Re: [PATCH v4 2/2] arm64: kexec_file: add crash dump support

[Will Deacon]

On Thu, Jan 09, 2020 at 09:46:55AM +0900, AKASHI Takahiro wrote:
> On Wed, Jan 08, 2020 at 05:48:39PM +0000, Will Deacon wrote:
> > On Mon, Dec 16, 2019 at 11:12:47AM +0900, AKASHI Takahiro wrote:
> > > Enabling crash dump (kdump) includes
> > > * prepare contents of ELF header of a core dump file, /proc/vmcore,
> > >   using crash_prepare_elf64_headers(), and
> > > * add two device tree properties, "linux,usable-memory-range" and
> > >   "linux,elfcorehdr", which represent respectively a memory range
> > >   to be used by crash dump kernel and the header's location
> > > 
> > > Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> > > Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> > > Cc: Will Deacon <will.deacon@xxxxxxx>
> > > Reviewed-by: James Morse <james.morse@xxxxxxx>
> > > Tested-and-reviewed-by: Bhupesh Sharma <bhsharma@xxxxxxxxxx>
> > > ---
> > >  arch/arm64/include/asm/kexec.h         |   4 +
> > >  arch/arm64/kernel/kexec_image.c        |   4 -
> > >  arch/arm64/kernel/machine_kexec_file.c | 106 ++++++++++++++++++++++++-
> > >  3 files changed, 106 insertions(+), 8 deletions(-)
> > > 
> > > diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
> > > index 12a561a54128..d24b527e8c00 100644
> > > --- a/arch/arm64/include/asm/kexec.h
> > > +++ b/arch/arm64/include/asm/kexec.h
> > > @@ -96,6 +96,10 @@ static inline void crash_post_resume(void) {}
> > >  struct kimage_arch {
> > >  	void *dtb;
> > >  	unsigned long dtb_mem;
> > > +	/* Core ELF header buffer */
> > > +	void *elf_headers;
> > > +	unsigned long elf_headers_mem;
> > > +	unsigned long elf_headers_sz;
> > >  };
> > 
> > This conflicts with the cleanup work from Pavel. Please can you check my
> > resolution? [1]
> 
> I don't know why we need to change a type of dtb_mem,
> otherwise it looks good.
> 
> (I also assume that you notice that kimage_arch is of no use for kexec.)

Yes, that's why I'd like the resolution checked. If you reckon it's cleaner
to drop Pavel's patch altogether in light of your changes, we can do that
instead.

Thoughts?

Will