Re: [PATCH v2] libebl: recognize FDO Packaging Metadata ELF note

[Mark Wielaard <mark@klomp.org>]

Hi Luca,

On Fri, 2022-03-25 at 11:17 +0000, Luca Boccassi wrote:
> On Fri, 2022-03-25 at 00:14 +0100, Mark Wielaard wrote:
> > I took the elf.h update separately. Tweaked your patch a little and
> > added a patch of my own to make elflint recognize the new note
> > type.
> > 
> >   [PATCH 1/3] libelf: Sync elf.h from glibc.
> >   [PATCH 2/3] libebl: recognize FDO Packaging Metadata ELF note
> >   [PATCH 3/3] elflint: Recognize NT_FDO_PACKAGING_METADATA
> 
> No problem at all, change looks good, thanks for following up.

Thanks, I pushed these three patches.
But I noticed an issue on s390x fedora 36.
This isn't just elfutils though, binutils also has trouble:

Displaying notes found in: .note.package
  Owner                Data size        Description
readelf: /usr/bin/bash: Warning: note with invalid namesz and/or descsz
found at offset 0x0
readelf: /usr/bin/bash: Warning:  type: 0x7e1afeca, namesize:
0x04000000, descsize: 0x78000000, alignment: 4

Note how it seems the sizes are swapped. s390x is a big endian
platform.

Do you happen to know what/how the notes are created and if that
process might produce bad little/big encoding issues?

> I have included the field in the first PoC that uses the spec in
> Debian, for the systemd packages:
> 
> $ readelf --notes /usr/lib/systemd/systemd | grep Packaging
>     Packaging Metadata:
> {"type":"deb","os":"debian","name":"systemd","architecture":"amd64","
> version":"250.4-1","debugInfoUrl":"https://debuginfod.debian.net"}

Nice, thanks. I'll look into how to pick up the debugInfoUrl and use
that automagically if possible.

BTW. I notice that Fedora has an osCpe field where Debian has an os
field. It would imho be good if one or the other got standardized.

Cheers,

Mark