kexec: support for kexec on panic using new system call (dd5f7260) · Commits · 戴 / test

arch/x86/include/asm/crash.h

0 → 100644

+9 −0

Original line number	Original line	Diff line number	Diff line
			#ifndef _ASM_X86_CRASH_H
			#define _ASM_X86_CRASH_H

			int crash_load_segments(struct kimage *image);
			int crash_copy_backup_region(struct kimage *image);
			int crash_setup_memmap_entries(struct kimage *image,
			struct boot_params *params);

			#endif /* _ASM_X86_CRASH_H */

arch/x86/include/asm/kexec.h

+27 −3

Original line number	Original line	Diff line number	Diff line
	@@ -25,6 +25,8 @@
	#include <asm/ptrace.h>		#include <asm/ptrace.h>
	#include <asm/bootparam.h>		#include <asm/bootparam.h>

			struct kimage;

	/*		/*
	* KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.		* KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
	* I.e. Maximum page that is mapped directly into kernel memory,		* I.e. Maximum page that is mapped directly into kernel memory,
	@@ -62,6 +64,10 @@
	# define KEXEC_ARCH KEXEC_ARCH_X86_64		# define KEXEC_ARCH KEXEC_ARCH_X86_64
	#endif		#endif

			/* Memory to backup during crash kdump */
			#define KEXEC_BACKUP_SRC_START (0UL)
			#define KEXEC_BACKUP_SRC_END (640 * 1024UL) /* 640K */

	/*		/*
	* CPU does not save ss and sp on stack if execution is already		* CPU does not save ss and sp on stack if execution is already
	* running in kernel mode at the time of NMI occurrence. This code		* running in kernel mode at the time of NMI occurrence. This code
	@@ -161,17 +167,35 @@ struct kimage_arch {
	pud_t *pud;		pud_t *pud;
	pmd_t *pmd;		pmd_t *pmd;
	pte_t *pte;		pte_t *pte;
			/* Details of backup region */
			unsigned long backup_src_start;
			unsigned long backup_src_sz;

			/* Physical address of backup segment */
			unsigned long backup_load_addr;

			/* Core ELF header buffer */
			void *elf_headers;
			unsigned long elf_headers_sz;
			unsigned long elf_load_addr;
	};		};
			#endif /* CONFIG_X86_32 */

			#ifdef CONFIG_X86_64
			/*
			* Number of elements and order of elements in this structure should match
			* with the ones in arch/x86/purgatory/entry64.S. If you make a change here
			* make an appropriate change in purgatory too.
			*/
	struct kexec_entry64_regs {		struct kexec_entry64_regs {
	uint64_t rax;		uint64_t rax;
	uint64_t rbx;
	uint64_t rcx;		uint64_t rcx;
	uint64_t rdx;		uint64_t rdx;
	uint64_t rsi;		uint64_t rbx;
	uint64_t rdi;
	uint64_t rsp;		uint64_t rsp;
	uint64_t rbp;		uint64_t rbp;
			uint64_t rsi;
			uint64_t rdi;
	uint64_t r8;		uint64_t r8;
	uint64_t r9;		uint64_t r9;
	uint64_t r10;		uint64_t r10;

arch/x86/kernel/crash.c

+563 −0

Original line number	Original line	Diff line number	Diff line
	@@ -4,9 +4,14 @@
	* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)		* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
	*		*
	* Copyright (C) IBM Corporation, 2004. All rights reserved.		* Copyright (C) IBM Corporation, 2004. All rights reserved.
			* Copyright (C) Red Hat Inc., 2014. All rights reserved.
			* Authors:
			* Vivek Goyal <vgoyal@redhat.com>
	*		*
	*/		*/

			#define pr_fmt(fmt) "kexec: " fmt

	#include <linux/types.h>		#include <linux/types.h>
	#include <linux/kernel.h>		#include <linux/kernel.h>
	#include <linux/smp.h>		#include <linux/smp.h>
	@@ -16,6 +21,7 @@
	#include <linux/elf.h>		#include <linux/elf.h>
	#include <linux/elfcore.h>		#include <linux/elfcore.h>
	#include <linux/module.h>		#include <linux/module.h>
			#include <linux/slab.h>

	#include <asm/processor.h>		#include <asm/processor.h>
	#include <asm/hardirq.h>		#include <asm/hardirq.h>
	@@ -28,6 +34,45 @@
	#include <asm/reboot.h>		#include <asm/reboot.h>
	#include <asm/virtext.h>		#include <asm/virtext.h>

			/* Alignment required for elf header segment */
			#define ELF_CORE_HEADER_ALIGN 4096

			/* This primarily represents number of split ranges due to exclusion */
			#define CRASH_MAX_RANGES 16

			struct crash_mem_range {
			u64 start, end;
			};

			struct crash_mem {
			unsigned int nr_ranges;
			struct crash_mem_range ranges[CRASH_MAX_RANGES];
			};

			/* Misc data about ram ranges needed to prepare elf headers */
			struct crash_elf_data {
			struct kimage *image;
			/*
			* Total number of ram ranges we have after various adjustments for
			* GART, crash reserved region etc.
			*/
			unsigned int max_nr_ranges;
			unsigned long gart_start, gart_end;

			/* Pointer to elf header */
			void *ehdr;
			/* Pointer to next phdr */
			void *bufp;
			struct crash_mem mem;
			};

			/* Used while preparing memory map entries for second kernel */
			struct crash_memmap_data {
			struct boot_params *params;
			/* Type of memory */
			unsigned int type;
			};

	int in_crash_kexec;		int in_crash_kexec;

	/*		/*
	@@ -39,6 +84,7 @@ int in_crash_kexec;
	*/		*/
	crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss = NULL;		crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss = NULL;
	EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss);		EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss);
			unsigned long crash_zero_bytes;

	static inline void cpu_crash_vmclear_loaded_vmcss(void)		static inline void cpu_crash_vmclear_loaded_vmcss(void)
	{		{
	@@ -135,3 +181,520 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
	#endif		#endif
	crash_save_cpu(regs, safe_smp_processor_id());		crash_save_cpu(regs, safe_smp_processor_id());
	}		}

			#ifdef CONFIG_X86_64

			static int get_nr_ram_ranges_callback(unsigned long start_pfn,
			unsigned long nr_pfn, void *arg)
			{
			int *nr_ranges = arg;

			(*nr_ranges)++;
			return 0;
			}

			static int get_gart_ranges_callback(u64 start, u64 end, void *arg)
			{
			struct crash_elf_data *ced = arg;

			ced->gart_start = start;
			ced->gart_end = end;

			/* Not expecting more than 1 gart aperture */
			return 1;
			}


			/* Gather all the required information to prepare elf headers for ram regions */
			static void fill_up_crash_elf_data(struct crash_elf_data *ced,
			struct kimage *image)
			{
			unsigned int nr_ranges = 0;

			ced->image = image;

			walk_system_ram_range(0, -1, &nr_ranges,
			get_nr_ram_ranges_callback);

			ced->max_nr_ranges = nr_ranges;

			/*
			* We don't create ELF headers for GART aperture as an attempt
			* to dump this memory in second kernel leads to hang/crash.
			* If gart aperture is present, one needs to exclude that region
			* and that could lead to need of extra phdr.
			*/
			walk_iomem_res("GART", IORESOURCE_MEM, 0, -1,
			ced, get_gart_ranges_callback);

			/*
			* If we have gart region, excluding that could potentially split
			* a memory range, resulting in extra header. Account for that.
			*/
			if (ced->gart_end)
			ced->max_nr_ranges++;

			/* Exclusion of crash region could split memory ranges */
			ced->max_nr_ranges++;

			/* If crashk_low_res is not 0, another range split possible */
			if (crashk_low_res.end != 0)
			ced->max_nr_ranges++;
			}

			static int exclude_mem_range(struct crash_mem *mem,
			unsigned long long mstart, unsigned long long mend)
			{
			int i, j;
			unsigned long long start, end;
			struct crash_mem_range temp_range = {0, 0};

			for (i = 0; i < mem->nr_ranges; i++) {
			start = mem->ranges[i].start;
			end = mem->ranges[i].end;

			if (mstart > end \|\| mend < start)
			continue;

			/* Truncate any area outside of range */
			if (mstart < start)
			mstart = start;
			if (mend > end)
			mend = end;

			/* Found completely overlapping range */
			if (mstart == start && mend == end) {
			mem->ranges[i].start = 0;
			mem->ranges[i].end = 0;
			if (i < mem->nr_ranges - 1) {
			/* Shift rest of the ranges to left */
			for (j = i; j < mem->nr_ranges - 1; j++) {
			mem->ranges[j].start =
			mem->ranges[j+1].start;
			mem->ranges[j].end =
			mem->ranges[j+1].end;
			}
			}
			mem->nr_ranges--;
			return 0;
			}

			if (mstart > start && mend < end) {
			/* Split original range */
			mem->ranges[i].end = mstart - 1;
			temp_range.start = mend + 1;
			temp_range.end = end;
			} else if (mstart != start)
			mem->ranges[i].end = mstart - 1;
			else
			mem->ranges[i].start = mend + 1;
			break;
			}

			/* If a split happend, add the split to array */
			if (!temp_range.end)
			return 0;

			/* Split happened */
			if (i == CRASH_MAX_RANGES - 1) {
			pr_err("Too many crash ranges after split\n");
			return -ENOMEM;
			}

			/* Location where new range should go */
			j = i + 1;
			if (j < mem->nr_ranges) {
			/* Move over all ranges one slot towards the end */
			for (i = mem->nr_ranges - 1; i >= j; i--)
			mem->ranges[i + 1] = mem->ranges[i];
			}

			mem->ranges[j].start = temp_range.start;
			mem->ranges[j].end = temp_range.end;
			mem->nr_ranges++;
			return 0;
			}

			/*
			* Look for any unwanted ranges between mstart, mend and remove them. This
			* might lead to split and split ranges are put in ced->mem.ranges[] array
			*/
			static int elf_header_exclude_ranges(struct crash_elf_data *ced,
			unsigned long long mstart, unsigned long long mend)
			{
			struct crash_mem *cmem = &ced->mem;
			int ret = 0;

			memset(cmem->ranges, 0, sizeof(cmem->ranges));

			cmem->ranges[0].start = mstart;
			cmem->ranges[0].end = mend;
			cmem->nr_ranges = 1;

			/* Exclude crashkernel region */
			ret = exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
			if (ret)
			return ret;

			ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
			if (ret)
			return ret;

			/* Exclude GART region */
			if (ced->gart_end) {
			ret = exclude_mem_range(cmem, ced->gart_start, ced->gart_end);
			if (ret)
			return ret;
			}

			return ret;
			}

			static int prepare_elf64_ram_headers_callback(u64 start, u64 end, void *arg)
			{
			struct crash_elf_data *ced = arg;
			Elf64_Ehdr *ehdr;
			Elf64_Phdr *phdr;
			unsigned long mstart, mend;
			struct kimage *image = ced->image;
			struct crash_mem *cmem;
			int ret, i;

			ehdr = ced->ehdr;

			/* Exclude unwanted mem ranges */
			ret = elf_header_exclude_ranges(ced, start, end);
			if (ret)
			return ret;

			/* Go through all the ranges in ced->mem.ranges[] and prepare phdr */
			cmem = &ced->mem;

			for (i = 0; i < cmem->nr_ranges; i++) {
			mstart = cmem->ranges[i].start;
			mend = cmem->ranges[i].end;

			phdr = ced->bufp;
			ced->bufp += sizeof(Elf64_Phdr);

			phdr->p_type = PT_LOAD;
			phdr->p_flags = PF_R\|PF_W\|PF_X;
			phdr->p_offset = mstart;

			/*
			* If a range matches backup region, adjust offset to backup
			* segment.
			*/
			if (mstart == image->arch.backup_src_start &&
			(mend - mstart + 1) == image->arch.backup_src_sz)
			phdr->p_offset = image->arch.backup_load_addr;

			phdr->p_paddr = mstart;
			phdr->p_vaddr = (unsigned long long) __va(mstart);
			phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
			phdr->p_align = 0;
			ehdr->e_phnum++;
			pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
			phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
			ehdr->e_phnum, phdr->p_offset);
			}

			return ret;
			}

			static int prepare_elf64_headers(struct crash_elf_data *ced,
			void *addr, unsigned long sz)
			{
			Elf64_Ehdr *ehdr;
			Elf64_Phdr *phdr;
			unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
			unsigned char buf, bufp;
			unsigned int cpu;
			unsigned long long notes_addr;
			int ret;

			/* extra phdr for vmcoreinfo elf note */
			nr_phdr = nr_cpus + 1;
			nr_phdr += ced->max_nr_ranges;

			/*
			* kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
			* area on x86_64 (ffffffff80000000 - ffffffffa0000000).
			* I think this is required by tools like gdb. So same physical
			* memory will be mapped in two elf headers. One will contain kernel
			* text virtual addresses and other will have __va(physical) addresses.
			*/

			nr_phdr++;
			elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
			elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);

			buf = vzalloc(elf_sz);
			if (!buf)
			return -ENOMEM;

			bufp = buf;
			ehdr = (Elf64_Ehdr *)bufp;
			bufp += sizeof(Elf64_Ehdr);
			memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
			ehdr->e_ident[EI_CLASS] = ELFCLASS64;
			ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
			ehdr->e_ident[EI_VERSION] = EV_CURRENT;
			ehdr->e_ident[EI_OSABI] = ELF_OSABI;
			memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
			ehdr->e_type = ET_CORE;
			ehdr->e_machine = ELF_ARCH;
			ehdr->e_version = EV_CURRENT;
			ehdr->e_phoff = sizeof(Elf64_Ehdr);
			ehdr->e_ehsize = sizeof(Elf64_Ehdr);
			ehdr->e_phentsize = sizeof(Elf64_Phdr);

			/* Prepare one phdr of type PT_NOTE for each present cpu */
			for_each_present_cpu(cpu) {
			phdr = (Elf64_Phdr *)bufp;
			bufp += sizeof(Elf64_Phdr);
			phdr->p_type = PT_NOTE;
			notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
			phdr->p_offset = phdr->p_paddr = notes_addr;
			phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
			(ehdr->e_phnum)++;
			}

			/* Prepare one PT_NOTE header for vmcoreinfo */
			phdr = (Elf64_Phdr *)bufp;
			bufp += sizeof(Elf64_Phdr);
			phdr->p_type = PT_NOTE;
			phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
			phdr->p_filesz = phdr->p_memsz = sizeof(vmcoreinfo_note);
			(ehdr->e_phnum)++;

			#ifdef CONFIG_X86_64
			/* Prepare PT_LOAD type program header for kernel text region */
			phdr = (Elf64_Phdr *)bufp;
			bufp += sizeof(Elf64_Phdr);
			phdr->p_type = PT_LOAD;
			phdr->p_flags = PF_R\|PF_W\|PF_X;
			phdr->p_vaddr = (Elf64_Addr)_text;
			phdr->p_filesz = phdr->p_memsz = _end - _text;
			phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
			(ehdr->e_phnum)++;
			#endif

			/* Prepare PT_LOAD headers for system ram chunks. */
			ced->ehdr = ehdr;
			ced->bufp = bufp;
			ret = walk_system_ram_res(0, -1, ced,
			prepare_elf64_ram_headers_callback);
			if (ret < 0)
			return ret;

			*addr = buf;
			*sz = elf_sz;
			return 0;
			}

			/* Prepare elf headers. Return addr and size */
			static int prepare_elf_headers(struct kimage image, void *addr,
			unsigned long *sz)
			{
			struct crash_elf_data *ced;
			int ret;

			ced = kzalloc(sizeof(*ced), GFP_KERNEL);
			if (!ced)
			return -ENOMEM;

			fill_up_crash_elf_data(ced, image);

			/* By default prepare 64bit headers */
			ret = prepare_elf64_headers(ced, addr, sz);
			kfree(ced);
			return ret;
			}

			static int add_e820_entry(struct boot_params params, struct e820entry entry)
			{
			unsigned int nr_e820_entries;

			nr_e820_entries = params->e820_entries;
			if (nr_e820_entries >= E820MAX)
			return 1;

			memcpy(&params->e820_map[nr_e820_entries], entry,
			sizeof(struct e820entry));
			params->e820_entries++;
			return 0;
			}

			static int memmap_entry_callback(u64 start, u64 end, void *arg)
			{
			struct crash_memmap_data *cmd = arg;
			struct boot_params *params = cmd->params;
			struct e820entry ei;

			ei.addr = start;
			ei.size = end - start + 1;
			ei.type = cmd->type;
			add_e820_entry(params, &ei);

			return 0;
			}

			static int memmap_exclude_ranges(struct kimage image, struct crash_mem cmem,
			unsigned long long mstart,
			unsigned long long mend)
			{
			unsigned long start, end;
			int ret = 0;

			cmem->ranges[0].start = mstart;
			cmem->ranges[0].end = mend;
			cmem->nr_ranges = 1;

			/* Exclude Backup region */
			start = image->arch.backup_load_addr;
			end = start + image->arch.backup_src_sz - 1;
			ret = exclude_mem_range(cmem, start, end);
			if (ret)
			return ret;

			/* Exclude elf header region */
			start = image->arch.elf_load_addr;
			end = start + image->arch.elf_headers_sz - 1;
			return exclude_mem_range(cmem, start, end);
			}

			/* Prepare memory map for crash dump kernel */
			int crash_setup_memmap_entries(struct kimage image, struct boot_params params)
			{
			int i, ret = 0;
			unsigned long flags;
			struct e820entry ei;
			struct crash_memmap_data cmd;
			struct crash_mem *cmem;

			cmem = vzalloc(sizeof(struct crash_mem));
			if (!cmem)
			return -ENOMEM;

			memset(&cmd, 0, sizeof(struct crash_memmap_data));
			cmd.params = params;

			/* Add first 640K segment */
			ei.addr = image->arch.backup_src_start;
			ei.size = image->arch.backup_src_sz;
			ei.type = E820_RAM;
			add_e820_entry(params, &ei);

			/* Add ACPI tables */
			cmd.type = E820_ACPI;
			flags = IORESOURCE_MEM \| IORESOURCE_BUSY;
			walk_iomem_res("ACPI Tables", flags, 0, -1, &cmd,
			memmap_entry_callback);

			/* Add ACPI Non-volatile Storage */
			cmd.type = E820_NVS;
			walk_iomem_res("ACPI Non-volatile Storage", flags, 0, -1, &cmd,
			memmap_entry_callback);

			/* Add crashk_low_res region */
			if (crashk_low_res.end) {
			ei.addr = crashk_low_res.start;
			ei.size = crashk_low_res.end - crashk_low_res.start + 1;
			ei.type = E820_RAM;
			add_e820_entry(params, &ei);
			}

			/* Exclude some ranges from crashk_res and add rest to memmap */
			ret = memmap_exclude_ranges(image, cmem, crashk_res.start,
			crashk_res.end);
			if (ret)
			goto out;

			for (i = 0; i < cmem->nr_ranges; i++) {
			ei.size = cmem->ranges[i].end - cmem->ranges[i].start + 1;

			/* If entry is less than a page, skip it */
			if (ei.size < PAGE_SIZE)
			continue;
			ei.addr = cmem->ranges[i].start;
			ei.type = E820_RAM;
			add_e820_entry(params, &ei);
			}

			out:
			vfree(cmem);
			return ret;
			}

			static int determine_backup_region(u64 start, u64 end, void *arg)
			{
			struct kimage *image = arg;

			image->arch.backup_src_start = start;
			image->arch.backup_src_sz = end - start + 1;

			/* Expecting only one range for backup region */
			return 1;
			}

			int crash_load_segments(struct kimage *image)
			{
			unsigned long src_start, src_sz, elf_sz;
			void *elf_addr;
			int ret;

			/*
			* Determine and load a segment for backup area. First 640K RAM
			* region is backup source
			*/

			ret = walk_system_ram_res(KEXEC_BACKUP_SRC_START, KEXEC_BACKUP_SRC_END,
			image, determine_backup_region);

			/* Zero or postive return values are ok */
			if (ret < 0)
			return ret;

			src_start = image->arch.backup_src_start;
			src_sz = image->arch.backup_src_sz;

			/* Add backup segment. */
			if (src_sz) {
			/*
			* Ideally there is no source for backup segment. This is
			* copied in purgatory after crash. Just add a zero filled
			* segment for now to make sure checksum logic works fine.
			*/
			ret = kexec_add_buffer(image, (char *)&crash_zero_bytes,
			sizeof(crash_zero_bytes), src_sz,
			PAGE_SIZE, 0, -1, 0,
			&image->arch.backup_load_addr);
			if (ret)
			return ret;
			pr_debug("Loaded backup region at 0x%lx backup_start=0x%lx memsz=0x%lx\n",
			image->arch.backup_load_addr, src_start, src_sz);
			}

			/* Prepare elf headers and add a segment */
			ret = prepare_elf_headers(image, &elf_addr, &elf_sz);
			if (ret)
			return ret;

			image->arch.elf_headers = elf_addr;
			image->arch.elf_headers_sz = elf_sz;

			ret = kexec_add_buffer(image, (char *)elf_addr, elf_sz, elf_sz,
			ELF_CORE_HEADER_ALIGN, 0, -1, 0,
			&image->arch.elf_load_addr);
			if (ret) {
			vfree((void *)image->arch.elf_headers);
			return ret;
			}
			pr_debug("Loaded ELF headers at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
			image->arch.elf_load_addr, elf_sz, elf_sz);

			return ret;
			}

			#endif /* CONFIG_X86_64 */

arch/x86/kernel/kexec-bzimage64.c

+45 −10

Original line number	Original line	Diff line number	Diff line
	@@ -21,6 +21,9 @@

	#include <asm/bootparam.h>		#include <asm/bootparam.h>
	#include <asm/setup.h>		#include <asm/setup.h>
			#include <asm/crash.h>

			#define MAX_ELFCOREHDR_STR_LEN 30 /* elfcorehdr=0x<64bit-value> */

	/*		/*
	* Defines lowest physical address for various segments. Not sure where		* Defines lowest physical address for various segments. Not sure where
	@@ -58,18 +61,24 @@ static int setup_initrd(struct boot_params *params,
	return 0;		return 0;
	}		}

	static int setup_cmdline(struct boot_params *params,		static int setup_cmdline(struct kimage image, struct boot_params params,
	unsigned long bootparams_load_addr,		unsigned long bootparams_load_addr,
	unsigned long cmdline_offset, char *cmdline,		unsigned long cmdline_offset, char *cmdline,
	unsigned long cmdline_len)		unsigned long cmdline_len)
	{		{
	char cmdline_ptr = ((char )params) + cmdline_offset;		char cmdline_ptr = ((char )params) + cmdline_offset;
	unsigned long cmdline_ptr_phys;		unsigned long cmdline_ptr_phys, len;
	uint32_t cmdline_low_32, cmdline_ext_32;		uint32_t cmdline_low_32, cmdline_ext_32;

	memcpy(cmdline_ptr, cmdline, cmdline_len);		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';		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_ptr_phys = bootparams_load_addr + cmdline_offset;
	cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;		cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
	cmdline_ext_32 = cmdline_ptr_phys >> 32;		cmdline_ext_32 = cmdline_ptr_phys >> 32;
	@@ -98,11 +107,12 @@ static int setup_memory_map_entries(struct boot_params *params)
	return 0;		return 0;
	}		}

	static int setup_boot_parameters(struct boot_params *params)		static int setup_boot_parameters(struct kimage *image,
			struct boot_params *params)
	{		{
	unsigned int nr_e820_entries;		unsigned int nr_e820_entries;
	unsigned long long mem_k, start, end;		unsigned long long mem_k, start, end;
	int i;		int i, ret = 0;

	/* Get subarch from existing bootparams */		/* Get subarch from existing bootparams */
	params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;		params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
	@@ -125,7 +135,13 @@ static int setup_boot_parameters(struct boot_params *params)
	/* Default sysdesc table */		/* Default sysdesc table */
	params->sys_desc_table.length = 0;		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_memory_map_entries(params);		setup_memory_map_entries(params);

	nr_e820_entries = params->e820_entries;		nr_e820_entries = params->e820_entries;

	for (i = 0; i < nr_e820_entries; i++) {		for (i = 0; i < nr_e820_entries; i++) {
	@@ -153,7 +169,7 @@ static int setup_boot_parameters(struct boot_params *params)
	memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,		memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
	EDD_MBR_SIG_MAX * sizeof(unsigned int));		EDD_MBR_SIG_MAX * sizeof(unsigned int));

	return 0;		return ret;
	}		}

	int bzImage64_probe(const char *buf, unsigned long len)		int bzImage64_probe(const char *buf, unsigned long len)
	@@ -240,6 +256,22 @@ void bzImage64_load(struct kimage image, char *kernel,
	return ERR_PTR(-EINVAL);		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		* Load purgatory. For 64bit entry point, purgatory code can be
	* anywhere.		* anywhere.
	@@ -254,7 +286,8 @@ void bzImage64_load(struct kimage image, char *kernel,
	pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);		pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);

	/* Load Bootparams and cmdline */		/* Load Bootparams and cmdline */
	params_cmdline_sz = sizeof(struct boot_params) + cmdline_len;		params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
			MAX_ELFCOREHDR_STR_LEN;
	params = kzalloc(params_cmdline_sz, GFP_KERNEL);		params = kzalloc(params_cmdline_sz, GFP_KERNEL);
	if (!params)		if (!params)
	return ERR_PTR(-ENOMEM);		return ERR_PTR(-ENOMEM);
	@@ -303,8 +336,8 @@ void bzImage64_load(struct kimage image, char *kernel,
	setup_initrd(params, initrd_load_addr, initrd_len);		setup_initrd(params, initrd_load_addr, initrd_len);
	}		}

	setup_cmdline(params, bootparam_load_addr, sizeof(struct boot_params),		setup_cmdline(image, params, bootparam_load_addr,
	cmdline, cmdline_len);		sizeof(struct boot_params), cmdline, cmdline_len);

	/* bootloader info. Do we need a separate ID for kexec kernel loader? */		/* bootloader info. Do we need a separate ID for kexec kernel loader? */
	params->hdr.type_of_loader = 0x0D << 4;		params->hdr.type_of_loader = 0x0D << 4;
	@@ -332,7 +365,9 @@ void bzImage64_load(struct kimage image, char *kernel,
	if (ret)		if (ret)
	goto out_free_params;		goto out_free_params;

	setup_boot_parameters(params);		ret = setup_boot_parameters(image, params);
			if (ret)
			goto out_free_params;

	/* Allocate loader specific data */		/* Allocate loader specific data */
	ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);		ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);

arch/x86/kernel/machine_kexec_64.c

+40 −0

Original line number	Original line	Diff line number	Diff line
	@@ -178,6 +178,38 @@ static void load_segments(void)
	);		);
	}		}

			/* Update purgatory as needed after various image segments have been prepared */
			static int arch_update_purgatory(struct kimage *image)
			{
			int ret = 0;

			if (!image->file_mode)
			return 0;

			/* Setup copying of backup region */
			if (image->type == KEXEC_TYPE_CRASH) {
			ret = kexec_purgatory_get_set_symbol(image, "backup_dest",
			&image->arch.backup_load_addr,
			sizeof(image->arch.backup_load_addr), 0);
			if (ret)
			return ret;

			ret = kexec_purgatory_get_set_symbol(image, "backup_src",
			&image->arch.backup_src_start,
			sizeof(image->arch.backup_src_start), 0);
			if (ret)
			return ret;

			ret = kexec_purgatory_get_set_symbol(image, "backup_sz",
			&image->arch.backup_src_sz,
			sizeof(image->arch.backup_src_sz), 0);
			if (ret)
			return ret;
			}

			return ret;
			}

	int machine_kexec_prepare(struct kimage *image)		int machine_kexec_prepare(struct kimage *image)
	{		{
	unsigned long start_pgtable;		unsigned long start_pgtable;
	@@ -191,6 +223,11 @@ int machine_kexec_prepare(struct kimage *image)
	if (result)		if (result)
	return result;		return result;

			/* update purgatory as needed */
			result = arch_update_purgatory(image);
			if (result)
			return result;

	return 0;		return 0;
	}		}

	@@ -315,6 +352,9 @@ int arch_kexec_kernel_image_probe(struct kimage image, void buf,

	void arch_kexec_kernel_image_load(struct kimage image)		void arch_kexec_kernel_image_load(struct kimage image)
	{		{
			vfree(image->arch.elf_headers);
			image->arch.elf_headers = NULL;

	if (!image->fops \|\| !image->fops->load)		if (!image->fops \|\| !image->fops->load)
	return ERR_PTR(-ENOEXEC);		return ERR_PTR(-ENOEXEC);

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