linux-kernel - Re: [PATCH] ARM: mtd-xip: work around clang/llvm bug

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: <CAK8P3a2anB0hD5J0JfPpJ_Gjc=NjoNC4k9nJ=t9H5AOBbdnfqg@mail.gmail.com>
Date:   Tue, 9 Jul 2019 20:40:51 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     Nick Desaulniers <ndesaulniers@...gle.com>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Russell King <linux@...linux.org.uk>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        clang-built-linux <clang-built-linux@...glegroups.com>
Subject: Re: [PATCH] ARM: mtd-xip: work around clang/llvm bug

On Tue, Jul 9, 2019 at 8:08 PM 'Nick Desaulniers' via Clang Built
Linux <clang-built-linux@...glegroups.com> wrote:
> On Tue, Jul 9, 2019 at 1:41 AM Linus Walleij <linus.walleij@...aro.org> wrote:
>
> > I guess this brings up the old question whether the compiler should
> > be worked around or just considered immature, but as it happens this
>
> Definitely a balancing act; we prioritize work based on what's
> feasible to work around vs must be implemented.  A lot of my time is
> going into validation of asm goto right now, but others are ramping up
> on the integrated assembler (clang itself can be invoked as a
> substitute for GNU AS; but there's not enough support to do `make
> AS=clang` for the kernel just yet).

Note that this bug is the same with both gas and AS=clang, which also
indicates that clang implemented the undocumented .rep directive
for compatibility.

Overall I think we are at the point where building the kernel with clang-8
is mature enough that we should work around bugs like this where it is
easy enough rather than waiting for clang-9.

      Arnd