David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 2 | /* |
| 3 | * Originally from efivars.c, |
| 4 | * |
| 5 | * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com> |
| 6 | * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com> |
| 7 | * |
| 8 | * This code takes all variables accessible from EFI runtime and |
| 9 | * exports them via sysfs |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 10 | */ |
| 11 | |
| 12 | #include <linux/efi.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/ucs2_string.h> |
| 16 | #include <linux/compat.h> |
| 17 | |
| 18 | #define EFIVARS_VERSION "0.08" |
| 19 | #define EFIVARS_DATE "2004-May-17" |
| 20 | |
| 21 | MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>"); |
| 22 | MODULE_DESCRIPTION("sysfs interface to EFI Variables"); |
| 23 | MODULE_LICENSE("GPL"); |
| 24 | MODULE_VERSION(EFIVARS_VERSION); |
| 25 | MODULE_ALIAS("platform:efivars"); |
| 26 | |
| 27 | LIST_HEAD(efivar_sysfs_list); |
| 28 | EXPORT_SYMBOL_GPL(efivar_sysfs_list); |
| 29 | |
| 30 | static struct kset *efivars_kset; |
| 31 | |
| 32 | static struct bin_attribute *efivars_new_var; |
| 33 | static struct bin_attribute *efivars_del_var; |
| 34 | |
| 35 | struct compat_efi_variable { |
| 36 | efi_char16_t VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)]; |
| 37 | efi_guid_t VendorGuid; |
| 38 | __u32 DataSize; |
| 39 | __u8 Data[1024]; |
| 40 | __u32 Status; |
| 41 | __u32 Attributes; |
| 42 | } __packed; |
| 43 | |
| 44 | struct efivar_attribute { |
| 45 | struct attribute attr; |
| 46 | ssize_t (*show) (struct efivar_entry *entry, char *buf); |
| 47 | ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); |
| 48 | }; |
| 49 | |
| 50 | #define EFIVAR_ATTR(_name, _mode, _show, _store) \ |
| 51 | struct efivar_attribute efivar_attr_##_name = { \ |
| 52 | .attr = {.name = __stringify(_name), .mode = _mode}, \ |
| 53 | .show = _show, \ |
| 54 | .store = _store, \ |
| 55 | }; |
| 56 | |
| 57 | #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr) |
| 58 | #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj) |
| 59 | |
| 60 | /* |
| 61 | * Prototype for sysfs creation function |
| 62 | */ |
| 63 | static int |
| 64 | efivar_create_sysfs_entry(struct efivar_entry *new_var); |
| 65 | |
| 66 | static ssize_t |
| 67 | efivar_guid_read(struct efivar_entry *entry, char *buf) |
| 68 | { |
| 69 | struct efi_variable *var = &entry->var; |
| 70 | char *str = buf; |
| 71 | |
| 72 | if (!entry || !buf) |
| 73 | return 0; |
| 74 | |
| 75 | efi_guid_to_str(&var->VendorGuid, str); |
| 76 | str += strlen(str); |
| 77 | str += sprintf(str, "\n"); |
| 78 | |
| 79 | return str - buf; |
| 80 | } |
| 81 | |
| 82 | static ssize_t |
| 83 | efivar_attr_read(struct efivar_entry *entry, char *buf) |
| 84 | { |
| 85 | struct efi_variable *var = &entry->var; |
| 86 | char *str = buf; |
| 87 | |
| 88 | if (!entry || !buf) |
| 89 | return -EINVAL; |
| 90 | |
| 91 | var->DataSize = 1024; |
| 92 | if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) |
| 93 | return -EIO; |
| 94 | |
| 95 | if (var->Attributes & EFI_VARIABLE_NON_VOLATILE) |
| 96 | str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n"); |
| 97 | if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) |
| 98 | str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n"); |
| 99 | if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) |
| 100 | str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n"); |
| 101 | if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) |
| 102 | str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n"); |
| 103 | if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) |
| 104 | str += sprintf(str, |
| 105 | "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n"); |
| 106 | if (var->Attributes & |
| 107 | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) |
| 108 | str += sprintf(str, |
| 109 | "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n"); |
| 110 | if (var->Attributes & EFI_VARIABLE_APPEND_WRITE) |
| 111 | str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n"); |
| 112 | return str - buf; |
| 113 | } |
| 114 | |
| 115 | static ssize_t |
| 116 | efivar_size_read(struct efivar_entry *entry, char *buf) |
| 117 | { |
| 118 | struct efi_variable *var = &entry->var; |
| 119 | char *str = buf; |
| 120 | |
| 121 | if (!entry || !buf) |
| 122 | return -EINVAL; |
| 123 | |
| 124 | var->DataSize = 1024; |
| 125 | if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) |
| 126 | return -EIO; |
| 127 | |
| 128 | str += sprintf(str, "0x%lx\n", var->DataSize); |
| 129 | return str - buf; |
| 130 | } |
| 131 | |
| 132 | static ssize_t |
| 133 | efivar_data_read(struct efivar_entry *entry, char *buf) |
| 134 | { |
| 135 | struct efi_variable *var = &entry->var; |
| 136 | |
| 137 | if (!entry || !buf) |
| 138 | return -EINVAL; |
| 139 | |
| 140 | var->DataSize = 1024; |
| 141 | if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) |
| 142 | return -EIO; |
| 143 | |
| 144 | memcpy(buf, var->Data, var->DataSize); |
| 145 | return var->DataSize; |
| 146 | } |
| 147 | |
| 148 | static inline int |
| 149 | sanity_check(struct efi_variable *var, efi_char16_t *name, efi_guid_t vendor, |
| 150 | unsigned long size, u32 attributes, u8 *data) |
| 151 | { |
| 152 | /* |
| 153 | * If only updating the variable data, then the name |
| 154 | * and guid should remain the same |
| 155 | */ |
| 156 | if (memcmp(name, var->VariableName, sizeof(var->VariableName)) || |
| 157 | efi_guidcmp(vendor, var->VendorGuid)) { |
| 158 | printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n"); |
| 159 | return -EINVAL; |
| 160 | } |
| 161 | |
| 162 | if ((size <= 0) || (attributes == 0)){ |
| 163 | printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n"); |
| 164 | return -EINVAL; |
| 165 | } |
| 166 | |
| 167 | if ((attributes & ~EFI_VARIABLE_MASK) != 0 || |
| 168 | efivar_validate(vendor, name, data, size) == false) { |
| 169 | printk(KERN_ERR "efivars: Malformed variable content\n"); |
| 170 | return -EINVAL; |
| 171 | } |
| 172 | |
| 173 | return 0; |
| 174 | } |
| 175 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 176 | static void |
| 177 | copy_out_compat(struct efi_variable *dst, struct compat_efi_variable *src) |
| 178 | { |
| 179 | memcpy(dst->VariableName, src->VariableName, EFI_VAR_NAME_LEN); |
| 180 | memcpy(dst->Data, src->Data, sizeof(src->Data)); |
| 181 | |
| 182 | dst->VendorGuid = src->VendorGuid; |
| 183 | dst->DataSize = src->DataSize; |
| 184 | dst->Attributes = src->Attributes; |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * We allow each variable to be edited via rewriting the |
| 189 | * entire efi variable structure. |
| 190 | */ |
| 191 | static ssize_t |
| 192 | efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) |
| 193 | { |
| 194 | struct efi_variable *new_var, *var = &entry->var; |
| 195 | efi_char16_t *name; |
| 196 | unsigned long size; |
| 197 | efi_guid_t vendor; |
| 198 | u32 attributes; |
| 199 | u8 *data; |
| 200 | int err; |
| 201 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 202 | if (in_compat_syscall()) { |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 203 | struct compat_efi_variable *compat; |
| 204 | |
| 205 | if (count != sizeof(*compat)) |
| 206 | return -EINVAL; |
| 207 | |
| 208 | compat = (struct compat_efi_variable *)buf; |
| 209 | attributes = compat->Attributes; |
| 210 | vendor = compat->VendorGuid; |
| 211 | name = compat->VariableName; |
| 212 | size = compat->DataSize; |
| 213 | data = compat->Data; |
| 214 | |
| 215 | err = sanity_check(var, name, vendor, size, attributes, data); |
| 216 | if (err) |
| 217 | return err; |
| 218 | |
| 219 | copy_out_compat(&entry->var, compat); |
| 220 | } else { |
| 221 | if (count != sizeof(struct efi_variable)) |
| 222 | return -EINVAL; |
| 223 | |
| 224 | new_var = (struct efi_variable *)buf; |
| 225 | |
| 226 | attributes = new_var->Attributes; |
| 227 | vendor = new_var->VendorGuid; |
| 228 | name = new_var->VariableName; |
| 229 | size = new_var->DataSize; |
| 230 | data = new_var->Data; |
| 231 | |
| 232 | err = sanity_check(var, name, vendor, size, attributes, data); |
| 233 | if (err) |
| 234 | return err; |
| 235 | |
| 236 | memcpy(&entry->var, new_var, count); |
| 237 | } |
| 238 | |
| 239 | err = efivar_entry_set(entry, attributes, size, data, NULL); |
| 240 | if (err) { |
| 241 | printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err); |
| 242 | return -EIO; |
| 243 | } |
| 244 | |
| 245 | return count; |
| 246 | } |
| 247 | |
| 248 | static ssize_t |
| 249 | efivar_show_raw(struct efivar_entry *entry, char *buf) |
| 250 | { |
| 251 | struct efi_variable *var = &entry->var; |
| 252 | struct compat_efi_variable *compat; |
| 253 | size_t size; |
| 254 | |
| 255 | if (!entry || !buf) |
| 256 | return 0; |
| 257 | |
| 258 | var->DataSize = 1024; |
| 259 | if (efivar_entry_get(entry, &entry->var.Attributes, |
| 260 | &entry->var.DataSize, entry->var.Data)) |
| 261 | return -EIO; |
| 262 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 263 | if (in_compat_syscall()) { |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 264 | compat = (struct compat_efi_variable *)buf; |
| 265 | |
| 266 | size = sizeof(*compat); |
| 267 | memcpy(compat->VariableName, var->VariableName, |
| 268 | EFI_VAR_NAME_LEN); |
| 269 | memcpy(compat->Data, var->Data, sizeof(compat->Data)); |
| 270 | |
| 271 | compat->VendorGuid = var->VendorGuid; |
| 272 | compat->DataSize = var->DataSize; |
| 273 | compat->Attributes = var->Attributes; |
| 274 | } else { |
| 275 | size = sizeof(*var); |
| 276 | memcpy(buf, var, size); |
| 277 | } |
| 278 | |
| 279 | return size; |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * Generic read/write functions that call the specific functions of |
| 284 | * the attributes... |
| 285 | */ |
| 286 | static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr, |
| 287 | char *buf) |
| 288 | { |
| 289 | struct efivar_entry *var = to_efivar_entry(kobj); |
| 290 | struct efivar_attribute *efivar_attr = to_efivar_attr(attr); |
| 291 | ssize_t ret = -EIO; |
| 292 | |
| 293 | if (!capable(CAP_SYS_ADMIN)) |
| 294 | return -EACCES; |
| 295 | |
| 296 | if (efivar_attr->show) { |
| 297 | ret = efivar_attr->show(var, buf); |
| 298 | } |
| 299 | return ret; |
| 300 | } |
| 301 | |
| 302 | static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr, |
| 303 | const char *buf, size_t count) |
| 304 | { |
| 305 | struct efivar_entry *var = to_efivar_entry(kobj); |
| 306 | struct efivar_attribute *efivar_attr = to_efivar_attr(attr); |
| 307 | ssize_t ret = -EIO; |
| 308 | |
| 309 | if (!capable(CAP_SYS_ADMIN)) |
| 310 | return -EACCES; |
| 311 | |
| 312 | if (efivar_attr->store) |
| 313 | ret = efivar_attr->store(var, buf, count); |
| 314 | |
| 315 | return ret; |
| 316 | } |
| 317 | |
| 318 | static const struct sysfs_ops efivar_attr_ops = { |
| 319 | .show = efivar_attr_show, |
| 320 | .store = efivar_attr_store, |
| 321 | }; |
| 322 | |
| 323 | static void efivar_release(struct kobject *kobj) |
| 324 | { |
| 325 | struct efivar_entry *var = to_efivar_entry(kobj); |
| 326 | kfree(var); |
| 327 | } |
| 328 | |
| 329 | static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL); |
| 330 | static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL); |
| 331 | static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL); |
| 332 | static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL); |
| 333 | static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw); |
| 334 | |
| 335 | static struct attribute *def_attrs[] = { |
| 336 | &efivar_attr_guid.attr, |
| 337 | &efivar_attr_size.attr, |
| 338 | &efivar_attr_attributes.attr, |
| 339 | &efivar_attr_data.attr, |
| 340 | &efivar_attr_raw_var.attr, |
| 341 | NULL, |
| 342 | }; |
| 343 | |
| 344 | static struct kobj_type efivar_ktype = { |
| 345 | .release = efivar_release, |
| 346 | .sysfs_ops = &efivar_attr_ops, |
| 347 | .default_attrs = def_attrs, |
| 348 | }; |
| 349 | |
| 350 | static ssize_t efivar_create(struct file *filp, struct kobject *kobj, |
| 351 | struct bin_attribute *bin_attr, |
| 352 | char *buf, loff_t pos, size_t count) |
| 353 | { |
| 354 | struct compat_efi_variable *compat = (struct compat_efi_variable *)buf; |
| 355 | struct efi_variable *new_var = (struct efi_variable *)buf; |
| 356 | struct efivar_entry *new_entry; |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 357 | bool need_compat = in_compat_syscall(); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 358 | efi_char16_t *name; |
| 359 | unsigned long size; |
| 360 | u32 attributes; |
| 361 | u8 *data; |
| 362 | int err; |
| 363 | |
| 364 | if (!capable(CAP_SYS_ADMIN)) |
| 365 | return -EACCES; |
| 366 | |
| 367 | if (need_compat) { |
| 368 | if (count != sizeof(*compat)) |
| 369 | return -EINVAL; |
| 370 | |
| 371 | attributes = compat->Attributes; |
| 372 | name = compat->VariableName; |
| 373 | size = compat->DataSize; |
| 374 | data = compat->Data; |
| 375 | } else { |
| 376 | if (count != sizeof(*new_var)) |
| 377 | return -EINVAL; |
| 378 | |
| 379 | attributes = new_var->Attributes; |
| 380 | name = new_var->VariableName; |
| 381 | size = new_var->DataSize; |
| 382 | data = new_var->Data; |
| 383 | } |
| 384 | |
| 385 | if ((attributes & ~EFI_VARIABLE_MASK) != 0 || |
| 386 | efivar_validate(new_var->VendorGuid, name, data, |
| 387 | size) == false) { |
| 388 | printk(KERN_ERR "efivars: Malformed variable content\n"); |
| 389 | return -EINVAL; |
| 390 | } |
| 391 | |
| 392 | new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL); |
| 393 | if (!new_entry) |
| 394 | return -ENOMEM; |
| 395 | |
| 396 | if (need_compat) |
| 397 | copy_out_compat(&new_entry->var, compat); |
| 398 | else |
| 399 | memcpy(&new_entry->var, new_var, sizeof(*new_var)); |
| 400 | |
| 401 | err = efivar_entry_set(new_entry, attributes, size, |
| 402 | data, &efivar_sysfs_list); |
| 403 | if (err) { |
| 404 | if (err == -EEXIST) |
| 405 | err = -EINVAL; |
| 406 | goto out; |
| 407 | } |
| 408 | |
| 409 | if (efivar_create_sysfs_entry(new_entry)) { |
| 410 | printk(KERN_WARNING "efivars: failed to create sysfs entry.\n"); |
| 411 | kfree(new_entry); |
| 412 | } |
| 413 | return count; |
| 414 | |
| 415 | out: |
| 416 | kfree(new_entry); |
| 417 | return err; |
| 418 | } |
| 419 | |
| 420 | static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, |
| 421 | struct bin_attribute *bin_attr, |
| 422 | char *buf, loff_t pos, size_t count) |
| 423 | { |
| 424 | struct efi_variable *del_var = (struct efi_variable *)buf; |
| 425 | struct compat_efi_variable *compat; |
| 426 | struct efivar_entry *entry; |
| 427 | efi_char16_t *name; |
| 428 | efi_guid_t vendor; |
| 429 | int err = 0; |
| 430 | |
| 431 | if (!capable(CAP_SYS_ADMIN)) |
| 432 | return -EACCES; |
| 433 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 434 | if (in_compat_syscall()) { |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 435 | if (count != sizeof(*compat)) |
| 436 | return -EINVAL; |
| 437 | |
| 438 | compat = (struct compat_efi_variable *)buf; |
| 439 | name = compat->VariableName; |
| 440 | vendor = compat->VendorGuid; |
| 441 | } else { |
| 442 | if (count != sizeof(*del_var)) |
| 443 | return -EINVAL; |
| 444 | |
| 445 | name = del_var->VariableName; |
| 446 | vendor = del_var->VendorGuid; |
| 447 | } |
| 448 | |
| 449 | if (efivar_entry_iter_begin()) |
| 450 | return -EINTR; |
| 451 | entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true); |
| 452 | if (!entry) |
| 453 | err = -EINVAL; |
| 454 | else if (__efivar_entry_delete(entry)) |
| 455 | err = -EIO; |
| 456 | |
| 457 | if (err) { |
| 458 | efivar_entry_iter_end(); |
| 459 | return err; |
| 460 | } |
| 461 | |
| 462 | if (!entry->scanning) { |
| 463 | efivar_entry_iter_end(); |
| 464 | efivar_unregister(entry); |
| 465 | } else |
| 466 | efivar_entry_iter_end(); |
| 467 | |
| 468 | /* It's dead Jim.... */ |
| 469 | return count; |
| 470 | } |
| 471 | |
| 472 | /** |
| 473 | * efivar_create_sysfs_entry - create a new entry in sysfs |
| 474 | * @new_var: efivar entry to create |
| 475 | * |
| 476 | * Returns 0 on success, negative error code on failure |
| 477 | */ |
| 478 | static int |
| 479 | efivar_create_sysfs_entry(struct efivar_entry *new_var) |
| 480 | { |
| 481 | int short_name_size; |
| 482 | char *short_name; |
| 483 | unsigned long utf8_name_size; |
| 484 | efi_char16_t *variable_name = new_var->var.VariableName; |
| 485 | int ret; |
| 486 | |
| 487 | /* |
| 488 | * Length of the variable bytes in UTF8, plus the '-' separator, |
| 489 | * plus the GUID, plus trailing NUL |
| 490 | */ |
| 491 | utf8_name_size = ucs2_utf8size(variable_name); |
| 492 | short_name_size = utf8_name_size + 1 + EFI_VARIABLE_GUID_LEN + 1; |
| 493 | |
| 494 | short_name = kmalloc(short_name_size, GFP_KERNEL); |
| 495 | if (!short_name) |
| 496 | return -ENOMEM; |
| 497 | |
| 498 | ucs2_as_utf8(short_name, variable_name, short_name_size); |
| 499 | |
| 500 | /* This is ugly, but necessary to separate one vendor's |
| 501 | private variables from another's. */ |
| 502 | short_name[utf8_name_size] = '-'; |
| 503 | efi_guid_to_str(&new_var->var.VendorGuid, |
| 504 | short_name + utf8_name_size + 1); |
| 505 | |
| 506 | new_var->kobj.kset = efivars_kset; |
| 507 | |
| 508 | ret = kobject_init_and_add(&new_var->kobj, &efivar_ktype, |
| 509 | NULL, "%s", short_name); |
| 510 | kfree(short_name); |
| 511 | if (ret) |
| 512 | return ret; |
| 513 | |
| 514 | kobject_uevent(&new_var->kobj, KOBJ_ADD); |
| 515 | if (efivar_entry_add(new_var, &efivar_sysfs_list)) { |
| 516 | efivar_unregister(new_var); |
| 517 | return -EINTR; |
| 518 | } |
| 519 | |
| 520 | return 0; |
| 521 | } |
| 522 | |
| 523 | static int |
| 524 | create_efivars_bin_attributes(void) |
| 525 | { |
| 526 | struct bin_attribute *attr; |
| 527 | int error; |
| 528 | |
| 529 | /* new_var */ |
| 530 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); |
| 531 | if (!attr) |
| 532 | return -ENOMEM; |
| 533 | |
| 534 | attr->attr.name = "new_var"; |
| 535 | attr->attr.mode = 0200; |
| 536 | attr->write = efivar_create; |
| 537 | efivars_new_var = attr; |
| 538 | |
| 539 | /* del_var */ |
| 540 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); |
| 541 | if (!attr) { |
| 542 | error = -ENOMEM; |
| 543 | goto out_free; |
| 544 | } |
| 545 | attr->attr.name = "del_var"; |
| 546 | attr->attr.mode = 0200; |
| 547 | attr->write = efivar_delete; |
| 548 | efivars_del_var = attr; |
| 549 | |
| 550 | sysfs_bin_attr_init(efivars_new_var); |
| 551 | sysfs_bin_attr_init(efivars_del_var); |
| 552 | |
| 553 | /* Register */ |
| 554 | error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var); |
| 555 | if (error) { |
| 556 | printk(KERN_ERR "efivars: unable to create new_var sysfs file" |
| 557 | " due to error %d\n", error); |
| 558 | goto out_free; |
| 559 | } |
| 560 | |
| 561 | error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var); |
| 562 | if (error) { |
| 563 | printk(KERN_ERR "efivars: unable to create del_var sysfs file" |
| 564 | " due to error %d\n", error); |
| 565 | sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); |
| 566 | goto out_free; |
| 567 | } |
| 568 | |
| 569 | return 0; |
| 570 | out_free: |
| 571 | kfree(efivars_del_var); |
| 572 | efivars_del_var = NULL; |
| 573 | kfree(efivars_new_var); |
| 574 | efivars_new_var = NULL; |
| 575 | return error; |
| 576 | } |
| 577 | |
| 578 | static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor, |
| 579 | unsigned long name_size, void *data) |
| 580 | { |
| 581 | struct efivar_entry *entry = data; |
| 582 | |
| 583 | if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false)) |
| 584 | return 0; |
| 585 | |
| 586 | memcpy(entry->var.VariableName, name, name_size); |
| 587 | memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); |
| 588 | |
| 589 | return 1; |
| 590 | } |
| 591 | |
| 592 | static void efivar_update_sysfs_entries(struct work_struct *work) |
| 593 | { |
| 594 | struct efivar_entry *entry; |
| 595 | int err; |
| 596 | |
| 597 | /* Add new sysfs entries */ |
| 598 | while (1) { |
| 599 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
| 600 | if (!entry) |
| 601 | return; |
| 602 | |
| 603 | err = efivar_init(efivar_update_sysfs_entry, entry, |
| 604 | false, &efivar_sysfs_list); |
| 605 | if (!err) |
| 606 | break; |
| 607 | |
| 608 | efivar_create_sysfs_entry(entry); |
| 609 | } |
| 610 | |
| 611 | kfree(entry); |
| 612 | } |
| 613 | |
| 614 | static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor, |
| 615 | unsigned long name_size, void *data) |
| 616 | { |
| 617 | struct efivar_entry *entry; |
| 618 | |
| 619 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
| 620 | if (!entry) |
| 621 | return -ENOMEM; |
| 622 | |
| 623 | memcpy(entry->var.VariableName, name, name_size); |
| 624 | memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); |
| 625 | |
| 626 | efivar_create_sysfs_entry(entry); |
| 627 | |
| 628 | return 0; |
| 629 | } |
| 630 | |
| 631 | static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data) |
| 632 | { |
| 633 | int err = efivar_entry_remove(entry); |
| 634 | |
| 635 | if (err) |
| 636 | return err; |
| 637 | efivar_unregister(entry); |
| 638 | return 0; |
| 639 | } |
| 640 | |
| 641 | static void efivars_sysfs_exit(void) |
| 642 | { |
| 643 | /* Remove all entries and destroy */ |
| 644 | int err; |
| 645 | |
| 646 | err = __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, |
| 647 | NULL, NULL); |
| 648 | if (err) { |
| 649 | pr_err("efivars: Failed to destroy sysfs entries\n"); |
| 650 | return; |
| 651 | } |
| 652 | |
| 653 | if (efivars_new_var) |
| 654 | sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); |
| 655 | if (efivars_del_var) |
| 656 | sysfs_remove_bin_file(&efivars_kset->kobj, efivars_del_var); |
| 657 | kfree(efivars_new_var); |
| 658 | kfree(efivars_del_var); |
| 659 | kset_unregister(efivars_kset); |
| 660 | } |
| 661 | |
| 662 | int efivars_sysfs_init(void) |
| 663 | { |
| 664 | struct kobject *parent_kobj = efivars_kobject(); |
| 665 | int error = 0; |
| 666 | |
| 667 | if (!efi_enabled(EFI_RUNTIME_SERVICES)) |
| 668 | return -ENODEV; |
| 669 | |
| 670 | /* No efivars has been registered yet */ |
| 671 | if (!parent_kobj) |
| 672 | return 0; |
| 673 | |
| 674 | printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, |
| 675 | EFIVARS_DATE); |
| 676 | |
| 677 | efivars_kset = kset_create_and_add("vars", NULL, parent_kobj); |
| 678 | if (!efivars_kset) { |
| 679 | printk(KERN_ERR "efivars: Subsystem registration failed.\n"); |
| 680 | return -ENOMEM; |
| 681 | } |
| 682 | |
| 683 | efivar_init(efivars_sysfs_callback, NULL, true, &efivar_sysfs_list); |
| 684 | |
| 685 | error = create_efivars_bin_attributes(); |
| 686 | if (error) { |
| 687 | efivars_sysfs_exit(); |
| 688 | return error; |
| 689 | } |
| 690 | |
| 691 | INIT_WORK(&efivar_work, efivar_update_sysfs_entries); |
| 692 | |
| 693 | return 0; |
| 694 | } |
| 695 | EXPORT_SYMBOL_GPL(efivars_sysfs_init); |
| 696 | |
| 697 | module_init(efivars_sysfs_init); |
| 698 | module_exit(efivars_sysfs_exit); |