |
| 420 | efi_status_t status; |
| 421 | unsigned long flags; |
| 422 | |
| 423 | spin_lock_irqsave(&efivars->lock, flags); |
| 424 | status = get_var_data_locked(efivars, var); |
| 425 | spin_unlock_irqrestore(&efivars->lock, flags); |
| 426 | |
| 427 | if (status != EFI_SUCCESS) { |
| 428 | printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n", |
| 429 | status); |
| 430 | } |
| 431 | return status; |
| 432 | } |
| 433 | |
| 434 | static efi_status_t |
| 435 | check_var_size_locked(struct efivars *efivars, u32 attributes, |
| 436 | unsigned long size) |
| 437 | { |
| 438 | u64 storage_size, remaining_size, max_size; |
| 439 | efi_status_t status; |
| 440 | const struct efivar_operations *fops = efivars->ops; |
| 441 | |
| 442 | if (!efivars->ops->query_variable_info) |
| 443 | return EFI_UNSUPPORTED; |
| 444 | |
| 445 | status = fops->query_variable_info(attributes, &storage_size, |
| 446 | &remaining_size, &max_size); |
| 447 | |
| 448 | if (status != EFI_SUCCESS) |
| 449 | return status; |
| 450 | |
| 451 | if (!storage_size || size > remaining_size || size > max_size || |
| 452 | (remaining_size - size) < (storage_size / 2)) |
| 453 | return EFI_OUT_OF_RESOURCES; |
| 454 | |
| 455 | return status; |
| 456 | } |
| 457 | |
| 458 | |
| 459 | static efi_status_t |
| 460 | check_var_size(struct efivars *efivars, u32 attributes, unsigned long size) |
| 461 | { |
| 462 | efi_status_t status; |
| 463 | unsigned long flags; |
| 464 | |
| 465 | spin_lock_irqsave(&efivars->lock, flags); |
| 466 | status = check_var_size_locked(efivars, attributes, size); |
| 467 | spin_unlock_irqrestore(&efivars->lock, flags); |
| 468 | |
| 469 | return status; |
| 470 | } |
| 471 | |
| 472 | static ssize_t |
| 473 | efivar_guid_read(struct efivar_entry *entry, char *buf) |
| 474 | { |
| 475 | struct efi_variable *var = &entry->var; |
| 476 | char *str = buf; |
| 477 | |
| 478 | if (!entry || !buf) |
| 479 | return 0; |
| 480 | |
| 481 | efi_guid_unparse(&var->VendorGuid, str); |
| 482 | str += strlen(str); |
| 483 | str += sprintf(str, "\n"); |
| 484 | |
| 485 | return str - buf; |
| 486 | } |
| 487 | |
| 488 | static ssize_t |
| 489 | efivar_attr_read(struct efivar_entry *entry, char *buf) |
| 490 | { |
| 491 | struct efi_variable *var = &entry->var; |
| 492 | char *str = buf; |
| 493 | efi_status_t status; |
| 494 | |
| 495 | if (!entry || !buf) |
| 496 | return -EINVAL; |
| 497 | |
| 498 | status = get_var_data(entry->efivars, var); |
| 499 | if (status != EFI_SUCCESS) |
| 500 | return -EIO; |
| 501 | |
| 502 | if (var->Attributes & EFI_VARIABLE_NON_VOLATILE) |
| 503 | str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n"); |
| 504 | if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) |
| 505 | str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n"); |
| 506 | if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) |
| 507 | str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n"); |
| 508 | if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) |
| 509 | str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n"); |
| 510 | if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) |
| 511 | str += sprintf(str, |
| 512 | "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n"); |
| 513 | if (var->Attributes & |
| 514 | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) |
| 515 | str += sprintf(str, |
| 516 | "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n"); |
| 517 | if (var->Attributes & EFI_VARIABLE_APPEND_WRITE) |
| 518 | str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n"); |
| 519 | return str - buf; |
| 520 | } |
| 521 | |
| 522 | static ssize_t |
| 523 | efivar_size_read(struct efivar_entry *entry, char *buf) |
| 524 | { |
| 525 | struct efi_variable *var = &entry->var; |
| 526 | char *str = buf; |
| 527 | efi_status_t status; |
| 528 | |
| 529 | if (!entry || !buf) |
| 530 | return -EINVAL; |
| 531 | |
| 532 | status = get_var_data(entry->efivars, var); |
| 533 | if (status != EFI_SUCCESS) |
| 534 | return -EIO; |
| 535 | |
| 536 | str += sprintf(str, "0x%lx\n", var->DataSize); |
| 537 | return str - buf; |
| 538 | } |
| 539 | |
| 540 | static ssize_t |
| 541 | efivar_data_read(struct efivar_entry *entry, char *buf) |
| 542 | { |
| 543 | struct efi_variable *var = &entry->var; |
| 544 | efi_status_t status; |
| 545 | |
| 546 | if (!entry || !buf) |
| 547 | return -EINVAL; |
| 548 | |
| 549 | status = get_var_data(entry->efivars, var); |
| 550 | if (status != EFI_SUCCESS) |
| 551 | return -EIO; |
| 552 | |
| 553 | memcpy(buf, var->Data, var->DataSize); |
| 554 | return var->DataSize; |
| 555 | } |
| 556 | /* |
| 557 | * We allow each variable to be edited via rewriting the |
| 558 | * entire efi variable structure. |
| 559 | */ |
| 560 | static ssize_t |
| 561 | efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) |
| 562 | { |
| 563 | struct efi_variable *new_var, *var = &entry->var; |
| 564 | struct efivars *efivars = entry->efivars; |
| 565 | efi_status_t status = EFI_NOT_FOUND; |
| 566 | |
| 567 | if (count != sizeof(struct efi_variable)) |
| 568 | return -EINVAL; |
| 569 | |
| 570 | new_var = (struct efi_variable *)buf; |
| 571 | /* |
| 572 | * If only updating the variable data, then the name |
| 573 | * and guid should remain the same |
| 574 | */ |
| 575 | if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) || |
| 576 | efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) { |
| 577 | printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n"); |
| 578 | return -EINVAL; |
| 579 | } |
| 580 | |
| 581 | if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){ |
| 582 | printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n"); |
| 583 | return -EINVAL; |
| 584 | } |
| 585 | |
| 586 | if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || |
| 587 | validate_var(new_var, new_var->Data, new_var->DataSize) == false) { |
| 588 | printk(KERN_ERR "efivars: Malformed variable content\n"); |
| 589 | return -EINVAL; |
| 590 | } |
| 591 | |
| 592 | spin_lock_irq(&efivars->lock); |
| 593 | |
| 594 | status = check_var_size_locked(efivars, new_var->Attributes, |
| 595 | new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); |
| 596 | |
| 597 | if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) |
| 598 | status = efivars->ops->set_variable(new_var->VariableName, |
| 599 | &new_var->VendorGuid, |
| 600 | new_var->Attributes, |
| 601 | new_var->DataSize, |
| 602 | new_var->Data); |
| 603 | |
| 604 | spin_unlock_irq(&efivars->lock); |
| 605 | |
| 606 | if (status != EFI_SUCCESS) { |
| 607 | printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", |
| 608 | status); |
| 609 | return -EIO; |
| 610 | } |
| 611 | |
| 612 | memcpy(&entry->var, new_var, count); |
| 613 | return count; |
| 614 | } |
| 615 | |
| 616 | static ssize_t |
| 617 | efivar_show_raw(struct efivar_entry *entry, char *buf) |
| 618 | { |
| 619 | struct efi_variable *var = &entry->var; |
| 620 | efi_status_t status; |
| 621 | |
| 622 | if (!entry || !buf) |
| 623 | return 0; |
| 624 | |
| 625 | status = get_var_data(entry->efivars, var); |
| 626 | if (status != EFI_SUCCESS) |
| 627 | return -EIO; |
| 628 | |
| 629 | memcpy(buf, var, sizeof(*var)); |
| 630 | return sizeof(*var); |
| 631 | } |
| 632 | |
| 633 | /* |
| 634 | * Generic read/write functions that call the specific functions of |
| 635 | * the attributes... |
| 636 | */ |
| 637 | static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr, |
| 638 | char *buf) |
| 639 | { |
| 640 | struct efivar_entry *var = to_efivar_entry(kobj); |
| 641 | struct efivar_attribute *efivar_attr = to_efivar_attr(attr); |
| 642 | ssize_t ret = -EIO; |
| 643 | |
| 644 | if (!capable(CAP_SYS_ADMIN)) |
| 645 | return -EACCES; |
| 646 | |
| 647 | if (efivar_attr->show) { |
| 648 | ret = efivar_attr->show(var, buf); |
| 649 | } |
| 650 | return ret; |
| 651 | } |
| 652 | |
| 653 | static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr, |
| 654 | const char *buf, size_t count) |
| 655 | { |
| 656 | struct efivar_entry *var = to_efivar_entry(kobj); |
| 657 | struct efivar_attribute *efivar_attr = to_efivar_attr(attr); |
| 658 | ssize_t ret = -EIO; |
| 659 | |
| 660 | if (!capable(CAP_SYS_ADMIN)) |
| 661 | return -EACCES; |
| 662 | |
| 663 | if (efivar_attr->store) |
| 664 | ret = efivar_attr->store(var, buf, count); |
| 665 | |
| 666 | return ret; |
| 667 | } |
| 668 | |
| 669 | static const struct sysfs_ops efivar_attr_ops = { |
| 670 | .show = efivar_attr_show, |
| 671 | .store = efivar_attr_store, |
| 672 | }; |
| 673 | |
| 674 | static void efivar_release(struct kobject *kobj) |
| 675 | { |
| 676 | struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj); |
| 677 | kfree(var); |
| 678 | } |
| 679 | |
| 680 | static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL); |
| 681 | static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL); |
| 682 | static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL); |
| 683 | static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL); |
| 684 | static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw); |
| 685 | |
| 686 | static struct attribute *def_attrs[] = { |
| 687 | &efivar_attr_guid.attr, |
| 688 | &efivar_attr_size.attr, |
| 689 | &efivar_attr_attributes.attr, |
| 690 | &efivar_attr_data.attr, |
| 691 | &efivar_attr_raw_var.attr, |
| 692 | NULL, |
| 693 | }; |
| 694 | |
| 695 | static struct kobj_type efivar_ktype = { |
| 696 | .release = efivar_release, |
| 697 | .sysfs_ops = &efivar_attr_ops, |
| 698 | .default_attrs = def_attrs, |
| 699 | }; |
| 700 | |
| 701 | static inline void |
| 702 | efivar_unregister(struct efivar_entry *var) |
| 703 | { |
| 704 | kobject_put(&var->kobj); |
| 705 | } |
| 706 | |
| 707 | static int efivarfs_file_open(struct inode *inode, struct file *file) |
| 708 | { |
| 709 | file->private_data = inode->i_private; |
| 710 | return 0; |
| 711 | } |
| 712 | |
| 713 | static int efi_status_to_err(efi_status_t status) |
| 714 | { |
| 715 | int err; |
| 716 | |
| 717 | switch (status) { |
| 718 | case EFI_INVALID_PARAMETER: |
| 719 | err = -EINVAL; |
| 720 | break; |
| 721 | case EFI_OUT_OF_RESOURCES: |
| 722 | err = -ENOSPC; |
| 723 | break; |
| 724 | case EFI_DEVICE_ERROR: |
| 725 | err = -EIO; |
| 726 | break; |
| 727 | case EFI_WRITE_PROTECTED: |
| 728 | err = -EROFS; |
| 729 | break; |
| 730 | case EFI_SECURITY_VIOLATION: |
| 731 | err = -EACCES; |
| 732 | break; |
| 733 | case EFI_NOT_FOUND: |
| 734 | err = -EIO; |
| 735 | break; |
| 736 | default: |
| 737 | err = -EINVAL; |
| 738 | } |
| 739 | |
| 740 | return err; |
| 741 | } |
| 742 | |
| 743 | static ssize_t efivarfs_file_write(struct file *file, |
| 744 | const char __user *userbuf, size_t count, loff_t *ppos) |
| 745 | { |
| 746 | struct efivar_entry *var = file->private_data; |
| 747 | struct efivars *efivars; |
| 748 | efi_status_t status; |
| 749 | void *data; |
| 750 | u32 attributes; |
| 751 | struct inode *inode = file->f_mapping->host; |
| 752 | unsigned long datasize = count - sizeof(attributes); |
| 753 | unsigned long newdatasize, varsize; |
| 754 | ssize_t bytes = 0; |
| 755 | |
| 756 | if (count < sizeof(attributes)) |
| 757 | return -EINVAL; |
| 758 | |
| 759 | if (copy_from_user(&attributes, userbuf, sizeof(attributes))) |
| 760 | return -EFAULT; |
| 761 | |
| 762 | if (attributes & ~(EFI_VARIABLE_MASK)) |
| 763 | return -EINVAL; |
| 764 | |
| 765 | efivars = var->efivars; |
| 766 | |
| 767 | /* |
| 768 | * Ensure that the user can't allocate arbitrarily large |
| 769 | * amounts of memory. Pick a default size of 64K if |
| 770 | * QueryVariableInfo() isn't supported by the firmware. |
| 771 | */ |
| 772 | |
| 773 | varsize = datasize + utf16_strsize(var->var.VariableName, 1024); |
| 774 | status = check_var_size(efivars, attributes, varsize); |
| 775 | |
| 776 | if (status != EFI_SUCCESS) { |
| 777 | if (status != EFI_UNSUPPORTED) |
| 778 | return efi_status_to_err(status); |
| 779 | |
| 780 | if (datasize > 65536) |
| 781 | return -ENOSPC; |
| 782 | } |
| 783 | |
| 784 | data = kmalloc(datasize, GFP_KERNEL); |
| 785 | if (!data) |
| 786 | return -ENOMEM; |
| 787 | |
| 788 | if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) { |
| 789 | bytes = -EFAULT; |
| 790 | goto out; |
| 791 | } |
| 792 | |
| 793 | if (validate_var(&var->var, data, datasize) == false) { |
| 794 | bytes = -EINVAL; |
| 795 | goto out; |
| 796 | } |
| 797 | |
| 798 | /* |
| 799 | * The lock here protects the get_variable call, the conditional |
| 800 | * set_variable call, and removal of the variable from the efivars |
| 801 | * list (in the case of an authenticated delete). |
| 802 | */ |
| 803 | spin_lock_irq(&efivars->lock); |
| 804 | |
| 805 | /* |
| 806 | * Ensure that the available space hasn't shrunk below the safe level |
| 807 | */ |
| 808 | |
| 809 | status = check_var_size_locked(efivars, attributes, varsize); |
| 810 | |
| 811 | if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED) { |
| 812 | spin_unlock_irq(&efivars->lock); |
| 813 | kfree(data); |
| 814 | |
| 815 | return efi_status_to_err(status); |
| 816 | } |
| 817 | |
| 818 | status = efivars->ops->set_variable(var->var.VariableName, |
| 819 | &var->var.VendorGuid, |
| 820 | attributes, datasize, |
| 821 | data); |
| 822 | |
| 823 | if (status != EFI_SUCCESS) { |
| 824 | spin_unlock_irq(&efivars->lock); |
| 825 | kfree(data); |
| 826 | |
| 827 | return efi_status_to_err(status); |
| 828 | } |
| 829 | |
| 830 | bytes = count; |
| 831 | |
| 832 | /* |
| 833 | * Writing to the variable may have caused a change in size (which |
| 834 | * could either be an append or an overwrite), or the variable to be |
| 835 | * deleted. Perform a GetVariable() so we can tell what actually |
| 836 | * happened. |
| 837 | */ |
| 838 | newdatasize = 0; |
| 839 | status = efivars->ops->get_variable(var->var.VariableName, |
| 840 | &var->var.VendorGuid, |
| 841 | NULL, &newdatasize, |
| 842 | NULL); |
| 843 | |
| 844 | if (status == EFI_BUFFER_TOO_SMALL) { |
| 845 | spin_unlock_irq(&efivars->lock); |
| 846 | mutex_lock(&inode->i_mutex); |
| 847 | i_size_write(inode, newdatasize + sizeof(attributes)); |
| 848 | mutex_unlock(&inode->i_mutex); |
| 849 | |
| 850 | } else if (status == EFI_NOT_FOUND) { |
| 851 | list_del(&var->list); |
| 852 | spin_unlock_irq(&efivars->lock); |
| 853 | efivar_unregister(var); |
| 854 | drop_nlink(inode); |
| 855 | d_delete(file->f_dentry); |
| 856 | dput(file->f_dentry); |
| 857 | |
| 858 | } else { |
| 859 | spin_unlock_irq(&efivars->lock); |
| 860 | pr_warn("efivarfs: inconsistent EFI variable implementation? " |
| 861 | "status = %lx\n", status); |
| 862 | } |
| 863 | |
| 864 | out: |
| 865 | kfree(data); |
| 866 | |
| 867 | return bytes; |
| 868 | } |
| 869 | |
| 870 | static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, |
| 871 | size_t count, loff_t *ppos) |
| 872 | { |
| 873 | struct efivar_entry *var = file->private_data; |
| 874 | struct efivars *efivars = var->efivars; |
| 875 | efi_status_t status; |
| 876 | unsigned long datasize = 0; |
| 877 | u32 attributes; |
| 878 | void *data; |
| 879 | ssize_t size = 0; |
| 880 | |
| 881 | spin_lock_irq(&efivars->lock); |
| 882 | status = efivars->ops->get_variable(var->var.VariableName, |
| 883 | &var->var.VendorGuid, |
| 884 | &attributes, &datasize, NULL); |
| 885 | spin_unlock_irq(&efivars->lock); |
| 886 | |
| 887 | if (status != EFI_BUFFER_TOO_SMALL) |
| 888 | return efi_status_to_err(status); |
| 889 | |
| 890 | data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL); |
| 891 | |
| 892 | if (!data) |
| 893 | return -ENOMEM; |
| 894 | |
| 895 | spin_lock_irq(&efivars->lock); |
| 896 | status = efivars->ops->get_variable(var->var.VariableName, |
| 897 | &var->var.VendorGuid, |
| 898 | &attributes, &datasize, |
| 899 | (data + sizeof(attributes))); |
| 900 | spin_unlock_irq(&efivars->lock); |
| 901 | |
| 902 | if (status != EFI_SUCCESS) { |
| 903 | size = efi_status_to_err(status); |
| 904 | goto out_free; |
| 905 | } |
| 906 | |
| 907 | memcpy(data, &attributes, sizeof(attributes)); |
| 908 | size = simple_read_from_buffer(userbuf, count, ppos, |
| 909 | data, datasize + sizeof(attributes)); |
| 910 | out_free: |
| 911 | kfree(data); |
| 912 | |
| 913 | return size; |
| 914 | } |
| 915 | |
| 916 | static void efivarfs_evict_inode(struct inode *inode) |
| 917 | { |
| 918 | clear_inode(inode); |
| 919 | } |
| 920 | |
| 921 | static const struct super_operations efivarfs_ops = { |
| 922 | .statfs = simple_statfs, |
| 923 | .drop_inode = generic_delete_inode, |
| 924 | .evict_inode = efivarfs_evict_inode, |
| 925 | .show_options = generic_show_options, |
| 926 | }; |
| 927 | |
| 928 | static struct super_block *efivarfs_sb; |
| 929 | |
| 930 | static const struct inode_operations efivarfs_dir_inode_operations; |
| 931 | |
| 932 | static const struct file_operations efivarfs_file_operations = { |
| 933 | .open = efivarfs_file_open, |
| 934 | .read = efivarfs_file_read, |
| 935 | .write = efivarfs_file_write, |
| 936 | .llseek = no_llseek, |
| 937 | }; |
| 938 | |
| 939 | static struct inode *efivarfs_get_inode(struct super_block *sb, |
| 940 | const struct inode *dir, int mode, dev_t dev) |
| 941 | { |
| 942 | struct inode *inode = new_inode(sb); |
| 943 | |
| 944 | if (inode) { |
| 945 | inode->i_ino = get_next_ino(); |
| 946 | inode->i_mode = mode; |
| 947 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 948 | switch (mode & S_IFMT) { |
| 949 | case S_IFREG: |
| 950 | inode->i_fop = &efivarfs_file_operations; |
| 951 | break; |
| 952 | case S_IFDIR: |
| 953 | inode->i_op = &efivarfs_dir_inode_operations; |
| 954 | inode->i_fop = &simple_dir_operations; |
| 955 | inc_nlink(inode); |
| 956 | break; |
| 957 | } |
| 958 | } |
| 959 | return inode; |
| 960 | } |
| 961 | |
| 962 | /* |
| 963 | * Return true if 'str' is a valid efivarfs filename of the form, |
| 964 | * |
| 965 | * VariableName-12345678-1234-1234-1234-1234567891bc |
| 966 | */ |
| 967 | static bool efivarfs_valid_name(const char *str, int len) |
| 968 | { |
| 969 | static const char dashes[GUID_LEN] = { |
| 970 | [8] = 1, [13] = 1, [18] = 1, [23] = 1 |
| 971 | }; |
| 972 | const char *s = str + len - GUID_LEN; |
| 973 | int i; |
| 974 | |
| 975 | /* |
| 976 | * We need a GUID, plus at least one letter for the variable name, |
| 977 | * plus the '-' separator |
| 978 | */ |
| 979 | if (len < GUID_LEN + 2) |
| 980 | return false; |
| 981 | |
| 982 | /* GUID must be preceded by a '-' */ |
| 983 | if (*(s - 1) != '-') |
| 984 | return false; |
| 985 | |
| 986 | /* |
| 987 | * Validate that 's' is of the correct format, e.g. |
| 988 | * |
| 989 | * 12345678-1234-1234-1234-123456789abc |
| 990 | */ |
| 991 | for (i = 0; i < GUID_LEN; i++) { |
| 992 | if (dashes[i]) { |
| 993 | if (*s++ != '-') |
| 994 | return false; |
| 995 | } else { |
| 996 | if (!isxdigit(*s++)) |
| 997 | return false; |
| 998 | } |
| 999 | } |
| 1000 | |
| 1001 | return true; |
| 1002 | } |
| 1003 | |
| 1004 | static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid) |
| 1005 | { |
| 1006 | guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]); |
| 1007 | guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]); |
| 1008 | guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]); |
| 1009 | guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]); |
| 1010 | guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]); |
| 1011 | guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]); |
| 1012 | guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]); |
| 1013 | guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]); |
| 1014 | guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]); |
| 1015 | guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]); |
| 1016 | guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]); |
| 1017 | guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]); |
| 1018 | guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]); |
| 1019 | guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]); |
| 1020 | guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]); |
| 1021 | guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]); |
| 1022 | } |
| 1023 | |
| 1024 | static int efivarfs_create(struct inode *dir, struct dentry *dentry, |
| 1025 | umode_t mode, bool excl) |
| 1026 | { |
| 1027 | struct inode *inode; |
| 1028 | struct efivars *efivars = &__efivars; |
| 1029 | struct efivar_entry *var; |
| 1030 | int namelen, i = 0, err = 0; |
| 1031 | |
| 1032 | if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len)) |
| 1033 | return -EINVAL; |
| 1034 | |
| 1035 | inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0); |
| 1036 | if (!inode) |
| 1037 | return -ENOMEM; |
| 1038 | |
| 1039 | var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); |
| 1040 | if (!var) { |
| 1041 | err = -ENOMEM; |
| 1042 | goto out; |
| 1043 | } |
| 1044 | |
| 1045 | /* length of the variable name itself: remove GUID and separator */ |
| 1046 | namelen = dentry->d_name.len - GUID_LEN - 1; |
| 1047 | |
| 1048 | efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1, |
| 1049 | &var->var.VendorGuid); |
| 1050 | |
| 1051 | for (i = 0; i < namelen; i++) |
| 1052 | var->var.VariableName[i] = dentry->d_name.name[i]; |
| 1053 | |
| 1054 | var->var.VariableName[i] = '\0'; |
| 1055 | |
| 1056 | inode->i_private = var; |
| 1057 | var->efivars = efivars; |
| 1058 | var->kobj.kset = efivars->kset; |
| 1059 | |
| 1060 | err = kobject_init_and_add(&var->kobj, &efivar_ktype, NULL, "%s", |
| 1061 | dentry->d_name.name); |
| 1062 | if (err) |
| 1063 | goto out; |
| 1064 | |
| 1065 | kobject_uevent(&var->kobj, KOBJ_ADD); |
| 1066 | spin_lock_irq(&efivars->lock); |
| 1067 | list_add(&var->list, &efivars->list); |
| 1068 | spin_unlock_irq(&efivars->lock); |
| 1069 | d_instantiate(dentry, inode); |
| 1070 | dget(dentry); |
| 1071 | out: |
| 1072 | if (err) { |
| 1073 | kfree(var); |
| 1074 | iput(inode); |
| 1075 | } |
| 1076 | return err; |
| 1077 | } |
| 1078 | |
| 1079 | static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) |
| 1080 | { |
| 1081 | struct efivar_entry *var = dentry->d_inode->i_private; |
| 1082 | struct efivars *efivars = var->efivars; |
| 1083 | efi_status_t status; |
| 1084 | |
| 1085 | spin_lock_irq(&efivars->lock); |
| 1086 | |
| 1087 | status = efivars->ops->set_variable(var->var.VariableName, |
| 1088 | &var->var.VendorGuid, |
| 1089 | 0, 0, NULL); |
| 1090 | |
| 1091 | if (status == EFI_SUCCESS || status == EFI_NOT_FOUND) { |
| 1092 | list_del(&var->list); |
| 1093 | spin_unlock_irq(&efivars->lock); |
| 1094 | efivar_unregister(var); |
| 1095 | drop_nlink(dentry->d_inode); |
| 1096 | dput(dentry); |
| 1097 | return 0; |
| 1098 | } |
| 1099 | |
| 1100 | spin_unlock_irq(&efivars->lock); |
| 1101 | return -EINVAL; |
| 1102 | }; |
| 1103 | |
| 1104 | /* |
| 1105 | * Compare two efivarfs file names. |
| 1106 | * |
| 1107 | * An efivarfs filename is composed of two parts, |
| 1108 | * |
| 1109 | * 1. A case-sensitive variable name |
| 1110 | * 2. A case-insensitive GUID |
| 1111 | * |
| 1112 | * So we need to perform a case-sensitive match on part 1 and a |
| 1113 | * case-insensitive match on part 2. |
| 1114 | */ |
| 1115 | static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode, |
| 1116 | const struct dentry *dentry, const struct inode *inode, |
| 1117 | unsigned int len, const char *str, |
| 1118 | const struct qstr *name) |
| 1119 | { |
| 1120 | int guid = len - GUID_LEN; |
| 1121 | |
| 1122 | if (name->len != len) |
| 1123 | return 1; |
| 1124 | |
| 1125 | /* Case-sensitive compare for the variable name */ |
| 1126 | if (memcmp(str, name->name, guid)) |
| 1127 | return 1; |
| 1128 | |
| 1129 | /* Case-insensitive compare for the GUID */ |
| 1130 | return strncasecmp(name->name + guid, str + guid, GUID_LEN); |
| 1131 | } |
| 1132 | |
| 1133 | static int efivarfs_d_hash(const struct dentry *dentry, |
| 1134 | const struct inode *inode, struct qstr *qstr) |
| 1135 | { |
| 1136 | unsigned long hash = init_name_hash(); |
| 1137 | const unsigned char *s = qstr->name; |
| 1138 | unsigned int len = qstr->len; |
| 1139 | |
| 1140 | if (!efivarfs_valid_name(s, len)) |
| 1141 | return -EINVAL; |
| 1142 | |
| 1143 | while (len-- > GUID_LEN) |
| 1144 | hash = partial_name_hash(*s++, hash); |
| 1145 | |
| 1146 | /* GUID is case-insensitive. */ |
| 1147 | while (len--) |
| 1148 | hash = partial_name_hash(tolower(*s++), hash); |
| 1149 | |
| 1150 | qstr->hash = end_name_hash(hash); |
| 1151 | return 0; |
| 1152 | } |
| 1153 | |
| 1154 | /* |
| 1155 | * Retaining negative dentries for an in-memory filesystem just wastes |
| 1156 | * memory and lookup time: arrange for them to be deleted immediately. |
| 1157 | */ |
| 1158 | static int efivarfs_delete_dentry(const struct dentry *dentry) |
| 1159 | { |
| 1160 | return 1; |
| 1161 | } |
| 1162 | |
| 1163 | static struct dentry_operations efivarfs_d_ops = { |
| 1164 | .d_compare = efivarfs_d_compare, |
| 1165 | .d_hash = efivarfs_d_hash, |
| 1166 | .d_delete = efivarfs_delete_dentry, |
| 1167 | }; |
| 1168 | |
| 1169 | static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name) |
| 1170 | { |
| 1171 | struct dentry *d; |
| 1172 | struct qstr q; |
| 1173 | int err; |
| 1174 | |
| 1175 | q.name = name; |
| 1176 | q.len = strlen(name); |
| 1177 | |
| 1178 | err = efivarfs_d_hash(NULL, NULL, &q); |
| 1179 | if (err) |
| 1180 | return ERR_PTR(err); |
| 1181 | |
| 1182 | d = d_alloc(parent, &q); |
| 1183 | if (d) |
| 1184 | return d; |
| 1185 | |
| 1186 | return ERR_PTR(-ENOMEM); |
| 1187 | } |
| 1188 | |
| 1189 | static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) |
| 1190 | { |
| 1191 | struct inode *inode = NULL; |
| 1192 | struct dentry *root; |
| 1193 | struct efivar_entry *entry, *n; |
| 1194 | struct efivars *efivars = &__efivars; |
| 1195 | char *name; |
| 1196 | int err = -ENOMEM; |
| 1197 | |
| 1198 | efivarfs_sb = sb; |
| 1199 | |
| 1200 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
| 1201 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 1202 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 1203 | sb->s_magic = EFIVARFS_MAGIC; |
| 1204 | sb->s_op = &efivarfs_ops; |
| 1205 | sb->s_d_op = &efivarfs_d_ops; |
| 1206 | sb->s_time_gran = 1; |
| 1207 | |
| 1208 | inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0); |
| 1209 | if (!inode) |
| 1210 | return -ENOMEM; |
| 1211 | inode->i_op = &efivarfs_dir_inode_operations; |
| 1212 | |
| 1213 | root = d_make_root(inode); |
| 1214 | sb->s_root = root; |
| 1215 | if (!root) |
| 1216 | return -ENOMEM; |
| 1217 | |
| 1218 | list_for_each_entry_safe(entry, n, &efivars->list, list) { |
| 1219 | struct dentry *dentry, *root = efivarfs_sb->s_root; |
| 1220 | unsigned long size = 0; |
| 1221 | int len, i; |
| 1222 | |
| 1223 | inode = NULL; |
| 1224 | |
| 1225 | len = utf16_strlen(entry->var.VariableName); |
| 1226 | |
| 1227 | /* name, plus '-', plus GUID, plus NUL*/ |
| 1228 | name = kmalloc(len + 1 + GUID_LEN + 1, GFP_ATOMIC); |
| 1229 | if (!name) |
| 1230 | goto fail; |
| 1231 | |
| 1232 | for (i = 0; i < len; i++) |
| 1233 | name[i] = entry->var.VariableName[i] & 0xFF; |
| 1234 | |
| 1235 | name[len] = '-'; |
| 1236 | |
| 1237 | efi_guid_unparse(&entry->var.VendorGuid, name + len + 1); |
| 1238 | |
| 1239 | name[len+GUID_LEN+1] = '\0'; |
| 1240 | |
| 1241 | inode = efivarfs_get_inode(efivarfs_sb, root->d_inode, |
| 1242 | S_IFREG | 0644, 0); |
| 1243 | if (!inode) |
| 1244 | goto fail_name; |
| 1245 | |
| 1246 | dentry = efivarfs_alloc_dentry(root, name); |
| 1247 | if (IS_ERR(dentry)) { |
| 1248 | err = PTR_ERR(dentry); |
| 1249 | goto fail_inode; |
| 1250 | } |
| 1251 | |
| 1252 | /* copied by the above to local storage in the dentry. */ |
| 1253 | kfree(name); |
| 1254 | |
| 1255 | spin_lock_irq(&efivars->lock); |
| 1256 | efivars->ops->get_variable(entry->var.VariableName, |
| 1257 | &entry->var.VendorGuid, |
| 1258 | &entry->var.Attributes, |
| 1259 | &size, |
| 1260 | NULL); |
| 1261 | spin_unlock_irq(&efivars->lock); |
| 1262 | |
| 1263 | mutex_lock(&inode->i_mutex); |
| 1264 | inode->i_private = entry; |
| 1265 | i_size_write(inode, size + sizeof(entry->var.Attributes)); |
| 1266 | mutex_unlock(&inode->i_mutex); |
| 1267 | d_add(dentry, inode); |
| 1268 | } |
| 1269 | |
| 1270 | return 0; |
| 1271 | |
| 1272 | fail_inode: |
| 1273 | iput(inode); |
| 1274 | fail_name: |
| 1275 | kfree(name); |
| 1276 | fail: |
| 1277 | return err; |
| 1278 | } |
| 1279 | |
| 1280 | static struct dentry *efivarfs_mount(struct file_system_type *fs_type, |
| 1281 | int flags, const char *dev_name, void *data) |
| 1282 | { |
| 1283 | return mount_single(fs_type, flags, data, efivarfs_fill_super); |
| 1284 | } |
| 1285 | |
| 1286 | static void efivarfs_kill_sb(struct super_block *sb) |
| 1287 | { |
| 1288 | kill_litter_super(sb); |
| 1289 | efivarfs_sb = NULL; |
| 1290 | } |
| 1291 | |
| 1292 | static struct file_system_type efivarfs_type = { |
| 1293 | .name = "efivarfs", |
| 1294 | .mount = efivarfs_mount, |
| 1295 | .kill_sb = efivarfs_kill_sb, |
| 1296 | }; |
| 1297 | MODULE_ALIAS_FS("efivarfs"); |
| 1298 | |
| 1299 | /* |
| 1300 | * Handle negative dentry. |
| 1301 | */ |
| 1302 | static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry, |
| 1303 | unsigned int flags) |
| 1304 | { |
| 1305 | if (dentry->d_name.len > NAME_MAX) |
| 1306 | return ERR_PTR(-ENAMETOOLONG); |
| 1307 | d_add(dentry, NULL); |
| 1308 | return NULL; |
| 1309 | } |
| 1310 | |
| 1311 | static const struct inode_operations efivarfs_dir_inode_operations = { |
| 1312 | .lookup = efivarfs_lookup, |
| 1313 | .unlink = efivarfs_unlink, |
| 1314 | .create = efivarfs_create, |
| 1315 | }; |
| 1316 | |
| 1317 | #ifdef CONFIG_EFI_VARS_PSTORE |
| 1318 | |
| 1319 | static int efi_pstore_open(struct pstore_info *psi) |
| 1320 | { |
| 1321 | struct efivars *efivars = psi->data; |
| 1322 | |
| 1323 | spin_lock_irq(&efivars->lock); |
| 1324 | efivars->walk_entry = list_first_entry(&efivars->list, |
| 1325 | struct efivar_entry, list); |
| 1326 | return 0; |
| 1327 | } |
| 1328 | |
| 1329 | static int efi_pstore_close(struct pstore_info *psi) |
| 1330 | { |
| 1331 | struct efivars *efivars = psi->data; |
| 1332 | |
| 1333 | spin_unlock_irq(&efivars->lock); |
| 1334 | return 0; |
| 1335 | } |
| 1336 | |
| 1337 | static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, |
| 1338 | int *count, struct timespec *timespec, |
| 1339 | char **buf, struct pstore_info *psi) |
| 1340 | { |
| 1341 | efi_guid_t vendor = LINUX_EFI_CRASH_GUID; |
| 1342 | struct efivars *efivars = psi->data; |
| 1343 | char name[DUMP_NAME_LEN]; |
| 1344 | int i; |
| 1345 | int cnt; |
| 1346 | unsigned int part, size; |
| 1347 | unsigned long time; |
| 1348 | |
| 1349 | while (&efivars->walk_entry->list != &efivars->list) { |
| 1350 | if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid, |
| 1351 | vendor)) { |
| 1352 | for (i = 0; i < DUMP_NAME_LEN; i++) { |
| 1353 | name[i] = efivars->walk_entry->var.VariableName[i]; |
| 1354 | } |
| 1355 | if (sscanf(name, "dump-type%u-%u-%d-%lu", |
| 1356 | type, &part, &cnt, &time) == 4) { |
| 1357 | *id = part; |
| 1358 | *count = cnt; |
| 1359 | timespec->tv_sec = time; |
| 1360 | timespec->tv_nsec = 0; |
| 1361 | } else if (sscanf(name, "dump-type%u-%u-%lu", |
| 1362 | type, &part, &time) == 3) { |
| 1363 | /* |
| 1364 | * Check if an old format, |
| 1365 | * which doesn't support holding |
| 1366 | * multiple logs, remains. |
| 1367 | */ |
| 1368 | *id = part; |
| 1369 | *count = 0; |
| 1370 | timespec->tv_sec = time; |
| 1371 | timespec->tv_nsec = 0; |
| 1372 | } else { |
| 1373 | efivars->walk_entry = list_entry( |
| 1374 | efivars->walk_entry->list.next, |
| 1375 | struct efivar_entry, list); |
| 1376 | continue; |
| 1377 | } |
| 1378 | |
| 1379 | get_var_data_locked(efivars, &efivars->walk_entry->var); |
| 1380 | size = efivars->walk_entry->var.DataSize; |
| 1381 | *buf = kmalloc(size, GFP_KERNEL); |
| 1382 | if (*buf == NULL) |
| 1383 | return -ENOMEM; |
| 1384 | memcpy(*buf, efivars->walk_entry->var.Data, |
| 1385 | size); |
| 1386 | efivars->walk_entry = list_entry( |
| 1387 | efivars->walk_entry->list.next, |
| 1388 | struct efivar_entry, list); |
| 1389 | return size; |
| 1390 | } |
| 1391 | efivars->walk_entry = list_entry(efivars->walk_entry->list.next, |
| 1392 | struct efivar_entry, list); |
| 1393 | } |
| 1394 | return 0; |
| 1395 | } |
| 1396 | |
| 1397 | static int efi_pstore_write(enum pstore_type_id type, |
| 1398 | enum kmsg_dump_reason reason, u64 *id, |
| 1399 | unsigned int part, int count, size_t size, |
| 1400 | struct pstore_info *psi) |
| 1401 | { |
| 1402 | char name[DUMP_NAME_LEN]; |
| 1403 | efi_char16_t efi_name[DUMP_NAME_LEN]; |
| 1404 | efi_guid_t vendor = LINUX_EFI_CRASH_GUID; |
| 1405 | struct efivars *efivars = psi->data; |
| 1406 | int i, ret = 0; |
| 1407 | efi_status_t status = EFI_NOT_FOUND; |
| 1408 | unsigned long flags; |
| 1409 | |
| 1410 | if (pstore_cannot_block_path(reason)) { |
| 1411 | /* |
| 1412 | * If the lock is taken by another cpu in non-blocking path, |
| 1413 | * this driver returns without entering firmware to avoid |
| 1414 | * hanging up. |
| 1415 | */ |
| 1416 | if (!spin_trylock_irqsave(&efivars->lock, flags)) |
| 1417 | return -EBUSY; |
| 1418 | } else |
| 1419 | spin_lock_irqsave(&efivars->lock, flags); |
| 1420 | |
| 1421 | /* |
| 1422 | * Check if there is a space enough to log. |
| 1423 | * size: a size of logging data |
| 1424 | * DUMP_NAME_LEN * 2: a maximum size of variable name |
| 1425 | */ |
| 1426 | |
| 1427 | status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES, |
| 1428 | size + DUMP_NAME_LEN * 2); |
| 1429 | |
| 1430 | if (status) { |
| 1431 | spin_unlock_irqrestore(&efivars->lock, flags); |
| 1432 | *id = part; |
| 1433 | return -ENOSPC; |
| 1434 | } |
| 1435 | |
| 1436 | sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, |
| 1437 | get_seconds()); |
| 1438 | |
| 1439 | for (i = 0; i < DUMP_NAME_LEN; i++) |
| 1440 | efi_name[i] = name[i]; |
| 1441 | |
| 1442 | efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES, |
| 1443 | size, psi->buf); |
| 1444 | |
| 1445 | spin_unlock_irqrestore(&efivars->lock, flags); |
| 1446 | |
| 1447 | if (reason == KMSG_DUMP_OOPS) |
| 1448 | schedule_work(&efivar_work); |
| 1449 | |
| 1450 | *id = part; |
| 1451 | return ret; |
| 1452 | }; |
| 1453 | |
| 1454 | static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, |
| 1455 | struct timespec time, struct pstore_info *psi) |
| 1456 | { |
| 1457 | char name[DUMP_NAME_LEN]; |
| 1458 | efi_char16_t efi_name[DUMP_NAME_LEN]; |
| 1459 | char name_old[DUMP_NAME_LEN]; |
| 1460 | efi_char16_t efi_name_old[DUMP_NAME_LEN]; |
| 1461 | efi_guid_t vendor = LINUX_EFI_CRASH_GUID; |
| 1462 | struct efivars *efivars = psi->data; |
| 1463 | struct efivar_entry *entry, *found = NULL; |
| 1464 | int i; |
| 1465 | |
| 1466 | sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count, |
| 1467 | time.tv_sec); |
| 1468 | |
| 1469 | spin_lock_irq(&efivars->lock); |
| 1470 | |
| 1471 | for (i = 0; i < DUMP_NAME_LEN; i++) |
| 1472 | efi_name[i] = name[i]; |
| 1473 | |
| 1474 | /* |
| 1475 | * Clean up an entry with the same name |
| 1476 | */ |
| 1477 | |
| 1478 | list_for_each_entry(entry, &efivars->list, list) { |
| 1479 | get_var_data_locked(efivars, &entry->var); |
| 1480 | |
| 1481 | if (efi_guidcmp(entry->var.VendorGuid, vendor)) |
| 1482 | continue; |
| 1483 | if (utf16_strncmp(entry->var.VariableName, efi_name, |
| 1484 | utf16_strlen(efi_name))) { |
| 1485 | /* |
| 1486 | * Check if an old format, |
| 1487 | * which doesn't support holding |
| 1488 | * multiple logs, remains. |
| 1489 | */ |
| 1490 | sprintf(name_old, "dump-type%u-%u-%lu", type, |
| 1491 | (unsigned int)id, time.tv_sec); |
| 1492 | |
| 1493 | for (i = 0; i < DUMP_NAME_LEN; i++) |
| 1494 | efi_name_old[i] = name_old[i]; |
| 1495 | |
| 1496 | if (utf16_strncmp(entry->var.VariableName, efi_name_old, |
| 1497 | utf16_strlen(efi_name_old))) |
| 1498 | continue; |
| 1499 | } |
| 1500 | |
| 1501 | /* found */ |
| 1502 | found = entry; |
| 1503 | efivars->ops->set_variable(entry->var.VariableName, |
| 1504 | &entry->var.VendorGuid, |
| 1505 | PSTORE_EFI_ATTRIBUTES, |
| 1506 | 0, NULL); |
| 1507 | break; |
| 1508 | } |
| 1509 | |
| 1510 | if (found) |
| 1511 | list_del(&found->list); |
| 1512 | |
| 1513 | spin_unlock_irq(&efivars->lock); |
| 1514 | |
| 1515 | if (found) |
| 1516 | efivar_unregister(found); |
| 1517 | |
| 1518 | return 0; |
| 1519 | } |
| 1520 | |
| 1521 | static struct pstore_info efi_pstore_info = { |
| 1522 | .owner = THIS_MODULE, |
| 1523 | .name = "efi", |
| 1524 | .open = efi_pstore_open, |
| 1525 | .close = efi_pstore_close, |
| 1526 | .read = efi_pstore_read, |
| 1527 | .write = efi_pstore_write, |
| 1528 | .erase = efi_pstore_erase, |
| 1529 | }; |
| 1530 | |
| 1531 | static void efivar_pstore_register(struct efivars *efivars) |
| 1532 | { |
| 1533 | efivars->efi_pstore_info = efi_pstore_info; |
| 1534 | efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); |
| 1535 | if (efivars->efi_pstore_info.buf) { |
| 1536 | efivars->efi_pstore_info.bufsize = 1024; |
| 1537 | efivars->efi_pstore_info.data = efivars; |
| 1538 | spin_lock_init(&efivars->efi_pstore_info.buf_lock); |
| 1539 | pstore_register(&efivars->efi_pstore_info); |
| 1540 | } |
| 1541 | } |
| 1542 | #else |
| 1543 | static void efivar_pstore_register(struct efivars *efivars) |
| 1544 | { |
| 1545 | return; |
| 1546 | } |
| 1547 | #endif |
| 1548 | |
| 1549 | static ssize_t efivar_create(struct file *filp, struct kobject *kobj, |
| 1550 | struct bin_attribute *bin_attr, |
| 1551 | char *buf, loff_t pos, size_t count) |
| 1552 | { |
| 1553 | struct efi_variable *new_var = (struct efi_variable *)buf; |
| 1554 | struct efivars *efivars = bin_attr->private; |
| 1555 | struct efivar_entry *search_efivar, *n; |
| 1556 | unsigned long strsize1, strsize2; |
| 1557 | efi_status_t status = EFI_NOT_FOUND; |
| 1558 | int found = 0; |
| 1559 | |
| 1560 | if (!capable(CAP_SYS_ADMIN)) |
| 1561 | return -EACCES; |
| 1562 | |
| 1563 | if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || |
| 1564 | validate_var(new_var, new_var->Data, new_var->DataSize) == false) { |
| 1565 | printk(KERN_ERR "efivars: Malformed variable content\n"); |
| 1566 | return -EINVAL; |
| 1567 | } |
| 1568 | |
| 1569 | spin_lock_irq(&efivars->lock); |
| 1570 | |
| 1571 | /* |
| 1572 | * Does this variable already exist? |
| 1573 | */ |
| 1574 | list_for_each_entry_safe(search_efivar, n, &efivars->list, list) { |
| 1575 | strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024); |
| 1576 | strsize2 = utf16_strsize(new_var->VariableName, 1024); |
| 1577 | if (strsize1 == strsize2 && |
| 1578 | !memcmp(&(search_efivar->var.VariableName), |
| 1579 | new_var->VariableName, strsize1) && |
| 1580 | !efi_guidcmp(search_efivar->var.VendorGuid, |
| 1581 | new_var->VendorGuid)) { |
| 1582 | found = 1; |
| 1583 | break; |
| 1584 | } |
| 1585 | } |
| 1586 | if (found) { |
| 1587 | spin_unlock_irq(&efivars->lock); |
| 1588 | return -EINVAL; |
| 1589 | } |
| 1590 | |
| 1591 | status = check_var_size_locked(efivars, new_var->Attributes, |
| 1592 | new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); |
| 1593 | |
| 1594 | if (status && status != EFI_UNSUPPORTED) { |
| 1595 | spin_unlock_irq(&efivars->lock); |
| 1596 | return efi_status_to_err(status); |
| 1597 | } |
| 1598 | |
| 1599 | /* now *really* create the variable via EFI */ |
| 1600 | status = efivars->ops->set_variable(new_var->VariableName, |
| 1601 | &new_var->VendorGuid, |
| 1602 | new_var->Attributes, |
| 1603 | new_var->DataSize, |
| 1604 | new_var->Data); |
| 1605 | |
| 1606 | if (status != EFI_SUCCESS) { |
| 1607 | printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", |
| 1608 | status); |
| 1609 | spin_unlock_irq(&efivars->lock); |
| 1610 | return -EIO; |
| 1611 | } |
| 1612 | spin_unlock_irq(&efivars->lock); |
| 1613 | |
| 1614 | /* Create the entry in sysfs. Locking is not required here */ |
| 1615 | status = efivar_create_sysfs_entry(efivars, |
| 1616 | utf16_strsize(new_var->VariableName, |
| 1617 | 1024), |
| 1618 | new_var->VariableName, |
| 1619 | &new_var->VendorGuid); |
| 1620 | if (status) { |
| 1621 | printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n"); |
| 1622 | } |
| 1623 | return count; |
| 1624 | } |
| 1625 | |
| 1626 | static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, |
| 1627 | struct bin_attribute *bin_attr, |
| 1628 | char *buf, loff_t pos, size_t count) |
| 1629 | { |
| 1630 | struct efi_variable *del_var = (struct efi_variable *)buf; |
| 1631 | struct efivars *efivars = bin_attr->private; |
| 1632 | struct efivar_entry *search_efivar, *n; |
| 1633 | unsigned long strsize1, strsize2; |
| 1634 | efi_status_t status = EFI_NOT_FOUND; |
| 1635 | int found = 0; |
| 1636 | |
| 1637 | if (!capable(CAP_SYS_ADMIN)) |
| 1638 | return -EACCES; |
| 1639 | |
| 1640 | spin_lock_irq(&efivars->lock); |
| 1641 | |
| 1642 | /* |
| 1643 | * Does this variable already exist? |
| 1644 | */ |
| 1645 | list_for_each_entry_safe(search_efivar, n, &efivars->list, list) { |
| 1646 | strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024); |
| 1647 | strsize2 = utf16_strsize(del_var->VariableName, 1024); |
| 1648 | if (strsize1 == strsize2 && |
| 1649 | !memcmp(&(search_efivar->var.VariableName), |
| 1650 | del_var->VariableName, strsize1) && |
| 1651 | !efi_guidcmp(search_efivar->var.VendorGuid, |
| 1652 | del_var->VendorGuid)) { |
| 1653 | found = 1; |
| 1654 | break; |
| 1655 | } |
| 1656 | } |
| 1657 | if (!found) { |
| 1658 | spin_unlock_irq(&efivars->lock); |
| 1659 | return -EINVAL; |
| 1660 | } |
| 1661 | /* force the Attributes/DataSize to 0 to ensure deletion */ |
| 1662 | del_var->Attributes = 0; |
| 1663 | del_var->DataSize = 0; |
| 1664 | |
| 1665 | status = efivars->ops->set_variable(del_var->VariableName, |
| 1666 | &del_var->VendorGuid, |
| 1667 | del_var->Attributes, |
| 1668 | del_var->DataSize, |
| 1669 | del_var->Data); |
| 1670 | |
| 1671 | if (status != EFI_SUCCESS) { |
| 1672 | printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", |
| 1673 | status); |
| 1674 | spin_unlock_irq(&efivars->lock); |
| 1675 | return -EIO; |
| 1676 | } |
| 1677 | list_del(&search_efivar->list); |
| 1678 | /* We need to release this lock before unregistering. */ |
| 1679 | spin_unlock_irq(&efivars->lock); |
| 1680 | efivar_unregister(search_efivar); |
| 1681 | |
| 1682 | /* It's dead Jim.... */ |
| 1683 | return count; |
| 1684 | } |
| 1685 | |
| 1686 | static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) |
| 1687 | { |
| 1688 | struct efivar_entry *entry, *n; |
| 1689 | struct efivars *efivars = &__efivars; |
| 1690 | unsigned long strsize1, strsize2; |
| 1691 | bool found = false; |
| 1692 | |
| 1693 | strsize1 = utf16_strsize(variable_name, 1024); |
| 1694 | list_for_each_entry_safe(entry, n, &efivars->list, list) { |
| 1695 | strsize2 = utf16_strsize(entry->var.VariableName, 1024); |
| 1696 | if (strsize1 == strsize2 && |
| 1697 | !memcmp(variable_name, &(entry->var.VariableName), |
| 1698 | strsize2) && |
| 1699 | !efi_guidcmp(entry->var.VendorGuid, |
| 1700 | *vendor)) { |
| 1701 | found = true; |
| 1702 | break; |
| 1703 | } |
| 1704 | } |
| 1705 | return found; |
| 1706 | } |
| 1707 | |
| 1708 | /* |
| 1709 | * Returns the size of variable_name, in bytes, including the |
| 1710 | * terminating NULL character, or variable_name_size if no NULL |
| 1711 | * character is found among the first variable_name_size bytes. |
| 1712 | */ |
| 1713 | static unsigned long var_name_strnsize(efi_char16_t *variable_name, |
| 1714 | unsigned long variable_name_size) |
| 1715 | { |
| 1716 | unsigned long len; |
| 1717 | efi_char16_t c; |
| 1718 | |
| 1719 | /* |
| 1720 | * The variable name is, by definition, a NULL-terminated |
| 1721 | * string, so make absolutely sure that variable_name_size is |
| 1722 | * the value we expect it to be. If not, return the real size. |
| 1723 | */ |
| 1724 | for (len = 2; len <= variable_name_size; len += sizeof(c)) { |
| 1725 | c = variable_name[(len / sizeof(c)) - 1]; |
| 1726 | if (!c) |
| 1727 | break; |
| 1728 | } |
| 1729 | |
| 1730 | return min(len, variable_name_size); |
| 1731 | } |
| 1732 | |
| 1733 | static void efivar_update_sysfs_entries(struct work_struct *work) |
| 1734 | { |
| 1735 | struct efivars *efivars = &__efivars; |
| 1736 | efi_guid_t vendor; |
| 1737 | efi_char16_t *variable_name; |
| 1738 | unsigned long variable_name_size = 1024; |
| 1739 | efi_status_t status = EFI_NOT_FOUND; |
| 1740 | bool found; |
| 1741 | |
| 1742 | /* Add new sysfs entries */ |
| 1743 | while (1) { |
| 1744 | variable_name = kzalloc(variable_name_size, GFP_KERNEL); |
| 1745 | if (!variable_name) { |
| 1746 | pr_err("efivars: Memory allocation failed.\n"); |
| 1747 | return; |
| 1748 | } |
| 1749 | |
| 1750 | spin_lock_irq(&efivars->lock); |
| 1751 | found = false; |
| 1752 | while (1) { |
| 1753 | variable_name_size = 1024; |
| 1754 | status = efivars->ops->get_next_variable( |
| 1755 | &variable_name_size, |
| 1756 | variable_name, |
| 1757 | &vendor); |
| 1758 | if (status != EFI_SUCCESS) { |
| 1759 | break; |
| 1760 | } else { |
| 1761 | if (!variable_is_present(variable_name, |
| 1762 | &vendor)) { |
| 1763 | found = true; |
| 1764 | break; |
| 1765 | } |
| 1766 | } |
| 1767 | } |
| 1768 | spin_unlock_irq(&efivars->lock); |
| 1769 | |
| 1770 | if (!found) { |
| 1771 | kfree(variable_name); |
| 1772 | break; |
| 1773 | } else { |
| 1774 | variable_name_size = var_name_strnsize(variable_name, |
| 1775 | variable_name_size); |
| 1776 | efivar_create_sysfs_entry(efivars, |
| 1777 | variable_name_size, |
| 1778 | variable_name, &vendor); |
| 1779 | } |
| 1780 | } |
| 1781 | } |
| 1782 | |
| 1783 | /* |
| 1784 | * Let's not leave out systab information that snuck into |
| 1785 | * the efivars driver |
| 1786 | */ |
| 1787 | static ssize_t systab_show(struct kobject *kobj, |
| 1788 | struct kobj_attribute *attr, char *buf) |
| 1789 | { |
| 1790 | char *str = buf; |
| 1791 | |
| 1792 | if (!kobj || !buf) |
| 1793 | return -EINVAL; |
| 1794 | |
| 1795 | if (efi.mps != EFI_INVALID_TABLE_ADDR) |
| 1796 | str += sprintf(str, "MPS=0x%lx\n", efi.mps); |
| 1797 | if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) |
| 1798 | str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20); |
| 1799 | if (efi.acpi != EFI_INVALID_TABLE_ADDR) |
| 1800 | str += sprintf(str, "ACPI=0x%lx\n", efi.acpi); |
| 1801 | if (efi.smbios != EFI_INVALID_TABLE_ADDR) |
| 1802 | str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios); |
| 1803 | if (efi.hcdp != EFI_INVALID_TABLE_ADDR) |
| 1804 | str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp); |
| 1805 | if (efi.boot_info != EFI_INVALID_TABLE_ADDR) |
| 1806 | str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info); |
| 1807 | if (efi.uga != EFI_INVALID_TABLE_ADDR) |
| 1808 | str += sprintf(str, "UGA=0x%lx\n", efi.uga); |
| 1809 | |
| 1810 | return str - buf; |
| 1811 | } |
| 1812 | |
| 1813 | static struct kobj_attribute efi_attr_systab = |
| 1814 | __ATTR(systab, 0400, systab_show, NULL); |
| 1815 | |
| 1816 | static struct attribute *efi_subsys_attrs[] = { |
| 1817 | &efi_attr_systab.attr, |
| 1818 | NULL, /* maybe more in the future? */ |
| 1819 | }; |
| 1820 | |
| 1821 | static struct attribute_group efi_subsys_attr_group = { |
| 1822 | .attrs = efi_subsys_attrs, |
| 1823 | }; |
| 1824 | |
| 1825 | static struct kobject *efi_kobj; |
| 1826 | |
| 1827 | /* |
| 1828 | * efivar_create_sysfs_entry() |
| 1829 | * Requires: |
| 1830 | * variable_name_size = number of bytes required to hold |
| 1831 | * variable_name (not counting the NULL |
| 1832 | * character at the end. |
| 1833 | * efivars->lock is not held on entry or exit. |
| 1834 | * Returns 1 on failure, 0 on success |
| 1835 | */ |
| 1836 | static int |
| 1837 | efivar_create_sysfs_entry(struct efivars *efivars, |
| 1838 | unsigned long variable_name_size, |
| 1839 | efi_char16_t *variable_name, |
| 1840 | efi_guid_t *vendor_guid) |
| 1841 | { |
| 1842 | int i, short_name_size; |
| 1843 | char *short_name; |
| 1844 | struct efivar_entry *new_efivar; |
| 1845 | |
| 1846 | /* |
| 1847 | * Length of the variable bytes in ASCII, plus the '-' separator, |
| 1848 | * plus the GUID, plus trailing NUL |
| 1849 | */ |
| 1850 | short_name_size = variable_name_size / sizeof(efi_char16_t) |
| 1851 | + 1 + GUID_LEN + 1; |
| 1852 | |
| 1853 | short_name = kzalloc(short_name_size, GFP_KERNEL); |
| 1854 | new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); |
| 1855 | |
| 1856 | if (!short_name || !new_efivar) { |
| 1857 | kfree(short_name); |
| 1858 | kfree(new_efivar); |
| 1859 | return 1; |
| 1860 | } |
| 1861 | |
| 1862 | new_efivar->efivars = efivars; |
| 1863 | memcpy(new_efivar->var.VariableName, variable_name, |
| 1864 | variable_name_size); |
| 1865 | memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t)); |
| 1866 | |
| 1867 | /* Convert Unicode to normal chars (assume top bits are 0), |
| 1868 | ala UTF-8 */ |
| 1869 | for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) { |
| 1870 | short_name[i] = variable_name[i] & 0xFF; |
| 1871 | } |
| 1872 | /* This is ugly, but necessary to separate one vendor's |
| 1873 | private variables from another's. */ |
| 1874 | |
| 1875 | *(short_name + strlen(short_name)) = '-'; |
| 1876 | efi_guid_unparse(vendor_guid, short_name + strlen(short_name)); |
| 1877 | |
| 1878 | new_efivar->kobj.kset = efivars->kset; |
| 1879 | i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL, |
| 1880 | "%s", short_name); |
| 1881 | if (i) { |
| 1882 | kfree(short_name); |
| 1883 | kfree(new_efivar); |
| 1884 | return 1; |
| 1885 | } |
| 1886 | |
| 1887 | kobject_uevent(&new_efivar->kobj, KOBJ_ADD); |
| 1888 | kfree(short_name); |
| 1889 | short_name = NULL; |
| 1890 | |
| 1891 | spin_lock_irq(&efivars->lock); |
| 1892 | list_add(&new_efivar->list, &efivars->list); |
| 1893 | spin_unlock_irq(&efivars->lock); |
| 1894 | |
| 1895 | return 0; |
| 1896 | } |
| 1897 | |
| 1898 | static int |
| 1899 | create_efivars_bin_attributes(struct efivars *efivars) |
| 1900 | { |
| 1901 | struct bin_attribute *attr; |
| 1902 | int error; |
| 1903 | |
| 1904 | /* new_var */ |
| 1905 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); |
| 1906 | if (!attr) |
| 1907 | return -ENOMEM; |
| 1908 | |
| 1909 | attr->attr.name = "new_var"; |
| 1910 | attr->attr.mode = 0200; |
| 1911 | attr->write = efivar_create; |
| 1912 | attr->private = efivars; |
| 1913 | efivars->new_var = attr; |
| 1914 | |
| 1915 | /* del_var */ |
| 1916 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); |
| 1917 | if (!attr) { |
| 1918 | error = -ENOMEM; |
| 1919 | goto out_free; |
| 1920 | } |
| 1921 | attr->attr.name = "del_var"; |
| 1922 | attr->attr.mode = 0200; |
| 1923 | attr->write = efivar_delete; |
| 1924 | attr->private = efivars; |
| 1925 | efivars->del_var = attr; |
| 1926 | |
| 1927 | sysfs_bin_attr_init(efivars->new_var); |
| 1928 | sysfs_bin_attr_init(efivars->del_var); |
| 1929 | |
| 1930 | /* Register */ |
| 1931 | error = sysfs_create_bin_file(&efivars->kset->kobj, |
| 1932 | efivars->new_var); |
| 1933 | if (error) { |
| 1934 | printk(KERN_ERR "efivars: unable to create new_var sysfs file" |
| 1935 | " due to error %d\n", error); |
| 1936 | goto out_free; |
| 1937 | } |
| 1938 | error = sysfs_create_bin_file(&efivars->kset->kobj, |
| 1939 | efivars->del_var); |
| 1940 | if (error) { |
| 1941 | printk(KERN_ERR "efivars: unable to create del_var sysfs file" |
| 1942 | " due to error %d\n", error); |
| 1943 | sysfs_remove_bin_file(&efivars->kset->kobj, |
| 1944 | efivars->new_var); |
| 1945 | goto out_free; |
| 1946 | } |
| 1947 | |
| 1948 | return 0; |
| 1949 | out_free: |
| 1950 | kfree(efivars->del_var); |
| 1951 | efivars->del_var = NULL; |
| 1952 | kfree(efivars->new_var); |
| 1953 | efivars->new_var = NULL; |
| 1954 | return error; |
| 1955 | } |
| 1956 | |
| 1957 | void unregister_efivars(struct efivars *efivars) |
| 1958 | { |
| 1959 | struct efivar_entry *entry, *n; |
| 1960 | |
| 1961 | list_for_each_entry_safe(entry, n, &efivars->list, list) { |
| 1962 | spin_lock_irq(&efivars->lock); |
| 1963 | list_del(&entry->list); |
| 1964 | spin_unlock_irq(&efivars->lock); |
| 1965 | efivar_unregister(entry); |
| 1966 | } |
| 1967 | if (efivars->new_var) |
| 1968 | sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var); |
| 1969 | if (efivars->del_var) |
| 1970 | sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var); |
| 1971 | kfree(efivars->new_var); |
| 1972 | kfree(efivars->del_var); |
| 1973 | kobject_put(efivars->kobject); |
| 1974 | kset_unregister(efivars->kset); |
| 1975 | } |
| 1976 | EXPORT_SYMBOL_GPL(unregister_efivars); |
| 1977 | |
| 1978 | int register_efivars(struct efivars *efivars, |
| 1979 | const struct efivar_operations *ops, |
| 1980 | struct kobject *parent_kobj) |
| 1981 | { |
| 1982 | efi_status_t status = EFI_NOT_FOUND; |
| 1983 | efi_guid_t vendor_guid; |
| 1984 | efi_char16_t *variable_name; |
| 1985 | unsigned long variable_name_size = 1024; |
| 1986 | int error = 0; |
| 1987 | |
| 1988 | variable_name = kzalloc(variable_name_size, GFP_KERNEL); |
| 1989 | if (!variable_name) { |
| 1990 | printk(KERN_ERR "efivars: Memory allocation failed.\n"); |
| 1991 | return -ENOMEM; |
| 1992 | } |
| 1993 | |
| 1994 | spin_lock_init(&efivars->lock); |
| 1995 | INIT_LIST_HEAD(&efivars->list); |
| 1996 | efivars->ops = ops; |
| 1997 | |
| 1998 | efivars->kset = kset_create_and_add("vars", NULL, parent_kobj); |
| 1999 | if (!efivars->kset) { |
| 2000 | printk(KERN_ERR "efivars: Subsystem registration failed.\n"); |
| 2001 | error = -ENOMEM; |
| 2002 | goto out; |
| 2003 | } |
| 2004 | |
| 2005 | efivars->kobject = kobject_create_and_add("efivars", parent_kobj); |
| 2006 | if (!efivars->kobject) { |
| 2007 | pr_err("efivars: Subsystem registration failed.\n"); |
| 2008 | error = -ENOMEM; |
| 2009 | kset_unregister(efivars->kset); |
| 2010 | goto out; |
| 2011 | } |
| 2012 | |
| 2013 | /* |
| 2014 | * Per EFI spec, the maximum storage allocated for both |
| 2015 | * the variable name and variable data is 1024 bytes. |
| 2016 | */ |
| 2017 | |
| 2018 | do { |
| 2019 | variable_name_size = 1024; |
| 2020 | |
| 2021 | status = ops->get_next_variable(&variable_name_size, |
| 2022 | variable_name, |
| 2023 | &vendor_guid); |
| 2024 | switch (status) { |
| 2025 | case EFI_SUCCESS: |
| 2026 | variable_name_size = var_name_strnsize(variable_name, |
| 2027 | variable_name_size); |
| 2028 | efivar_create_sysfs_entry(efivars, |
| 2029 | variable_name_size, |
| 2030 | variable_name, |
| 2031 | &vendor_guid); |
| 2032 | break; |
| 2033 | case EFI_NOT_FOUND: |
| 2034 | break; |
| 2035 | default: |
| 2036 | printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n", |
| 2037 | status); |
| 2038 | status = EFI_NOT_FOUND; |
| 2039 | break; |
| 2040 | } |
| 2041 | } while (status != EFI_NOT_FOUND); |
| 2042 | |
| 2043 | error = create_efivars_bin_attributes(efivars); |
| 2044 | if (error) |
| 2045 | unregister_efivars(efivars); |
| 2046 | |
| 2047 | if (!efivars_pstore_disable) |
| 2048 | efivar_pstore_register(efivars); |
| 2049 | |
| 2050 | register_filesystem(&efivarfs_type); |
| 2051 | |
| 2052 | out: |
| 2053 | kfree(variable_name); |
| 2054 | |
| 2055 | return error; |
| 2056 | } |
| 2057 | EXPORT_SYMBOL_GPL(register_efivars); |
| 2058 | |
| 2059 | /* |
| 2060 | * For now we register the efi subsystem with the firmware subsystem |
| 2061 | * and the vars subsystem with the efi subsystem. In the future, it |
| 2062 | * might make sense to split off the efi subsystem into its own |
| 2063 | * driver, but for now only efivars will register with it, so just |
| 2064 | * include it here. |
| 2065 | */ |
| 2066 | |
| 2067 | static int __init |
| 2068 | efivars_init(void) |
| 2069 | { |
| 2070 | int error = 0; |
| 2071 | |
| 2072 | printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, |
| 2073 | EFIVARS_DATE); |
| 2074 | |
| 2075 | if (!efi_enabled(EFI_RUNTIME_SERVICES)) |
| 2076 | return 0; |
| 2077 | |
| 2078 | /* For now we'll register the efi directory at /sys/firmware/efi */ |
| 2079 | efi_kobj = kobject_create_and_add("efi", firmware_kobj); |
| 2080 | if (!efi_kobj) { |
| 2081 | printk(KERN_ERR "efivars: Firmware registration failed.\n"); |
| 2082 | return -ENOMEM; |
| 2083 | } |
| 2084 | |
| 2085 | ops.get_variable = efi.get_variable; |
| 2086 | ops.set_variable = efi.set_variable; |
| 2087 | ops.get_next_variable = efi.get_next_variable; |
| 2088 | ops.query_variable_info = efi.query_variable_info; |
| 2089 | |
| 2090 | error = register_efivars(&__efivars, &ops, efi_kobj); |
| 2091 | if (error) |
| 2092 | goto err_put; |
| 2093 | |
| 2094 | /* Don't forget the systab entry */ |
| 2095 | error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group); |
| 2096 | if (error) { |
| 2097 | printk(KERN_ERR |
| 2098 | "efivars: Sysfs attribute export failed with error %d.\n", |
| 2099 | error); |
| 2100 | goto err_unregister; |
| 2101 | } |
| 2102 | |
| 2103 | return 0; |
| 2104 | |
| 2105 | err_unregister: |
| 2106 | unregister_efivars(&__efivars); |
| 2107 | err_put: |
| 2108 | kobject_put(efi_kobj); |
| 2109 | return error; |
| 2110 | } |
| 2111 | |
| 2112 | static void __exit |
| 2113 | efivars_exit(void) |
| 2114 | { |
| 2115 | cancel_work_sync(&efivar_work); |
| 2116 | |
| 2117 | if (efi_enabled(EFI_RUNTIME_SERVICES)) { |
| 2118 | unregister_efivars(&__efivars); |
| 2119 | kobject_put(efi_kobj); |
| 2120 | } |
| 2121 | } |
| 2122 | |
| 2123 | module_init(efivars_init); |
| 2124 | module_exit(efivars_exit); |
| 2125 | |