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 const efi_system_table_t *efi_system_table; 25 const efi_dxe_services_table_t *efi_dxe_table; 26 static efi_loaded_image_t *image = NULL; 27 static efi_memory_attribute_protocol_t *memattr; 28 29 typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t; 30 union sev_memory_acceptance_protocol { 31 struct { 32 efi_status_t (__efiapi * allow_unaccepted_memory)( 33 sev_memory_acceptance_protocol_t *); 34 }; 35 struct { 36 u32 allow_unaccepted_memory; 37 } mixed_mode; 38 }; 39 40 static efi_status_t 41 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) 42 { 43 struct pci_setup_rom *rom = NULL; 44 efi_status_t status; 45 unsigned long size; 46 uint64_t romsize; 47 void *romimage; 48 49 /* 50 * Some firmware images contain EFI function pointers at the place where 51 * the romimage and romsize fields are supposed to be. Typically the EFI 52 * code is mapped at high addresses, translating to an unrealistically 53 * large romsize. The UEFI spec limits the size of option ROMs to 16 54 * MiB so we reject any ROMs over 16 MiB in size to catch this. 55 */ 56 romimage = efi_table_attr(pci, romimage); 57 romsize = efi_table_attr(pci, romsize); 58 if (!romimage || !romsize || romsize > SZ_16M) 59 return EFI_INVALID_PARAMETER; 60 61 size = romsize + sizeof(*rom); 62 63 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 64 (void **)&rom); 65 if (status != EFI_SUCCESS) { 66 efi_err("Failed to allocate memory for 'rom'\n"); 67 return status; 68 } 69 70 memset(rom, 0, sizeof(*rom)); 71 72 rom->data.type = SETUP_PCI; 73 rom->data.len = size - sizeof(struct setup_data); 74 rom->data.next = 0; 75 rom->pcilen = romsize; 76 *__rom = rom; 77 78 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 79 PCI_VENDOR_ID, 1, &rom->vendor); 80 81 if (status != EFI_SUCCESS) { 82 efi_err("Failed to read rom->vendor\n"); 83 goto free_struct; 84 } 85 86 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 87 PCI_DEVICE_ID, 1, &rom->devid); 88 89 if (status != EFI_SUCCESS) { 90 efi_err("Failed to read rom->devid\n"); 91 goto free_struct; 92 } 93 94 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus, 95 &rom->device, &rom->function); 96 97 if (status != EFI_SUCCESS) 98 goto free_struct; 99 100 memcpy(rom->romdata, romimage, romsize); 101 return status; 102 103 free_struct: 104 efi_bs_call(free_pool, rom); 105 return status; 106 } 107 108 /* 109 * There's no way to return an informative status from this function, 110 * because any analysis (and printing of error messages) needs to be 111 * done directly at the EFI function call-site. 112 * 113 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we 114 * just didn't find any PCI devices, but there's no way to tell outside 115 * the context of the call. 116 */ 117 static void setup_efi_pci(struct boot_params *params) 118 { 119 efi_status_t status; 120 void **pci_handle = NULL; 121 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID; 122 unsigned long size = 0; 123 struct setup_data *data; 124 efi_handle_t h; 125 int i; 126 127 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 128 &pci_proto, NULL, &size, pci_handle); 129 130 if (status == EFI_BUFFER_TOO_SMALL) { 131 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 132 (void **)&pci_handle); 133 134 if (status != EFI_SUCCESS) { 135 efi_err("Failed to allocate memory for 'pci_handle'\n"); 136 return; 137 } 138 139 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 140 &pci_proto, NULL, &size, pci_handle); 141 } 142 143 if (status != EFI_SUCCESS) 144 goto free_handle; 145 146 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 147 148 while (data && data->next) 149 data = (struct setup_data *)(unsigned long)data->next; 150 151 for_each_efi_handle(h, pci_handle, size, i) { 152 efi_pci_io_protocol_t *pci = NULL; 153 struct pci_setup_rom *rom; 154 155 status = efi_bs_call(handle_protocol, h, &pci_proto, 156 (void **)&pci); 157 if (status != EFI_SUCCESS || !pci) 158 continue; 159 160 status = preserve_pci_rom_image(pci, &rom); 161 if (status != EFI_SUCCESS) 162 continue; 163 164 if (data) 165 data->next = (unsigned long)rom; 166 else 167 params->hdr.setup_data = (unsigned long)rom; 168 169 data = (struct setup_data *)rom; 170 } 171 172 free_handle: 173 efi_bs_call(free_pool, pci_handle); 174 } 175 176 static void retrieve_apple_device_properties(struct boot_params *boot_params) 177 { 178 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID; 179 struct setup_data *data, *new; 180 efi_status_t status; 181 u32 size = 0; 182 apple_properties_protocol_t *p; 183 184 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p); 185 if (status != EFI_SUCCESS) 186 return; 187 188 if (efi_table_attr(p, version) != 0x10000) { 189 efi_err("Unsupported properties proto version\n"); 190 return; 191 } 192 193 efi_call_proto(p, get_all, NULL, &size); 194 if (!size) 195 return; 196 197 do { 198 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, 199 size + sizeof(struct setup_data), 200 (void **)&new); 201 if (status != EFI_SUCCESS) { 202 efi_err("Failed to allocate memory for 'properties'\n"); 203 return; 204 } 205 206 status = efi_call_proto(p, get_all, new->data, &size); 207 208 if (status == EFI_BUFFER_TOO_SMALL) 209 efi_bs_call(free_pool, new); 210 } while (status == EFI_BUFFER_TOO_SMALL); 211 212 new->type = SETUP_APPLE_PROPERTIES; 213 new->len = size; 214 new->next = 0; 215 216 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data; 217 if (!data) { 218 boot_params->hdr.setup_data = (unsigned long)new; 219 } else { 220 while (data->next) 221 data = (struct setup_data *)(unsigned long)data->next; 222 data->next = (unsigned long)new; 223 } 224 } 225 226 void efi_adjust_memory_range_protection(unsigned long start, 227 unsigned long size) 228 { 229 efi_status_t status; 230 efi_gcd_memory_space_desc_t desc; 231 unsigned long end, next; 232 unsigned long rounded_start, rounded_end; 233 unsigned long unprotect_start, unprotect_size; 234 235 rounded_start = rounddown(start, EFI_PAGE_SIZE); 236 rounded_end = roundup(start + size, EFI_PAGE_SIZE); 237 238 if (memattr != NULL) { 239 efi_call_proto(memattr, clear_memory_attributes, rounded_start, 240 rounded_end - rounded_start, EFI_MEMORY_XP); 241 return; 242 } 243 244 if (efi_dxe_table == NULL) 245 return; 246 247 /* 248 * Don't modify memory region attributes, they are 249 * already suitable, to lower the possibility to 250 * encounter firmware bugs. 251 */ 252 253 for (end = start + size; start < end; start = next) { 254 255 status = efi_dxe_call(get_memory_space_descriptor, start, &desc); 256 257 if (status != EFI_SUCCESS) 258 return; 259 260 next = desc.base_address + desc.length; 261 262 /* 263 * Only system memory is suitable for trampoline/kernel image placement, 264 * so only this type of memory needs its attributes to be modified. 265 */ 266 267 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory || 268 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0) 269 continue; 270 271 unprotect_start = max(rounded_start, (unsigned long)desc.base_address); 272 unprotect_size = min(rounded_end, next) - unprotect_start; 273 274 status = efi_dxe_call(set_memory_space_attributes, 275 unprotect_start, unprotect_size, 276 EFI_MEMORY_WB); 277 278 if (status != EFI_SUCCESS) { 279 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n", 280 unprotect_start, 281 unprotect_start + unprotect_size, 282 status); 283 } 284 } 285 } 286 287 static void setup_unaccepted_memory(void) 288 { 289 efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID; 290 sev_memory_acceptance_protocol_t *proto; 291 efi_status_t status; 292 293 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 294 return; 295 296 /* 297 * Enable unaccepted memory before calling exit boot services in order 298 * for the UEFI to not accept all memory on EBS. 299 */ 300 status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL, 301 (void **)&proto); 302 if (status != EFI_SUCCESS) 303 return; 304 305 status = efi_call_proto(proto, allow_unaccepted_memory); 306 if (status != EFI_SUCCESS) 307 efi_err("Memory acceptance protocol failed\n"); 308 } 309 310 static efi_char16_t *efistub_fw_vendor(void) 311 { 312 unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor); 313 314 return (efi_char16_t *)vendor; 315 } 316 317 static const efi_char16_t apple[] = L"Apple"; 318 319 static void setup_quirks(struct boot_params *boot_params) 320 { 321 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) && 322 !memcmp(efistub_fw_vendor(), apple, sizeof(apple))) 323 retrieve_apple_device_properties(boot_params); 324 } 325 326 /* 327 * See if we have Universal Graphics Adapter (UGA) protocol 328 */ 329 static efi_status_t 330 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size) 331 { 332 efi_status_t status; 333 u32 width, height; 334 void **uga_handle = NULL; 335 efi_uga_draw_protocol_t *uga = NULL, *first_uga; 336 efi_handle_t handle; 337 int i; 338 339 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 340 (void **)&uga_handle); 341 if (status != EFI_SUCCESS) 342 return status; 343 344 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 345 uga_proto, NULL, &size, uga_handle); 346 if (status != EFI_SUCCESS) 347 goto free_handle; 348 349 height = 0; 350 width = 0; 351 352 first_uga = NULL; 353 for_each_efi_handle(handle, uga_handle, size, i) { 354 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID; 355 u32 w, h, depth, refresh; 356 void *pciio; 357 358 status = efi_bs_call(handle_protocol, handle, uga_proto, 359 (void **)&uga); 360 if (status != EFI_SUCCESS) 361 continue; 362 363 pciio = NULL; 364 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio); 365 366 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh); 367 if (status == EFI_SUCCESS && (!first_uga || pciio)) { 368 width = w; 369 height = h; 370 371 /* 372 * Once we've found a UGA supporting PCIIO, 373 * don't bother looking any further. 374 */ 375 if (pciio) 376 break; 377 378 first_uga = uga; 379 } 380 } 381 382 if (!width && !height) 383 goto free_handle; 384 385 /* EFI framebuffer */ 386 si->orig_video_isVGA = VIDEO_TYPE_EFI; 387 388 si->lfb_depth = 32; 389 si->lfb_width = width; 390 si->lfb_height = height; 391 392 si->red_size = 8; 393 si->red_pos = 16; 394 si->green_size = 8; 395 si->green_pos = 8; 396 si->blue_size = 8; 397 si->blue_pos = 0; 398 si->rsvd_size = 8; 399 si->rsvd_pos = 24; 400 401 free_handle: 402 efi_bs_call(free_pool, uga_handle); 403 404 return status; 405 } 406 407 static void setup_graphics(struct boot_params *boot_params) 408 { 409 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; 410 struct screen_info *si; 411 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; 412 efi_status_t status; 413 unsigned long size; 414 void **gop_handle = NULL; 415 void **uga_handle = NULL; 416 417 si = &boot_params->screen_info; 418 memset(si, 0, sizeof(*si)); 419 420 size = 0; 421 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 422 &graphics_proto, NULL, &size, gop_handle); 423 if (status == EFI_BUFFER_TOO_SMALL) 424 status = efi_setup_gop(si, &graphics_proto, size); 425 426 if (status != EFI_SUCCESS) { 427 size = 0; 428 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 429 &uga_proto, NULL, &size, uga_handle); 430 if (status == EFI_BUFFER_TOO_SMALL) 431 setup_uga(si, &uga_proto, size); 432 } 433 } 434 435 436 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) 437 { 438 efi_bs_call(exit, handle, status, 0, NULL); 439 for(;;) 440 asm("hlt"); 441 } 442 443 void __noreturn efi_stub_entry(efi_handle_t handle, 444 efi_system_table_t *sys_table_arg, 445 struct boot_params *boot_params); 446 447 /* 448 * Because the x86 boot code expects to be passed a boot_params we 449 * need to create one ourselves (usually the bootloader would create 450 * one for us). 451 */ 452 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 453 efi_system_table_t *sys_table_arg) 454 { 455 struct boot_params *boot_params; 456 struct setup_header *hdr; 457 void *image_base; 458 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; 459 int options_size = 0; 460 efi_status_t status; 461 char *cmdline_ptr; 462 463 efi_system_table = sys_table_arg; 464 465 /* Check if we were booted by the EFI firmware */ 466 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 467 efi_exit(handle, EFI_INVALID_PARAMETER); 468 469 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); 470 if (status != EFI_SUCCESS) { 471 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); 472 efi_exit(handle, status); 473 } 474 475 image_base = efi_table_attr(image, image_base); 476 477 status = efi_allocate_pages(sizeof(struct boot_params), 478 (unsigned long *)&boot_params, ULONG_MAX); 479 if (status != EFI_SUCCESS) { 480 efi_err("Failed to allocate lowmem for boot params\n"); 481 efi_exit(handle, status); 482 } 483 484 memset(boot_params, 0x0, sizeof(struct boot_params)); 485 486 hdr = &boot_params->hdr; 487 488 /* Copy the setup header from the second sector to boot_params */ 489 memcpy(&hdr->jump, image_base + 512, 490 sizeof(struct setup_header) - offsetof(struct setup_header, jump)); 491 492 /* 493 * Fill out some of the header fields ourselves because the 494 * EFI firmware loader doesn't load the first sector. 495 */ 496 hdr->root_flags = 1; 497 hdr->vid_mode = 0xffff; 498 hdr->boot_flag = 0xAA55; 499 500 hdr->type_of_loader = 0x21; 501 502 /* Convert unicode cmdline to ascii */ 503 cmdline_ptr = efi_convert_cmdline(image, &options_size); 504 if (!cmdline_ptr) 505 goto fail; 506 507 efi_set_u64_split((unsigned long)cmdline_ptr, 508 &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr); 509 510 hdr->ramdisk_image = 0; 511 hdr->ramdisk_size = 0; 512 513 /* 514 * Disregard any setup data that was provided by the bootloader: 515 * setup_data could be pointing anywhere, and we have no way of 516 * authenticating or validating the payload. 517 */ 518 hdr->setup_data = 0; 519 520 efi_stub_entry(handle, sys_table_arg, boot_params); 521 /* not reached */ 522 523 fail: 524 efi_free(sizeof(struct boot_params), (unsigned long)boot_params); 525 526 efi_exit(handle, status); 527 } 528 529 static void add_e820ext(struct boot_params *params, 530 struct setup_data *e820ext, u32 nr_entries) 531 { 532 struct setup_data *data; 533 534 e820ext->type = SETUP_E820_EXT; 535 e820ext->len = nr_entries * sizeof(struct boot_e820_entry); 536 e820ext->next = 0; 537 538 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 539 540 while (data && data->next) 541 data = (struct setup_data *)(unsigned long)data->next; 542 543 if (data) 544 data->next = (unsigned long)e820ext; 545 else 546 params->hdr.setup_data = (unsigned long)e820ext; 547 } 548 549 static efi_status_t 550 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) 551 { 552 struct boot_e820_entry *entry = params->e820_table; 553 struct efi_info *efi = ¶ms->efi_info; 554 struct boot_e820_entry *prev = NULL; 555 u32 nr_entries; 556 u32 nr_desc; 557 int i; 558 559 nr_entries = 0; 560 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; 561 562 for (i = 0; i < nr_desc; i++) { 563 efi_memory_desc_t *d; 564 unsigned int e820_type = 0; 565 unsigned long m = efi->efi_memmap; 566 567 #ifdef CONFIG_X86_64 568 m |= (u64)efi->efi_memmap_hi << 32; 569 #endif 570 571 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); 572 switch (d->type) { 573 case EFI_RESERVED_TYPE: 574 case EFI_RUNTIME_SERVICES_CODE: 575 case EFI_RUNTIME_SERVICES_DATA: 576 case EFI_MEMORY_MAPPED_IO: 577 case EFI_MEMORY_MAPPED_IO_PORT_SPACE: 578 case EFI_PAL_CODE: 579 e820_type = E820_TYPE_RESERVED; 580 break; 581 582 case EFI_UNUSABLE_MEMORY: 583 e820_type = E820_TYPE_UNUSABLE; 584 break; 585 586 case EFI_ACPI_RECLAIM_MEMORY: 587 e820_type = E820_TYPE_ACPI; 588 break; 589 590 case EFI_LOADER_CODE: 591 case EFI_LOADER_DATA: 592 case EFI_BOOT_SERVICES_CODE: 593 case EFI_BOOT_SERVICES_DATA: 594 case EFI_CONVENTIONAL_MEMORY: 595 if (efi_soft_reserve_enabled() && 596 (d->attribute & EFI_MEMORY_SP)) 597 e820_type = E820_TYPE_SOFT_RESERVED; 598 else 599 e820_type = E820_TYPE_RAM; 600 break; 601 602 case EFI_ACPI_MEMORY_NVS: 603 e820_type = E820_TYPE_NVS; 604 break; 605 606 case EFI_PERSISTENT_MEMORY: 607 e820_type = E820_TYPE_PMEM; 608 break; 609 610 case EFI_UNACCEPTED_MEMORY: 611 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 612 continue; 613 e820_type = E820_TYPE_RAM; 614 process_unaccepted_memory(d->phys_addr, 615 d->phys_addr + PAGE_SIZE * d->num_pages); 616 break; 617 default: 618 continue; 619 } 620 621 /* Merge adjacent mappings */ 622 if (prev && prev->type == e820_type && 623 (prev->addr + prev->size) == d->phys_addr) { 624 prev->size += d->num_pages << 12; 625 continue; 626 } 627 628 if (nr_entries == ARRAY_SIZE(params->e820_table)) { 629 u32 need = (nr_desc - i) * sizeof(struct e820_entry) + 630 sizeof(struct setup_data); 631 632 if (!e820ext || e820ext_size < need) 633 return EFI_BUFFER_TOO_SMALL; 634 635 /* boot_params map full, switch to e820 extended */ 636 entry = (struct boot_e820_entry *)e820ext->data; 637 } 638 639 entry->addr = d->phys_addr; 640 entry->size = d->num_pages << PAGE_SHIFT; 641 entry->type = e820_type; 642 prev = entry++; 643 nr_entries++; 644 } 645 646 if (nr_entries > ARRAY_SIZE(params->e820_table)) { 647 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); 648 649 add_e820ext(params, e820ext, nr_e820ext); 650 nr_entries -= nr_e820ext; 651 } 652 653 params->e820_entries = (u8)nr_entries; 654 655 return EFI_SUCCESS; 656 } 657 658 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, 659 u32 *e820ext_size) 660 { 661 efi_status_t status; 662 unsigned long size; 663 664 size = sizeof(struct setup_data) + 665 sizeof(struct e820_entry) * nr_desc; 666 667 if (*e820ext) { 668 efi_bs_call(free_pool, *e820ext); 669 *e820ext = NULL; 670 *e820ext_size = 0; 671 } 672 673 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 674 (void **)e820ext); 675 if (status == EFI_SUCCESS) 676 *e820ext_size = size; 677 678 return status; 679 } 680 681 static efi_status_t allocate_e820(struct boot_params *params, 682 struct setup_data **e820ext, 683 u32 *e820ext_size) 684 { 685 struct efi_boot_memmap *map; 686 efi_status_t status; 687 __u32 nr_desc; 688 689 status = efi_get_memory_map(&map, false); 690 if (status != EFI_SUCCESS) 691 return status; 692 693 nr_desc = map->map_size / map->desc_size; 694 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) { 695 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) + 696 EFI_MMAP_NR_SLACK_SLOTS; 697 698 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); 699 } 700 701 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS) 702 status = allocate_unaccepted_bitmap(nr_desc, map); 703 704 efi_bs_call(free_pool, map); 705 return status; 706 } 707 708 struct exit_boot_struct { 709 struct boot_params *boot_params; 710 struct efi_info *efi; 711 }; 712 713 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, 714 void *priv) 715 { 716 const char *signature; 717 struct exit_boot_struct *p = priv; 718 719 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE 720 : EFI32_LOADER_SIGNATURE; 721 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); 722 723 efi_set_u64_split((unsigned long)efi_system_table, 724 &p->efi->efi_systab, &p->efi->efi_systab_hi); 725 p->efi->efi_memdesc_size = map->desc_size; 726 p->efi->efi_memdesc_version = map->desc_ver; 727 efi_set_u64_split((unsigned long)map->map, 728 &p->efi->efi_memmap, &p->efi->efi_memmap_hi); 729 p->efi->efi_memmap_size = map->map_size; 730 731 return EFI_SUCCESS; 732 } 733 734 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 735 { 736 struct setup_data *e820ext = NULL; 737 __u32 e820ext_size = 0; 738 efi_status_t status; 739 struct exit_boot_struct priv; 740 741 priv.boot_params = boot_params; 742 priv.efi = &boot_params->efi_info; 743 744 status = allocate_e820(boot_params, &e820ext, &e820ext_size); 745 if (status != EFI_SUCCESS) 746 return status; 747 748 /* Might as well exit boot services now */ 749 status = efi_exit_boot_services(handle, &priv, exit_boot_func); 750 if (status != EFI_SUCCESS) 751 return status; 752 753 /* Historic? */ 754 boot_params->alt_mem_k = 32 * 1024; 755 756 status = setup_e820(boot_params, e820ext, e820ext_size); 757 if (status != EFI_SUCCESS) 758 return status; 759 760 return EFI_SUCCESS; 761 } 762 763 static bool have_unsupported_snp_features(void) 764 { 765 u64 unsupported; 766 767 unsupported = snp_get_unsupported_features(sev_get_status()); 768 if (unsupported) { 769 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n", 770 unsupported); 771 return true; 772 } 773 return false; 774 } 775 776 static void efi_get_seed(void *seed, int size) 777 { 778 efi_get_random_bytes(size, seed); 779 780 /* 781 * This only updates seed[0] when running on 32-bit, but in that case, 782 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit. 783 */ 784 *(unsigned long *)seed ^= kaslr_get_random_long("EFI"); 785 } 786 787 static void error(char *str) 788 { 789 efi_warn("Decompression failed: %s\n", str); 790 } 791 792 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry) 793 { 794 unsigned long virt_addr = LOAD_PHYSICAL_ADDR; 795 unsigned long addr, alloc_size, entry; 796 efi_status_t status; 797 u32 seed[2] = {}; 798 799 /* determine the required size of the allocation */ 800 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size), 801 MIN_KERNEL_ALIGN); 802 803 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) { 804 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size; 805 static const efi_char16_t ami[] = L"American Megatrends"; 806 807 efi_get_seed(seed, sizeof(seed)); 808 809 virt_addr += (range * seed[1]) >> 32; 810 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1); 811 812 /* 813 * Older Dell systems with AMI UEFI firmware v2.0 may hang 814 * while decompressing the kernel if physical address 815 * randomization is enabled. 816 * 817 * https://bugzilla.kernel.org/show_bug.cgi?id=218173 818 */ 819 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION && 820 !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) { 821 efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n"); 822 seed[0] = 0; 823 } 824 } 825 826 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr, 827 seed[0], EFI_LOADER_CODE, 828 EFI_X86_KERNEL_ALLOC_LIMIT); 829 if (status != EFI_SUCCESS) 830 return status; 831 832 entry = decompress_kernel((void *)addr, virt_addr, error); 833 if (entry == ULONG_MAX) { 834 efi_free(alloc_size, addr); 835 return EFI_LOAD_ERROR; 836 } 837 838 *kernel_entry = addr + entry; 839 840 efi_adjust_memory_range_protection(addr, kernel_total_size); 841 842 return EFI_SUCCESS; 843 } 844 845 static void __noreturn enter_kernel(unsigned long kernel_addr, 846 struct boot_params *boot_params) 847 { 848 /* enter decompressed kernel with boot_params pointer in RSI/ESI */ 849 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params)); 850 851 unreachable(); 852 } 853 854 /* 855 * On success, this routine will jump to the relocated image directly and never 856 * return. On failure, it will exit to the firmware via efi_exit() instead of 857 * returning. 858 */ 859 void __noreturn efi_stub_entry(efi_handle_t handle, 860 efi_system_table_t *sys_table_arg, 861 struct boot_params *boot_params) 862 { 863 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID; 864 struct setup_header *hdr = &boot_params->hdr; 865 const struct linux_efi_initrd *initrd = NULL; 866 unsigned long kernel_entry; 867 efi_status_t status; 868 869 boot_params_pointer = boot_params; 870 871 efi_system_table = sys_table_arg; 872 /* Check if we were booted by the EFI firmware */ 873 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 874 efi_exit(handle, EFI_INVALID_PARAMETER); 875 876 if (have_unsupported_snp_features()) 877 efi_exit(handle, EFI_UNSUPPORTED); 878 879 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) { 880 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID); 881 if (efi_dxe_table && 882 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) { 883 efi_warn("Ignoring DXE services table: invalid signature\n"); 884 efi_dxe_table = NULL; 885 } 886 } 887 888 /* grab the memory attributes protocol if it exists */ 889 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr); 890 891 status = efi_setup_5level_paging(); 892 if (status != EFI_SUCCESS) { 893 efi_err("efi_setup_5level_paging() failed!\n"); 894 goto fail; 895 } 896 897 #ifdef CONFIG_CMDLINE_BOOL 898 status = efi_parse_options(CONFIG_CMDLINE); 899 if (status != EFI_SUCCESS) { 900 efi_err("Failed to parse options\n"); 901 goto fail; 902 } 903 #endif 904 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { 905 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | 906 ((u64)boot_params->ext_cmd_line_ptr << 32)); 907 status = efi_parse_options((char *)cmdline_paddr); 908 if (status != EFI_SUCCESS) { 909 efi_err("Failed to parse options\n"); 910 goto fail; 911 } 912 } 913 914 status = efi_decompress_kernel(&kernel_entry); 915 if (status != EFI_SUCCESS) { 916 efi_err("Failed to decompress kernel\n"); 917 goto fail; 918 } 919 920 /* 921 * At this point, an initrd may already have been loaded by the 922 * bootloader and passed via bootparams. We permit an initrd loaded 923 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. 924 * 925 * If the device path is not present, any command-line initrd= 926 * arguments will be processed only if image is not NULL, which will be 927 * the case only if we were loaded via the PE entry point. 928 */ 929 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX, 930 &initrd); 931 if (status != EFI_SUCCESS) 932 goto fail; 933 if (initrd && initrd->size > 0) { 934 efi_set_u64_split(initrd->base, &hdr->ramdisk_image, 935 &boot_params->ext_ramdisk_image); 936 efi_set_u64_split(initrd->size, &hdr->ramdisk_size, 937 &boot_params->ext_ramdisk_size); 938 } 939 940 941 /* 942 * If the boot loader gave us a value for secure_boot then we use that, 943 * otherwise we ask the BIOS. 944 */ 945 if (boot_params->secure_boot == efi_secureboot_mode_unset) 946 boot_params->secure_boot = efi_get_secureboot(); 947 948 /* Ask the firmware to clear memory on unclean shutdown */ 949 efi_enable_reset_attack_mitigation(); 950 951 efi_random_get_seed(); 952 953 efi_retrieve_tpm2_eventlog(); 954 955 setup_graphics(boot_params); 956 957 setup_efi_pci(boot_params); 958 959 setup_quirks(boot_params); 960 961 setup_unaccepted_memory(); 962 963 status = exit_boot(boot_params, handle); 964 if (status != EFI_SUCCESS) { 965 efi_err("exit_boot() failed!\n"); 966 goto fail; 967 } 968 969 /* 970 * Call the SEV init code while still running with the firmware's 971 * GDT/IDT, so #VC exceptions will be handled by EFI. 972 */ 973 sev_enable(boot_params); 974 975 efi_5level_switch(); 976 977 enter_kernel(kernel_entry, boot_params); 978 fail: 979 efi_err("efi_stub_entry() failed!\n"); 980 981 efi_exit(handle, status); 982 } 983 984 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL 985 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 986 struct boot_params *boot_params) 987 { 988 extern char _bss[], _ebss[]; 989 990 memset(_bss, 0, _ebss - _bss); 991 efi_stub_entry(handle, sys_table_arg, boot_params); 992 } 993 994 #ifndef CONFIG_EFI_MIXED 995 extern __alias(efi_handover_entry) 996 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 997 struct boot_params *boot_params); 998 999 extern __alias(efi_handover_entry) 1000 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 1001 struct boot_params *boot_params); 1002 #endif 1003 #endif 1004