Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <CAHk-=whfuea587g8rh2DeLFFGYxiVuh-bzq22osJwz3q4SOfmA@mail.gmail.com>
 <CAEJqkgi3w+zvMkRBP4VtAewX1UJxrVNRQ03MtRN_yH-PwOOScQ@mail.gmail.com>
 <20200616203352.GA1815527@rani.riverdale.lan> <CAEJqkghzD_6F2N=M65uYHzpOOJ8bvMw18JCfwsiQoH-kToPKLQ@mail.gmail.com>
 <20200616212536.GA1934393@rani.riverdale.lan>
In-Reply-To: <20200616212536.GA1934393@rani.riverdale.lan>
From:   Gabriel C <nix.or.die@googlemail.com>
Date:   Wed, 17 Jun 2020 00:00:14 +0200
Message-ID: <CAEJqkgij-_Z1S-F=ooHr=OYcE8biHr1Z-RGgOzHpC7Y0wm7BhA@mail.gmail.com>
Subject: Re: Linux 5.8-rc1
To:     Arvind Sankar <nivedita@alum.mit.edu>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Hans de Goede <hdegoede@redhat.com>,
        Borislav Petkov <bp@alien8.de>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Am Di., 16. Juni 2020 um 23:25 Uhr schrieb Arvind Sankar
<nivedita@alum.mit.edu>:
>
> On Tue, Jun 16, 2020 at 11:17:08PM +0200, Gabriel C wrote:
> > Am Di., 16. Juni 2020 um 22:33 Uhr schrieb Arvind Sankar
> > <nivedita@alum.mit.edu>:
> > >
> > > Can you attach the output of gcc -dumpspecs and gcc -v? I suspect your
> > > compiler enables stack protector by default. My distro compiler does
> > > that too, but not if -ffreestanding is enabled (which it is for the
> > > purgatory).
> > >
> >
> > Files including config uploaded to there:
> >
> > http://crazy.dev.frugalware.org/kernel/
> >
>
> Yeah, your gcc doesn't have the -ffreestanding handling. Mine (from
> gentoo) has this in the -dumpspecs output:
>
> *cc1_options:
> ... %{nostdlib|nodefaultlibs|ffreestanding:-fno-stack-protector} ...
>
> to switch off the default ssp when the standard libraries aren't available.

I wondered what they enable to do that. it turns out it is a custom patch.
While I think having that is not bad, such patches lead to bugs like this one.