Re: [PATCH 0/8] kexec_file_load implementation for PowerPC

[Dave Young]

On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> 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.
> Hooks are 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 that same
> 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.

But seems there's no error handling in patches about KEXEC_ON_CRASH?
It would be good to either sending out the whole set or handle the error
cases correctly.

[snip]

Thanks
Dave

[PATCH 0/8] 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.
Hooks are 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 that same
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.

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.

Thiago Jung Bauermann (8):
  kexec_file: Remove unused members from struct kexec_buf.
  kexec_file: Generalize 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 | 373 
 arch/powerpc/kernel/kexec_elf_64.c| 564 ++
 arch/powerpc/kernel/machine_kexec_64.c| 142 
 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 |  10 +
 kernel/kexec_file.c   | 102 --
 kernel/kexec_internal.h   |   2 -
 36 files changed, 2504 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

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1.9.1