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Date:   Fri, 10 Jan 2020 12:56:45 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Borislav Petkov <bp@alien8.de>, Mauro Rossi <issor.oruam@gmail.com>
Cc:     Arvind Sankar <nivedita@alum.mit.edu>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org,
        Thomas Lendacky <Thomas.Lendacky@amd.com>
Subject: Re: [PATCH] x86/tools/relocs: Add _etext and __end_of_kernel_reserve
 to S_REL
Message-ID: <202001101255.3F360ED562@keescook>
References: <20200110202349.1881840-1-nivedita@alum.mit.edu>
 <20200110203828.GK19453@zn.tnic>
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On Fri, Jan 10, 2020 at 09:38:28PM +0100, Borislav Petkov wrote:
> On Fri, Jan 10, 2020 at 03:23:49PM -0500, Arvind Sankar wrote:
> > Pre-2.23 binutils makes symbols defined outside sections absolute, so
> > these two symbols break the build on old linkers.
> 
> -ENOTENOUGHINFO
> 
> Which old linkers, how exactly do they break the build, etc etc?
> 
> Please give exact reproduction steps.

Mauro (now CCed) ran into this too, but on 32-bit builds only with older
binutils. I hadn't set up an environment to try to reproduce it yet, but
it seems like this patch would fix it. Mauro can you test this? Does it
fix it for you too?

https://lore.kernel.org/lkml/20200110202349.1881840-1-nivedita@alum.mit.edu/

-Kees

-- 
Kees Cook