drivers/firmware/efi/libstub/x86-stub.c

   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 __free(efi_pool) = 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
  79         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
  80                                 PCI_VENDOR_ID, 1, &rom->vendor);
  81
  82         if (status != EFI_SUCCESS) {
  83                 efi_err("Failed to read rom->vendor\n");
  84                 return status;
  85         }
  86
  87         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
  88                                 PCI_DEVICE_ID, 1, &rom->devid);
  89
  90         if (status != EFI_SUCCESS) {
  91                 efi_err("Failed to read rom->devid\n");
  92                 return status;
  93         }
  94
  95         status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
  96                                 &rom->device, &rom->function);
  97
  98         if (status != EFI_SUCCESS)
  99                 return status;
 100
 101         memcpy(rom->romdata, romimage, romsize);
 102         *__rom = no_free_ptr(rom);
 103         return EFI_SUCCESS;
 104 }
 105
 106 /*
 107  * There's no way to return an informative status from this function,
 108  * because any analysis (and printing of error messages) needs to be
 109  * done directly at the EFI function call-site.
 110  *
 111  * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
 112  * just didn't find any PCI devices, but there's no way to tell outside
 113  * the context of the call.
 114  */
 115 static void setup_efi_pci(struct boot_params *params)
 116 {
 117         efi_status_t status;
 118         efi_handle_t *pci_handle __free(efi_pool) = NULL;
 119         efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
 120         struct setup_data *data;
 121         unsigned long num;
 122         efi_handle_t h;
 123
 124         status = efi_bs_call(locate_handle_buffer, EFI_LOCATE_BY_PROTOCOL,
 125                              &pci_proto, NULL, &num, &pci_handle);
 126         if (status != EFI_SUCCESS)
 127                 return;
 128
 129         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 130
 131         while (data && data->next)
 132                 data = (struct setup_data *)(unsigned long)data->next;
 133
 134         for_each_efi_handle(h, pci_handle, num) {
 135                 efi_pci_io_protocol_t *pci = NULL;
 136                 struct pci_setup_rom *rom;
 137
 138                 status = efi_bs_call(handle_protocol, h, &pci_proto,
 139                                      (void **)&pci);
 140                 if (status != EFI_SUCCESS || !pci)
 141                         continue;
 142
 143                 status = preserve_pci_rom_image(pci, &rom);
 144                 if (status != EFI_SUCCESS)
 145                         continue;
 146
 147                 if (data)
 148                         data->next = (unsigned long)rom;
 149                 else
 150                         params->hdr.setup_data = (unsigned long)rom;
 151
 152                 data = (struct setup_data *)rom;
 153         }
 154 }
 155
 156 static void retrieve_apple_device_properties(struct boot_params *boot_params)
 157 {
 158         efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
 159         struct setup_data *data, *new;
 160         efi_status_t status;
 161         u32 size = 0;
 162         apple_properties_protocol_t *p;
 163
 164         status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
 165         if (status != EFI_SUCCESS)
 166                 return;
 167
 168         if (efi_table_attr(p, version) != 0x10000) {
 169                 efi_err("Unsupported properties proto version\n");
 170                 return;
 171         }
 172
 173         efi_call_proto(p, get_all, NULL, &size);
 174         if (!size)
 175                 return;
 176
 177         do {
 178                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
 179                                      size + sizeof(struct setup_data),
 180                                      (void **)&new);
 181                 if (status != EFI_SUCCESS) {
 182                         efi_err("Failed to allocate memory for 'properties'\n");
 183                         return;
 184                 }
 185
 186                 status = efi_call_proto(p, get_all, new->data, &size);
 187
 188                 if (status == EFI_BUFFER_TOO_SMALL)
 189                         efi_bs_call(free_pool, new);
 190         } while (status == EFI_BUFFER_TOO_SMALL);
 191
 192         new->type = SETUP_APPLE_PROPERTIES;
 193         new->len  = size;
 194         new->next = 0;
 195
 196         data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
 197         if (!data) {
 198                 boot_params->hdr.setup_data = (unsigned long)new;
 199         } else {
 200                 while (data->next)
 201                         data = (struct setup_data *)(unsigned long)data->next;
 202                 data->next = (unsigned long)new;
 203         }
 204 }
 205
 206 static bool apple_match_product_name(void)
 207 {
 208         static const char type1_product_matches[][15] = {
 209                 "MacBookPro11,3",
 210                 "MacBookPro11,5",
 211                 "MacBookPro13,3",
 212                 "MacBookPro14,3",
 213                 "MacBookPro15,1",
 214                 "MacBookPro15,3",
 215                 "MacBookPro16,1",
 216                 "MacBookPro16,4",
 217         };
 218         const struct efi_smbios_type1_record *record;
 219         const u8 *product;
 220
 221         record = (struct efi_smbios_type1_record *)efi_get_smbios_record(1);
 222         if (!record)
 223                 return false;
 224
 225         product = efi_get_smbios_string(record, product_name);
 226         if (!product)
 227                 return false;
 228
 229         for (int i = 0; i < ARRAY_SIZE(type1_product_matches); i++) {
 230                 if (!strcmp(product, type1_product_matches[i]))
 231                         return true;
 232         }
 233
 234         return false;
 235 }
 236
 237 static void apple_set_os(void)
 238 {
 239         struct {
 240                 unsigned long version;
 241                 efi_status_t (__efiapi *set_os_version)(const char *);
 242                 efi_status_t (__efiapi *set_os_vendor)(const char *);
 243         } *set_os;
 244         efi_status_t status;
 245
 246         if (!efi_is_64bit() || !apple_match_product_name())
 247                 return;
 248
 249         status = efi_bs_call(locate_protocol, &APPLE_SET_OS_PROTOCOL_GUID, NULL,
 250                              (void **)&set_os);
 251         if (status != EFI_SUCCESS)
 252                 return;
 253
 254         if (set_os->version >= 2) {
 255                 status = set_os->set_os_vendor("Apple Inc.");
 256                 if (status != EFI_SUCCESS)
 257                         efi_err("Failed to set OS vendor via apple_set_os\n");
 258         }
 259
 260         if (set_os->version > 0) {
 261                 /* The version being set doesn't seem to matter */
 262                 status = set_os->set_os_version("Mac OS X 10.9");
 263                 if (status != EFI_SUCCESS)
 264                         efi_err("Failed to set OS version via apple_set_os\n");
 265         }
 266 }
 267
 268 efi_status_t efi_adjust_memory_range_protection(unsigned long start,
 269                                                 unsigned long size)
 270 {
 271         efi_status_t status;
 272         efi_gcd_memory_space_desc_t desc;
 273         unsigned long end, next;
 274         unsigned long rounded_start, rounded_end;
 275         unsigned long unprotect_start, unprotect_size;
 276
 277         rounded_start = rounddown(start, EFI_PAGE_SIZE);
 278         rounded_end = roundup(start + size, EFI_PAGE_SIZE);
 279
 280         if (memattr != NULL) {
 281                 status = efi_call_proto(memattr, set_memory_attributes,
 282                                         rounded_start,
 283                                         rounded_end - rounded_start,
 284                                         EFI_MEMORY_RO);
 285                 if (status != EFI_SUCCESS) {
 286                         efi_warn("Failed to set EFI_MEMORY_RO attribute\n");
 287                         return status;
 288                 }
 289
 290                 status = efi_call_proto(memattr, clear_memory_attributes,
 291                                         rounded_start,
 292                                         rounded_end - rounded_start,
 293                                         EFI_MEMORY_XP);
 294                 if (status != EFI_SUCCESS)
 295                         efi_warn("Failed to clear EFI_MEMORY_XP attribute\n");
 296                 return status;
 297         }
 298
 299         if (efi_dxe_table == NULL)
 300                 return EFI_SUCCESS;
 301
 302         /*
 303          * Don't modify memory region attributes, they are
 304          * already suitable, to lower the possibility to
 305          * encounter firmware bugs.
 306          */
 307
 308         for (end = start + size; start < end; start = next) {
 309
 310                 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
 311
 312                 if (status != EFI_SUCCESS)
 313                         break;
 314
 315                 next = desc.base_address + desc.length;
 316
 317                 /*
 318                  * Only system memory is suitable for trampoline/kernel image placement,
 319                  * so only this type of memory needs its attributes to be modified.
 320                  */
 321
 322                 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
 323                     (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
 324                         continue;
 325
 326                 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
 327                 unprotect_size = min(rounded_end, next) - unprotect_start;
 328
 329                 status = efi_dxe_call(set_memory_space_attributes,
 330                                       unprotect_start, unprotect_size,
 331                                       EFI_MEMORY_WB);
 332
 333                 if (status != EFI_SUCCESS) {
 334                         efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
 335                                  unprotect_start,
 336                                  unprotect_start + unprotect_size,
 337                                  status);
 338                         break;
 339                 }
 340         }
 341         return EFI_SUCCESS;
 342 }
 343
 344 static void setup_unaccepted_memory(void)
 345 {
 346         efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID;
 347         sev_memory_acceptance_protocol_t *proto;
 348         efi_status_t status;
 349
 350         if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
 351                 return;
 352
 353         /*
 354          * Enable unaccepted memory before calling exit boot services in order
 355          * for the UEFI to not accept all memory on EBS.
 356          */
 357         status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL,
 358                              (void **)&proto);
 359         if (status != EFI_SUCCESS)
 360                 return;
 361
 362         status = efi_call_proto(proto, allow_unaccepted_memory);
 363         if (status != EFI_SUCCESS)
 364                 efi_err("Memory acceptance protocol failed\n");
 365 }
 366
 367 static efi_char16_t *efistub_fw_vendor(void)
 368 {
 369         unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor);
 370
 371         return (efi_char16_t *)vendor;
 372 }
 373
 374 static const efi_char16_t apple[] = L"Apple";
 375
 376 static void setup_quirks(struct boot_params *boot_params)
 377 {
 378         if (!memcmp(efistub_fw_vendor(), apple, sizeof(apple))) {
 379                 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
 380                         retrieve_apple_device_properties(boot_params);
 381
 382                 apple_set_os();
 383         }
 384 }
 385
 386 static void setup_graphics(struct boot_params *boot_params)
 387 {
 388         struct screen_info *si = memset(&boot_params->screen_info, 0, sizeof(*si));
 389
 390         efi_setup_gop(si);
 391 }
 392
 393 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
 394 {
 395         efi_bs_call(exit, handle, status, 0, NULL);
 396         for(;;)
 397                 asm("hlt");
 398 }
 399
 400 void __noreturn efi_stub_entry(efi_handle_t handle,
 401                                efi_system_table_t *sys_table_arg,
 402                                struct boot_params *boot_params);
 403
 404 /*
 405  * Because the x86 boot code expects to be passed a boot_params we
 406  * need to create one ourselves (usually the bootloader would create
 407  * one for us).
 408  */
 409 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 410                                    efi_system_table_t *sys_table_arg)
 411 {
 412         efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
 413         struct boot_params *boot_params;
 414         struct setup_header *hdr;
 415         efi_status_t status;
 416         unsigned long alloc;
 417         char *cmdline_ptr;
 418
 419         efi_system_table = sys_table_arg;
 420
 421         /* Check if we were booted by the EFI firmware */
 422         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 423                 efi_exit(handle, EFI_INVALID_PARAMETER);
 424
 425         status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
 426         if (status != EFI_SUCCESS) {
 427                 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
 428                 efi_exit(handle, status);
 429         }
 430
 431         status = efi_allocate_pages(PARAM_SIZE, &alloc, ULONG_MAX);
 432         if (status != EFI_SUCCESS)
 433                 efi_exit(handle, status);
 434
 435         boot_params = memset((void *)alloc, 0x0, PARAM_SIZE);
 436         hdr         = &boot_params->hdr;
 437
 438         /* Assign the setup_header fields that the kernel actually cares about */
 439         hdr->root_flags = 1;
 440         hdr->vid_mode   = 0xffff;
 441
 442         hdr->type_of_loader = 0x21;
 443         hdr->initrd_addr_max = INT_MAX;
 444
 445         /* Convert unicode cmdline to ascii */
 446         cmdline_ptr = efi_convert_cmdline(image);
 447         if (!cmdline_ptr) {
 448                 efi_free(PARAM_SIZE, alloc);
 449                 efi_exit(handle, EFI_OUT_OF_RESOURCES);
 450         }
 451
 452         efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr,
 453                           &boot_params->ext_cmd_line_ptr);
 454
 455         efi_stub_entry(handle, sys_table_arg, boot_params);
 456         /* not reached */
 457 }
 458
 459 static void add_e820ext(struct boot_params *params,
 460                         struct setup_data *e820ext, u32 nr_entries)
 461 {
 462         struct setup_data *data;
 463
 464         e820ext->type = SETUP_E820_EXT;
 465         e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
 466         e820ext->next = 0;
 467
 468         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 469
 470         while (data && data->next)
 471                 data = (struct setup_data *)(unsigned long)data->next;
 472
 473         if (data)
 474                 data->next = (unsigned long)e820ext;
 475         else
 476                 params->hdr.setup_data = (unsigned long)e820ext;
 477 }
 478
 479 static efi_status_t
 480 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
 481 {
 482         struct boot_e820_entry *entry = params->e820_table;
 483         struct efi_info *efi = &params->efi_info;
 484         struct boot_e820_entry *prev = NULL;
 485         u32 nr_entries;
 486         u32 nr_desc;
 487         int i;
 488
 489         nr_entries = 0;
 490         nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
 491
 492         for (i = 0; i < nr_desc; i++) {
 493                 efi_memory_desc_t *d;
 494                 unsigned int e820_type = 0;
 495                 unsigned long m = efi->efi_memmap;
 496
 497 #ifdef CONFIG_X86_64
 498                 m |= (u64)efi->efi_memmap_hi << 32;
 499 #endif
 500
 501                 d = efi_memdesc_ptr(m, efi->efi_memdesc_size, i);
 502                 switch (d->type) {
 503                 case EFI_RESERVED_TYPE:
 504                 case EFI_RUNTIME_SERVICES_CODE:
 505                 case EFI_RUNTIME_SERVICES_DATA:
 506                 case EFI_MEMORY_MAPPED_IO:
 507                 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
 508                 case EFI_PAL_CODE:
 509                         e820_type = E820_TYPE_RESERVED;
 510                         break;
 511
 512                 case EFI_UNUSABLE_MEMORY:
 513                         e820_type = E820_TYPE_UNUSABLE;
 514                         break;
 515
 516                 case EFI_ACPI_RECLAIM_MEMORY:
 517                         e820_type = E820_TYPE_ACPI;
 518                         break;
 519
 520                 case EFI_LOADER_CODE:
 521                 case EFI_LOADER_DATA:
 522                 case EFI_BOOT_SERVICES_CODE:
 523                 case EFI_BOOT_SERVICES_DATA:
 524                 case EFI_CONVENTIONAL_MEMORY:
 525                         if (efi_soft_reserve_enabled() &&
 526                             (d->attribute & EFI_MEMORY_SP))
 527                                 e820_type = E820_TYPE_SOFT_RESERVED;
 528                         else
 529                                 e820_type = E820_TYPE_RAM;
 530                         break;
 531
 532                 case EFI_ACPI_MEMORY_NVS:
 533                         e820_type = E820_TYPE_NVS;
 534                         break;
 535
 536                 case EFI_PERSISTENT_MEMORY:
 537                         e820_type = E820_TYPE_PMEM;
 538                         break;
 539
 540                 case EFI_UNACCEPTED_MEMORY:
 541                         if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
 542                                 continue;
 543                         e820_type = E820_TYPE_RAM;
 544                         process_unaccepted_memory(d->phys_addr,
 545                                                   d->phys_addr + PAGE_SIZE * d->num_pages);
 546                         break;
 547                 default:
 548                         continue;
 549                 }
 550
 551                 /* Merge adjacent mappings */
 552                 if (prev && prev->type == e820_type &&
 553                     (prev->addr + prev->size) == d->phys_addr) {
 554                         prev->size += d->num_pages << 12;
 555                         continue;
 556                 }
 557
 558                 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
 559                         u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
 560                                    sizeof(struct setup_data);
 561
 562                         if (!e820ext || e820ext_size < need)
 563                                 return EFI_BUFFER_TOO_SMALL;
 564
 565                         /* boot_params map full, switch to e820 extended */
 566                         entry = (struct boot_e820_entry *)e820ext->data;
 567                 }
 568
 569                 entry->addr = d->phys_addr;
 570                 entry->size = d->num_pages << PAGE_SHIFT;
 571                 entry->type = e820_type;
 572                 prev = entry++;
 573                 nr_entries++;
 574         }
 575
 576         if (nr_entries > ARRAY_SIZE(params->e820_table)) {
 577                 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
 578
 579                 add_e820ext(params, e820ext, nr_e820ext);
 580                 nr_entries -= nr_e820ext;
 581         }
 582
 583         params->e820_entries = (u8)nr_entries;
 584
 585         return EFI_SUCCESS;
 586 }
 587
 588 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
 589                                   u32 *e820ext_size)
 590 {
 591         efi_status_t status;
 592         unsigned long size;
 593
 594         size = sizeof(struct setup_data) +
 595                 sizeof(struct e820_entry) * nr_desc;
 596
 597         if (*e820ext) {
 598                 efi_bs_call(free_pool, *e820ext);
 599                 *e820ext = NULL;
 600                 *e820ext_size = 0;
 601         }
 602
 603         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 604                              (void **)e820ext);
 605         if (status == EFI_SUCCESS)
 606                 *e820ext_size = size;
 607
 608         return status;
 609 }
 610
 611 static efi_status_t allocate_e820(struct boot_params *params,
 612                                   struct setup_data **e820ext,
 613                                   u32 *e820ext_size)
 614 {
 615         struct efi_boot_memmap *map __free(efi_pool) = NULL;
 616         efi_status_t status;
 617         __u32 nr_desc;
 618
 619         status = efi_get_memory_map(&map, false);
 620         if (status != EFI_SUCCESS)
 621                 return status;
 622
 623         nr_desc = map->map_size / map->desc_size;
 624         if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
 625                 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
 626                                  EFI_MMAP_NR_SLACK_SLOTS;
 627
 628                 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
 629                 if (status != EFI_SUCCESS)
 630                         return status;
 631         }
 632
 633         if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
 634                 return allocate_unaccepted_bitmap(nr_desc, map);
 635
 636         return EFI_SUCCESS;
 637 }
 638
 639 struct exit_boot_struct {
 640         struct boot_params      *boot_params;
 641         struct efi_info         *efi;
 642 };
 643
 644 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
 645                                    void *priv)
 646 {
 647         const char *signature;
 648         struct exit_boot_struct *p = priv;
 649
 650         signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
 651                                    : EFI32_LOADER_SIGNATURE;
 652         memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
 653
 654         efi_set_u64_split((unsigned long)efi_system_table,
 655                           &p->efi->efi_systab, &p->efi->efi_systab_hi);
 656         p->efi->efi_memdesc_size        = map->desc_size;
 657         p->efi->efi_memdesc_version     = map->desc_ver;
 658         efi_set_u64_split((unsigned long)map->map,
 659                           &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
 660         p->efi->efi_memmap_size         = map->map_size;
 661
 662         return EFI_SUCCESS;
 663 }
 664
 665 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
 666 {
 667         struct setup_data *e820ext = NULL;
 668         __u32 e820ext_size = 0;
 669         efi_status_t status;
 670         struct exit_boot_struct priv;
 671
 672         priv.boot_params        = boot_params;
 673         priv.efi                = &boot_params->efi_info;
 674
 675         status = allocate_e820(boot_params, &e820ext, &e820ext_size);
 676         if (status != EFI_SUCCESS)
 677                 return status;
 678
 679         /* Might as well exit boot services now */
 680         status = efi_exit_boot_services(handle, &priv, exit_boot_func);
 681         if (status != EFI_SUCCESS)
 682                 return status;
 683
 684         /* Historic? */
 685         boot_params->alt_mem_k  = 32 * 1024;
 686
 687         status = setup_e820(boot_params, e820ext, e820ext_size);
 688         if (status != EFI_SUCCESS)
 689                 return status;
 690
 691         return EFI_SUCCESS;
 692 }
 693
 694 static bool have_unsupported_snp_features(void)
 695 {
 696         u64 unsupported;
 697
 698         unsupported = snp_get_unsupported_features(sev_get_status());
 699         if (unsupported) {
 700                 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n",
 701                         unsupported);
 702                 return true;
 703         }
 704         return false;
 705 }
 706
 707 static void efi_get_seed(void *seed, int size)
 708 {
 709         efi_get_random_bytes(size, seed);
 710
 711         /*
 712          * This only updates seed[0] when running on 32-bit, but in that case,
 713          * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
 714          */
 715         *(unsigned long *)seed ^= kaslr_get_random_long("EFI");
 716 }
 717
 718 static void error(char *str)
 719 {
 720         efi_warn("Decompression failed: %s\n", str);
 721 }
 722
 723 static const char *cmdline_memmap_override;
 724
 725 static efi_status_t parse_options(const char *cmdline)
 726 {
 727         static const char opts[][14] = {
 728                 "mem=", "memmap=", "hugepages="
 729         };
 730
 731         for (int i = 0; i < ARRAY_SIZE(opts); i++) {
 732                 const char *p = strstr(cmdline, opts[i]);
 733
 734                 if (p == cmdline || (p > cmdline && isspace(p[-1]))) {
 735                         cmdline_memmap_override = opts[i];
 736                         break;
 737                 }
 738         }
 739
 740         return efi_parse_options(cmdline);
 741 }
 742
 743 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
 744 {
 745         unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
 746         unsigned long addr, alloc_size, entry;
 747         efi_status_t status;
 748         u32 seed[2] = {};
 749
 750         /* determine the required size of the allocation */
 751         alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
 752                            MIN_KERNEL_ALIGN);
 753
 754         if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
 755                 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
 756                 static const efi_char16_t ami[] = L"American Megatrends";
 757
 758                 efi_get_seed(seed, sizeof(seed));
 759
 760                 virt_addr += (range * seed[1]) >> 32;
 761                 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
 762
 763                 /*
 764                  * Older Dell systems with AMI UEFI firmware v2.0 may hang
 765                  * while decompressing the kernel if physical address
 766                  * randomization is enabled.
 767                  *
 768                  * https://bugzilla.kernel.org/show_bug.cgi?id=218173
 769                  */
 770                 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
 771                     !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
 772                         efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
 773                         seed[0] = 0;
 774                 } else if (cmdline_memmap_override) {
 775                         efi_info("%s detected on the kernel command line - disabling physical KASLR\n",
 776                                  cmdline_memmap_override);
 777                         seed[0] = 0;
 778                 }
 779
 780                 boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
 781         }
 782
 783         status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
 784                                   seed[0], EFI_LOADER_CODE,
 785                                   LOAD_PHYSICAL_ADDR,
 786                                   EFI_X86_KERNEL_ALLOC_LIMIT);
 787         if (status != EFI_SUCCESS)
 788                 return status;
 789
 790         entry = decompress_kernel((void *)addr, virt_addr, error);
 791         if (entry == ULONG_MAX) {
 792                 efi_free(alloc_size, addr);
 793                 return EFI_LOAD_ERROR;
 794         }
 795
 796         *kernel_entry = addr + entry;
 797
 798         return efi_adjust_memory_range_protection(addr, kernel_text_size);
 799 }
 800
 801 static void __noreturn enter_kernel(unsigned long kernel_addr,
 802                                     struct boot_params *boot_params)
 803 {
 804         /* enter decompressed kernel with boot_params pointer in RSI/ESI */
 805         asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
 806
 807         unreachable();
 808 }
 809
 810 /*
 811  * On success, this routine will jump to the relocated image directly and never
 812  * return.  On failure, it will exit to the firmware via efi_exit() instead of
 813  * returning.
 814  */
 815 void __noreturn efi_stub_entry(efi_handle_t handle,
 816                                efi_system_table_t *sys_table_arg,
 817                                struct boot_params *boot_params)
 818 {
 819         efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
 820         struct setup_header *hdr = &boot_params->hdr;
 821         const struct linux_efi_initrd *initrd = NULL;
 822         unsigned long kernel_entry;
 823         efi_status_t status;
 824
 825         boot_params_ptr = boot_params;
 826
 827         efi_system_table = sys_table_arg;
 828         /* Check if we were booted by the EFI firmware */
 829         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 830                 efi_exit(handle, EFI_INVALID_PARAMETER);
 831
 832         if (have_unsupported_snp_features())
 833                 efi_exit(handle, EFI_UNSUPPORTED);
 834
 835         if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
 836                 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
 837                 if (efi_dxe_table &&
 838                     efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
 839                         efi_warn("Ignoring DXE services table: invalid signature\n");
 840                         efi_dxe_table = NULL;
 841                 }
 842         }
 843
 844         /* grab the memory attributes protocol if it exists */
 845         efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
 846
 847         status = efi_setup_5level_paging();
 848         if (status != EFI_SUCCESS) {
 849                 efi_err("efi_setup_5level_paging() failed!\n");
 850                 goto fail;
 851         }
 852
 853 #ifdef CONFIG_CMDLINE_BOOL
 854         status = parse_options(CONFIG_CMDLINE);
 855         if (status != EFI_SUCCESS) {
 856                 efi_err("Failed to parse options\n");
 857                 goto fail;
 858         }
 859 #endif
 860         if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
 861                 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
 862                                                ((u64)boot_params->ext_cmd_line_ptr << 32));
 863                 status = parse_options((char *)cmdline_paddr);
 864                 if (status != EFI_SUCCESS) {
 865                         efi_err("Failed to parse options\n");
 866                         goto fail;
 867                 }
 868         }
 869
 870         if (efi_mem_encrypt > 0)
 871                 hdr->xloadflags |= XLF_MEM_ENCRYPTION;
 872
 873         status = efi_decompress_kernel(&kernel_entry);
 874         if (status != EFI_SUCCESS) {
 875                 efi_err("Failed to decompress kernel\n");
 876                 goto fail;
 877         }
 878
 879         /*
 880          * At this point, an initrd may already have been loaded by the
 881          * bootloader and passed via bootparams. We permit an initrd loaded
 882          * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
 883          *
 884          * If the device path is not present, any command-line initrd=
 885          * arguments will be processed only if image is not NULL, which will be
 886          * the case only if we were loaded via the PE entry point.
 887          */
 888         status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
 889                                  &initrd);
 890         if (status != EFI_SUCCESS)
 891                 goto fail;
 892         if (initrd && initrd->size > 0) {
 893                 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
 894                                   &boot_params->ext_ramdisk_image);
 895                 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
 896                                   &boot_params->ext_ramdisk_size);
 897         }
 898
 899
 900         /*
 901          * If the boot loader gave us a value for secure_boot then we use that,
 902          * otherwise we ask the BIOS.
 903          */
 904         if (boot_params->secure_boot == efi_secureboot_mode_unset)
 905                 boot_params->secure_boot = efi_get_secureboot();
 906
 907         /* Ask the firmware to clear memory on unclean shutdown */
 908         efi_enable_reset_attack_mitigation();
 909
 910         efi_random_get_seed();
 911
 912         efi_retrieve_eventlog();
 913
 914         setup_graphics(boot_params);
 915
 916         setup_efi_pci(boot_params);
 917
 918         setup_quirks(boot_params);
 919
 920         setup_unaccepted_memory();
 921
 922         status = exit_boot(boot_params, handle);
 923         if (status != EFI_SUCCESS) {
 924                 efi_err("exit_boot() failed!\n");
 925                 goto fail;
 926         }
 927
 928         /*
 929          * Call the SEV init code while still running with the firmware's
 930          * GDT/IDT, so #VC exceptions will be handled by EFI.
 931          */
 932         sev_enable(boot_params);
 933
 934         efi_5level_switch();
 935
 936         enter_kernel(kernel_entry, boot_params);
 937 fail:
 938         efi_err("efi_stub_entry() failed!\n");
 939
 940         efi_exit(handle, status);
 941 }
 942
 943 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL
 944 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
 945                         struct boot_params *boot_params)
 946 {
 947         memset(_bss, 0, _ebss - _bss);
 948         efi_stub_entry(handle, sys_table_arg, boot_params);
 949 }
 950
 951 #ifndef CONFIG_EFI_MIXED
 952 extern __alias(efi_handover_entry)
 953 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
 954                       struct boot_params *boot_params);
 955
 956 extern __alias(efi_handover_entry)
 957 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
 958                       struct boot_params *boot_params);
 959 #endif
 960 #endif