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 const efi_char16_t apple[] = L"Apple"; 311 312 static void setup_quirks(struct boot_params *boot_params) 313 { 314 efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long) 315 efi_table_attr(efi_system_table, fw_vendor); 316 317 if (!memcmp(fw_vendor, apple, sizeof(apple))) { 318 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES)) 319 retrieve_apple_device_properties(boot_params); 320 } 321 } 322 323 /* 324 * See if we have Universal Graphics Adapter (UGA) protocol 325 */ 326 static efi_status_t 327 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size) 328 { 329 efi_status_t status; 330 u32 width, height; 331 void **uga_handle = NULL; 332 efi_uga_draw_protocol_t *uga = NULL, *first_uga; 333 efi_handle_t handle; 334 int i; 335 336 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 337 (void **)&uga_handle); 338 if (status != EFI_SUCCESS) 339 return status; 340 341 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 342 uga_proto, NULL, &size, uga_handle); 343 if (status != EFI_SUCCESS) 344 goto free_handle; 345 346 height = 0; 347 width = 0; 348 349 first_uga = NULL; 350 for_each_efi_handle(handle, uga_handle, size, i) { 351 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID; 352 u32 w, h, depth, refresh; 353 void *pciio; 354 355 status = efi_bs_call(handle_protocol, handle, uga_proto, 356 (void **)&uga); 357 if (status != EFI_SUCCESS) 358 continue; 359 360 pciio = NULL; 361 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio); 362 363 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh); 364 if (status == EFI_SUCCESS && (!first_uga || pciio)) { 365 width = w; 366 height = h; 367 368 /* 369 * Once we've found a UGA supporting PCIIO, 370 * don't bother looking any further. 371 */ 372 if (pciio) 373 break; 374 375 first_uga = uga; 376 } 377 } 378 379 if (!width && !height) 380 goto free_handle; 381 382 /* EFI framebuffer */ 383 si->orig_video_isVGA = VIDEO_TYPE_EFI; 384 385 si->lfb_depth = 32; 386 si->lfb_width = width; 387 si->lfb_height = height; 388 389 si->red_size = 8; 390 si->red_pos = 16; 391 si->green_size = 8; 392 si->green_pos = 8; 393 si->blue_size = 8; 394 si->blue_pos = 0; 395 si->rsvd_size = 8; 396 si->rsvd_pos = 24; 397 398 free_handle: 399 efi_bs_call(free_pool, uga_handle); 400 401 return status; 402 } 403 404 static void setup_graphics(struct boot_params *boot_params) 405 { 406 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; 407 struct screen_info *si; 408 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; 409 efi_status_t status; 410 unsigned long size; 411 void **gop_handle = NULL; 412 void **uga_handle = NULL; 413 414 si = &boot_params->screen_info; 415 memset(si, 0, sizeof(*si)); 416 417 size = 0; 418 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 419 &graphics_proto, NULL, &size, gop_handle); 420 if (status == EFI_BUFFER_TOO_SMALL) 421 status = efi_setup_gop(si, &graphics_proto, size); 422 423 if (status != EFI_SUCCESS) { 424 size = 0; 425 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 426 &uga_proto, NULL, &size, uga_handle); 427 if (status == EFI_BUFFER_TOO_SMALL) 428 setup_uga(si, &uga_proto, size); 429 } 430 } 431 432 433 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) 434 { 435 efi_bs_call(exit, handle, status, 0, NULL); 436 for(;;) 437 asm("hlt"); 438 } 439 440 void __noreturn efi_stub_entry(efi_handle_t handle, 441 efi_system_table_t *sys_table_arg, 442 struct boot_params *boot_params); 443 444 /* 445 * Because the x86 boot code expects to be passed a boot_params we 446 * need to create one ourselves (usually the bootloader would create 447 * one for us). 448 */ 449 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 450 efi_system_table_t *sys_table_arg) 451 { 452 struct boot_params *boot_params; 453 struct setup_header *hdr; 454 void *image_base; 455 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; 456 int options_size = 0; 457 efi_status_t status; 458 char *cmdline_ptr; 459 460 efi_system_table = sys_table_arg; 461 462 /* Check if we were booted by the EFI firmware */ 463 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 464 efi_exit(handle, EFI_INVALID_PARAMETER); 465 466 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); 467 if (status != EFI_SUCCESS) { 468 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); 469 efi_exit(handle, status); 470 } 471 472 image_base = efi_table_attr(image, image_base); 473 474 status = efi_allocate_pages(sizeof(struct boot_params), 475 (unsigned long *)&boot_params, ULONG_MAX); 476 if (status != EFI_SUCCESS) { 477 efi_err("Failed to allocate lowmem for boot params\n"); 478 efi_exit(handle, status); 479 } 480 481 memset(boot_params, 0x0, sizeof(struct boot_params)); 482 483 hdr = &boot_params->hdr; 484 485 /* Copy the setup header from the second sector to boot_params */ 486 memcpy(&hdr->jump, image_base + 512, 487 sizeof(struct setup_header) - offsetof(struct setup_header, jump)); 488 489 /* 490 * Fill out some of the header fields ourselves because the 491 * EFI firmware loader doesn't load the first sector. 492 */ 493 hdr->root_flags = 1; 494 hdr->vid_mode = 0xffff; 495 hdr->boot_flag = 0xAA55; 496 497 hdr->type_of_loader = 0x21; 498 499 /* Convert unicode cmdline to ascii */ 500 cmdline_ptr = efi_convert_cmdline(image, &options_size); 501 if (!cmdline_ptr) 502 goto fail; 503 504 efi_set_u64_split((unsigned long)cmdline_ptr, 505 &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr); 506 507 hdr->ramdisk_image = 0; 508 hdr->ramdisk_size = 0; 509 510 /* 511 * Disregard any setup data that was provided by the bootloader: 512 * setup_data could be pointing anywhere, and we have no way of 513 * authenticating or validating the payload. 514 */ 515 hdr->setup_data = 0; 516 517 efi_stub_entry(handle, sys_table_arg, boot_params); 518 /* not reached */ 519 520 fail: 521 efi_free(sizeof(struct boot_params), (unsigned long)boot_params); 522 523 efi_exit(handle, status); 524 } 525 526 static void add_e820ext(struct boot_params *params, 527 struct setup_data *e820ext, u32 nr_entries) 528 { 529 struct setup_data *data; 530 531 e820ext->type = SETUP_E820_EXT; 532 e820ext->len = nr_entries * sizeof(struct boot_e820_entry); 533 e820ext->next = 0; 534 535 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 536 537 while (data && data->next) 538 data = (struct setup_data *)(unsigned long)data->next; 539 540 if (data) 541 data->next = (unsigned long)e820ext; 542 else 543 params->hdr.setup_data = (unsigned long)e820ext; 544 } 545 546 static efi_status_t 547 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) 548 { 549 struct boot_e820_entry *entry = params->e820_table; 550 struct efi_info *efi = ¶ms->efi_info; 551 struct boot_e820_entry *prev = NULL; 552 u32 nr_entries; 553 u32 nr_desc; 554 int i; 555 556 nr_entries = 0; 557 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; 558 559 for (i = 0; i < nr_desc; i++) { 560 efi_memory_desc_t *d; 561 unsigned int e820_type = 0; 562 unsigned long m = efi->efi_memmap; 563 564 #ifdef CONFIG_X86_64 565 m |= (u64)efi->efi_memmap_hi << 32; 566 #endif 567 568 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); 569 switch (d->type) { 570 case EFI_RESERVED_TYPE: 571 case EFI_RUNTIME_SERVICES_CODE: 572 case EFI_RUNTIME_SERVICES_DATA: 573 case EFI_MEMORY_MAPPED_IO: 574 case EFI_MEMORY_MAPPED_IO_PORT_SPACE: 575 case EFI_PAL_CODE: 576 e820_type = E820_TYPE_RESERVED; 577 break; 578 579 case EFI_UNUSABLE_MEMORY: 580 e820_type = E820_TYPE_UNUSABLE; 581 break; 582 583 case EFI_ACPI_RECLAIM_MEMORY: 584 e820_type = E820_TYPE_ACPI; 585 break; 586 587 case EFI_LOADER_CODE: 588 case EFI_LOADER_DATA: 589 case EFI_BOOT_SERVICES_CODE: 590 case EFI_BOOT_SERVICES_DATA: 591 case EFI_CONVENTIONAL_MEMORY: 592 if (efi_soft_reserve_enabled() && 593 (d->attribute & EFI_MEMORY_SP)) 594 e820_type = E820_TYPE_SOFT_RESERVED; 595 else 596 e820_type = E820_TYPE_RAM; 597 break; 598 599 case EFI_ACPI_MEMORY_NVS: 600 e820_type = E820_TYPE_NVS; 601 break; 602 603 case EFI_PERSISTENT_MEMORY: 604 e820_type = E820_TYPE_PMEM; 605 break; 606 607 case EFI_UNACCEPTED_MEMORY: 608 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 609 continue; 610 e820_type = E820_TYPE_RAM; 611 process_unaccepted_memory(d->phys_addr, 612 d->phys_addr + PAGE_SIZE * d->num_pages); 613 break; 614 default: 615 continue; 616 } 617 618 /* Merge adjacent mappings */ 619 if (prev && prev->type == e820_type && 620 (prev->addr + prev->size) == d->phys_addr) { 621 prev->size += d->num_pages << 12; 622 continue; 623 } 624 625 if (nr_entries == ARRAY_SIZE(params->e820_table)) { 626 u32 need = (nr_desc - i) * sizeof(struct e820_entry) + 627 sizeof(struct setup_data); 628 629 if (!e820ext || e820ext_size < need) 630 return EFI_BUFFER_TOO_SMALL; 631 632 /* boot_params map full, switch to e820 extended */ 633 entry = (struct boot_e820_entry *)e820ext->data; 634 } 635 636 entry->addr = d->phys_addr; 637 entry->size = d->num_pages << PAGE_SHIFT; 638 entry->type = e820_type; 639 prev = entry++; 640 nr_entries++; 641 } 642 643 if (nr_entries > ARRAY_SIZE(params->e820_table)) { 644 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); 645 646 add_e820ext(params, e820ext, nr_e820ext); 647 nr_entries -= nr_e820ext; 648 } 649 650 params->e820_entries = (u8)nr_entries; 651 652 return EFI_SUCCESS; 653 } 654 655 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, 656 u32 *e820ext_size) 657 { 658 efi_status_t status; 659 unsigned long size; 660 661 size = sizeof(struct setup_data) + 662 sizeof(struct e820_entry) * nr_desc; 663 664 if (*e820ext) { 665 efi_bs_call(free_pool, *e820ext); 666 *e820ext = NULL; 667 *e820ext_size = 0; 668 } 669 670 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 671 (void **)e820ext); 672 if (status == EFI_SUCCESS) 673 *e820ext_size = size; 674 675 return status; 676 } 677 678 static efi_status_t allocate_e820(struct boot_params *params, 679 struct setup_data **e820ext, 680 u32 *e820ext_size) 681 { 682 struct efi_boot_memmap *map; 683 efi_status_t status; 684 __u32 nr_desc; 685 686 status = efi_get_memory_map(&map, false); 687 if (status != EFI_SUCCESS) 688 return status; 689 690 nr_desc = map->map_size / map->desc_size; 691 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) { 692 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) + 693 EFI_MMAP_NR_SLACK_SLOTS; 694 695 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); 696 } 697 698 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS) 699 status = allocate_unaccepted_bitmap(nr_desc, map); 700 701 efi_bs_call(free_pool, map); 702 return status; 703 } 704 705 struct exit_boot_struct { 706 struct boot_params *boot_params; 707 struct efi_info *efi; 708 }; 709 710 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, 711 void *priv) 712 { 713 const char *signature; 714 struct exit_boot_struct *p = priv; 715 716 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE 717 : EFI32_LOADER_SIGNATURE; 718 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); 719 720 efi_set_u64_split((unsigned long)efi_system_table, 721 &p->efi->efi_systab, &p->efi->efi_systab_hi); 722 p->efi->efi_memdesc_size = map->desc_size; 723 p->efi->efi_memdesc_version = map->desc_ver; 724 efi_set_u64_split((unsigned long)map->map, 725 &p->efi->efi_memmap, &p->efi->efi_memmap_hi); 726 p->efi->efi_memmap_size = map->map_size; 727 728 return EFI_SUCCESS; 729 } 730 731 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 732 { 733 struct setup_data *e820ext = NULL; 734 __u32 e820ext_size = 0; 735 efi_status_t status; 736 struct exit_boot_struct priv; 737 738 priv.boot_params = boot_params; 739 priv.efi = &boot_params->efi_info; 740 741 status = allocate_e820(boot_params, &e820ext, &e820ext_size); 742 if (status != EFI_SUCCESS) 743 return status; 744 745 /* Might as well exit boot services now */ 746 status = efi_exit_boot_services(handle, &priv, exit_boot_func); 747 if (status != EFI_SUCCESS) 748 return status; 749 750 /* Historic? */ 751 boot_params->alt_mem_k = 32 * 1024; 752 753 status = setup_e820(boot_params, e820ext, e820ext_size); 754 if (status != EFI_SUCCESS) 755 return status; 756 757 return EFI_SUCCESS; 758 } 759 760 static bool have_unsupported_snp_features(void) 761 { 762 u64 unsupported; 763 764 unsupported = snp_get_unsupported_features(sev_get_status()); 765 if (unsupported) { 766 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n", 767 unsupported); 768 return true; 769 } 770 return false; 771 } 772 773 static void efi_get_seed(void *seed, int size) 774 { 775 efi_get_random_bytes(size, seed); 776 777 /* 778 * This only updates seed[0] when running on 32-bit, but in that case, 779 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit. 780 */ 781 *(unsigned long *)seed ^= kaslr_get_random_long("EFI"); 782 } 783 784 static void error(char *str) 785 { 786 efi_warn("Decompression failed: %s\n", str); 787 } 788 789 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry) 790 { 791 unsigned long virt_addr = LOAD_PHYSICAL_ADDR; 792 unsigned long addr, alloc_size, entry; 793 efi_status_t status; 794 u32 seed[2] = {}; 795 796 /* determine the required size of the allocation */ 797 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size), 798 MIN_KERNEL_ALIGN); 799 800 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) { 801 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size; 802 803 efi_get_seed(seed, sizeof(seed)); 804 805 virt_addr += (range * seed[1]) >> 32; 806 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1); 807 } 808 809 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr, 810 seed[0], EFI_LOADER_CODE, 811 EFI_X86_KERNEL_ALLOC_LIMIT); 812 if (status != EFI_SUCCESS) 813 return status; 814 815 entry = decompress_kernel((void *)addr, virt_addr, error); 816 if (entry == ULONG_MAX) { 817 efi_free(alloc_size, addr); 818 return EFI_LOAD_ERROR; 819 } 820 821 *kernel_entry = addr + entry; 822 823 efi_adjust_memory_range_protection(addr, kernel_total_size); 824 825 return EFI_SUCCESS; 826 } 827 828 static void __noreturn enter_kernel(unsigned long kernel_addr, 829 struct boot_params *boot_params) 830 { 831 /* enter decompressed kernel with boot_params pointer in RSI/ESI */ 832 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params)); 833 834 unreachable(); 835 } 836 837 /* 838 * On success, this routine will jump to the relocated image directly and never 839 * return. On failure, it will exit to the firmware via efi_exit() instead of 840 * returning. 841 */ 842 void __noreturn efi_stub_entry(efi_handle_t handle, 843 efi_system_table_t *sys_table_arg, 844 struct boot_params *boot_params) 845 { 846 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID; 847 struct setup_header *hdr = &boot_params->hdr; 848 const struct linux_efi_initrd *initrd = NULL; 849 unsigned long kernel_entry; 850 efi_status_t status; 851 852 boot_params_pointer = boot_params; 853 854 efi_system_table = sys_table_arg; 855 /* Check if we were booted by the EFI firmware */ 856 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 857 efi_exit(handle, EFI_INVALID_PARAMETER); 858 859 if (have_unsupported_snp_features()) 860 efi_exit(handle, EFI_UNSUPPORTED); 861 862 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) { 863 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID); 864 if (efi_dxe_table && 865 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) { 866 efi_warn("Ignoring DXE services table: invalid signature\n"); 867 efi_dxe_table = NULL; 868 } 869 } 870 871 /* grab the memory attributes protocol if it exists */ 872 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr); 873 874 status = efi_setup_5level_paging(); 875 if (status != EFI_SUCCESS) { 876 efi_err("efi_setup_5level_paging() failed!\n"); 877 goto fail; 878 } 879 880 #ifdef CONFIG_CMDLINE_BOOL 881 status = efi_parse_options(CONFIG_CMDLINE); 882 if (status != EFI_SUCCESS) { 883 efi_err("Failed to parse options\n"); 884 goto fail; 885 } 886 #endif 887 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { 888 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | 889 ((u64)boot_params->ext_cmd_line_ptr << 32)); 890 status = efi_parse_options((char *)cmdline_paddr); 891 if (status != EFI_SUCCESS) { 892 efi_err("Failed to parse options\n"); 893 goto fail; 894 } 895 } 896 897 status = efi_decompress_kernel(&kernel_entry); 898 if (status != EFI_SUCCESS) { 899 efi_err("Failed to decompress kernel\n"); 900 goto fail; 901 } 902 903 /* 904 * At this point, an initrd may already have been loaded by the 905 * bootloader and passed via bootparams. We permit an initrd loaded 906 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. 907 * 908 * If the device path is not present, any command-line initrd= 909 * arguments will be processed only if image is not NULL, which will be 910 * the case only if we were loaded via the PE entry point. 911 */ 912 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX, 913 &initrd); 914 if (status != EFI_SUCCESS) 915 goto fail; 916 if (initrd && initrd->size > 0) { 917 efi_set_u64_split(initrd->base, &hdr->ramdisk_image, 918 &boot_params->ext_ramdisk_image); 919 efi_set_u64_split(initrd->size, &hdr->ramdisk_size, 920 &boot_params->ext_ramdisk_size); 921 } 922 923 924 /* 925 * If the boot loader gave us a value for secure_boot then we use that, 926 * otherwise we ask the BIOS. 927 */ 928 if (boot_params->secure_boot == efi_secureboot_mode_unset) 929 boot_params->secure_boot = efi_get_secureboot(); 930 931 /* Ask the firmware to clear memory on unclean shutdown */ 932 efi_enable_reset_attack_mitigation(); 933 934 efi_random_get_seed(); 935 936 efi_retrieve_tpm2_eventlog(); 937 938 setup_graphics(boot_params); 939 940 setup_efi_pci(boot_params); 941 942 setup_quirks(boot_params); 943 944 setup_unaccepted_memory(); 945 946 status = exit_boot(boot_params, handle); 947 if (status != EFI_SUCCESS) { 948 efi_err("exit_boot() failed!\n"); 949 goto fail; 950 } 951 952 /* 953 * Call the SEV init code while still running with the firmware's 954 * GDT/IDT, so #VC exceptions will be handled by EFI. 955 */ 956 sev_enable(boot_params); 957 958 efi_5level_switch(); 959 960 enter_kernel(kernel_entry, boot_params); 961 fail: 962 efi_err("efi_stub_entry() failed!\n"); 963 964 efi_exit(handle, status); 965 } 966 967 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL 968 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 969 struct boot_params *boot_params) 970 { 971 extern char _bss[], _ebss[]; 972 973 memset(_bss, 0, _ebss - _bss); 974 efi_stub_entry(handle, sys_table_arg, boot_params); 975 } 976 977 #ifndef CONFIG_EFI_MIXED 978 extern __alias(efi_handover_entry) 979 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 980 struct boot_params *boot_params); 981 982 extern __alias(efi_handover_entry) 983 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 984 struct boot_params *boot_params); 985 #endif 986 #endif 987