1 // SPDX-License-Identifier: GPL-2.0-only 2 3 /* ----------------------------------------------------------------------- 4 * 5 * Copyright 2011 Intel Corporation; author Matt Fleming 6 * 7 * ----------------------------------------------------------------------- */ 8 9 #include <linux/efi.h> 10 #include <linux/pci.h> 11 #include <linux/stddef.h> 12 13 #include <asm/efi.h> 14 #include <asm/e820/types.h> 15 #include <asm/setup.h> 16 #include <asm/desc.h> 17 #include <asm/boot.h> 18 #include <asm/kaslr.h> 19 #include <asm/sev.h> 20 21 #include "efistub.h" 22 #include "x86-stub.h" 23 24 extern char _bss[], _ebss[]; 25 26 const efi_system_table_t *efi_system_table; 27 const efi_dxe_services_table_t *efi_dxe_table; 28 static efi_loaded_image_t *image = NULL; 29 static efi_memory_attribute_protocol_t *memattr; 30 31 typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t; 32 union sev_memory_acceptance_protocol { 33 struct { 34 efi_status_t (__efiapi * allow_unaccepted_memory)( 35 sev_memory_acceptance_protocol_t *); 36 }; 37 struct { 38 u32 allow_unaccepted_memory; 39 } mixed_mode; 40 }; 41 42 static efi_status_t 43 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) 44 { 45 struct pci_setup_rom *rom __free(efi_pool) = NULL; 46 efi_status_t status; 47 unsigned long size; 48 uint64_t romsize; 49 void *romimage; 50 51 /* 52 * Some firmware images contain EFI function pointers at the place where 53 * the romimage and romsize fields are supposed to be. Typically the EFI 54 * code is mapped at high addresses, translating to an unrealistically 55 * large romsize. The UEFI spec limits the size of option ROMs to 16 56 * MiB so we reject any ROMs over 16 MiB in size to catch this. 57 */ 58 romimage = efi_table_attr(pci, romimage); 59 romsize = efi_table_attr(pci, romsize); 60 if (!romimage || !romsize || romsize > SZ_16M) 61 return EFI_INVALID_PARAMETER; 62 63 size = romsize + sizeof(*rom); 64 65 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 66 (void **)&rom); 67 if (status != EFI_SUCCESS) { 68 efi_err("Failed to allocate memory for 'rom'\n"); 69 return status; 70 } 71 72 memset(rom, 0, sizeof(*rom)); 73 74 rom->data.type = SETUP_PCI; 75 rom->data.len = size - sizeof(struct setup_data); 76 rom->data.next = 0; 77 rom->pcilen = romsize; 78 79 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 80 PCI_VENDOR_ID, 1, &rom->vendor); 81 82 if (status != EFI_SUCCESS) { 83 efi_err("Failed to read rom->vendor\n"); 84 return status; 85 } 86 87 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 88 PCI_DEVICE_ID, 1, &rom->devid); 89 90 if (status != EFI_SUCCESS) { 91 efi_err("Failed to read rom->devid\n"); 92 return status; 93 } 94 95 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus, 96 &rom->device, &rom->function); 97 98 if (status != EFI_SUCCESS) 99 return status; 100 101 memcpy(rom->romdata, romimage, romsize); 102 *__rom = no_free_ptr(rom); 103 return EFI_SUCCESS; 104 } 105 106 /* 107 * There's no way to return an informative status from this function, 108 * because any analysis (and printing of error messages) needs to be 109 * done directly at the EFI function call-site. 110 * 111 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we 112 * just didn't find any PCI devices, but there's no way to tell outside 113 * the context of the call. 114 */ 115 static void setup_efi_pci(struct boot_params *params) 116 { 117 efi_status_t status; 118 efi_handle_t *pci_handle __free(efi_pool) = NULL; 119 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID; 120 struct setup_data *data; 121 unsigned long num; 122 efi_handle_t h; 123 124 status = efi_bs_call(locate_handle_buffer, EFI_LOCATE_BY_PROTOCOL, 125 &pci_proto, NULL, &num, &pci_handle); 126 if (status != EFI_SUCCESS) 127 return; 128 129 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 130 131 while (data && data->next) 132 data = (struct setup_data *)(unsigned long)data->next; 133 134 for_each_efi_handle(h, pci_handle, num) { 135 efi_pci_io_protocol_t *pci = NULL; 136 struct pci_setup_rom *rom; 137 138 status = efi_bs_call(handle_protocol, h, &pci_proto, 139 (void **)&pci); 140 if (status != EFI_SUCCESS || !pci) 141 continue; 142 143 status = preserve_pci_rom_image(pci, &rom); 144 if (status != EFI_SUCCESS) 145 continue; 146 147 if (data) 148 data->next = (unsigned long)rom; 149 else 150 params->hdr.setup_data = (unsigned long)rom; 151 152 data = (struct setup_data *)rom; 153 } 154 } 155 156 static void retrieve_apple_device_properties(struct boot_params *boot_params) 157 { 158 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID; 159 struct setup_data *data, *new; 160 efi_status_t status; 161 u32 size = 0; 162 apple_properties_protocol_t *p; 163 164 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p); 165 if (status != EFI_SUCCESS) 166 return; 167 168 if (efi_table_attr(p, version) != 0x10000) { 169 efi_err("Unsupported properties proto version\n"); 170 return; 171 } 172 173 efi_call_proto(p, get_all, NULL, &size); 174 if (!size) 175 return; 176 177 do { 178 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, 179 size + sizeof(struct setup_data), 180 (void **)&new); 181 if (status != EFI_SUCCESS) { 182 efi_err("Failed to allocate memory for 'properties'\n"); 183 return; 184 } 185 186 status = efi_call_proto(p, get_all, new->data, &size); 187 188 if (status == EFI_BUFFER_TOO_SMALL) 189 efi_bs_call(free_pool, new); 190 } while (status == EFI_BUFFER_TOO_SMALL); 191 192 new->type = SETUP_APPLE_PROPERTIES; 193 new->len = size; 194 new->next = 0; 195 196 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data; 197 if (!data) { 198 boot_params->hdr.setup_data = (unsigned long)new; 199 } else { 200 while (data->next) 201 data = (struct setup_data *)(unsigned long)data->next; 202 data->next = (unsigned long)new; 203 } 204 } 205 206 struct smbios_entry_point { 207 u8 anchor[4]; 208 u8 ep_checksum; 209 u8 ep_length; 210 u8 major_version; 211 u8 minor_version; 212 u16 max_size_entry; 213 u8 ep_rev; 214 u8 reserved[5]; 215 216 struct __packed { 217 u8 anchor[5]; 218 u8 checksum; 219 u16 st_length; 220 u32 st_address; 221 u16 number_of_entries; 222 u8 bcd_rev; 223 } intm; 224 }; 225 226 static bool verify_ep_checksum(const void *ptr, int length) 227 { 228 u8 sum = 0; 229 230 for (int i = 0; i < length; i++) 231 sum += ((u8 *)ptr)[i]; 232 233 return sum == 0; 234 } 235 236 static bool verify_ep_integrity(const struct smbios_entry_point *ep) 237 { 238 if (memcmp(ep->anchor, "_SM_", sizeof(ep->anchor)) != 0) 239 return false; 240 241 if (memcmp(ep->intm.anchor, "_DMI_", sizeof(ep->intm.anchor)) != 0) 242 return false; 243 244 if (!verify_ep_checksum(ep, ep->ep_length) || 245 !verify_ep_checksum(&ep->intm, sizeof(ep->intm))) 246 return false; 247 248 return true; 249 } 250 251 static const struct efi_smbios_record *search_record(void *table, u32 length, 252 u8 type) 253 { 254 const u8 *p, *end; 255 256 p = (u8 *)table; 257 end = p + length; 258 259 while (p + sizeof(struct efi_smbios_record) < end) { 260 const struct efi_smbios_record *hdr = 261 (struct efi_smbios_record *)p; 262 const u8 *next; 263 264 if (hdr->type == type) 265 return hdr; 266 267 /* Type 127 = End-of-Table */ 268 if (hdr->type == 0x7F) 269 return NULL; 270 271 /* Jumping to the unformed section */ 272 next = p + hdr->length; 273 274 /* Unformed section ends with 0000h */ 275 while ((next[0] != 0 || next[1] != 0) && next + 1 < end) 276 next++; 277 278 next += 2; 279 p = next; 280 } 281 282 return NULL; 283 } 284 285 static const struct efi_smbios_record *get_table_record(u8 type) 286 { 287 const struct smbios_entry_point *ep; 288 289 /* 290 * Locate the legacy 32-bit SMBIOS entrypoint in memory, and parse it 291 * directly. Needed by some Macs that do not implement the EFI protocol. 292 */ 293 ep = get_efi_config_table(SMBIOS_TABLE_GUID); 294 if (!ep) 295 return NULL; 296 297 if (!verify_ep_integrity(ep)) 298 return NULL; 299 300 return search_record((void *)(unsigned long)ep->intm.st_address, 301 ep->intm.st_length, type); 302 } 303 304 static bool apple_match_product_name(void) 305 { 306 static const char type1_product_matches[][15] = { 307 "MacBookPro11,3", 308 "MacBookPro11,5", 309 "MacBookPro13,3", 310 "MacBookPro14,3", 311 "MacBookPro15,1", 312 "MacBookPro15,3", 313 "MacBookPro16,1", 314 "MacBookPro16,4", 315 }; 316 const struct efi_smbios_type1_record *record; 317 const u8 *product; 318 319 record = (struct efi_smbios_type1_record *) 320 (efi_get_smbios_record(1) ?: get_table_record(1)); 321 if (!record) 322 return false; 323 324 product = efi_get_smbios_string(record, product_name); 325 if (!product) 326 return false; 327 328 for (int i = 0; i < ARRAY_SIZE(type1_product_matches); i++) { 329 if (!strcmp(product, type1_product_matches[i])) 330 return true; 331 } 332 333 return false; 334 } 335 336 static void apple_set_os(void) 337 { 338 struct { 339 unsigned long version; 340 efi_status_t (__efiapi *set_os_version)(const char *); 341 efi_status_t (__efiapi *set_os_vendor)(const char *); 342 } *set_os; 343 efi_status_t status; 344 345 if (!efi_is_64bit() || !apple_match_product_name()) 346 return; 347 348 status = efi_bs_call(locate_protocol, &APPLE_SET_OS_PROTOCOL_GUID, NULL, 349 (void **)&set_os); 350 if (status != EFI_SUCCESS) 351 return; 352 353 if (set_os->version >= 2) { 354 status = set_os->set_os_vendor("Apple Inc."); 355 if (status != EFI_SUCCESS) 356 efi_err("Failed to set OS vendor via apple_set_os\n"); 357 } 358 359 if (set_os->version > 0) { 360 /* The version being set doesn't seem to matter */ 361 status = set_os->set_os_version("Mac OS X 10.9"); 362 if (status != EFI_SUCCESS) 363 efi_err("Failed to set OS version via apple_set_os\n"); 364 } 365 } 366 367 efi_status_t efi_adjust_memory_range_protection(unsigned long start, 368 unsigned long size) 369 { 370 efi_status_t status; 371 efi_gcd_memory_space_desc_t desc; 372 unsigned long end, next; 373 unsigned long rounded_start, rounded_end; 374 unsigned long unprotect_start, unprotect_size; 375 376 rounded_start = rounddown(start, EFI_PAGE_SIZE); 377 rounded_end = roundup(start + size, EFI_PAGE_SIZE); 378 379 if (memattr != NULL) { 380 status = efi_call_proto(memattr, set_memory_attributes, 381 rounded_start, 382 rounded_end - rounded_start, 383 EFI_MEMORY_RO); 384 if (status != EFI_SUCCESS) { 385 efi_warn("Failed to set EFI_MEMORY_RO attribute\n"); 386 return status; 387 } 388 389 status = efi_call_proto(memattr, clear_memory_attributes, 390 rounded_start, 391 rounded_end - rounded_start, 392 EFI_MEMORY_XP); 393 if (status != EFI_SUCCESS) 394 efi_warn("Failed to clear EFI_MEMORY_XP attribute\n"); 395 return status; 396 } 397 398 if (efi_dxe_table == NULL) 399 return EFI_SUCCESS; 400 401 /* 402 * Don't modify memory region attributes, if they are 403 * already suitable, to lower the possibility to 404 * encounter firmware bugs. 405 */ 406 407 for (end = start + size; start < end; start = next) { 408 409 status = efi_dxe_call(get_memory_space_descriptor, start, &desc); 410 411 if (status != EFI_SUCCESS) 412 break; 413 414 next = desc.base_address + desc.length; 415 416 /* 417 * Only system memory and more reliable memory are suitable for 418 * trampoline/kernel image placement. So only those memory types 419 * may need to have attributes modified. 420 */ 421 422 if ((desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory && 423 desc.gcd_memory_type != EfiGcdMemoryTypeMoreReliable) || 424 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0) 425 continue; 426 427 unprotect_start = max(rounded_start, (unsigned long)desc.base_address); 428 unprotect_size = min(rounded_end, next) - unprotect_start; 429 430 status = efi_dxe_call(set_memory_space_attributes, 431 unprotect_start, unprotect_size, 432 EFI_MEMORY_WB); 433 434 if (status != EFI_SUCCESS) { 435 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n", 436 unprotect_start, 437 unprotect_start + unprotect_size, 438 status); 439 break; 440 } 441 } 442 return EFI_SUCCESS; 443 } 444 445 static void setup_unaccepted_memory(void) 446 { 447 efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID; 448 sev_memory_acceptance_protocol_t *proto; 449 efi_status_t status; 450 451 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 452 return; 453 454 /* 455 * Enable unaccepted memory before calling exit boot services in order 456 * for the UEFI to not accept all memory on EBS. 457 */ 458 status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL, 459 (void **)&proto); 460 if (status != EFI_SUCCESS) 461 return; 462 463 status = efi_call_proto(proto, allow_unaccepted_memory); 464 if (status != EFI_SUCCESS) 465 efi_err("Memory acceptance protocol failed\n"); 466 } 467 468 static efi_char16_t *efistub_fw_vendor(void) 469 { 470 unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor); 471 472 return (efi_char16_t *)vendor; 473 } 474 475 static const efi_char16_t apple[] = L"Apple"; 476 477 static void setup_quirks(struct boot_params *boot_params) 478 { 479 if (!memcmp(efistub_fw_vendor(), apple, sizeof(apple))) { 480 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES)) 481 retrieve_apple_device_properties(boot_params); 482 483 apple_set_os(); 484 } 485 } 486 487 static void setup_graphics(struct boot_params *boot_params) 488 { 489 struct screen_info *si = memset(&boot_params->screen_info, 0, sizeof(*si)); 490 struct edid_info *edid = memset(&boot_params->edid_info, 0, sizeof(*edid)); 491 492 efi_setup_graphics(si, edid); 493 } 494 495 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) 496 { 497 efi_bs_call(exit, handle, status, 0, NULL); 498 for(;;) 499 asm("hlt"); 500 } 501 502 /* 503 * Because the x86 boot code expects to be passed a boot_params we 504 * need to create one ourselves (usually the bootloader would create 505 * one for us). 506 */ 507 static efi_status_t efi_allocate_bootparams(efi_handle_t handle, 508 struct boot_params **bp) 509 { 510 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; 511 struct boot_params *boot_params; 512 struct setup_header *hdr; 513 efi_status_t status; 514 unsigned long alloc; 515 char *cmdline_ptr; 516 517 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); 518 if (status != EFI_SUCCESS) { 519 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); 520 return status; 521 } 522 523 status = efi_allocate_pages(PARAM_SIZE, &alloc, ULONG_MAX); 524 if (status != EFI_SUCCESS) 525 return status; 526 527 boot_params = memset((void *)alloc, 0x0, PARAM_SIZE); 528 hdr = &boot_params->hdr; 529 530 /* Assign the setup_header fields that the kernel actually cares about */ 531 hdr->root_flags = 1; 532 hdr->vid_mode = 0xffff; 533 534 hdr->type_of_loader = 0x21; 535 hdr->initrd_addr_max = INT_MAX; 536 537 /* Convert unicode cmdline to ascii */ 538 cmdline_ptr = efi_convert_cmdline(image); 539 if (!cmdline_ptr) { 540 efi_free(PARAM_SIZE, alloc); 541 return EFI_OUT_OF_RESOURCES; 542 } 543 544 efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr, 545 &boot_params->ext_cmd_line_ptr); 546 547 *bp = boot_params; 548 return EFI_SUCCESS; 549 } 550 551 static void add_e820ext(struct boot_params *params, 552 struct setup_data *e820ext, u32 nr_entries) 553 { 554 struct setup_data *data; 555 556 e820ext->type = SETUP_E820_EXT; 557 e820ext->len = nr_entries * sizeof(struct boot_e820_entry); 558 e820ext->next = 0; 559 560 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 561 562 while (data && data->next) 563 data = (struct setup_data *)(unsigned long)data->next; 564 565 if (data) 566 data->next = (unsigned long)e820ext; 567 else 568 params->hdr.setup_data = (unsigned long)e820ext; 569 } 570 571 static efi_status_t 572 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) 573 { 574 struct boot_e820_entry *entry = params->e820_table; 575 struct efi_info *efi = ¶ms->efi_info; 576 struct boot_e820_entry *prev = NULL; 577 u32 nr_entries; 578 u32 nr_desc; 579 int i; 580 581 nr_entries = 0; 582 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; 583 584 for (i = 0; i < nr_desc; i++) { 585 efi_memory_desc_t *d; 586 unsigned int e820_type = 0; 587 unsigned long m = efi->efi_memmap; 588 589 #ifdef CONFIG_X86_64 590 m |= (u64)efi->efi_memmap_hi << 32; 591 #endif 592 593 d = efi_memdesc_ptr(m, efi->efi_memdesc_size, i); 594 switch (d->type) { 595 case EFI_RESERVED_TYPE: 596 case EFI_RUNTIME_SERVICES_CODE: 597 case EFI_RUNTIME_SERVICES_DATA: 598 case EFI_MEMORY_MAPPED_IO: 599 case EFI_MEMORY_MAPPED_IO_PORT_SPACE: 600 case EFI_PAL_CODE: 601 e820_type = E820_TYPE_RESERVED; 602 break; 603 604 case EFI_UNUSABLE_MEMORY: 605 e820_type = E820_TYPE_UNUSABLE; 606 break; 607 608 case EFI_ACPI_RECLAIM_MEMORY: 609 e820_type = E820_TYPE_ACPI; 610 break; 611 612 case EFI_LOADER_CODE: 613 case EFI_LOADER_DATA: 614 case EFI_BOOT_SERVICES_CODE: 615 case EFI_BOOT_SERVICES_DATA: 616 case EFI_CONVENTIONAL_MEMORY: 617 if (efi_soft_reserve_enabled() && 618 (d->attribute & EFI_MEMORY_SP)) 619 e820_type = E820_TYPE_SOFT_RESERVED; 620 else 621 e820_type = E820_TYPE_RAM; 622 break; 623 624 case EFI_ACPI_MEMORY_NVS: 625 e820_type = E820_TYPE_NVS; 626 break; 627 628 case EFI_PERSISTENT_MEMORY: 629 e820_type = E820_TYPE_PMEM; 630 break; 631 632 case EFI_UNACCEPTED_MEMORY: 633 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 634 continue; 635 e820_type = E820_TYPE_RAM; 636 process_unaccepted_memory(d->phys_addr, 637 d->phys_addr + PAGE_SIZE * d->num_pages); 638 break; 639 default: 640 continue; 641 } 642 643 /* Merge adjacent mappings */ 644 if (prev && prev->type == e820_type && 645 (prev->addr + prev->size) == d->phys_addr) { 646 prev->size += d->num_pages << 12; 647 continue; 648 } 649 650 if (nr_entries == ARRAY_SIZE(params->e820_table)) { 651 u32 need = (nr_desc - i) * sizeof(struct e820_entry) + 652 sizeof(struct setup_data); 653 654 if (!e820ext || e820ext_size < need) 655 return EFI_BUFFER_TOO_SMALL; 656 657 /* boot_params map full, switch to e820 extended */ 658 entry = (struct boot_e820_entry *)e820ext->data; 659 } 660 661 entry->addr = d->phys_addr; 662 entry->size = d->num_pages << PAGE_SHIFT; 663 entry->type = e820_type; 664 prev = entry++; 665 nr_entries++; 666 } 667 668 if (nr_entries > ARRAY_SIZE(params->e820_table)) { 669 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); 670 671 add_e820ext(params, e820ext, nr_e820ext); 672 nr_entries -= nr_e820ext; 673 } 674 675 params->e820_entries = (u8)nr_entries; 676 677 return EFI_SUCCESS; 678 } 679 680 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, 681 u32 *e820ext_size) 682 { 683 efi_status_t status; 684 unsigned long size; 685 686 size = sizeof(struct setup_data) + 687 sizeof(struct e820_entry) * nr_desc; 688 689 if (*e820ext) { 690 efi_bs_call(free_pool, *e820ext); 691 *e820ext = NULL; 692 *e820ext_size = 0; 693 } 694 695 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 696 (void **)e820ext); 697 if (status == EFI_SUCCESS) 698 *e820ext_size = size; 699 700 return status; 701 } 702 703 static efi_status_t allocate_e820(struct boot_params *params, 704 struct setup_data **e820ext, 705 u32 *e820ext_size) 706 { 707 struct efi_boot_memmap *map __free(efi_pool) = NULL; 708 efi_status_t status; 709 __u32 nr_desc; 710 711 status = efi_get_memory_map(&map, false); 712 if (status != EFI_SUCCESS) 713 return status; 714 715 nr_desc = map->map_size / map->desc_size; 716 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) { 717 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) + 718 EFI_MMAP_NR_SLACK_SLOTS; 719 720 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); 721 if (status != EFI_SUCCESS) 722 return status; 723 } 724 725 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 726 return allocate_unaccepted_bitmap(nr_desc, map); 727 728 return EFI_SUCCESS; 729 } 730 731 struct exit_boot_struct { 732 struct boot_params *boot_params; 733 struct efi_info *efi; 734 }; 735 736 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, 737 void *priv) 738 { 739 const char *signature; 740 struct exit_boot_struct *p = priv; 741 742 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE 743 : EFI32_LOADER_SIGNATURE; 744 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); 745 746 efi_set_u64_split((unsigned long)efi_system_table, 747 &p->efi->efi_systab, &p->efi->efi_systab_hi); 748 p->efi->efi_memdesc_size = map->desc_size; 749 p->efi->efi_memdesc_version = map->desc_ver; 750 efi_set_u64_split((unsigned long)map->map, 751 &p->efi->efi_memmap, &p->efi->efi_memmap_hi); 752 p->efi->efi_memmap_size = map->map_size; 753 754 return EFI_SUCCESS; 755 } 756 757 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 758 { 759 struct setup_data *e820ext = NULL; 760 __u32 e820ext_size = 0; 761 efi_status_t status; 762 struct exit_boot_struct priv; 763 764 priv.boot_params = boot_params; 765 priv.efi = &boot_params->efi_info; 766 767 status = allocate_e820(boot_params, &e820ext, &e820ext_size); 768 if (status != EFI_SUCCESS) 769 return status; 770 771 /* Might as well exit boot services now */ 772 status = efi_exit_boot_services(handle, &priv, exit_boot_func); 773 if (status != EFI_SUCCESS) 774 return status; 775 776 /* Historic? */ 777 boot_params->alt_mem_k = 32 * 1024; 778 779 status = setup_e820(boot_params, e820ext, e820ext_size); 780 if (status != EFI_SUCCESS) 781 return status; 782 783 return EFI_SUCCESS; 784 } 785 786 static bool have_unsupported_snp_features(void) 787 { 788 u64 unsupported; 789 790 unsupported = snp_get_unsupported_features(sev_get_status()); 791 if (unsupported) { 792 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n", 793 unsupported); 794 return true; 795 } 796 return false; 797 } 798 799 static void efi_get_seed(void *seed, int size) 800 { 801 efi_get_random_bytes(size, seed); 802 803 /* 804 * This only updates seed[0] when running on 32-bit, but in that case, 805 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit. 806 */ 807 *(unsigned long *)seed ^= kaslr_get_random_long("EFI"); 808 } 809 810 static void error(char *str) 811 { 812 efi_warn("Decompression failed: %s\n", str); 813 } 814 815 static const char *cmdline_memmap_override; 816 817 static efi_status_t parse_options(const char *cmdline) 818 { 819 static const char opts[][14] = { 820 "mem=", "memmap=", "hugepages=" 821 }; 822 823 for (int i = 0; i < ARRAY_SIZE(opts); i++) { 824 const char *p = strstr(cmdline, opts[i]); 825 826 if (p == cmdline || (p > cmdline && isspace(p[-1]))) { 827 cmdline_memmap_override = opts[i]; 828 break; 829 } 830 } 831 832 return efi_parse_options(cmdline); 833 } 834 835 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry, 836 struct boot_params *boot_params) 837 { 838 unsigned long virt_addr = LOAD_PHYSICAL_ADDR; 839 unsigned long addr, alloc_size, entry; 840 efi_status_t status; 841 u32 seed[2] = {}; 842 843 boot_params_ptr = boot_params; 844 845 /* determine the required size of the allocation */ 846 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size), 847 MIN_KERNEL_ALIGN); 848 849 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) { 850 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size; 851 static const efi_char16_t ami[] = L"American Megatrends"; 852 853 efi_get_seed(seed, sizeof(seed)); 854 855 virt_addr += (range * seed[1]) >> 32; 856 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1); 857 858 /* 859 * Older Dell systems with AMI UEFI firmware v2.0 may hang 860 * while decompressing the kernel if physical address 861 * randomization is enabled. 862 * 863 * https://bugzilla.kernel.org/show_bug.cgi?id=218173 864 */ 865 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION && 866 !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) { 867 efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n"); 868 seed[0] = 0; 869 } else if (cmdline_memmap_override) { 870 efi_info("%s detected on the kernel command line - disabling physical KASLR\n", 871 cmdline_memmap_override); 872 seed[0] = 0; 873 } 874 875 boot_params->hdr.loadflags |= KASLR_FLAG; 876 } 877 878 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr, 879 seed[0], EFI_LOADER_CODE, 880 LOAD_PHYSICAL_ADDR, 881 EFI_X86_KERNEL_ALLOC_LIMIT); 882 if (status != EFI_SUCCESS) 883 return status; 884 885 entry = decompress_kernel((void *)addr, virt_addr, error); 886 if (entry == ULONG_MAX) { 887 efi_free(alloc_size, addr); 888 return EFI_LOAD_ERROR; 889 } 890 891 *kernel_entry = addr + entry; 892 893 return efi_adjust_memory_range_protection(addr, kernel_text_size) ?: 894 efi_adjust_memory_range_protection(addr + kernel_inittext_offset, 895 kernel_inittext_size); 896 } 897 898 static void __noreturn enter_kernel(unsigned long kernel_addr, 899 struct boot_params *boot_params) 900 { 901 /* enter decompressed kernel with boot_params pointer in RSI/ESI */ 902 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params)); 903 904 unreachable(); 905 } 906 907 /* 908 * On success, this routine will jump to the relocated image directly and never 909 * return. On failure, it will exit to the firmware via efi_exit() instead of 910 * returning. 911 */ 912 void __noreturn efi_stub_entry(efi_handle_t handle, 913 efi_system_table_t *sys_table_arg, 914 struct boot_params *boot_params) 915 916 { 917 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID; 918 const struct linux_efi_initrd *initrd = NULL; 919 unsigned long kernel_entry; 920 struct setup_header *hdr; 921 efi_status_t status; 922 923 efi_system_table = sys_table_arg; 924 /* Check if we were booted by the EFI firmware */ 925 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 926 efi_exit(handle, EFI_INVALID_PARAMETER); 927 928 if (!IS_ENABLED(CONFIG_EFI_HANDOVER_PROTOCOL) || !boot_params) { 929 status = efi_allocate_bootparams(handle, &boot_params); 930 if (status != EFI_SUCCESS) 931 efi_exit(handle, status); 932 } 933 934 hdr = &boot_params->hdr; 935 936 if (have_unsupported_snp_features()) 937 efi_exit(handle, EFI_UNSUPPORTED); 938 939 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) { 940 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID); 941 if (efi_dxe_table && 942 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) { 943 efi_warn("Ignoring DXE services table: invalid signature\n"); 944 efi_dxe_table = NULL; 945 } 946 } 947 948 /* grab the memory attributes protocol if it exists */ 949 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr); 950 951 status = efi_setup_5level_paging(); 952 if (status != EFI_SUCCESS) { 953 efi_err("efi_setup_5level_paging() failed!\n"); 954 goto fail; 955 } 956 957 #ifdef CONFIG_CMDLINE_BOOL 958 status = parse_options(CONFIG_CMDLINE); 959 if (status != EFI_SUCCESS) { 960 efi_err("Failed to parse options\n"); 961 goto fail; 962 } 963 #endif 964 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { 965 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | 966 ((u64)boot_params->ext_cmd_line_ptr << 32)); 967 status = parse_options((char *)cmdline_paddr); 968 if (status != EFI_SUCCESS) { 969 efi_err("Failed to parse options\n"); 970 goto fail; 971 } 972 } 973 974 if (efi_mem_encrypt > 0) 975 hdr->xloadflags |= XLF_MEM_ENCRYPTION; 976 977 status = efi_decompress_kernel(&kernel_entry, boot_params); 978 if (status != EFI_SUCCESS) { 979 efi_err("Failed to decompress kernel\n"); 980 goto fail; 981 } 982 983 /* 984 * At this point, an initrd may already have been loaded by the 985 * bootloader and passed via bootparams. We permit an initrd loaded 986 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. 987 * 988 * If the device path is not present, any command-line initrd= 989 * arguments will be processed only if image is not NULL, which will be 990 * the case only if we were loaded via the PE entry point. 991 */ 992 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX, 993 &initrd); 994 if (status != EFI_SUCCESS) 995 goto fail; 996 if (initrd && initrd->size > 0) { 997 efi_set_u64_split(initrd->base, &hdr->ramdisk_image, 998 &boot_params->ext_ramdisk_image); 999 efi_set_u64_split(initrd->size, &hdr->ramdisk_size, 1000 &boot_params->ext_ramdisk_size); 1001 } 1002 1003 1004 /* 1005 * If the boot loader gave us a value for secure_boot then we use that, 1006 * otherwise we ask the BIOS. 1007 */ 1008 if (boot_params->secure_boot == efi_secureboot_mode_unset) 1009 boot_params->secure_boot = efi_get_secureboot(); 1010 1011 /* Ask the firmware to clear memory on unclean shutdown */ 1012 efi_enable_reset_attack_mitigation(); 1013 1014 efi_random_get_seed(); 1015 1016 efi_retrieve_eventlog(); 1017 1018 setup_graphics(boot_params); 1019 1020 setup_efi_pci(boot_params); 1021 1022 setup_quirks(boot_params); 1023 1024 setup_unaccepted_memory(); 1025 1026 status = exit_boot(boot_params, handle); 1027 if (status != EFI_SUCCESS) { 1028 efi_err("exit_boot() failed!\n"); 1029 goto fail; 1030 } 1031 1032 /* 1033 * Call the SEV init code while still running with the firmware's 1034 * GDT/IDT, so #VC exceptions will be handled by EFI. 1035 */ 1036 sev_enable(boot_params); 1037 1038 efi_5level_switch(); 1039 1040 enter_kernel(kernel_entry, boot_params); 1041 fail: 1042 efi_err("efi_stub_entry() failed!\n"); 1043 1044 efi_exit(handle, status); 1045 } 1046 1047 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 1048 efi_system_table_t *sys_table_arg) 1049 { 1050 efi_stub_entry(handle, sys_table_arg, NULL); 1051 } 1052 1053 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL 1054 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 1055 struct boot_params *boot_params) 1056 { 1057 memset(_bss, 0, _ebss - _bss); 1058 efi_stub_entry(handle, sys_table_arg, boot_params); 1059 } 1060 1061 #ifndef CONFIG_EFI_MIXED 1062 extern __alias(efi_handover_entry) 1063 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 1064 struct boot_params *boot_params); 1065 1066 extern __alias(efi_handover_entry) 1067 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 1068 struct boot_params *boot_params); 1069 #endif 1070 #endif 1071