| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Kexec bzImage loader |
| * |
| * Copyright (C) 2014 Red Hat Inc. |
| * Authors: |
| * Vivek Goyal <vgoyal@redhat.com> |
| */ |
| |
| #define pr_fmt(fmt) "kexec-bzImage64: " fmt |
| |
| #include <linux/string.h> |
| #include <linux/printk.h> |
| #include <linux/errno.h> |
| #include <linux/slab.h> |
| #include <linux/kexec.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/efi.h> |
| #include <linux/verification.h> |
| |
| #include <asm/bootparam.h> |
| #include <asm/setup.h> |
| #include <asm/crash.h> |
| #include <asm/efi.h> |
| #include <asm/e820/api.h> |
| #include <asm/kexec-bzimage64.h> |
| |
| #define MAX_ELFCOREHDR_STR_LEN 30 /* elfcorehdr=0x<64bit-value> */ |
| |
| /* |
| * Defines lowest physical address for various segments. Not sure where |
| * exactly these limits came from. Current bzimage64 loader in kexec-tools |
| * uses these so I am retaining it. It can be changed over time as we gain |
| * more insight. |
| */ |
| #define MIN_PURGATORY_ADDR 0x3000 |
| #define MIN_BOOTPARAM_ADDR 0x3000 |
| #define MIN_KERNEL_LOAD_ADDR 0x100000 |
| #define MIN_INITRD_LOAD_ADDR 0x1000000 |
| |
| /* |
| * This is a place holder for all boot loader specific data structure which |
| * gets allocated in one call but gets freed much later during cleanup |
| * time. Right now there is only one field but it can grow as need be. |
| */ |
| struct bzimage64_data { |
| /* |
| * Temporary buffer to hold bootparams buffer. This should be |
| * freed once the bootparam segment has been loaded. |
| */ |
| void *bootparams_buf; |
| }; |
| |
| static int setup_initrd(struct boot_params *params, |
| unsigned long initrd_load_addr, unsigned long initrd_len) |
| { |
| params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL; |
| params->hdr.ramdisk_size = initrd_len & 0xffffffffUL; |
| |
| params->ext_ramdisk_image = initrd_load_addr >> 32; |
| params->ext_ramdisk_size = initrd_len >> 32; |
| |
| return 0; |
| } |
| |
| static int setup_cmdline(struct kimage *image, struct boot_params *params, |
| unsigned long bootparams_load_addr, |
| unsigned long cmdline_offset, char *cmdline, |
| unsigned long cmdline_len) |
| { |
| char *cmdline_ptr = ((char *)params) + cmdline_offset; |
| unsigned long cmdline_ptr_phys, len = 0; |
| uint32_t cmdline_low_32, cmdline_ext_32; |
| |
| if (image->type == KEXEC_TYPE_CRASH) { |
| len = sprintf(cmdline_ptr, |
| "elfcorehdr=0x%lx ", image->arch.elf_load_addr); |
| } |
| memcpy(cmdline_ptr + len, cmdline, cmdline_len); |
| cmdline_len += len; |
| |
| cmdline_ptr[cmdline_len - 1] = '\0'; |
| |
| pr_debug("Final command line is: %s\n", cmdline_ptr); |
| cmdline_ptr_phys = bootparams_load_addr + cmdline_offset; |
| cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL; |
| cmdline_ext_32 = cmdline_ptr_phys >> 32; |
| |
| params->hdr.cmd_line_ptr = cmdline_low_32; |
| if (cmdline_ext_32) |
| params->ext_cmd_line_ptr = cmdline_ext_32; |
| |
| return 0; |
| } |
| |
| static int setup_e820_entries(struct boot_params *params) |
| { |
| unsigned int nr_e820_entries; |
| |
| nr_e820_entries = e820_table_kexec->nr_entries; |
| |
| /* TODO: Pass entries more than E820_MAX_ENTRIES_ZEROPAGE in bootparams setup data */ |
| if (nr_e820_entries > E820_MAX_ENTRIES_ZEROPAGE) |
| nr_e820_entries = E820_MAX_ENTRIES_ZEROPAGE; |
| |
| params->e820_entries = nr_e820_entries; |
| memcpy(¶ms->e820_table, &e820_table_kexec->entries, nr_e820_entries*sizeof(struct e820_entry)); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_EFI |
| static int setup_efi_info_memmap(struct boot_params *params, |
| unsigned long params_load_addr, |
| unsigned int efi_map_offset, |
| unsigned int efi_map_sz) |
| { |
| void *efi_map = (void *)params + efi_map_offset; |
| unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset; |
| struct efi_info *ei = ¶ms->efi_info; |
| |
| if (!efi_map_sz) |
| return 0; |
| |
| efi_runtime_map_copy(efi_map, efi_map_sz); |
| |
| ei->efi_memmap = efi_map_phys_addr & 0xffffffff; |
| ei->efi_memmap_hi = efi_map_phys_addr >> 32; |
| ei->efi_memmap_size = efi_map_sz; |
| |
| return 0; |
| } |
| |
| static int |
| prepare_add_efi_setup_data(struct boot_params *params, |
| unsigned long params_load_addr, |
| unsigned int efi_setup_data_offset) |
| { |
| unsigned long setup_data_phys; |
| struct setup_data *sd = (void *)params + efi_setup_data_offset; |
| struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data); |
| |
| esd->fw_vendor = efi.fw_vendor; |
| esd->runtime = efi.runtime; |
| esd->tables = efi.config_table; |
| esd->smbios = efi.smbios; |
| |
| sd->type = SETUP_EFI; |
| sd->len = sizeof(struct efi_setup_data); |
| |
| /* Add setup data */ |
| setup_data_phys = params_load_addr + efi_setup_data_offset; |
| sd->next = params->hdr.setup_data; |
| params->hdr.setup_data = setup_data_phys; |
| |
| return 0; |
| } |
| |
| static int |
| setup_efi_state(struct boot_params *params, unsigned long params_load_addr, |
| unsigned int efi_map_offset, unsigned int efi_map_sz, |
| unsigned int efi_setup_data_offset) |
| { |
| struct efi_info *current_ei = &boot_params.efi_info; |
| struct efi_info *ei = ¶ms->efi_info; |
| |
| if (!efi_enabled(EFI_RUNTIME_SERVICES)) |
| return 0; |
| |
| if (!current_ei->efi_memmap_size) |
| return 0; |
| |
| /* |
| * If 1:1 mapping is not enabled, second kernel can not setup EFI |
| * and use EFI run time services. User space will have to pass |
| * acpi_rsdp=<addr> on kernel command line to make second kernel boot |
| * without efi. |
| */ |
| if (efi_enabled(EFI_OLD_MEMMAP)) |
| return 0; |
| |
| ei->efi_loader_signature = current_ei->efi_loader_signature; |
| ei->efi_systab = current_ei->efi_systab; |
| ei->efi_systab_hi = current_ei->efi_systab_hi; |
| |
| ei->efi_memdesc_version = current_ei->efi_memdesc_version; |
| ei->efi_memdesc_size = efi_get_runtime_map_desc_size(); |
| |
| setup_efi_info_memmap(params, params_load_addr, efi_map_offset, |
| efi_map_sz); |
| prepare_add_efi_setup_data(params, params_load_addr, |
| efi_setup_data_offset); |
| return 0; |
| } |
| #endif /* CONFIG_EFI */ |
| |
| static int |
| setup_boot_parameters(struct kimage *image, struct boot_params *params, |
| unsigned long params_load_addr, |
| unsigned int efi_map_offset, unsigned int efi_map_sz, |
| unsigned int efi_setup_data_offset) |
| { |
| unsigned int nr_e820_entries; |
| unsigned long long mem_k, start, end; |
| int i, ret = 0; |
| |
| /* Get subarch from existing bootparams */ |
| params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch; |
| |
| /* Copying screen_info will do? */ |
| memcpy(¶ms->screen_info, &boot_params.screen_info, |
| sizeof(struct screen_info)); |
| |
| /* Fill in memsize later */ |
| params->screen_info.ext_mem_k = 0; |
| params->alt_mem_k = 0; |
| |
| /* Always fill in RSDP: it is either 0 or a valid value */ |
| params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr; |
| |
| /* Default APM info */ |
| memset(¶ms->apm_bios_info, 0, sizeof(params->apm_bios_info)); |
| |
| /* Default drive info */ |
| memset(¶ms->hd0_info, 0, sizeof(params->hd0_info)); |
| memset(¶ms->hd1_info, 0, sizeof(params->hd1_info)); |
| |
| if (image->type == KEXEC_TYPE_CRASH) { |
| ret = crash_setup_memmap_entries(image, params); |
| if (ret) |
| return ret; |
| } else |
| setup_e820_entries(params); |
| |
| nr_e820_entries = params->e820_entries; |
| |
| for (i = 0; i < nr_e820_entries; i++) { |
| if (params->e820_table[i].type != E820_TYPE_RAM) |
| continue; |
| start = params->e820_table[i].addr; |
| end = params->e820_table[i].addr + params->e820_table[i].size - 1; |
| |
| if ((start <= 0x100000) && end > 0x100000) { |
| mem_k = (end >> 10) - (0x100000 >> 10); |
| params->screen_info.ext_mem_k = mem_k; |
| params->alt_mem_k = mem_k; |
| if (mem_k > 0xfc00) |
| params->screen_info.ext_mem_k = 0xfc00; /* 64M*/ |
| if (mem_k > 0xffffffff) |
| params->alt_mem_k = 0xffffffff; |
| } |
| } |
| |
| #ifdef CONFIG_EFI |
| /* Setup EFI state */ |
| setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz, |
| efi_setup_data_offset); |
| #endif |
| /* Setup EDD info */ |
| memcpy(params->eddbuf, boot_params.eddbuf, |
| EDDMAXNR * sizeof(struct edd_info)); |
| params->eddbuf_entries = boot_params.eddbuf_entries; |
| |
| memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer, |
| EDD_MBR_SIG_MAX * sizeof(unsigned int)); |
| |
| return ret; |
| } |
| |
| static int bzImage64_probe(const char *buf, unsigned long len) |
| { |
| int ret = -ENOEXEC; |
| struct setup_header *header; |
| |
| /* kernel should be at least two sectors long */ |
| if (len < 2 * 512) { |
| pr_err("File is too short to be a bzImage\n"); |
| return ret; |
| } |
| |
| header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr)); |
| if (memcmp((char *)&header->header, "HdrS", 4) != 0) { |
| pr_err("Not a bzImage\n"); |
| return ret; |
| } |
| |
| if (header->boot_flag != 0xAA55) { |
| pr_err("No x86 boot sector present\n"); |
| return ret; |
| } |
| |
| if (header->version < 0x020C) { |
| pr_err("Must be at least protocol version 2.12\n"); |
| return ret; |
| } |
| |
| if (!(header->loadflags & LOADED_HIGH)) { |
| pr_err("zImage not a bzImage\n"); |
| return ret; |
| } |
| |
| if (!(header->xloadflags & XLF_KERNEL_64)) { |
| pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n"); |
| return ret; |
| } |
| |
| if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) { |
| pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n"); |
| return ret; |
| } |
| |
| /* |
| * Can't handle 32bit EFI as it does not allow loading kernel |
| * above 4G. This should be handled by 32bit bzImage loader |
| */ |
| if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) { |
| pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n"); |
| return ret; |
| } |
| |
| if (!(header->xloadflags & XLF_5LEVEL) && pgtable_l5_enabled()) { |
| pr_err("bzImage cannot handle 5-level paging mode.\n"); |
| return ret; |
| } |
| |
| /* I've got a bzImage */ |
| pr_debug("It's a relocatable bzImage64\n"); |
| ret = 0; |
| |
| return ret; |
| } |
| |
| static void *bzImage64_load(struct kimage *image, char *kernel, |
| unsigned long kernel_len, char *initrd, |
| unsigned long initrd_len, char *cmdline, |
| unsigned long cmdline_len) |
| { |
| |
| struct setup_header *header; |
| int setup_sects, kern16_size, ret = 0; |
| unsigned long setup_header_size, params_cmdline_sz; |
| struct boot_params *params; |
| unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr; |
| struct bzimage64_data *ldata; |
| struct kexec_entry64_regs regs64; |
| void *stack; |
| unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr); |
| unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset; |
| struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX, |
| .top_down = true }; |
| struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR, |
| .buf_max = ULONG_MAX, .top_down = true }; |
| |
| header = (struct setup_header *)(kernel + setup_hdr_offset); |
| setup_sects = header->setup_sects; |
| if (setup_sects == 0) |
| setup_sects = 4; |
| |
| kern16_size = (setup_sects + 1) * 512; |
| if (kernel_len < kern16_size) { |
| pr_err("bzImage truncated\n"); |
| return ERR_PTR(-ENOEXEC); |
| } |
| |
| if (cmdline_len > header->cmdline_size) { |
| pr_err("Kernel command line too long\n"); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| /* |
| * In case of crash dump, we will append elfcorehdr=<addr> to |
| * command line. Make sure it does not overflow |
| */ |
| if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) { |
| pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n"); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| /* Allocate and load backup region */ |
| if (image->type == KEXEC_TYPE_CRASH) { |
| ret = crash_load_segments(image); |
| if (ret) |
| return ERR_PTR(ret); |
| } |
| |
| /* |
| * Load purgatory. For 64bit entry point, purgatory code can be |
| * anywhere. |
| */ |
| ret = kexec_load_purgatory(image, &pbuf); |
| if (ret) { |
| pr_err("Loading purgatory failed\n"); |
| return ERR_PTR(ret); |
| } |
| |
| pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem); |
| |
| |
| /* |
| * Load Bootparams and cmdline and space for efi stuff. |
| * |
| * Allocate memory together for multiple data structures so |
| * that they all can go in single area/segment and we don't |
| * have to create separate segment for each. Keeps things |
| * little bit simple |
| */ |
| efi_map_sz = efi_get_runtime_map_size(); |
| params_cmdline_sz = sizeof(struct boot_params) + cmdline_len + |
| MAX_ELFCOREHDR_STR_LEN; |
| params_cmdline_sz = ALIGN(params_cmdline_sz, 16); |
| kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) + |
| sizeof(struct setup_data) + |
| sizeof(struct efi_setup_data); |
| |
| params = kzalloc(kbuf.bufsz, GFP_KERNEL); |
| if (!params) |
| return ERR_PTR(-ENOMEM); |
| efi_map_offset = params_cmdline_sz; |
| efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16); |
| |
| /* Copy setup header onto bootparams. Documentation/x86/boot.rst */ |
| setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset; |
| |
| /* Is there a limit on setup header size? */ |
| memcpy(¶ms->hdr, (kernel + setup_hdr_offset), setup_header_size); |
| |
| kbuf.buffer = params; |
| kbuf.memsz = kbuf.bufsz; |
| kbuf.buf_align = 16; |
| kbuf.buf_min = MIN_BOOTPARAM_ADDR; |
| ret = kexec_add_buffer(&kbuf); |
| if (ret) |
| goto out_free_params; |
| bootparam_load_addr = kbuf.mem; |
| pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n", |
| bootparam_load_addr, kbuf.bufsz, kbuf.bufsz); |
| |
| /* Load kernel */ |
| kbuf.buffer = kernel + kern16_size; |
| kbuf.bufsz = kernel_len - kern16_size; |
| kbuf.memsz = PAGE_ALIGN(header->init_size); |
| kbuf.buf_align = header->kernel_alignment; |
| kbuf.buf_min = MIN_KERNEL_LOAD_ADDR; |
| kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; |
| ret = kexec_add_buffer(&kbuf); |
| if (ret) |
| goto out_free_params; |
| kernel_load_addr = kbuf.mem; |
| |
| pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", |
| kernel_load_addr, kbuf.bufsz, kbuf.memsz); |
| |
| /* Load initrd high */ |
| if (initrd) { |
| kbuf.buffer = initrd; |
| kbuf.bufsz = kbuf.memsz = initrd_len; |
| kbuf.buf_align = PAGE_SIZE; |
| kbuf.buf_min = MIN_INITRD_LOAD_ADDR; |
| kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; |
| ret = kexec_add_buffer(&kbuf); |
| if (ret) |
| goto out_free_params; |
| initrd_load_addr = kbuf.mem; |
| |
| pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", |
| initrd_load_addr, initrd_len, initrd_len); |
| |
| setup_initrd(params, initrd_load_addr, initrd_len); |
| } |
| |
| setup_cmdline(image, params, bootparam_load_addr, |
| sizeof(struct boot_params), cmdline, cmdline_len); |
| |
| /* bootloader info. Do we need a separate ID for kexec kernel loader? */ |
| params->hdr.type_of_loader = 0x0D << 4; |
| params->hdr.loadflags = 0; |
| |
| /* Setup purgatory regs for entry */ |
| ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64, |
| sizeof(regs64), 1); |
| if (ret) |
| goto out_free_params; |
| |
| regs64.rbx = 0; /* Bootstrap Processor */ |
| regs64.rsi = bootparam_load_addr; |
| regs64.rip = kernel_load_addr + 0x200; |
| stack = kexec_purgatory_get_symbol_addr(image, "stack_end"); |
| if (IS_ERR(stack)) { |
| pr_err("Could not find address of symbol stack_end\n"); |
| ret = -EINVAL; |
| goto out_free_params; |
| } |
| |
| regs64.rsp = (unsigned long)stack; |
| ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64, |
| sizeof(regs64), 0); |
| if (ret) |
| goto out_free_params; |
| |
| ret = setup_boot_parameters(image, params, bootparam_load_addr, |
| efi_map_offset, efi_map_sz, |
| efi_setup_data_offset); |
| if (ret) |
| goto out_free_params; |
| |
| /* Allocate loader specific data */ |
| ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL); |
| if (!ldata) { |
| ret = -ENOMEM; |
| goto out_free_params; |
| } |
| |
| /* |
| * Store pointer to params so that it could be freed after loading |
| * params segment has been loaded and contents have been copied |
| * somewhere else. |
| */ |
| ldata->bootparams_buf = params; |
| return ldata; |
| |
| out_free_params: |
| kfree(params); |
| return ERR_PTR(ret); |
| } |
| |
| /* This cleanup function is called after various segments have been loaded */ |
| static int bzImage64_cleanup(void *loader_data) |
| { |
| struct bzimage64_data *ldata = loader_data; |
| |
| if (!ldata) |
| return 0; |
| |
| kfree(ldata->bootparams_buf); |
| ldata->bootparams_buf = NULL; |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG |
| static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len) |
| { |
| int ret; |
| |
| ret = verify_pefile_signature(kernel, kernel_len, |
| VERIFY_USE_SECONDARY_KEYRING, |
| VERIFYING_KEXEC_PE_SIGNATURE); |
| if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) { |
| ret = verify_pefile_signature(kernel, kernel_len, |
| VERIFY_USE_PLATFORM_KEYRING, |
| VERIFYING_KEXEC_PE_SIGNATURE); |
| } |
| return ret; |
| } |
| #endif |
| |
| const struct kexec_file_ops kexec_bzImage64_ops = { |
| .probe = bzImage64_probe, |
| .load = bzImage64_load, |
| .cleanup = bzImage64_cleanup, |
| #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG |
| .verify_sig = bzImage64_verify_sig, |
| #endif |
| }; |