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