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Subject[PATCH v3 04/10] kexec_file: factor out crashdump elf header function from x86
Date
prepare_elf_headers() can also be useful for other architectures,
including arm64. So let it factored out.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
---
arch/x86/kernel/crash.c | 324 ------------------------------------------------
include/linux/kexec.h | 17 +++
kernel/kexec_file.c | 308 +++++++++++++++++++++++++++++++++++++++++++++
kernel/kexec_internal.h | 20 +++
4 files changed, 345 insertions(+), 324 deletions(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 44404e2307bb..3c6b880f6dbf 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -21,7 +21,6 @@
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <linux/export.h>
-#include <linux/slab.h>
#include <linux/vmalloc.h>

#include <asm/processor.h>
@@ -41,34 +40,6 @@
/* 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
- * crash reserved region, etc.
- */
- unsigned int max_nr_ranges;
-
- /* 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;
@@ -209,301 +180,6 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
}

#ifdef CONFIG_KEXEC_FILE
-static int get_nr_ram_ranges_callback(u64 start, u64 end, void *arg)
-{
- unsigned int *nr_ranges = arg;
-
- (*nr_ranges)++;
- return 0;
-}
-
-
-/* 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_res(0, -1, &nr_ranges,
- get_nr_ram_ranges_callback);
-
- ced->max_nr_ranges = 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)
- 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;
-
- if (crashk_low_res.end) {
- ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.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 = VMCOREINFO_NOTE_SIZE;
- (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 e820_entry *entry)
{
unsigned int nr_e820_entries;
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 4a2b24d94e04..7547a3c1f94e 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -182,6 +182,23 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
int (*func)(u64, u64, void *));
extern int kexec_add_buffer(struct kexec_buf *kbuf);
int kexec_locate_mem_hole(struct kexec_buf *kbuf);
+extern int prepare_elf_headers(struct kimage *image, void **addr,
+ unsigned long *sz);
+
+/* 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];
+};
+
+extern int exclude_mem_range(struct crash_mem *mem,
+ unsigned long long mstart, unsigned long long mend);
#endif /* CONFIG_KEXEC_FILE */

struct kimage {
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 6203b54e04c5..6a0e31e175af 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -22,6 +22,11 @@
#include <linux/ima.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/vmalloc.h>
#include "kexec_internal.h"
@@ -1051,3 +1056,306 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,

return 0;
}
+
+static int get_nr_ram_ranges_callback(u64 start, u64 end, void *arg)
+{
+ unsigned int *nr_ranges = arg;
+
+ (*nr_ranges)++;
+ return 0;
+}
+
+
+/* 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_res(0, -1, &nr_ranges,
+ get_nr_ram_ranges_callback);
+
+ ced->max_nr_ranges = nr_ranges;
+
+ /* Exclusion of crash region could split memory ranges */
+ ced->max_nr_ranges++;
+
+#ifdef CONFIG_X86_64
+ /* If crashk_low_res is not 0, another range split possible */
+ if (crashk_low_res.end)
+ ced->max_nr_ranges++;
+#endif
+}
+
+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 happened, 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;
+
+#ifdef CONFIG_X86_64
+ if (crashk_low_res.end) {
+ ret = exclude_mem_range(cmem, crashk_low_res.start,
+ crashk_low_res.end);
+ if (ret)
+ return ret;
+ }
+#endif
+
+ 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;
+#ifdef CONFIG_X86_64
+ struct kimage *image = ced->image;
+#endif
+ 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;
+
+#ifdef CONFIG_X86_64
+ /*
+ * 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;
+#endif
+
+ 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 = VMCOREINFO_NOTE_SIZE;
+ (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 */
+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;
+}
diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h
index 50dfcb039a41..3c7a034f1fe1 100644
--- a/kernel/kexec_internal.h
+++ b/kernel/kexec_internal.h
@@ -16,6 +16,26 @@ extern struct mutex kexec_mutex;

#ifdef CONFIG_KEXEC_FILE
#include <linux/purgatory.h>
+
+/* Alignment required for elf header segment */
+#define ELF_CORE_HEADER_ALIGN 4096
+
+/* 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
+ * crash reserved region, etc.
+ */
+ unsigned int max_nr_ranges;
+
+ /* Pointer to elf header */
+ void *ehdr;
+ /* Pointer to next phdr */
+ void *bufp;
+ struct crash_mem mem;
+};
+
void kimage_file_post_load_cleanup(struct kimage *image);
extern char kexec_purgatory[];
extern size_t kexec_purgatory_size;
--
2.14.1
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