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 24extern char _bss[], _ebss[]; 25 26const efi_system_table_t *efi_system_table; 27const efi_dxe_services_table_t *efi_dxe_table; 28static efi_loaded_image_t *image = NULL; 29static efi_memory_attribute_protocol_t *memattr; 30 31typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t; 32union 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 42static efi_status_t 43preserve_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 105free_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 */ 119static 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 174free_handle: 175 efi_bs_call(free_pool, pci_handle); 176} 177 178static 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 228efi_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 304static 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 327static 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 334static const efi_char16_t apple[] = L"Apple"; 335 336static 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 */ 346static efi_status_t 347setup_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 418free_handle: 419 efi_bs_call(free_pool, uga_handle); 420 421 return status; 422} 423 424static 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 453static 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 460void __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 */ 469efi_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 hdr->initrd_addr_max = INT_MAX; 500 501 /* Convert unicode cmdline to ascii */ 502 cmdline_ptr = efi_convert_cmdline(image, &options_size); 503 if (!cmdline_ptr) 504 goto fail; 505 506 efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr, 507 &boot_params.ext_cmd_line_ptr); 508 509 efi_stub_entry(handle, sys_table_arg, &boot_params); 510 /* not reached */ 511 512fail: 513 efi_exit(handle, status); 514} 515 516static void add_e820ext(struct boot_params *params, 517 struct setup_data *e820ext, u32 nr_entries) 518{ 519 struct setup_data *data; 520 521 e820ext->type = SETUP_E820_EXT; 522 e820ext->len = nr_entries * sizeof(struct boot_e820_entry); 523 e820ext->next = 0; 524 525 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 526 527 while (data && data->next) 528 data = (struct setup_data *)(unsigned long)data->next; 529 530 if (data) 531 data->next = (unsigned long)e820ext; 532 else 533 params->hdr.setup_data = (unsigned long)e820ext; 534} 535 536static efi_status_t 537setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) 538{ 539 struct boot_e820_entry *entry = params->e820_table; 540 struct efi_info *efi = ¶ms->efi_info; 541 struct boot_e820_entry *prev = NULL; 542 u32 nr_entries; 543 u32 nr_desc; 544 int i; 545 546 nr_entries = 0; 547 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; 548 549 for (i = 0; i < nr_desc; i++) { 550 efi_memory_desc_t *d; 551 unsigned int e820_type = 0; 552 unsigned long m = efi->efi_memmap; 553 554#ifdef CONFIG_X86_64 555 m |= (u64)efi->efi_memmap_hi << 32; 556#endif 557 558 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); 559 switch (d->type) { 560 case EFI_RESERVED_TYPE: 561 case EFI_RUNTIME_SERVICES_CODE: 562 case EFI_RUNTIME_SERVICES_DATA: 563 case EFI_MEMORY_MAPPED_IO: 564 case EFI_MEMORY_MAPPED_IO_PORT_SPACE: 565 case EFI_PAL_CODE: 566 e820_type = E820_TYPE_RESERVED; 567 break; 568 569 case EFI_UNUSABLE_MEMORY: 570 e820_type = E820_TYPE_UNUSABLE; 571 break; 572 573 case EFI_ACPI_RECLAIM_MEMORY: 574 e820_type = E820_TYPE_ACPI; 575 break; 576 577 case EFI_LOADER_CODE: 578 case EFI_LOADER_DATA: 579 case EFI_BOOT_SERVICES_CODE: 580 case EFI_BOOT_SERVICES_DATA: 581 case EFI_CONVENTIONAL_MEMORY: 582 if (efi_soft_reserve_enabled() && 583 (d->attribute & EFI_MEMORY_SP)) 584 e820_type = E820_TYPE_SOFT_RESERVED; 585 else 586 e820_type = E820_TYPE_RAM; 587 break; 588 589 case EFI_ACPI_MEMORY_NVS: 590 e820_type = E820_TYPE_NVS; 591 break; 592 593 case EFI_PERSISTENT_MEMORY: 594 e820_type = E820_TYPE_PMEM; 595 break; 596 597 case EFI_UNACCEPTED_MEMORY: 598 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 599 continue; 600 e820_type = E820_TYPE_RAM; 601 process_unaccepted_memory(d->phys_addr, 602 d->phys_addr + PAGE_SIZE * d->num_pages); 603 break; 604 default: 605 continue; 606 } 607 608 /* Merge adjacent mappings */ 609 if (prev && prev->type == e820_type && 610 (prev->addr + prev->size) == d->phys_addr) { 611 prev->size += d->num_pages << 12; 612 continue; 613 } 614 615 if (nr_entries == ARRAY_SIZE(params->e820_table)) { 616 u32 need = (nr_desc - i) * sizeof(struct e820_entry) + 617 sizeof(struct setup_data); 618 619 if (!e820ext || e820ext_size < need) 620 return EFI_BUFFER_TOO_SMALL; 621 622 /* boot_params map full, switch to e820 extended */ 623 entry = (struct boot_e820_entry *)e820ext->data; 624 } 625 626 entry->addr = d->phys_addr; 627 entry->size = d->num_pages << PAGE_SHIFT; 628 entry->type = e820_type; 629 prev = entry++; 630 nr_entries++; 631 } 632 633 if (nr_entries > ARRAY_SIZE(params->e820_table)) { 634 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); 635 636 add_e820ext(params, e820ext, nr_e820ext); 637 nr_entries -= nr_e820ext; 638 } 639 640 params->e820_entries = (u8)nr_entries; 641 642 return EFI_SUCCESS; 643} 644 645static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, 646 u32 *e820ext_size) 647{ 648 efi_status_t status; 649 unsigned long size; 650 651 size = sizeof(struct setup_data) + 652 sizeof(struct e820_entry) * nr_desc; 653 654 if (*e820ext) { 655 efi_bs_call(free_pool, *e820ext); 656 *e820ext = NULL; 657 *e820ext_size = 0; 658 } 659 660 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 661 (void **)e820ext); 662 if (status == EFI_SUCCESS) 663 *e820ext_size = size; 664 665 return status; 666} 667 668static efi_status_t allocate_e820(struct boot_params *params, 669 struct setup_data **e820ext, 670 u32 *e820ext_size) 671{ 672 struct efi_boot_memmap *map; 673 efi_status_t status; 674 __u32 nr_desc; 675 676 status = efi_get_memory_map(&map, false); 677 if (status != EFI_SUCCESS) 678 return status; 679 680 nr_desc = map->map_size / map->desc_size; 681 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) { 682 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) + 683 EFI_MMAP_NR_SLACK_SLOTS; 684 685 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); 686 } 687 688 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS) 689 status = allocate_unaccepted_bitmap(nr_desc, map); 690 691 efi_bs_call(free_pool, map); 692 return status; 693} 694 695struct exit_boot_struct { 696 struct boot_params *boot_params; 697 struct efi_info *efi; 698}; 699 700static efi_status_t exit_boot_func(struct efi_boot_memmap *map, 701 void *priv) 702{ 703 const char *signature; 704 struct exit_boot_struct *p = priv; 705 706 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE 707 : EFI32_LOADER_SIGNATURE; 708 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); 709 710 efi_set_u64_split((unsigned long)efi_system_table, 711 &p->efi->efi_systab, &p->efi->efi_systab_hi); 712 p->efi->efi_memdesc_size = map->desc_size; 713 p->efi->efi_memdesc_version = map->desc_ver; 714 efi_set_u64_split((unsigned long)map->map, 715 &p->efi->efi_memmap, &p->efi->efi_memmap_hi); 716 p->efi->efi_memmap_size = map->map_size; 717 718 return EFI_SUCCESS; 719} 720 721static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 722{ 723 struct setup_data *e820ext = NULL; 724 __u32 e820ext_size = 0; 725 efi_status_t status; 726 struct exit_boot_struct priv; 727 728 priv.boot_params = boot_params; 729 priv.efi = &boot_params->efi_info; 730 731 status = allocate_e820(boot_params, &e820ext, &e820ext_size); 732 if (status != EFI_SUCCESS) 733 return status; 734 735 /* Might as well exit boot services now */ 736 status = efi_exit_boot_services(handle, &priv, exit_boot_func); 737 if (status != EFI_SUCCESS) 738 return status; 739 740 /* Historic? */ 741 boot_params->alt_mem_k = 32 * 1024; 742 743 status = setup_e820(boot_params, e820ext, e820ext_size); 744 if (status != EFI_SUCCESS) 745 return status; 746 747 return EFI_SUCCESS; 748} 749 750static bool have_unsupported_snp_features(void) 751{ 752 u64 unsupported; 753 754 unsupported = snp_get_unsupported_features(sev_get_status()); 755 if (unsupported) { 756 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n", 757 unsupported); 758 return true; 759 } 760 return false; 761} 762 763static void efi_get_seed(void *seed, int size) 764{ 765 efi_get_random_bytes(size, seed); 766 767 /* 768 * This only updates seed[0] when running on 32-bit, but in that case, 769 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit. 770 */ 771 *(unsigned long *)seed ^= kaslr_get_random_long("EFI"); 772} 773 774static void error(char *str) 775{ 776 efi_warn("Decompression failed: %s\n", str); 777} 778 779static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry) 780{ 781 unsigned long virt_addr = LOAD_PHYSICAL_ADDR; 782 unsigned long addr, alloc_size, entry; 783 efi_status_t status; 784 u32 seed[2] = {}; 785 786 /* determine the required size of the allocation */ 787 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size), 788 MIN_KERNEL_ALIGN); 789 790 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) { 791 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size; 792 static const efi_char16_t ami[] = L"American Megatrends"; 793 794 efi_get_seed(seed, sizeof(seed)); 795 796 virt_addr += (range * seed[1]) >> 32; 797 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1); 798 799 /* 800 * Older Dell systems with AMI UEFI firmware v2.0 may hang 801 * while decompressing the kernel if physical address 802 * randomization is enabled. 803 * 804 * https://bugzilla.kernel.org/show_bug.cgi?id=218173 805 */ 806 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION && 807 !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) { 808 efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n"); 809 seed[0] = 0; 810 } 811 812 boot_params_ptr->hdr.loadflags |= KASLR_FLAG; 813 } 814 815 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr, 816 seed[0], EFI_LOADER_CODE, 817 LOAD_PHYSICAL_ADDR, 818 EFI_X86_KERNEL_ALLOC_LIMIT); 819 if (status != EFI_SUCCESS) 820 return status; 821 822 entry = decompress_kernel((void *)addr, virt_addr, error); 823 if (entry == ULONG_MAX) { 824 efi_free(alloc_size, addr); 825 return EFI_LOAD_ERROR; 826 } 827 828 *kernel_entry = addr + entry; 829 830 return efi_adjust_memory_range_protection(addr, kernel_text_size); 831} 832 833static void __noreturn enter_kernel(unsigned long kernel_addr, 834 struct boot_params *boot_params) 835{ 836 /* enter decompressed kernel with boot_params pointer in RSI/ESI */ 837 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params)); 838 839 unreachable(); 840} 841 842/* 843 * On success, this routine will jump to the relocated image directly and never 844 * return. On failure, it will exit to the firmware via efi_exit() instead of 845 * returning. 846 */ 847void __noreturn efi_stub_entry(efi_handle_t handle, 848 efi_system_table_t *sys_table_arg, 849 struct boot_params *boot_params) 850{ 851 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID; 852 struct setup_header *hdr = &boot_params->hdr; 853 const struct linux_efi_initrd *initrd = NULL; 854 unsigned long kernel_entry; 855 efi_status_t status; 856 857 boot_params_ptr = boot_params; 858 859 efi_system_table = sys_table_arg; 860 /* Check if we were booted by the EFI firmware */ 861 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 862 efi_exit(handle, EFI_INVALID_PARAMETER); 863 864 if (have_unsupported_snp_features()) 865 efi_exit(handle, EFI_UNSUPPORTED); 866 867 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) { 868 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID); 869 if (efi_dxe_table && 870 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) { 871 efi_warn("Ignoring DXE services table: invalid signature\n"); 872 efi_dxe_table = NULL; 873 } 874 } 875 876 /* grab the memory attributes protocol if it exists */ 877 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr); 878 879 status = efi_setup_5level_paging(); 880 if (status != EFI_SUCCESS) { 881 efi_err("efi_setup_5level_paging() failed!\n"); 882 goto fail; 883 } 884 885#ifdef CONFIG_CMDLINE_BOOL 886 status = efi_parse_options(CONFIG_CMDLINE); 887 if (status != EFI_SUCCESS) { 888 efi_err("Failed to parse options\n"); 889 goto fail; 890 } 891#endif 892 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { 893 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | 894 ((u64)boot_params->ext_cmd_line_ptr << 32)); 895 status = efi_parse_options((char *)cmdline_paddr); 896 if (status != EFI_SUCCESS) { 897 efi_err("Failed to parse options\n"); 898 goto fail; 899 } 900 } 901 902 if (efi_mem_encrypt > 0) 903 hdr->xloadflags |= XLF_MEM_ENCRYPTION; 904 905 status = efi_decompress_kernel(&kernel_entry); 906 if (status != EFI_SUCCESS) { 907 efi_err("Failed to decompress kernel\n"); 908 goto fail; 909 } 910 911 /* 912 * At this point, an initrd may already have been loaded by the 913 * bootloader and passed via bootparams. We permit an initrd loaded 914 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. 915 * 916 * If the device path is not present, any command-line initrd= 917 * arguments will be processed only if image is not NULL, which will be 918 * the case only if we were loaded via the PE entry point. 919 */ 920 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX, 921 &initrd); 922 if (status != EFI_SUCCESS) 923 goto fail; 924 if (initrd && initrd->size > 0) { 925 efi_set_u64_split(initrd->base, &hdr->ramdisk_image, 926 &boot_params->ext_ramdisk_image); 927 efi_set_u64_split(initrd->size, &hdr->ramdisk_size, 928 &boot_params->ext_ramdisk_size); 929 } 930 931 932 /* 933 * If the boot loader gave us a value for secure_boot then we use that, 934 * otherwise we ask the BIOS. 935 */ 936 if (boot_params->secure_boot == efi_secureboot_mode_unset) 937 boot_params->secure_boot = efi_get_secureboot(); 938 939 /* Ask the firmware to clear memory on unclean shutdown */ 940 efi_enable_reset_attack_mitigation(); 941 942 efi_random_get_seed(); 943 944 efi_retrieve_eventlog(); 945 946 setup_graphics(boot_params); 947 948 setup_efi_pci(boot_params); 949 950 setup_quirks(boot_params); 951 952 setup_unaccepted_memory(); 953 954 status = exit_boot(boot_params, handle); 955 if (status != EFI_SUCCESS) { 956 efi_err("exit_boot() failed!\n"); 957 goto fail; 958 } 959 960 /* 961 * Call the SEV init code while still running with the firmware's 962 * GDT/IDT, so #VC exceptions will be handled by EFI. 963 */ 964 sev_enable(boot_params); 965 966 efi_5level_switch(); 967 968 enter_kernel(kernel_entry, boot_params); 969fail: 970 efi_err("efi_stub_entry() failed!\n"); 971 972 efi_exit(handle, status); 973} 974 975#ifdef CONFIG_EFI_HANDOVER_PROTOCOL 976void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 977 struct boot_params *boot_params) 978{ 979 memset(_bss, 0, _ebss - _bss); 980 efi_stub_entry(handle, sys_table_arg, boot_params); 981} 982 983#ifndef CONFIG_EFI_MIXED 984extern __alias(efi_handover_entry) 985void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 986 struct boot_params *boot_params); 987 988extern __alias(efi_handover_entry) 989void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, 990 struct boot_params *boot_params); 991#endif 992#endif 993