linux-kernel - Re: [RFC][PATCH 2/3] objtool: Find relocation base section using sh

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200528170010.xe46x3tvz4npvovj@treble>
Date:   Thu, 28 May 2020 12:00:10 -0500
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Matt Helsley <mhelsley@...are.com>
Cc:     linux-kernel@...r.kernel.org,
        Peter Zijlstra <peterz@...radead.org>,
        Steven Rostedt <rostedt@...dmis.org>
Subject: Re: [RFC][PATCH 2/3] objtool: Find relocation base section using
 sh_info

On Thu, May 28, 2020 at 09:02:47AM -0700, Matt Helsley wrote:
> On Thu, May 28, 2020 at 09:09:16AM -0500, Josh Poimboeuf wrote:
> > On Wed, May 27, 2020 at 09:42:32AM -0700, Matt Helsley wrote:
> > > Currently objtool uses a naming heuristic to find the "base"
> > > section to apply the relocation(s) to. The standard defines
> > > the SHF_INFO_LINK flag (SHF => in the section header flags)
> > > which indicates when the section header's sh_info field can
> > > be used to find the necessary section.
> > > 
> > > Warns when the heuristic is used as a fallback and changes
> > > the name heuristic calculation to handle rela (explicit
> > > addend) and now rel (implicit addend) relocations.
> > 
> > Does this fallback case actually happen?
> 
> Not that I could see. I was thinking about taking it out but
> I haven't tried this set with clang or other toolchains. So
> I was wondering if you think holding off before removing it
> would be wise or if you'd rather just remove it.

I just realized somebody already submitted an almost identical patch:

  https://lkml.kernel.org/r/20200421182501.149101-1-samitolvanen@google.com

Which I'll be merging soon... so you can just drop this one.

Then you can base your next version of this set on top of that patch, if
it hasn't been merged yet.

-- 
Josh