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 efi_status_t 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 status = efi_call_proto(memattr, clear_memory_attributes, 240 rounded_start, 241 rounded_end - rounded_start, 242 EFI_MEMORY_XP); 243 if (status != EFI_SUCCESS) 244 efi_warn("Failed to clear EFI_MEMORY_XP attribute\n"); 245 return status; 246 } 247 248 if (efi_dxe_table == NULL) 249 return EFI_SUCCESS; 250 251 /* 252 * Don't modify memory region attributes, they are 253 * already suitable, to lower the possibility to 254 * encounter firmware bugs. 255 */ 256 257 for (end = start + size; start < end; start = next) { 258 259 status = efi_dxe_call(get_memory_space_descriptor, start, &desc); 260 261 if (status != EFI_SUCCESS) 262 break; 263 264 next = desc.base_address + desc.length; 265 266 /* 267 * Only system memory is suitable for trampoline/kernel image placement, 268 * so only this type of memory needs its attributes to be modified. 269 */ 270 271 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory || 272 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0) 273 continue; 274 275 unprotect_start = max(rounded_start, (unsigned long)desc.base_address); 276 unprotect_size = min(rounded_end, next) - unprotect_start; 277 278 status = efi_dxe_call(set_memory_space_attributes, 279 unprotect_start, unprotect_size, 280 EFI_MEMORY_WB); 281 282 if (status != EFI_SUCCESS) { 283 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n", 284 unprotect_start, 285 unprotect_start + unprotect_size, 286 status); 287 break; 288 } 289 } 290 return EFI_SUCCESS; 291 } 292 293 static void setup_unaccepted_memory(void) 294 { 295 efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID; 296 sev_memory_acceptance_protocol_t *proto; 297 efi_status_t status; 298 299 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 300 return; 301 302 /* 303 * Enable unaccepted memory before calling exit boot services in order 304 * for the UEFI to not accept all memory on EBS. 305 */ 306 status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL, 307 (void **)&proto); 308 if (status != EFI_SUCCESS) 309 return; 310 311 status = efi_call_proto(proto, allow_unaccepted_memory); 312 if (status != EFI_SUCCESS) 313 efi_err("Memory acceptance protocol failed\n"); 314 } 315 316 static efi_char16_t *efistub_fw_vendor(void) 317 { 318 unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor); 319 320 return (efi_char16_t *)vendor; 321 } 322 323 static const efi_char16_t apple[] = L"Apple"; 324 325 static void setup_quirks(struct boot_params *boot_params) 326 { 327 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) && 328 !memcmp(efistub_fw_vendor(), apple, sizeof(apple))) 329 retrieve_apple_device_properties(boot_params); 330 } 331 332 /* 333 * See if we have Universal Graphics Adapter (UGA) protocol 334 */ 335 static efi_status_t 336 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size) 337 { 338 efi_status_t status; 339 u32 width, height; 340 void **uga_handle = NULL; 341 efi_uga_draw_protocol_t *uga = NULL, *first_uga; 342 efi_handle_t handle; 343 int i; 344 345 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 346 (void **)&uga_handle); 347 if (status != EFI_SUCCESS) 348 return status; 349 350 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 351 uga_proto, NULL, &size, uga_handle); 352 if (status != EFI_SUCCESS) 353 goto free_handle; 354 355 height = 0; 356 width = 0; 357 358 first_uga = NULL; 359 for_each_efi_handle(handle, uga_handle, size, i) { 360 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID; 361 u32 w, h, depth, refresh; 362 void *pciio; 363 364 status = efi_bs_call(handle_protocol, handle, uga_proto, 365 (void **)&uga); 366 if (status != EFI_SUCCESS) 367 continue; 368 369 pciio = NULL; 370 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio); 371 372 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh); 373 if (status == EFI_SUCCESS && (!first_uga || pciio)) { 374 width = w; 375 height = h; 376 377 /* 378 * Once we've found a UGA supporting PCIIO, 379 * don't bother looking any further. 380 */ 381 if (pciio) 382 break; 383 384 first_uga = uga; 385 } 386 } 387 388 if (!width && !height) 389 goto free_handle; 390 391 /* EFI framebuffer */ 392 si->orig_video_isVGA = VIDEO_TYPE_EFI; 393 394 si->lfb_depth = 32; 395 si->lfb_width = width; 396 si->lfb_height = height; 397 398 si->red_size = 8; 399 si->red_pos = 16; 400 si->green_size = 8; 401 si->green_pos = 8; 402 si->blue_size = 8; 403 si->blue_pos = 0; 404 si->rsvd_size = 8; 405 si->rsvd_pos = 24; 406 407 free_handle: 408 efi_bs_call(free_pool, uga_handle); 409 410 return status; 411 } 412 413 static void setup_graphics(struct boot_params *boot_params) 414 { 415 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; 416 struct screen_info *si; 417 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; 418 efi_status_t status; 419 unsigned long size; 420 void **gop_handle = NULL; 421 void **uga_handle = NULL; 422 423 si = &boot_params->screen_info; 424 memset(si, 0, sizeof(*si)); 425 426 size = 0; 427 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 428 &graphics_proto, NULL, &size, gop_handle); 429 if (status == EFI_BUFFER_TOO_SMALL) 430 status = efi_setup_gop(si, &graphics_proto, size); 431 432 if (status != EFI_SUCCESS) { 433 size = 0; 434 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 435 &uga_proto, NULL, &size, uga_handle); 436 if (status == EFI_BUFFER_TOO_SMALL) 437 setup_uga(si, &uga_proto, size); 438 } 439 } 440 441 442 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) 443 { 444 efi_bs_call(exit, handle, status, 0, NULL); 445 for(;;) 446 asm("hlt"); 447 } 448 449 void __noreturn efi_stub_entry(efi_handle_t handle, 450 efi_system_table_t *sys_table_arg, 451 struct boot_params *boot_params); 452 453 /* 454 * Because the x86 boot code expects to be passed a boot_params we 455 * need to create one ourselves (usually the bootloader would create 456 * one for us). 457 */ 458 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 459 efi_system_table_t *sys_table_arg) 460 { 461 struct boot_params *boot_params; 462 struct setup_header *hdr; 463 void *image_base; 464 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; 465 int options_size = 0; 466 efi_status_t status; 467 char *cmdline_ptr; 468 469 efi_system_table = sys_table_arg; 470 471 /* Check if we were booted by the EFI firmware */ 472 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 473 efi_exit(handle, EFI_INVALID_PARAMETER); 474 475 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); 476 if (status != EFI_SUCCESS) { 477 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); 478 efi_exit(handle, status); 479 } 480 481 image_base = efi_table_attr(image, image_base); 482 483 status = efi_allocate_pages(sizeof(struct boot_params), 484 (unsigned long *)&boot_params, ULONG_MAX); 485 if (status != EFI_SUCCESS) { 486 efi_err("Failed to allocate lowmem for boot params\n"); 487 efi_exit(handle, status); 488 } 489 490 memset(boot_params, 0x0, sizeof(struct boot_params)); 491 492 hdr = &boot_params->hdr; 493 494 /* Copy the setup header from the second sector to boot_params */ 495 memcpy(&hdr->jump, image_base + 512, 496 sizeof(struct setup_header) - offsetof(struct setup_header, jump)); 497 498 /* 499 * Fill out some of the header fields ourselves because the 500 * EFI firmware loader doesn't load the first sector. 501 */ 502 hdr->root_flags = 1; 503 hdr->vid_mode = 0xffff; 504 hdr->boot_flag = 0xAA55; 505 506 hdr->type_of_loader = 0x21; 507 508 /* Convert unicode cmdline to ascii */ 509 cmdline_ptr = efi_convert_cmdline(image, &options_size); 510 if (!cmdline_ptr) 511 goto fail; 512 513 efi_set_u64_split((unsigned long)cmdline_ptr, 514 &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr); 515 516 hdr->ramdisk_image = 0; 517 hdr->ramdisk_size = 0; 518 519 /* 520 * Disregard any setup data that was provided by the bootloader: 521 * setup_data could be pointing anywhere, and we have no way of 522 * authenticating or validating the payload. 523 */ 524 hdr->setup_data = 0; 525 526 efi_stub_entry(handle, sys_table_arg, boot_params); 527 /* not reached */ 528 529 fail: 530 efi_free(sizeof(struct boot_params), (unsigned long)boot_params); 531 532 efi_exit(handle, status); 533 } 534 535 static void add_e820ext(struct boot_params *params, 536 struct setup_data *e820ext, u32 nr_entries) 537 { 538 struct setup_data *data; 539 540 e820ext->type = SETUP_E820_EXT; 541 e820ext->len = nr_entries * sizeof(struct boot_e820_entry); 542 e820ext->next = 0; 543 544 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 545 546 while (data && data->next) 547 data = (struct setup_data *)(unsigned long)data->next; 548 549 if (data) 550 data->next = (unsigned long)e820ext; 551 else 552 params->hdr.setup_data = (unsigned long)e820ext; 553 } 554 555 static efi_status_t 556 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) 557 { 558 struct boot_e820_entry *entry = params->e820_table; 559 struct efi_info *efi = ¶ms->efi_info; 560 struct boot_e820_entry *prev = NULL; 561 u32 nr_entries; 562 u32 nr_desc; 563 int i; 564 565 nr_entries = 0; 566 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; 567 568 for (i = 0; i < nr_desc; i++) { 569 efi_memory_desc_t *d; 570 unsigned int e820_type = 0; 571 unsigned long m = efi->efi_memmap; 572 573 #ifdef CONFIG_X86_64 574 m |= (u64)efi->efi_memmap_hi << 32; 575 #endif 576 577 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); 578 switch (d->type) { 579 case EFI_RESERVED_TYPE: 580 case EFI_RUNTIME_SERVICES_CODE: 581 case EFI_RUNTIME_SERVICES_DATA: 582 case EFI_MEMORY_MAPPED_IO: 583 case EFI_MEMORY_MAPPED_IO_PORT_SPACE: 584 case EFI_PAL_CODE: 585 e820_type = E820_TYPE_RESERVED; 586 break; 587 588 case EFI_UNUSABLE_MEMORY: 589 e820_type = E820_TYPE_UNUSABLE; 590 break; 591 592 case EFI_ACPI_RECLAIM_MEMORY: 593 e820_type = E820_TYPE_ACPI; 594 break; 595 596 case EFI_LOADER_CODE: 597 case EFI_LOADER_DATA: 598 case EFI_BOOT_SERVICES_CODE: 599 case EFI_BOOT_SERVICES_DATA: 600 case EFI_CONVENTIONAL_MEMORY: 601 if (efi_soft_reserve_enabled() && 602 (d->attribute & EFI_MEMORY_SP)) 603 e820_type = E820_TYPE_SOFT_RESERVED; 604 else 605 e820_type = E820_TYPE_RAM; 606 break; 607 608 case EFI_ACPI_MEMORY_NVS: 609 e820_type = E820_TYPE_NVS; 610 break; 611 612 case EFI_PERSISTENT_MEMORY: 613 e820_type = E820_TYPE_PMEM; 614 break; 615 616 case EFI_UNACCEPTED_MEMORY: 617 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 618 continue; 619 e820_type = E820_TYPE_RAM; 620 process_unaccepted_memory(d->phys_addr, 621 d->phys_addr + PAGE_SIZE * d->num_pages); 622 break; 623 default: 624 continue; 625 } 626 627 /* Merge adjacent mappings */ 628 if (prev && prev->type == e820_type && 629 (prev->addr + prev->size) == d->phys_addr) { 630 prev->size += d->num_pages << 12; 631 continue; 632 } 633 634 if (nr_entries == ARRAY_SIZE(params->e820_table)) { 635 u32 need = (nr_desc - i) * sizeof(struct e820_entry) + 636 sizeof(struct setup_data); 637 638 if (!e820ext || e820ext_size < need) 639 return EFI_BUFFER_TOO_SMALL; 640 641 /* boot_params map full, switch to e820 extended */ 642 entry = (struct boot_e820_entry *)e820ext->data; 643 } 644 645 entry->addr = d->phys_addr; 646 entry->size = d->num_pages << PAGE_SHIFT; 647 entry->type = e820_type; 648 prev = entry++; 649 nr_entries++; 650 } 651 652 if (nr_entries > ARRAY_SIZE(params->e820_table)) { 653 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); 654 655 add_e820ext(params, e820ext, nr_e820ext); 656 nr_entries -= nr_e820ext; 657 } 658 659 params->e820_entries = (u8)nr_entries; 660 661 return EFI_SUCCESS; 662 } 663 664 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, 665 u32 *e820ext_size) 666 { 667 efi_status_t status; 668 unsigned long size; 669 670 size = sizeof(struct setup_data) + 671 sizeof(struct e820_entry) * nr_desc; 672 673 if (*e820ext) { 674 efi_bs_call(free_pool, *e820ext); 675 *e820ext = NULL; 676 *e820ext_size = 0; 677 } 678 679 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 680 (void **)e820ext); 681 if (status == EFI_SUCCESS) 682 *e820ext_size = size; 683 684 return status; 685 } 686 687 static efi_status_t allocate_e820(struct boot_params *params, 688 struct setup_data **e820ext, 689 u32 *e820ext_size) 690 { 691 struct efi_boot_memmap *map; 692 efi_status_t status; 693 __u32 nr_desc; 694 695 status = efi_get_memory_map(&map, false); 696 if (status != EFI_SUCCESS) 697 return status; 698 699 nr_desc = map->map_size / map->desc_size; 700 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) { 701 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) + 702 EFI_MMAP_NR_SLACK_SLOTS; 703 704 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); 705 } 706 707 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS) 708 status = allocate_unaccepted_bitmap(nr_desc, map); 709 710 efi_bs_call(free_pool, map); 711 return status; 712 } 713 714 struct exit_boot_struct { 715 struct boot_params *boot_params; 716 struct efi_info *efi; 717 }; 718 719 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, 720 void *priv) 721 { 722 const char *signature; 723 struct exit_boot_struct *p = priv; 724 725 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE 726 : EFI32_LOADER_SIGNATURE; 727 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); 728 729 efi_set_u64_split((unsigned long)efi_system_table, 730 &p->efi->efi_systab, &p->efi->efi_systab_hi); 731 p->efi->efi_memdesc_size = map->desc_size; 732 p->efi->efi_memdesc_version = map->desc_ver; 733 efi_set_u64_split((unsigned long)map->map, 734 &p->efi->efi_memmap, &p->efi->efi_memmap_hi); 735 p->efi->efi_memmap_size = map->map_size; 736 737 return EFI_SUCCESS; 738 } 739 740 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 741 { 742 struct setup_data *e820ext = NULL; 743 __u32 e820ext_size = 0; 744 efi_status_t status; 745 struct exit_boot_struct priv; 746 747 priv.boot_params = boot_params; 748 priv.efi = &boot_params->efi_info; 749 750 status = allocate_e820(boot_params, &e820ext, &e820ext_size); 751 if (status != EFI_SUCCESS) 752 return status; 753 754 /* Might as well exit boot services now */ 755 status = efi_exit_boot_services(handle, &priv, exit_boot_func); 756 if (status != EFI_SUCCESS) 757 return status; 758 759 /* Historic? */ 760 boot_params->alt_mem_k = 32 * 1024; 761 762 status = setup_e820(boot_params, e820ext, e820ext_size); 763 if (status != EFI_SUCCESS) 764 return status; 765 766 return EFI_SUCCESS; 767 } 768 769 static bool have_unsupported_snp_features(void) 770 { 771 u64 unsupported; 772 773 unsupported = snp_get_unsupported_features(sev_get_status()); 774 if (unsupported) { 775 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n", 776 unsupported); 777 return true; 778 } 779 return false; 780 } 781 782 static void efi_get_seed(void *seed, int size) 783 { 784 efi_get_random_bytes(size, seed); 785 786 /* 787 * This only updates seed[0] when running on 32-bit, but in that case, 788 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit. 789 */ 790 *(unsigned long *)seed ^= kaslr_get_random_long("EFI"); 791 } 792 793 static void error(char *str) 794 { 795 efi_warn("Decompression failed: %s\n", str); 796 } 797 798 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry) 799 { 800 unsigned long virt_addr = LOAD_PHYSICAL_ADDR; 801 unsigned long addr, alloc_size, entry; 802 efi_status_t status; 803 u32 seed[2] = {}; 804 805 /* determine the required size of the allocation */ 806 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size), 807 MIN_KERNEL_ALIGN); 808 809 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) { 810 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size; 811 static const efi_char16_t ami[] = L"American Megatrends"; 812 813 efi_get_seed(seed, sizeof(seed)); 814 815 virt_addr += (range * seed[1]) >> 32; 816 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1); 817 818 /* 819 * Older Dell systems with AMI UEFI firmware v2.0 may hang 820 * while decompressing the kernel if physical address 821 * randomization is enabled. 822 * 823 * https://bugzilla.kernel.org/show_bug.cgi?id=218173 824 */ 825 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION && 826 !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) { 827 efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n"); 828 seed[0] = 0; 829 } 830 } 831 832 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr, 833 seed[0], EFI_LOADER_CODE, 834 EFI_X86_KERNEL_ALLOC_LIMIT); 835 if (status != EFI_SUCCESS) 836 return status; 837 838 entry = decompress_kernel((void *)addr, virt_addr, error); 839 if (entry == ULONG_MAX) { 840 efi_free(alloc_size, addr); 841 return EFI_LOAD_ERROR; 842 } 843 844 *kernel_entry = addr + entry; 845 846 return efi_adjust_memory_range_protection(addr, kernel_total_size); 847 } 848 849 static void __noreturn enter_kernel(unsigned long kernel_addr, 850 struct boot_params *boot_params) 851 { 852 /* enter decompressed kernel with boot_params pointer in RSI/ESI */ 853 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params)); 854 855 unreachable(); 856 } 857 858 /* 859 * On success, this routine will jump to the relocated image directly and never 860 * return. On failure, it will exit to the firmware via efi_exit() instead of 861 * returning. 862 */ 863 void __noreturn efi_stub_entry(efi_handle_t handle, 864 efi_system_table_t *sys_table_arg, 865 struct boot_params *boot_params) 866 { 867 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID; 868 struct setup_header *hdr = &boot_params->hdr; 869 const struct linux_efi_initrd *initrd = NULL; 870 unsigned long kernel_entry; 871 efi_status_t status; 872 873 boot_params_pointer = boot_params; 874 875 efi_system_table = sys_table_arg; 876 /* Check if we were booted by the EFI firmware */ 877 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 878 efi_exit(handle, EFI_INVALID_PARAMETER); 879 880 if (have_unsupported_snp_features()) 881 efi_exit(handle, EFI_UNSUPPORTED); 882 883 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) { 884 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID); 885 if (efi_dxe_table && 886 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) { 887 efi_warn("Ignoring DXE services table: invalid signature\n"); 888 efi_dxe_table = NULL; 889 } 890 } 891 892 /* grab the memory attributes protocol if it exists */ 893 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr); 894 895 status = efi_setup_5level_paging(); 896 if (status != EFI_SUCCESS) { 897 efi_err("efi_setup_5level_paging() failed!\n"); 898 goto fail; 899 } 900 901 #ifdef CONFIG_CMDLINE_BOOL 902 status = efi_parse_options(CONFIG_CMDLINE); 903 if (status != EFI_SUCCESS) { 904 efi_err("Failed to parse options\n"); 905 goto fail; 906 } 907 #endif 908 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { 909 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | 910 ((u64)boot_params->ext_cmd_line_ptr << 32)); 911 status = efi_parse_options((char *)cmdline_paddr); 912 if (status != EFI_SUCCESS) { 913 efi_err("Failed to parse options\n"); 914 goto fail; 915 } 916 } 917 918 status = efi_decompress_kernel(&kernel_entry); 919 if (status != EFI_SUCCESS) { 920 efi_err("Failed to decompress kernel\n"); 921 goto fail; 922 } 923 924 /* 925 * At this point, an initrd may already have been loaded by the 926 * bootloader and passed via bootparams. We permit an initrd loaded 927 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. 928 * 929 * If the device path is not present, any command-line initrd= 930 * arguments will be processed only if image is not NULL, which will be 931 * the case only if we were loaded via the PE entry point. 932 */ 933 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX, 934 &initrd); 935 if (status != EFI_SUCCESS) 936 goto fail; 937 if (initrd && initrd->size > 0) { 938 efi_set_u64_split(initrd->base, &hdr->ramdisk_image, 939 &boot_params->ext_ramdisk_image); 940 efi_set_u64_split(initrd->size, &hdr->ramdisk_size, 941 &boot_params->ext_ramdisk_size); 942 } 943 944 945 /* 946 * If the boot loader gave us a value for secure_boot then we use that, 947 * otherwise we ask the BIOS. 948 */ 949 if (boot_params->secure_boot == efi_secureboot_mode_unset) 950 boot_params->secure_boot = efi_get_secureboot(); 951 952 /* Ask the firmware to clear memory on unclean shutdown */ 953 efi_enable_reset_attack_mitigation(); 954 955 efi_random_get_seed(); 956 957 efi_retrieve_tpm2_eventlog(); 958 959 setup_graphics(boot_params); 960 961 setup_efi_pci(boot_params); 962 963 setup_quirks(boot_params); 964 965 setup_unaccepted_memory(); 966 967 status = exit_boot(boot_params, handle); 968 if (status != EFI_SUCCESS) { 969 efi_err("exit_boot() failed!\n"); 970 goto fail; 971 } 972 973 /* 974 * Call the SEV init code while still running with the firmware's 975 * GDT/IDT, so #VC exceptions will be handled by EFI. 976 */ 977 sev_enable(boot_params); 978 979 efi_5level_switch(); 980 981 enter_kernel(kernel_entry, boot_params); 982 fail: 983 efi_err("efi_stub_entry() failed!\n"); 984 985 efi_exit(handle, status); 986 } 987 988 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL 989 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 990 struct boot_params *boot_params) 991 { 992 extern char _bss[], _ebss[]; 993 994 memset(_bss, 0, _ebss - _bss); 995 efi_stub_entry(handle, sys_table_arg, boot_params); 996 } 997 998 #ifndef CONFIG_EFI_MIXED 999 extern __alias(efi_handover_entry) 1000 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 1001 struct boot_params *boot_params); 1002 1003 extern __alias(efi_handover_entry) 1004 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 1005 struct boot_params *boot_params); 1006 #endif 1007 #endif 1008