// SPDX-License-Identifier: GPL-2.0-only /* ----------------------------------------------------------------------- * * Copyright 2011 Intel Corporation; author Matt Fleming * * ----------------------------------------------------------------------- */ #include #include #include #include #include #include #include #include #include #include #include "efistub.h" #include "x86-stub.h" extern char _bss[], _ebss[]; const efi_system_table_t *efi_system_table; const efi_dxe_services_table_t *efi_dxe_table; static efi_loaded_image_t *image = NULL; static efi_memory_attribute_protocol_t *memattr; typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t; union sev_memory_acceptance_protocol { struct { efi_status_t (__efiapi * allow_unaccepted_memory)( sev_memory_acceptance_protocol_t *); }; struct { u32 allow_unaccepted_memory; } mixed_mode; }; static efi_status_t preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) { struct pci_setup_rom *rom = NULL; efi_status_t status; unsigned long size; uint64_t romsize; void *romimage; /* * Some firmware images contain EFI function pointers at the place where * the romimage and romsize fields are supposed to be. Typically the EFI * code is mapped at high addresses, translating to an unrealistically * large romsize. The UEFI spec limits the size of option ROMs to 16 * MiB so we reject any ROMs over 16 MiB in size to catch this. */ romimage = efi_table_attr(pci, romimage); romsize = efi_table_attr(pci, romsize); if (!romimage || !romsize || romsize > SZ_16M) return EFI_INVALID_PARAMETER; size = romsize + sizeof(*rom); status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)&rom); if (status != EFI_SUCCESS) { efi_err("Failed to allocate memory for 'rom'\n"); return status; } memset(rom, 0, sizeof(*rom)); rom->data.type = SETUP_PCI; rom->data.len = size - sizeof(struct setup_data); rom->data.next = 0; rom->pcilen = romsize; *__rom = rom; status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, PCI_VENDOR_ID, 1, &rom->vendor); if (status != EFI_SUCCESS) { efi_err("Failed to read rom->vendor\n"); goto free_struct; } status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, PCI_DEVICE_ID, 1, &rom->devid); if (status != EFI_SUCCESS) { efi_err("Failed to read rom->devid\n"); goto free_struct; } status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus, &rom->device, &rom->function); if (status != EFI_SUCCESS) goto free_struct; memcpy(rom->romdata, romimage, romsize); return status; free_struct: efi_bs_call(free_pool, rom); return status; } /* * There's no way to return an informative status from this function, * because any analysis (and printing of error messages) needs to be * done directly at the EFI function call-site. * * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we * just didn't find any PCI devices, but there's no way to tell outside * the context of the call. */ static void setup_efi_pci(struct boot_params *params) { efi_status_t status; void **pci_handle = NULL; efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID; unsigned long size = 0; struct setup_data *data; efi_handle_t h; int i; status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &pci_proto, NULL, &size, pci_handle); if (status == EFI_BUFFER_TOO_SMALL) { status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)&pci_handle); if (status != EFI_SUCCESS) { efi_err("Failed to allocate memory for 'pci_handle'\n"); return; } status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &pci_proto, NULL, &size, pci_handle); } if (status != EFI_SUCCESS) goto free_handle; data = (struct setup_data *)(unsigned long)params->hdr.setup_data; while (data && data->next) data = (struct setup_data *)(unsigned long)data->next; for_each_efi_handle(h, pci_handle, size, i) { efi_pci_io_protocol_t *pci = NULL; struct pci_setup_rom *rom; status = efi_bs_call(handle_protocol, h, &pci_proto, (void **)&pci); if (status != EFI_SUCCESS || !pci) continue; status = preserve_pci_rom_image(pci, &rom); if (status != EFI_SUCCESS) continue; if (data) data->next = (unsigned long)rom; else params->hdr.setup_data = (unsigned long)rom; data = (struct setup_data *)rom; } free_handle: efi_bs_call(free_pool, pci_handle); } static void retrieve_apple_device_properties(struct boot_params *boot_params) { efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID; struct setup_data *data, *new; efi_status_t status; u32 size = 0; apple_properties_protocol_t *p; status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p); if (status != EFI_SUCCESS) return; if (efi_table_attr(p, version) != 0x10000) { efi_err("Unsupported properties proto version\n"); return; } efi_call_proto(p, get_all, NULL, &size); if (!size) return; do { status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size + sizeof(struct setup_data), (void **)&new); if (status != EFI_SUCCESS) { efi_err("Failed to allocate memory for 'properties'\n"); return; } status = efi_call_proto(p, get_all, new->data, &size); if (status == EFI_BUFFER_TOO_SMALL) efi_bs_call(free_pool, new); } while (status == EFI_BUFFER_TOO_SMALL); new->type = SETUP_APPLE_PROPERTIES; new->len = size; new->next = 0; data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data; if (!data) { boot_params->hdr.setup_data = (unsigned long)new; } else { while (data->next) data = (struct setup_data *)(unsigned long)data->next; data->next = (unsigned long)new; } } static bool apple_match_product_name(void) { static const char type1_product_matches[][15] = { "MacBookPro11,3", "MacBookPro11,5", "MacBookPro13,3", "MacBookPro14,3", "MacBookPro15,1", "MacBookPro15,3", "MacBookPro16,1", "MacBookPro16,4", }; const struct efi_smbios_type1_record *record; const u8 *product; record = (struct efi_smbios_type1_record *)efi_get_smbios_record(1); if (!record) return false; product = efi_get_smbios_string(record, product_name); if (!product) return false; for (int i = 0; i < ARRAY_SIZE(type1_product_matches); i++) { if (!strcmp(product, type1_product_matches[i])) return true; } return false; } static void apple_set_os(void) { struct { unsigned long version; efi_status_t (__efiapi *set_os_version)(const char *); efi_status_t (__efiapi *set_os_vendor)(const char *); } *set_os; efi_status_t status; if (!efi_is_64bit() || !apple_match_product_name()) return; status = efi_bs_call(locate_protocol, &APPLE_SET_OS_PROTOCOL_GUID, NULL, (void **)&set_os); if (status != EFI_SUCCESS) return; if (set_os->version >= 2) { status = set_os->set_os_vendor("Apple Inc."); if (status != EFI_SUCCESS) efi_err("Failed to set OS vendor via apple_set_os\n"); } if (set_os->version > 0) { /* The version being set doesn't seem to matter */ status = set_os->set_os_version("Mac OS X 10.9"); if (status != EFI_SUCCESS) efi_err("Failed to set OS version via apple_set_os\n"); } } efi_status_t efi_adjust_memory_range_protection(unsigned long start, unsigned long size) { efi_status_t status; efi_gcd_memory_space_desc_t desc; unsigned long end, next; unsigned long rounded_start, rounded_end; unsigned long unprotect_start, unprotect_size; rounded_start = rounddown(start, EFI_PAGE_SIZE); rounded_end = roundup(start + size, EFI_PAGE_SIZE); if (memattr != NULL) { status = efi_call_proto(memattr, set_memory_attributes, rounded_start, rounded_end - rounded_start, EFI_MEMORY_RO); if (status != EFI_SUCCESS) { efi_warn("Failed to set EFI_MEMORY_RO attribute\n"); return status; } status = efi_call_proto(memattr, clear_memory_attributes, rounded_start, rounded_end - rounded_start, EFI_MEMORY_XP); if (status != EFI_SUCCESS) efi_warn("Failed to clear EFI_MEMORY_XP attribute\n"); return status; } if (efi_dxe_table == NULL) return EFI_SUCCESS; /* * Don't modify memory region attributes, they are * already suitable, to lower the possibility to * encounter firmware bugs. */ for (end = start + size; start < end; start = next) { status = efi_dxe_call(get_memory_space_descriptor, start, &desc); if (status != EFI_SUCCESS) break; next = desc.base_address + desc.length; /* * Only system memory is suitable for trampoline/kernel image placement, * so only this type of memory needs its attributes to be modified. */ if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory || (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0) continue; unprotect_start = max(rounded_start, (unsigned long)desc.base_address); unprotect_size = min(rounded_end, next) - unprotect_start; status = efi_dxe_call(set_memory_space_attributes, unprotect_start, unprotect_size, EFI_MEMORY_WB); if (status != EFI_SUCCESS) { efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n", unprotect_start, unprotect_start + unprotect_size, status); break; } } return EFI_SUCCESS; } static void setup_unaccepted_memory(void) { efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID; sev_memory_acceptance_protocol_t *proto; efi_status_t status; if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) return; /* * Enable unaccepted memory before calling exit boot services in order * for the UEFI to not accept all memory on EBS. */ status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL, (void **)&proto); if (status != EFI_SUCCESS) return; status = efi_call_proto(proto, allow_unaccepted_memory); if (status != EFI_SUCCESS) efi_err("Memory acceptance protocol failed\n"); } static efi_char16_t *efistub_fw_vendor(void) { unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor); return (efi_char16_t *)vendor; } static const efi_char16_t apple[] = L"Apple"; static void setup_quirks(struct boot_params *boot_params) { if (!memcmp(efistub_fw_vendor(), apple, sizeof(apple))) { if (IS_ENABLED(CONFIG_APPLE_PROPERTIES)) retrieve_apple_device_properties(boot_params); apple_set_os(); } } /* * See if we have Universal Graphics Adapter (UGA) protocol */ static efi_status_t setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size) { efi_status_t status; u32 width, height; void **uga_handle = NULL; efi_uga_draw_protocol_t *uga = NULL, *first_uga; efi_handle_t handle; int i; status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)&uga_handle); if (status != EFI_SUCCESS) return status; status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, uga_proto, NULL, &size, uga_handle); if (status != EFI_SUCCESS) goto free_handle; height = 0; width = 0; first_uga = NULL; for_each_efi_handle(handle, uga_handle, size, i) { efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID; u32 w, h, depth, refresh; void *pciio; status = efi_bs_call(handle_protocol, handle, uga_proto, (void **)&uga); if (status != EFI_SUCCESS) continue; pciio = NULL; efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio); status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh); if (status == EFI_SUCCESS && (!first_uga || pciio)) { width = w; height = h; /* * Once we've found a UGA supporting PCIIO, * don't bother looking any further. */ if (pciio) break; first_uga = uga; } } if (!width && !height) goto free_handle; /* EFI framebuffer */ si->orig_video_isVGA = VIDEO_TYPE_EFI; si->lfb_depth = 32; si->lfb_width = width; si->lfb_height = height; si->red_size = 8; si->red_pos = 16; si->green_size = 8; si->green_pos = 8; si->blue_size = 8; si->blue_pos = 0; si->rsvd_size = 8; si->rsvd_pos = 24; free_handle: efi_bs_call(free_pool, uga_handle); return status; } static void setup_graphics(struct boot_params *boot_params) { efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; struct screen_info *si; efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; efi_status_t status; unsigned long size; void **gop_handle = NULL; void **uga_handle = NULL; si = &boot_params->screen_info; memset(si, 0, sizeof(*si)); size = 0; status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &graphics_proto, NULL, &size, gop_handle); if (status == EFI_BUFFER_TOO_SMALL) status = efi_setup_gop(si, &graphics_proto, size); if (status != EFI_SUCCESS) { size = 0; status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &uga_proto, NULL, &size, uga_handle); if (status == EFI_BUFFER_TOO_SMALL) setup_uga(si, &uga_proto, size); } } static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) { efi_bs_call(exit, handle, status, 0, NULL); for(;;) asm("hlt"); } void __noreturn efi_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, struct boot_params *boot_params); /* * Because the x86 boot code expects to be passed a boot_params we * need to create one ourselves (usually the bootloader would create * one for us). */ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg) { efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; struct boot_params *boot_params; struct setup_header *hdr; efi_status_t status; unsigned long alloc; char *cmdline_ptr; efi_system_table = sys_table_arg; /* Check if we were booted by the EFI firmware */ if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) efi_exit(handle, EFI_INVALID_PARAMETER); status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); if (status != EFI_SUCCESS) { efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); efi_exit(handle, status); } status = efi_allocate_pages(PARAM_SIZE, &alloc, ULONG_MAX); if (status != EFI_SUCCESS) efi_exit(handle, status); boot_params = memset((void *)alloc, 0x0, PARAM_SIZE); hdr = &boot_params->hdr; /* Assign the setup_header fields that the kernel actually cares about */ hdr->root_flags = 1; hdr->vid_mode = 0xffff; hdr->type_of_loader = 0x21; hdr->initrd_addr_max = INT_MAX; /* Convert unicode cmdline to ascii */ cmdline_ptr = efi_convert_cmdline(image); if (!cmdline_ptr) { efi_free(PARAM_SIZE, alloc); efi_exit(handle, EFI_OUT_OF_RESOURCES); } efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr); efi_stub_entry(handle, sys_table_arg, boot_params); /* not reached */ } static void add_e820ext(struct boot_params *params, struct setup_data *e820ext, u32 nr_entries) { struct setup_data *data; e820ext->type = SETUP_E820_EXT; e820ext->len = nr_entries * sizeof(struct boot_e820_entry); e820ext->next = 0; data = (struct setup_data *)(unsigned long)params->hdr.setup_data; while (data && data->next) data = (struct setup_data *)(unsigned long)data->next; if (data) data->next = (unsigned long)e820ext; else params->hdr.setup_data = (unsigned long)e820ext; } static efi_status_t setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) { struct boot_e820_entry *entry = params->e820_table; struct efi_info *efi = ¶ms->efi_info; struct boot_e820_entry *prev = NULL; u32 nr_entries; u32 nr_desc; int i; nr_entries = 0; nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; for (i = 0; i < nr_desc; i++) { efi_memory_desc_t *d; unsigned int e820_type = 0; unsigned long m = efi->efi_memmap; #ifdef CONFIG_X86_64 m |= (u64)efi->efi_memmap_hi << 32; #endif d = efi_memdesc_ptr(m, efi->efi_memdesc_size, i); switch (d->type) { case EFI_RESERVED_TYPE: case EFI_RUNTIME_SERVICES_CODE: case EFI_RUNTIME_SERVICES_DATA: case EFI_MEMORY_MAPPED_IO: case EFI_MEMORY_MAPPED_IO_PORT_SPACE: case EFI_PAL_CODE: e820_type = E820_TYPE_RESERVED; break; case EFI_UNUSABLE_MEMORY: e820_type = E820_TYPE_UNUSABLE; break; case EFI_ACPI_RECLAIM_MEMORY: e820_type = E820_TYPE_ACPI; break; case EFI_LOADER_CODE: case EFI_LOADER_DATA: case EFI_BOOT_SERVICES_CODE: case EFI_BOOT_SERVICES_DATA: case EFI_CONVENTIONAL_MEMORY: if (efi_soft_reserve_enabled() && (d->attribute & EFI_MEMORY_SP)) e820_type = E820_TYPE_SOFT_RESERVED; else e820_type = E820_TYPE_RAM; break; case EFI_ACPI_MEMORY_NVS: e820_type = E820_TYPE_NVS; break; case EFI_PERSISTENT_MEMORY: e820_type = E820_TYPE_PMEM; break; case EFI_UNACCEPTED_MEMORY: if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) continue; e820_type = E820_TYPE_RAM; process_unaccepted_memory(d->phys_addr, d->phys_addr + PAGE_SIZE * d->num_pages); break; default: continue; } /* Merge adjacent mappings */ if (prev && prev->type == e820_type && (prev->addr + prev->size) == d->phys_addr) { prev->size += d->num_pages << 12; continue; } if (nr_entries == ARRAY_SIZE(params->e820_table)) { u32 need = (nr_desc - i) * sizeof(struct e820_entry) + sizeof(struct setup_data); if (!e820ext || e820ext_size < need) return EFI_BUFFER_TOO_SMALL; /* boot_params map full, switch to e820 extended */ entry = (struct boot_e820_entry *)e820ext->data; } entry->addr = d->phys_addr; entry->size = d->num_pages << PAGE_SHIFT; entry->type = e820_type; prev = entry++; nr_entries++; } if (nr_entries > ARRAY_SIZE(params->e820_table)) { u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); add_e820ext(params, e820ext, nr_e820ext); nr_entries -= nr_e820ext; } params->e820_entries = (u8)nr_entries; return EFI_SUCCESS; } static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, u32 *e820ext_size) { efi_status_t status; unsigned long size; size = sizeof(struct setup_data) + sizeof(struct e820_entry) * nr_desc; if (*e820ext) { efi_bs_call(free_pool, *e820ext); *e820ext = NULL; *e820ext_size = 0; } status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)e820ext); if (status == EFI_SUCCESS) *e820ext_size = size; return status; } static efi_status_t allocate_e820(struct boot_params *params, struct setup_data **e820ext, u32 *e820ext_size) { struct efi_boot_memmap *map; efi_status_t status; __u32 nr_desc; status = efi_get_memory_map(&map, false); if (status != EFI_SUCCESS) return status; nr_desc = map->map_size / map->desc_size; if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) { u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) + EFI_MMAP_NR_SLACK_SLOTS; status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); } if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS) status = allocate_unaccepted_bitmap(nr_desc, map); efi_bs_call(free_pool, map); return status; } struct exit_boot_struct { struct boot_params *boot_params; struct efi_info *efi; }; static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv) { const char *signature; struct exit_boot_struct *p = priv; signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE : EFI32_LOADER_SIGNATURE; memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); efi_set_u64_split((unsigned long)efi_system_table, &p->efi->efi_systab, &p->efi->efi_systab_hi); p->efi->efi_memdesc_size = map->desc_size; p->efi->efi_memdesc_version = map->desc_ver; efi_set_u64_split((unsigned long)map->map, &p->efi->efi_memmap, &p->efi->efi_memmap_hi); p->efi->efi_memmap_size = map->map_size; return EFI_SUCCESS; } static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) { struct setup_data *e820ext = NULL; __u32 e820ext_size = 0; efi_status_t status; struct exit_boot_struct priv; priv.boot_params = boot_params; priv.efi = &boot_params->efi_info; status = allocate_e820(boot_params, &e820ext, &e820ext_size); if (status != EFI_SUCCESS) return status; /* Might as well exit boot services now */ status = efi_exit_boot_services(handle, &priv, exit_boot_func); if (status != EFI_SUCCESS) return status; /* Historic? */ boot_params->alt_mem_k = 32 * 1024; status = setup_e820(boot_params, e820ext, e820ext_size); if (status != EFI_SUCCESS) return status; return EFI_SUCCESS; } static bool have_unsupported_snp_features(void) { u64 unsupported; unsupported = snp_get_unsupported_features(sev_get_status()); if (unsupported) { efi_err("Unsupported SEV-SNP features detected: 0x%llx\n", unsupported); return true; } return false; } static void efi_get_seed(void *seed, int size) { efi_get_random_bytes(size, seed); /* * This only updates seed[0] when running on 32-bit, but in that case, * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit. */ *(unsigned long *)seed ^= kaslr_get_random_long("EFI"); } static void error(char *str) { efi_warn("Decompression failed: %s\n", str); } static const char *cmdline_memmap_override; static efi_status_t parse_options(const char *cmdline) { static const char opts[][14] = { "mem=", "memmap=", "hugepages=" }; for (int i = 0; i < ARRAY_SIZE(opts); i++) { const char *p = strstr(cmdline, opts[i]); if (p == cmdline || (p > cmdline && isspace(p[-1]))) { cmdline_memmap_override = opts[i]; break; } } return efi_parse_options(cmdline); } static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry) { unsigned long virt_addr = LOAD_PHYSICAL_ADDR; unsigned long addr, alloc_size, entry; efi_status_t status; u32 seed[2] = {}; /* determine the required size of the allocation */ alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size), MIN_KERNEL_ALIGN); if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) { u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size; static const efi_char16_t ami[] = L"American Megatrends"; efi_get_seed(seed, sizeof(seed)); virt_addr += (range * seed[1]) >> 32; virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1); /* * Older Dell systems with AMI UEFI firmware v2.0 may hang * while decompressing the kernel if physical address * randomization is enabled. * * https://bugzilla.kernel.org/show_bug.cgi?id=218173 */ if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION && !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) { efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n"); seed[0] = 0; } else if (cmdline_memmap_override) { efi_info("%s detected on the kernel command line - disabling physical KASLR\n", cmdline_memmap_override); seed[0] = 0; } boot_params_ptr->hdr.loadflags |= KASLR_FLAG; } status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr, seed[0], EFI_LOADER_CODE, LOAD_PHYSICAL_ADDR, EFI_X86_KERNEL_ALLOC_LIMIT); if (status != EFI_SUCCESS) return status; entry = decompress_kernel((void *)addr, virt_addr, error); if (entry == ULONG_MAX) { efi_free(alloc_size, addr); return EFI_LOAD_ERROR; } *kernel_entry = addr + entry; return efi_adjust_memory_range_protection(addr, kernel_text_size); } static void __noreturn enter_kernel(unsigned long kernel_addr, struct boot_params *boot_params) { /* enter decompressed kernel with boot_params pointer in RSI/ESI */ asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params)); unreachable(); } /* * On success, this routine will jump to the relocated image directly and never * return. On failure, it will exit to the firmware via efi_exit() instead of * returning. */ void __noreturn efi_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, struct boot_params *boot_params) { efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID; struct setup_header *hdr = &boot_params->hdr; const struct linux_efi_initrd *initrd = NULL; unsigned long kernel_entry; efi_status_t status; boot_params_ptr = boot_params; efi_system_table = sys_table_arg; /* Check if we were booted by the EFI firmware */ if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) efi_exit(handle, EFI_INVALID_PARAMETER); if (have_unsupported_snp_features()) efi_exit(handle, EFI_UNSUPPORTED); if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) { efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID); if (efi_dxe_table && efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) { efi_warn("Ignoring DXE services table: invalid signature\n"); efi_dxe_table = NULL; } } /* grab the memory attributes protocol if it exists */ efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr); status = efi_setup_5level_paging(); if (status != EFI_SUCCESS) { efi_err("efi_setup_5level_paging() failed!\n"); goto fail; } #ifdef CONFIG_CMDLINE_BOOL status = parse_options(CONFIG_CMDLINE); if (status != EFI_SUCCESS) { efi_err("Failed to parse options\n"); goto fail; } #endif if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | ((u64)boot_params->ext_cmd_line_ptr << 32)); status = parse_options((char *)cmdline_paddr); if (status != EFI_SUCCESS) { efi_err("Failed to parse options\n"); goto fail; } } if (efi_mem_encrypt > 0) hdr->xloadflags |= XLF_MEM_ENCRYPTION; status = efi_decompress_kernel(&kernel_entry); if (status != EFI_SUCCESS) { efi_err("Failed to decompress kernel\n"); goto fail; } /* * At this point, an initrd may already have been loaded by the * bootloader and passed via bootparams. We permit an initrd loaded * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. * * If the device path is not present, any command-line initrd= * arguments will be processed only if image is not NULL, which will be * the case only if we were loaded via the PE entry point. */ status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX, &initrd); if (status != EFI_SUCCESS) goto fail; if (initrd && initrd->size > 0) { efi_set_u64_split(initrd->base, &hdr->ramdisk_image, &boot_params->ext_ramdisk_image); efi_set_u64_split(initrd->size, &hdr->ramdisk_size, &boot_params->ext_ramdisk_size); } /* * If the boot loader gave us a value for secure_boot then we use that, * otherwise we ask the BIOS. */ if (boot_params->secure_boot == efi_secureboot_mode_unset) boot_params->secure_boot = efi_get_secureboot(); /* Ask the firmware to clear memory on unclean shutdown */ efi_enable_reset_attack_mitigation(); efi_random_get_seed(); efi_retrieve_eventlog(); setup_graphics(boot_params); setup_efi_pci(boot_params); setup_quirks(boot_params); setup_unaccepted_memory(); status = exit_boot(boot_params, handle); if (status != EFI_SUCCESS) { efi_err("exit_boot() failed!\n"); goto fail; } /* * Call the SEV init code while still running with the firmware's * GDT/IDT, so #VC exceptions will be handled by EFI. */ sev_enable(boot_params); efi_5level_switch(); enter_kernel(kernel_entry, boot_params); fail: efi_err("efi_stub_entry() failed!\n"); efi_exit(handle, status); } #ifdef CONFIG_EFI_HANDOVER_PROTOCOL void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, struct boot_params *boot_params) { memset(_bss, 0, _ebss - _bss); efi_stub_entry(handle, sys_table_arg, boot_params); } #ifndef CONFIG_EFI_MIXED extern __alias(efi_handover_entry) void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, struct boot_params *boot_params); extern __alias(efi_handover_entry) void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, struct boot_params *boot_params); #endif #endif