linux-kernel - Re: [PATCH] arch: x86: power: cpu: init %gs before __restore_processor

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Message-ID: <20200915182530.GV14436@zn.tnic>
Date:   Tue, 15 Sep 2020 20:25:30 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Nick Desaulniers <ndesaulniers@...gle.com>
Cc:     Roman Kiryanov <rkir@...gle.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Pavel Machek <pavel@....cz>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
        linux-pm@...r.kernel.org, Greg KH <gregkh@...uxfoundation.org>,
        Alistair Delva <adelva@...gle.com>,
        Haitao Shan <hshan@...gle.com>,
        lkml <linux-kernel@...r.kernel.org>,
        Sami Tolvanen <samitolvanen@...gle.com>,
        clang-built-linux <clang-built-linux@...glegroups.com>
Subject: Re: [PATCH] arch: x86: power: cpu: init %gs before
 __restore_processor_state (clang)

On Tue, Sep 15, 2020 at 11:00:30AM -0700, Nick Desaulniers wrote:
> This is exactly the same code from __restore_processor_state. 

No, this patch is adding 

#ifdef __clang__

and I don't like the sprinkling around of those compiler-specific
workarounds which we have to carry forward forever or at least until
that compiler version is deprecated. We already carry fixes for broken
hardware, broken BIOSes, broken peripherals,... can you follow the
progression? :)

So your argument about testing unreleased compilers in the other thread
makes a lot of sense so that stuff like that can be fixed in time, and
in the compiler, where it belongs (that is, *if* it belongs there).

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette