555 lines
15 KiB
C
Executable File
555 lines
15 KiB
C
Executable File
/*
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* Kexec bzImage loader
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*
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* Copyright (C) 2014 Red Hat Inc.
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* Authors:
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* Vivek Goyal <vgoyal@redhat.com>
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*
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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*/
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#define pr_fmt(fmt) "kexec-bzImage64: " fmt
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#include <linux/string.h>
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#include <linux/printk.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/kexec.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/efi.h>
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#include <linux/verify_pefile.h>
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#include <keys/system_keyring.h>
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#include <asm/bootparam.h>
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#include <asm/setup.h>
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#include <asm/crash.h>
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#include <asm/efi.h>
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#include <asm/kexec-bzimage64.h>
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#define MAX_ELFCOREHDR_STR_LEN 30 /* elfcorehdr=0x<64bit-value> */
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/*
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* Defines lowest physical address for various segments. Not sure where
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* exactly these limits came from. Current bzimage64 loader in kexec-tools
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* uses these so I am retaining it. It can be changed over time as we gain
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* more insight.
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*/
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#define MIN_PURGATORY_ADDR 0x3000
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#define MIN_BOOTPARAM_ADDR 0x3000
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#define MIN_KERNEL_LOAD_ADDR 0x100000
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#define MIN_INITRD_LOAD_ADDR 0x1000000
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/*
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* This is a place holder for all boot loader specific data structure which
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* gets allocated in one call but gets freed much later during cleanup
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* time. Right now there is only one field but it can grow as need be.
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*/
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struct bzimage64_data {
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/*
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* Temporary buffer to hold bootparams buffer. This should be
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* freed once the bootparam segment has been loaded.
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*/
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void *bootparams_buf;
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};
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static int setup_initrd(struct boot_params *params,
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unsigned long initrd_load_addr, unsigned long initrd_len)
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{
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params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL;
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params->hdr.ramdisk_size = initrd_len & 0xffffffffUL;
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params->ext_ramdisk_image = initrd_load_addr >> 32;
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params->ext_ramdisk_size = initrd_len >> 32;
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return 0;
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}
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static int setup_cmdline(struct kimage *image, struct boot_params *params,
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unsigned long bootparams_load_addr,
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unsigned long cmdline_offset, char *cmdline,
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unsigned long cmdline_len)
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{
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char *cmdline_ptr = ((char *)params) + cmdline_offset;
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unsigned long cmdline_ptr_phys, len;
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uint32_t cmdline_low_32, cmdline_ext_32;
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memcpy(cmdline_ptr, cmdline, cmdline_len);
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if (image->type == KEXEC_TYPE_CRASH) {
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len = sprintf(cmdline_ptr + cmdline_len - 1,
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" elfcorehdr=0x%lx", image->arch.elf_load_addr);
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cmdline_len += len;
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}
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cmdline_ptr[cmdline_len - 1] = '\0';
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pr_debug("Final command line is: %s\n", cmdline_ptr);
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cmdline_ptr_phys = bootparams_load_addr + cmdline_offset;
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cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
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cmdline_ext_32 = cmdline_ptr_phys >> 32;
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params->hdr.cmd_line_ptr = cmdline_low_32;
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if (cmdline_ext_32)
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params->ext_cmd_line_ptr = cmdline_ext_32;
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return 0;
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}
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static int setup_e820_entries(struct boot_params *params)
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{
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unsigned int nr_e820_entries;
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nr_e820_entries = e820_saved.nr_map;
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/* TODO: Pass entries more than E820MAX in bootparams setup data */
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if (nr_e820_entries > E820MAX)
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nr_e820_entries = E820MAX;
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params->e820_entries = nr_e820_entries;
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memcpy(¶ms->e820_map, &e820_saved.map,
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nr_e820_entries * sizeof(struct e820entry));
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return 0;
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}
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#ifdef CONFIG_EFI
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static int setup_efi_info_memmap(struct boot_params *params,
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unsigned long params_load_addr,
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unsigned int efi_map_offset,
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unsigned int efi_map_sz)
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{
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void *efi_map = (void *)params + efi_map_offset;
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unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
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struct efi_info *ei = ¶ms->efi_info;
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if (!efi_map_sz)
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return 0;
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efi_runtime_map_copy(efi_map, efi_map_sz);
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ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
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ei->efi_memmap_hi = efi_map_phys_addr >> 32;
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ei->efi_memmap_size = efi_map_sz;
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return 0;
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}
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static int
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prepare_add_efi_setup_data(struct boot_params *params,
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unsigned long params_load_addr,
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unsigned int efi_setup_data_offset)
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{
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unsigned long setup_data_phys;
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struct setup_data *sd = (void *)params + efi_setup_data_offset;
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struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);
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esd->fw_vendor = efi.fw_vendor;
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esd->runtime = efi.runtime;
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esd->tables = efi.config_table;
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esd->smbios = efi.smbios;
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sd->type = SETUP_EFI;
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sd->len = sizeof(struct efi_setup_data);
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/* Add setup data */
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setup_data_phys = params_load_addr + efi_setup_data_offset;
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sd->next = params->hdr.setup_data;
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params->hdr.setup_data = setup_data_phys;
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return 0;
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}
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static int
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setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
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unsigned int efi_map_offset, unsigned int efi_map_sz,
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unsigned int efi_setup_data_offset)
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{
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struct efi_info *current_ei = &boot_params.efi_info;
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struct efi_info *ei = ¶ms->efi_info;
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if (!current_ei->efi_memmap_size)
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return 0;
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/*
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* If 1:1 mapping is not enabled, second kernel can not setup EFI
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* and use EFI run time services. User space will have to pass
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* acpi_rsdp=<addr> on kernel command line to make second kernel boot
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* without efi.
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*/
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if (efi_enabled(EFI_OLD_MEMMAP))
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return 0;
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ei->efi_loader_signature = current_ei->efi_loader_signature;
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ei->efi_systab = current_ei->efi_systab;
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ei->efi_systab_hi = current_ei->efi_systab_hi;
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ei->efi_memdesc_version = current_ei->efi_memdesc_version;
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ei->efi_memdesc_size = efi_get_runtime_map_desc_size();
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setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
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efi_map_sz);
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prepare_add_efi_setup_data(params, params_load_addr,
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efi_setup_data_offset);
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return 0;
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}
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#endif /* CONFIG_EFI */
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static int
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setup_boot_parameters(struct kimage *image, struct boot_params *params,
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unsigned long params_load_addr,
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unsigned int efi_map_offset, unsigned int efi_map_sz,
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unsigned int efi_setup_data_offset)
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{
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unsigned int nr_e820_entries;
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unsigned long long mem_k, start, end;
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int i, ret = 0;
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/* Get subarch from existing bootparams */
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params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
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/* Copying screen_info will do? */
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memcpy(¶ms->screen_info, &boot_params.screen_info,
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sizeof(struct screen_info));
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/* Fill in memsize later */
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params->screen_info.ext_mem_k = 0;
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params->alt_mem_k = 0;
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/* Default APM info */
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memset(¶ms->apm_bios_info, 0, sizeof(params->apm_bios_info));
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/* Default drive info */
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memset(¶ms->hd0_info, 0, sizeof(params->hd0_info));
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memset(¶ms->hd1_info, 0, sizeof(params->hd1_info));
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/* Default sysdesc table */
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params->sys_desc_table.length = 0;
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if (image->type == KEXEC_TYPE_CRASH) {
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ret = crash_setup_memmap_entries(image, params);
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if (ret)
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return ret;
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} else
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setup_e820_entries(params);
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nr_e820_entries = params->e820_entries;
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for (i = 0; i < nr_e820_entries; i++) {
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if (params->e820_map[i].type != E820_RAM)
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continue;
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start = params->e820_map[i].addr;
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end = params->e820_map[i].addr + params->e820_map[i].size - 1;
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if ((start <= 0x100000) && end > 0x100000) {
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mem_k = (end >> 10) - (0x100000 >> 10);
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params->screen_info.ext_mem_k = mem_k;
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params->alt_mem_k = mem_k;
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if (mem_k > 0xfc00)
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params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
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if (mem_k > 0xffffffff)
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params->alt_mem_k = 0xffffffff;
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}
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}
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#ifdef CONFIG_EFI
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/* Setup EFI state */
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setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
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efi_setup_data_offset);
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#endif
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/* Setup EDD info */
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memcpy(params->eddbuf, boot_params.eddbuf,
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EDDMAXNR * sizeof(struct edd_info));
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params->eddbuf_entries = boot_params.eddbuf_entries;
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memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
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EDD_MBR_SIG_MAX * sizeof(unsigned int));
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return ret;
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}
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static int bzImage64_probe(const char *buf, unsigned long len)
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{
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int ret = -ENOEXEC;
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struct setup_header *header;
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/* kernel should be atleast two sectors long */
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if (len < 2 * 512) {
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pr_err("File is too short to be a bzImage\n");
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return ret;
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}
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header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
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if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
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pr_err("Not a bzImage\n");
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return ret;
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}
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if (header->boot_flag != 0xAA55) {
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pr_err("No x86 boot sector present\n");
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return ret;
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}
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if (header->version < 0x020C) {
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pr_err("Must be at least protocol version 2.12\n");
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return ret;
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}
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if (!(header->loadflags & LOADED_HIGH)) {
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pr_err("zImage not a bzImage\n");
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return ret;
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}
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if (!(header->xloadflags & XLF_KERNEL_64)) {
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pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
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return ret;
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}
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if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
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pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
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return ret;
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}
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/*
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* Can't handle 32bit EFI as it does not allow loading kernel
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* above 4G. This should be handled by 32bit bzImage loader
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*/
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if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
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pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
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return ret;
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}
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/* I've got a bzImage */
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pr_debug("It's a relocatable bzImage64\n");
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ret = 0;
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return ret;
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}
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static void *bzImage64_load(struct kimage *image, char *kernel,
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unsigned long kernel_len, char *initrd,
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unsigned long initrd_len, char *cmdline,
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unsigned long cmdline_len)
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{
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struct setup_header *header;
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int setup_sects, kern16_size, ret = 0;
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unsigned long setup_header_size, params_cmdline_sz, params_misc_sz;
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struct boot_params *params;
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unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
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unsigned long purgatory_load_addr;
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unsigned long kernel_bufsz, kernel_memsz, kernel_align;
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char *kernel_buf;
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struct bzimage64_data *ldata;
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struct kexec_entry64_regs regs64;
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void *stack;
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unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
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unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
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header = (struct setup_header *)(kernel + setup_hdr_offset);
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setup_sects = header->setup_sects;
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if (setup_sects == 0)
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setup_sects = 4;
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kern16_size = (setup_sects + 1) * 512;
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if (kernel_len < kern16_size) {
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pr_err("bzImage truncated\n");
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return ERR_PTR(-ENOEXEC);
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}
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if (cmdline_len > header->cmdline_size) {
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pr_err("Kernel command line too long\n");
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return ERR_PTR(-EINVAL);
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}
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/*
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* In case of crash dump, we will append elfcorehdr=<addr> to
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* command line. Make sure it does not overflow
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*/
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if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
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pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
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return ERR_PTR(-EINVAL);
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}
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/* Allocate and load backup region */
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if (image->type == KEXEC_TYPE_CRASH) {
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ret = crash_load_segments(image);
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if (ret)
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return ERR_PTR(ret);
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}
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/*
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* Load purgatory. For 64bit entry point, purgatory code can be
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* anywhere.
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*/
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ret = kexec_load_purgatory(image, MIN_PURGATORY_ADDR, ULONG_MAX, 1,
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&purgatory_load_addr);
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if (ret) {
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pr_err("Loading purgatory failed\n");
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return ERR_PTR(ret);
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}
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pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
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/*
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* Load Bootparams and cmdline and space for efi stuff.
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*
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* Allocate memory together for multiple data structures so
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* that they all can go in single area/segment and we don't
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* have to create separate segment for each. Keeps things
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* little bit simple
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*/
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efi_map_sz = efi_get_runtime_map_size();
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efi_map_sz = ALIGN(efi_map_sz, 16);
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params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
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MAX_ELFCOREHDR_STR_LEN;
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params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
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params_misc_sz = params_cmdline_sz + efi_map_sz +
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sizeof(struct setup_data) +
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sizeof(struct efi_setup_data);
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params = kzalloc(params_misc_sz, GFP_KERNEL);
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if (!params)
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return ERR_PTR(-ENOMEM);
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efi_map_offset = params_cmdline_sz;
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efi_setup_data_offset = efi_map_offset + efi_map_sz;
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/* Copy setup header onto bootparams. Documentation/x86/boot.txt */
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setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
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/* Is there a limit on setup header size? */
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memcpy(¶ms->hdr, (kernel + setup_hdr_offset), setup_header_size);
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ret = kexec_add_buffer(image, (char *)params, params_misc_sz,
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params_misc_sz, 16, MIN_BOOTPARAM_ADDR,
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ULONG_MAX, 1, &bootparam_load_addr);
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if (ret)
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goto out_free_params;
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pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
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bootparam_load_addr, params_misc_sz, params_misc_sz);
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/* Load kernel */
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kernel_buf = kernel + kern16_size;
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kernel_bufsz = kernel_len - kern16_size;
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kernel_memsz = PAGE_ALIGN(header->init_size);
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kernel_align = header->kernel_alignment;
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ret = kexec_add_buffer(image, kernel_buf,
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kernel_bufsz, kernel_memsz, kernel_align,
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MIN_KERNEL_LOAD_ADDR, ULONG_MAX, 1,
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&kernel_load_addr);
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if (ret)
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goto out_free_params;
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pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
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kernel_load_addr, kernel_memsz, kernel_memsz);
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/* Load initrd high */
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if (initrd) {
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ret = kexec_add_buffer(image, initrd, initrd_len, initrd_len,
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PAGE_SIZE, MIN_INITRD_LOAD_ADDR,
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ULONG_MAX, 1, &initrd_load_addr);
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if (ret)
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goto out_free_params;
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pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
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initrd_load_addr, initrd_len, initrd_len);
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setup_initrd(params, initrd_load_addr, initrd_len);
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}
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setup_cmdline(image, params, bootparam_load_addr,
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sizeof(struct boot_params), cmdline, cmdline_len);
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/* bootloader info. Do we need a separate ID for kexec kernel loader? */
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params->hdr.type_of_loader = 0x0D << 4;
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params->hdr.loadflags = 0;
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/* Setup purgatory regs for entry */
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ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64,
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sizeof(regs64), 1);
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if (ret)
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goto out_free_params;
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regs64.rbx = 0; /* Bootstrap Processor */
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regs64.rsi = bootparam_load_addr;
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regs64.rip = kernel_load_addr + 0x200;
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stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
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if (IS_ERR(stack)) {
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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)
|
|
{
|
|
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
|
|
};
|