Reproducible Builds Hackathon Hamburg 2017, May 5-7

[Holger Levsen]

Hi,

with some more delay, there's finally a wiki page announcing the hackathon:

https://wiki.debian.org/ReproducibleBuilds/HamburgHackathon2017

It should have all the information needed, so I wont repeat much here, except
the very basic:

when: 2017, May 5-7
where: Hamburg, Germany, inside+outside the CCC Hamburg hackerspace
why: to hack on reproducible builds everyhwere

If you have questions not answered on that wiki page, please ask and I'll try
to answer :)

If you plan to attend, or want, please add your name to that wiki page. And
if you cannot edit that wiki page, because it's in the Debian wiki and you
don't have an account there, please mail me, and I'll happily add you there :)

I've also been wondering whether to add this to 
https://reproducible-builds.org/events/
and have to decided to rather quickly (+finally) get this started, using a
Debian wiki page… we can still add it to the webpage at any time.

Further suggestions and help much welcome, especially with getting sponsoring
for the event.

Looking forward to see you in Hamburg! (or elsewhere! :)


-- 
cheers,
Holger


signature.asc
Description: Digital signature
___
Reproducible-builds mailing list
Reproducible-builds@lists.alioth.debian.org
http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/reproducible-builds

Re: binutils/ld.bfd, -fdebug-prefix-map, FILE entries (was: Re: dietlibc; build path issue on ARM despite -fdebug-prefix-map)

[Holger Levsen]

Hi Christian,

On Sat, Feb 18, 2017 at 02:19:52PM +0100, Christian Seiler wrote:
[...]
> I believe the issue stems from this code in binutils/bfd:
> 
> http://sources.debian.net/src/binutils/2.27.90.20170218-1/bfd/elflink.c/#L9757-L9778
> 
> The file name at this point is just the argument passed to the linker,
> irrespective of whether it's an absolute path or a relative one, and
> no prefix is applied at all.
> 
> The initial problem with dietlibc is that on ARM paltforms the
> startup code has local symbols in the assembly, which it doesn't
> on x86, so the problem has never surfaced on x86 in the past.
> 
> Which means this is a broader class of bugs that every time one
> has an assembly file that doesn't contain a ".file" directive
> and contains local symbols, ld.bfd will output a FILE entry
> which may contain an absolute path of the object file (depending on
> how the file name was passed to the linker), which can break
> reproducibility.
> 
> 
> For dietlibc (after Stretch), I can just add .file directives
> everywhere, so I can work around this issue.
> 
> But to make sure this doesn't happen at all anymore (there might
> be other software with hand-crafted assembly out there that has
> similar issues), I believe binutils should also be altered to
> support SOURCE_PREFIX_MAP in these cases.
> 
> Unfortunately, I know way too little about the details of binutils
> to feel comfortable in creating a patch (it was hard enough to find
> the suspected place where the path is injected), so all I can do 
> here is report my findings. Hopefully someone with more binutils-fu
> is able to pick this up.

do you know whether this has been fixed in the recent binutils uploads?

if not maybe you can file these findings as a bug, so they don't get lost 
on the mailinglist?


-- 
cheers,
Holger


signature.asc
Description: Digital signature
___
Reproducible-builds mailing list
Reproducible-builds@lists.alioth.debian.org
http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/reproducible-builds