kexec: support for kexec on panic using new system call (dd5f7260) · Commits · e / devices / android_kernel_xiaomi_nabu

arch/x86/include/asm/crash.h

0 → 100644

+9 −0

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

		struct kimage;

		/*
		* KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
		* I.e. Maximum page that is mapped directly into kernel memory,
		@@ -62,6 +64,10 @@
		# define KEXEC_ARCH KEXEC_ARCH_X86_64
		#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
		* running in kernel mode at the time of NMI occurrence. This code
		@@ -161,17 +167,35 @@ struct kimage_arch {
		pud_t *pud;
		pmd_t *pmd;
		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 {
		uint64_t rax;
		uint64_t rbx;
		uint64_t rcx;
		uint64_t rdx;
		uint64_t rsi;
		uint64_t rdi;
		uint64_t rbx;
		uint64_t rsp;
		uint64_t rbp;
		uint64_t rsi;
		uint64_t rdi;
		uint64_t r8;
		uint64_t r9;
		uint64_t r10;

arch/x86/kernel/crash.c

+563 −0

Original line number	Diff line number	Diff line
		@@ -4,9 +4,14 @@
		* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
		*
		* 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/kernel.h>
		#include <linux/smp.h>
		@@ -16,6 +21,7 @@
		#include <linux/elf.h>
		#include <linux/elfcore.h>
		#include <linux/module.h>
		#include <linux/slab.h>

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

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

		static inline void cpu_crash_vmclear_loaded_vmcss(void)
		{
		@@ -135,3 +181,520 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
		#endif
		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	Diff line number	Diff line
		@@ -21,6 +21,9 @@

		#include <asm/bootparam.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
		@@ -58,18 +61,24 @@ static int setup_initrd(struct boot_params *params,
		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 cmdline_offset, char *cmdline,
		unsigned long cmdline_len)
		{
		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;

		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;
		@@ -98,11 +107,12 @@ static int setup_memory_map_entries(struct boot_params *params)
		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 long long mem_k, start, end;
		int i;
		int i, ret = 0;

		/* Get subarch from existing bootparams */
		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 */
		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);

		nr_e820_entries = params->e820_entries;

		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,
		EDD_MBR_SIG_MAX * sizeof(unsigned int));

		return 0;
		return ret;
		}

		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);
		}

		/*
		* 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.
		@@ -254,7 +286,8 @@ void bzImage64_load(struct kimage image, char *kernel,
		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_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
		MAX_ELFCOREHDR_STR_LEN;
		params = kzalloc(params_cmdline_sz, GFP_KERNEL);
		if (!params)
		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_cmdline(params, bootparam_load_addr, sizeof(struct boot_params),
		cmdline, cmdline_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;
		@@ -332,7 +365,9 @@ void bzImage64_load(struct kimage image, char *kernel,
		if (ret)
		goto out_free_params;

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

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

arch/x86/kernel/machine_kexec_64.c

+40 −0

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

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

		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)
		{
		vfree(image->arch.elf_headers);
		image->arch.elf_headers = NULL;

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