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    Subject[PATCH v15 1/7] crash: move crash_prepare_elf64_headers()
    Date
    At the outcome of this patch set, the crash_prepare_elf64_headers()
    is utilized on both the kexec_file_load() and kexec_load() paths. As
    such, need to move this function out of kexec_file.c and into a
    common location crash_core.c.

    No functionality change.

    Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
    Acked-by: Baoquan He <bhe@redhat.com>
    ---
    kernel/crash_core.c | 100 ++++++++++++++++++++++++++++++++++++++++++++
    kernel/kexec_file.c | 99 -------------------------------------------
    2 files changed, 100 insertions(+), 99 deletions(-)

    diff --git a/kernel/crash_core.c b/kernel/crash_core.c
    index a0eb4d5cf557..46c160d14045 100644
    --- a/kernel/crash_core.c
    +++ b/kernel/crash_core.c
    @@ -10,6 +10,7 @@
    #include <linux/utsname.h>
    #include <linux/vmalloc.h>
    #include <linux/sizes.h>
    +#include <linux/kexec.h>

    #include <asm/page.h>
    #include <asm/sections.h>
    @@ -314,6 +315,105 @@ static int __init parse_crashkernel_dummy(char *arg)
    }
    early_param("crashkernel", parse_crashkernel_dummy);

    +int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
    + 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;
    + unsigned int cpu, i;
    + unsigned long long notes_addr;
    + unsigned long mstart, mend;
    +
    + /* extra phdr for vmcoreinfo ELF note */
    + nr_phdr = nr_cpus + 1;
    + nr_phdr += mem->nr_ranges;
    +
    + /*
    + * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
    + * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
    + * 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;
    +
    + ehdr = (Elf64_Ehdr *)buf;
    + phdr = (Elf64_Phdr *)(ehdr + 1);
    + 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->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)++;
    + phdr++;
    + }
    +
    + /* Prepare one PT_NOTE header for vmcoreinfo */
    + 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)++;
    + phdr++;
    +
    + /* Prepare PT_LOAD type program header for kernel text region */
    + if (need_kernel_map) {
    + phdr->p_type = PT_LOAD;
    + phdr->p_flags = PF_R|PF_W|PF_X;
    + phdr->p_vaddr = (unsigned long) _text;
    + phdr->p_filesz = phdr->p_memsz = _end - _text;
    + phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
    + ehdr->e_phnum++;
    + phdr++;
    + }
    +
    + /* Go through all the ranges in mem->ranges[] and prepare phdr */
    + for (i = 0; i < mem->nr_ranges; i++) {
    + mstart = mem->ranges[i].start;
    + mend = mem->ranges[i].end;
    +
    + phdr->p_type = PT_LOAD;
    + phdr->p_flags = PF_R|PF_W|PF_X;
    + phdr->p_offset = mstart;
    +
    + phdr->p_paddr = mstart;
    + phdr->p_vaddr = (unsigned 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);
    + phdr++;
    + }
    +
    + *addr = buf;
    + *sz = elf_sz;
    + return 0;
    +}
    +
    Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
    void *data, size_t data_len)
    {
    diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
    index 45637511e0de..f98d1742872b 100644
    --- a/kernel/kexec_file.c
    +++ b/kernel/kexec_file.c
    @@ -1217,102 +1217,3 @@ int crash_exclude_mem_range(struct crash_mem *mem,
    mem->nr_ranges++;
    return 0;
    }
    -
    -int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
    - 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;
    - unsigned int cpu, i;
    - unsigned long long notes_addr;
    - unsigned long mstart, mend;
    -
    - /* extra phdr for vmcoreinfo ELF note */
    - nr_phdr = nr_cpus + 1;
    - nr_phdr += mem->nr_ranges;
    -
    - /*
    - * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
    - * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
    - * 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;
    -
    - ehdr = (Elf64_Ehdr *)buf;
    - phdr = (Elf64_Phdr *)(ehdr + 1);
    - 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->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)++;
    - phdr++;
    - }
    -
    - /* Prepare one PT_NOTE header for vmcoreinfo */
    - 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)++;
    - phdr++;
    -
    - /* Prepare PT_LOAD type program header for kernel text region */
    - if (need_kernel_map) {
    - phdr->p_type = PT_LOAD;
    - phdr->p_flags = PF_R|PF_W|PF_X;
    - phdr->p_vaddr = (unsigned long) _text;
    - phdr->p_filesz = phdr->p_memsz = _end - _text;
    - phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
    - ehdr->e_phnum++;
    - phdr++;
    - }
    -
    - /* Go through all the ranges in mem->ranges[] and prepare phdr */
    - for (i = 0; i < mem->nr_ranges; i++) {
    - mstart = mem->ranges[i].start;
    - mend = mem->ranges[i].end;
    -
    - phdr->p_type = PT_LOAD;
    - phdr->p_flags = PF_R|PF_W|PF_X;
    - phdr->p_offset = mstart;
    -
    - phdr->p_paddr = mstart;
    - phdr->p_vaddr = (unsigned 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);
    - phdr++;
    - }
    -
    - *addr = buf;
    - *sz = elf_sz;
    - return 0;
    -}
    --
    2.31.1
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      Last update: 2022-12-09 16:38    [W:4.645 / U:0.008 seconds]
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