[PATCH v2 0/9] kexec_file_load implementation for PowerPC

[Thiago Jung Bauermann]

Hello,

This patch series implements the kexec_file_load system call on PowerPC.

It starts by removing an x86 assumption from kexec_file: kexec_add_buffer uses
iomem to find reserved memory ranges, but PowerPC uses the memblock subsystem.
A hook is added so that each arch can specify how memory ranges can be found.

Also, the memory-walking logic in kexec_add_buffer is useful in this
implementation to find a free area for the purgatory's stack, so the next
patch moves that logic to kexec_locate_mem_hole.

The kexec_file_load system call needs to apply relocations to the purgatory
but adding code for that would duplicate functionality with the module loading
mechanism, which also needs to apply relocations to the kernel modules.
Therefore, this patch series factors out the module relocation code so that it
can be shared.

One thing that is still missing is crashkernel support, which I intend to
submit shortly. For now, arch_kexec_kernel_image_probe rejects crash kernels.

This code is based on kexec-tools, but with many modifications to adapt it to
the kernel environment and facilities. Except the purgatory, which only has
minimal changes.

Changes for v2:

- All patches: forgot to add Signed-off-by lines in v1, so added them now.
- Patch "kexec_file: Generalize kexec_add_buffer.": broke in two, one
  adding arch_kexec_walk_mem and the other adding kexec_locate_mem_hole.
- Patch "powerpc: Implement kexec_file_load.":
    - Moved relocation changes and the arch_kexec_walk_mem implementation to
      the next patch in the series.
    - Removed pr_fmt from machine_kexec_64.c, since the patch doesn't add
      any call to pr_debug in that file.
    - Changed arch_kexec_kernel_image_probe to reject crash kernels.

Thiago Jung Bauermann (9):
  kexec_file: Remove unused members from struct kexec_buf.
  kexec_file: Generalize kexec_add_buffer.
  kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.
  powerpc: Factor out relocation code from module_64.c to elf_util_64.c.
  powerpc: Generalize elf64_apply_relocate_add.
  powerpc: Add functions to read ELF files of any endianness.
  powerpc: Implement kexec_file_load.
  powerpc: Add support for loading ELF kernels with kexec_file_load.
  powerpc: Add purgatory for kexec_file_load implementation.

 arch/powerpc/Kconfig                      |  13 +
 arch/powerpc/Makefile                     |   4 +
 arch/powerpc/include/asm/elf_util.h       |  92 +++++
 arch/powerpc/include/asm/kexec_elf_64.h   |  10 +
 arch/powerpc/include/asm/module.h         |  14 +-
 arch/powerpc/include/asm/systbl.h         |   1 +
 arch/powerpc/include/asm/unistd.h         |   2 +-
 arch/powerpc/include/uapi/asm/unistd.h    |   1 +
 arch/powerpc/kernel/Makefile              |   7 +
 arch/powerpc/kernel/elf_util.c            | 476 +++++++++++++++++++++++++
 arch/powerpc/kernel/elf_util_64.c         | 372 ++++++++++++++++++++
 arch/powerpc/kernel/kexec_elf_64.c        | 564 ++++++++++++++++++++++++++++++
 arch/powerpc/kernel/machine_kexec_64.c    | 151 ++++++++
 arch/powerpc/kernel/module_64.c           | 328 +++--------------
 arch/powerpc/purgatory/.gitignore         |   2 +
 arch/powerpc/purgatory/Makefile           |  36 ++
 arch/powerpc/purgatory/console-ppc64.c    |  43 +++
 arch/powerpc/purgatory/crashdump-ppc64.h  |  42 +++
 arch/powerpc/purgatory/crashdump_backup.c |  40 +++
 arch/powerpc/purgatory/crtsavres.S        |   5 +
 arch/powerpc/purgatory/hvCall.S           |  27 ++
 arch/powerpc/purgatory/hvCall.h           |   8 +
 arch/powerpc/purgatory/kexec-sha256.h     |  11 +
 arch/powerpc/purgatory/ppc64_asm.h        |  18 +
 arch/powerpc/purgatory/printf.c           | 171 +++++++++
 arch/powerpc/purgatory/purgatory-ppc64.c  |  46 +++
 arch/powerpc/purgatory/purgatory-ppc64.h  |   6 +
 arch/powerpc/purgatory/purgatory.c        |  66 ++++
 arch/powerpc/purgatory/purgatory.h        |  11 +
 arch/powerpc/purgatory/sha256.c           |   6 +
 arch/powerpc/purgatory/sha256.h           |   1 +
 arch/powerpc/purgatory/string.S           |   1 +
 arch/powerpc/purgatory/v2wrap.S           | 139 ++++++++
 include/linux/kexec.h                     |   7 +
 kernel/kexec_file.c                       | 116 ++++--
 kernel/kexec_internal.h                   |   2 -
 36 files changed, 2523 insertions(+), 316 deletions(-)
 create mode 100644 arch/powerpc/include/asm/elf_util.h
 create mode 100644 arch/powerpc/include/asm/kexec_elf_64.h
 create mode 100644 arch/powerpc/kernel/elf_util.c
 create mode 100644 arch/powerpc/kernel/elf_util_64.c
 create mode 100644 arch/powerpc/kernel/kexec_elf_64.c
 create mode 100644 arch/powerpc/purgatory/.gitignore
 create mode 100644 arch/powerpc/purgatory/Makefile
 create mode 100644 arch/powerpc/purgatory/console-ppc64.c
 create mode 100644 arch/powerpc/purgatory/crashdump-ppc64.h
 create mode 100644 arch/powerpc/purgatory/crashdump_backup.c
 create mode 100644 arch/powerpc/purgatory/crtsavres.S
 create mode 100644 arch/powerpc/purgatory/hvCall.S
 create mode 100644 arch/powerpc/purgatory/hvCall.h
 create mode 100644 arch/powerpc/purgatory/kexec-sha256.h
 create mode 100644 arch/powerpc/purgatory/ppc64_asm.h
 create mode 100644 arch/powerpc/purgatory/printf.c
 create mode 100644 arch/powerpc/purgatory/purgatory-ppc64.c
 create mode 100644 arch/powerpc/purgatory/purgatory-ppc64.h
 create mode 100644 arch/powerpc/purgatory/purgatory.c
 create mode 100644 arch/powerpc/purgatory/purgatory.h
 create mode 100644 arch/powerpc/purgatory/sha256.c
 create mode 100644 arch/powerpc/purgatory/sha256.h
 create mode 100644 arch/powerpc/purgatory/string.S
 create mode 100644 arch/powerpc/purgatory/v2wrap.S

-- 
1.9.1