kexec-bzImage64: support for loading bzImage using 64bit entry (27f48d3e) · Commits · 戴 / test

arch/x86/include/asm/kexec-bzimage64.h

0 → 100644

+6 −0

Original line number	Diff line number	Diff line
		#ifndef _ASM_KEXEC_BZIMAGE64_H
		#define _ASM_KEXEC_BZIMAGE64_H

		extern struct kexec_file_ops kexec_bzImage64_ops;

		#endif /* _ASM_KEXE_BZIMAGE64_H */

arch/x86/include/asm/kexec.h

+21 −0

Original line number	Diff line number	Diff line
		@@ -23,6 +23,7 @@

		#include <asm/page.h>
		#include <asm/ptrace.h>
		#include <asm/bootparam.h>

		/*
		* KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
		@@ -161,6 +162,26 @@ struct kimage_arch {
		pmd_t *pmd;
		pte_t *pte;
		};

		struct kexec_entry64_regs {
		uint64_t rax;
		uint64_t rbx;
		uint64_t rcx;
		uint64_t rdx;
		uint64_t rsi;
		uint64_t rdi;
		uint64_t rsp;
		uint64_t rbp;
		uint64_t r8;
		uint64_t r9;
		uint64_t r10;
		uint64_t r11;
		uint64_t r12;
		uint64_t r13;
		uint64_t r14;
		uint64_t r15;
		uint64_t rip;
		};
		#endif

		typedef void crash_vmclear_fn(void);

arch/x86/kernel/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -118,4 +118,5 @@ ifeq ($(CONFIG_X86_64),y)

		obj-$(CONFIG_PCI_MMCONFIG) += mmconf-fam10h_64.o
		obj-y += vsmp_64.o
		obj-$(CONFIG_KEXEC) += kexec-bzimage64.o
		endif

arch/x86/kernel/kexec-bzimage64.c

0 → 100644

+375 −0

Original line number	Diff line number	Diff line
		/*
		* 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 <asm/bootparam.h>
		#include <asm/setup.h>

		/*
		* 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 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;
		uint32_t cmdline_low_32, cmdline_ext_32;

		memcpy(cmdline_ptr, cmdline, cmdline_len);
		cmdline_ptr[cmdline_len - 1] = '\0';

		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_memory_map_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(&params->e820_map, &e820_saved.map,
		nr_e820_entries * sizeof(struct e820entry));

		return 0;
		}

		static int setup_boot_parameters(struct boot_params *params)
		{
		unsigned int nr_e820_entries;
		unsigned long long mem_k, start, end;
		int i;

		/* Get subarch from existing bootparams */
		params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;

		/* Copying screen_info will do? */
		memcpy(&params->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(&params->apm_bios_info, 0, sizeof(params->apm_bios_info));

		/* Default drive info */
		memset(&params->hd0_info, 0, sizeof(params->hd0_info));
		memset(&params->hd1_info, 0, sizeof(params->hd1_info));

		/* Default sysdesc table */
		params->sys_desc_table.length = 0;

		setup_memory_map_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;
		}
		}

		/* 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 0;
		}

		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;
		}

		/* 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;
		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);

		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);
		}

		/*
		* 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 */
		params_cmdline_sz = sizeof(struct boot_params) + cmdline_len;
		params = kzalloc(params_cmdline_sz, GFP_KERNEL);
		if (!params)
		return ERR_PTR(-ENOMEM);

		/* 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(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);

		ret = kexec_add_buffer(image, (char *)params, params_cmdline_sz,
		params_cmdline_sz, 16, MIN_BOOTPARAM_ADDR,
		ULONG_MAX, 1, &bootparam_load_addr);
		if (ret)
		goto out_free_params;
		pr_debug("Loaded boot_param and command line at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
		bootparam_load_addr, params_cmdline_sz, params_cmdline_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(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", &regs64,
		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", &regs64,
		sizeof(regs64), 0);
		if (ret)
		goto out_free_params;

		setup_boot_parameters(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;
		}

		struct kexec_file_ops kexec_bzImage64_ops = {
		.probe = bzImage64_probe,
		.load = bzImage64_load,
		.cleanup = bzImage64_cleanup,
		};

arch/x86/kernel/machine_kexec_64.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -23,9 +23,10 @@
		#include <asm/tlbflush.h>
		#include <asm/mmu_context.h>
		#include <asm/debugreg.h>
		#include <asm/kexec-bzimage64.h>

		static struct kexec_file_ops *kexec_file_loaders[] = {
		NULL,
		&kexec_bzImage64_ops,
		};

		static void free_transition_pgtable(struct kimage *image)
		@@ -328,7 +329,7 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
		if (!image->fops \|\| !image->fops->cleanup)
		return 0;

		return image->fops->cleanup(image);
		return image->fops->cleanup(image->image_loader_data);
		}

		/*

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