diff options
Diffstat (limited to 'arch/x86/kernel/kexec-bzimage64.c')
| -rw-r--r-- | arch/x86/kernel/kexec-bzimage64.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c new file mode 100644 index 000000000000..9642b9b33655 --- /dev/null +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -0,0 +1,553 @@ +/* + * Kexec bzImage loader + * + * Copyright (C) 2014 Red Hat Inc. + * Authors: + * Vivek Goyal <vgoyal@redhat.com> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#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/verify_pefile.h> +#include <keys/system_keyring.h> + +#include <asm/bootparam.h> +#include <asm/setup.h> +#include <asm/crash.h> +#include <asm/efi.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; + uint32_t cmdline_low_32, cmdline_ext_32; + + memcpy(cmdline_ptr, cmdline, cmdline_len); + if (image->type == KEXEC_TYPE_CRASH) { + len = sprintf(cmdline_ptr + cmdline_len - 1, + " elfcorehdr=0x%lx", image->arch.elf_load_addr); + 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_saved.nr_map; + + /* TODO: Pass entries more than E820MAX in bootparams setup data */ + if (nr_e820_entries > E820MAX) + nr_e820_entries = E820MAX; + + params->e820_entries = nr_e820_entries; + memcpy(¶ms->e820_map, &e820_saved.map, + nr_e820_entries * sizeof(struct e820entry)); + + 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 (!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; + + /* 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)); + + /* Default sysdesc table */ + params->sys_desc_table.length = 0; + + 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_map[i].type != E820_RAM) + continue; + start = params->e820_map[i].addr; + end = params->e820_map[i].addr + params->e820_map[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; +} + +int bzImage64_probe(const char *buf, unsigned long len) +{ + int ret = -ENOEXEC; + struct setup_header *header; + + /* kernel should be atleast 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; + } + + /* I've got a bzImage */ + pr_debug("It's a relocatable bzImage64\n"); + ret = 0; + + return ret; +} + +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, params_misc_sz; + struct boot_params *params; + unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr; + unsigned long purgatory_load_addr; + unsigned long kernel_bufsz, kernel_memsz, kernel_align; + char *kernel_buf; + 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; + + 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, MIN_PURGATORY_ADDR, ULONG_MAX, 1, + &purgatory_load_addr); + if (ret) { + pr_err("Loading purgatory failed\n"); + return ERR_PTR(ret); + } + + pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr); + + + /* + * 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(); + efi_map_sz = ALIGN(efi_map_sz, 16); + params_cmdline_sz = sizeof(struct boot_params) + cmdline_len + + MAX_ELFCOREHDR_STR_LEN; + params_cmdline_sz = ALIGN(params_cmdline_sz, 16); + params_misc_sz = params_cmdline_sz + efi_map_sz + + sizeof(struct setup_data) + + sizeof(struct efi_setup_data); + + params = kzalloc(params_misc_sz, GFP_KERNEL); + if (!params) + return ERR_PTR(-ENOMEM); + efi_map_offset = params_cmdline_sz; + efi_setup_data_offset = efi_map_offset + efi_map_sz; + + /* Copy setup header onto bootparams. Documentation/x86/boot.txt */ + 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); + + ret = kexec_add_buffer(image, (char *)params, params_misc_sz, + params_misc_sz, 16, MIN_BOOTPARAM_ADDR, + ULONG_MAX, 1, &bootparam_load_addr); + if (ret) + goto out_free_params; + pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + bootparam_load_addr, params_misc_sz, params_misc_sz); + + /* Load kernel */ + kernel_buf = kernel + kern16_size; + kernel_bufsz = kernel_len - kern16_size; + kernel_memsz = PAGE_ALIGN(header->init_size); + kernel_align = header->kernel_alignment; + + ret = kexec_add_buffer(image, kernel_buf, + kernel_bufsz, kernel_memsz, kernel_align, + MIN_KERNEL_LOAD_ADDR, ULONG_MAX, 1, + &kernel_load_addr); + if (ret) + goto out_free_params; + + pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + kernel_load_addr, kernel_memsz, kernel_memsz); + + /* Load initrd high */ + if (initrd) { + ret = kexec_add_buffer(image, initrd, initrd_len, initrd_len, + PAGE_SIZE, MIN_INITRD_LOAD_ADDR, + ULONG_MAX, 1, &initrd_load_addr); + if (ret) + goto out_free_params; + + 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 */ +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 +int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len) +{ + bool trusted; + int ret; + + ret = verify_pefile_signature(kernel, kernel_len, + system_trusted_keyring, &trusted); + if (ret < 0) + return ret; + if (!trusted) + return -EKEYREJECTED; + return 0; +} +#endif + +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 +}; |