Re: [PATCH 00/17] Add kexec_file_load support to s390

[Philipp Rudo]

Hi Dave,

I just browsed AKASHI's patches (v7). The way I see it the common code changes
are on different areas of kexec_file and shouldn't get in conflict. Only in the
arch code (s390 and arm64) some function calls might need an update. But I have
to take a closer look on the patches first.

@AKASHI: Welcome to the list. While browsing I couldn't find any
arch_apply_relocation function for arm64. These require the biggest changes in
my patch set. Did I just miss it or does arm64 work differently?

@Dave: Happy holiday

Thanks
Philipp

On Wed, 14 Feb 2018 15:35:43 +0800
Dave Young <dyoung@xxxxxxxxxx> wrote:

> Hi Philipp,
> 
> I added AKASHI in cc, he posted arm64 kexec_file series previously.
> I would like to read both series especially the general part, but
> maybe at the end of this month because of a holiday..
> 
> From the patch log the cleanup looks nice, but still need read the
> details.
> 
> On 02/12/18 at 11:07am, Philipp Rudo wrote:
> > Hi everybody
> > 
> > resending the series as there was no reaction, yet. Furthermore i was told
> > that Andrew and the x86 list should also be CCed, so welcome.
> > 
> > No changes made to the patches since first time i sent them. The patches
> > apply to the current master (v4.16-rc1).
> > 
> > Thanks
> > Philipp
> > 
> > ---
> > 
> > this series adds the kexec_file_load system call to s390. Before the system
> > call is added there are some preparations/clean ups to common
> > kexec_file_load. In detail this series contains:
> > 
> > Patch #1&2: Minor cleanups/fixes.
> > 
> > Patch #3-9: Clean up the purgatory load/relocation code. Especially remove
> > the mis-use of the purgatory_info->sechdrs->sh_offset field, currently
> > holding a pointer into either kexec_purgatory (ro) or purgatory_buf (rw)
> > depending on the section. With these patches the section address will be
> > calculated verbosely and sh_offset will contain the offset of the section
> > in the stripped purgatory binary (purgatory_buf).
> > 
> > Patch #10: Allows architectures to set the purgaory load address. This
> > patch is important for s390 as the kernel and purgatory have to be loaded
> > to fixed addresses. In current code this is impossible as the purgatory
> > load is opaque to the architecture.
> > 
> > Patch #11: Moves x86 purgatories sha implementation to common lib/
> > directory.
> > 
> > Patches #12-17 finally adds the kexec_file_load system call to s390.
> > 
> > Please note that I had to touch arch code for x86 and power a little. In
> > theory this should not change the behavior but I don't have a way to test
> > it. Cross-compiling with defconfig(*) works fine for both.
> > 
> > Thanks
> > Philipp
> > 
> > (*) On x86 with the orc unwinder turned off. objtool SEGFAULTs on s390...
> > 
> > Philipp Rudo (17):
> >   kexec_file: Silence compile warnings
> >   kexec_file: Remove checks in kexec_purgatory_load
> >   kexec_file: Make purgatory_info->ehdr const
> >   kexec_file: Search symbols in read-only kexec_purgatory
> >   kexec_file: Use read-only sections in arch_kexec_apply_relocations*
> >   kexec_file: Split up __kexec_load_puragory
> >   kexec_file: Simplify kexec_purgatory_setup_sechdrs 1
> >   kexec_file: Simplify kexec_purgatory_setup_sechdrs 2
> >   kexec_file: Remove mis-use of sh_offset field
> >   kexec_file: Allow archs to set purgatory load address
> >   kexec_file: Move purgatories sha256 to common code
> >   s390/kexec_file: Prepare setup.h for kexec_file_load
> >   s390/kexec_file: Add purgatory
> >   s390/kexec_file: Add kexec_file_load system call
> >   s390/kexec_file: Add image loader
> >   s390/kexec_file: Add crash support to image loader
> >   s390/kexec_file: Add ELF loader
> > 
> >  arch/powerpc/kernel/kexec_elf_64.c             |   9 +-
> >  arch/s390/Kbuild                               |   1 +
> >  arch/s390/Kconfig                              |   4 +
> >  arch/s390/include/asm/kexec.h                  |  23 ++
> >  arch/s390/include/asm/purgatory.h              |  17 ++
> >  arch/s390/include/asm/setup.h                  |  40 ++-
> >  arch/s390/kernel/Makefile                      |   1 +
> >  arch/s390/kernel/asm-offsets.c                 |   5 +
> >  arch/s390/kernel/compat_wrapper.c              |   1 +
> >  arch/s390/kernel/kexec_elf.c                   | 149 ++++++++++
> >  arch/s390/kernel/kexec_image.c                 |  78 +++++
> >  arch/s390/kernel/machine_kexec_file.c          | 291 +++++++++++++++++++
> >  arch/s390/kernel/syscalls/syscall.tbl          |   1 +
> >  arch/s390/purgatory/Makefile                   |  37 +++
> >  arch/s390/purgatory/head.S                     | 279 ++++++++++++++++++
> >  arch/s390/purgatory/purgatory.c                |  42 +++
> >  arch/x86/kernel/kexec-bzimage64.c              |   8 +-
> >  arch/x86/kernel/machine_kexec_64.c             |  66 ++---
> >  arch/x86/purgatory/Makefile                    |   3 +
> >  arch/x86/purgatory/purgatory.c                 |   2 +-
> >  include/linux/kexec.h                          |  38 +--
> >  {arch/x86/purgatory => include/linux}/sha256.h |  10 +-
> >  kernel/kexec_file.c                            | 375 ++++++++++++-------------
> >  {arch/x86/purgatory => lib}/sha256.c           |   4 +-
> >  24 files changed, 1200 insertions(+), 284 deletions(-)
> >  create mode 100644 arch/s390/include/asm/purgatory.h
> >  create mode 100644 arch/s390/kernel/kexec_elf.c
> >  create mode 100644 arch/s390/kernel/kexec_image.c
> >  create mode 100644 arch/s390/kernel/machine_kexec_file.c
> >  create mode 100644 arch/s390/purgatory/Makefile
> >  create mode 100644 arch/s390/purgatory/head.S
> >  create mode 100644 arch/s390/purgatory/purgatory.c
> >  rename {arch/x86/purgatory => include/linux}/sha256.h (63%)
> >  rename {arch/x86/purgatory => lib}/sha256.c (99%)
> > 
> > -- 
> > 2.13.5
> > 
> > 
> > _______________________________________________
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> > kexec@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/kexec  
> 
> Thanks
> Dave
>