From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [PATCH 6/7] md/raid10, LLVM: get rid of variable length array
Date: Fri, 24 Mar 2017 14:50:24 +0100
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Cc: Borislav Petkov <bp@alien8.de>,
        Alexander Potapenko <glider@google.com>,
        Michael Davidson <md@google.com>,
        Michal Marek <mmarek@suse.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Shaohua Li <shli@kernel.org>,
        Matthias Kaehlcke <mka@chromium.org>,
        "x86@kernel.org" <x86@kernel.org>,
        "open list:KERNEL BUILD + fi..." <linux-kbuild@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-crypto@vger.kernel.org, linux-raid@vger.kernel.org,
        kbuild-all@01.org, Fengguang Wu <fengguang.wu@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Return-path: <linux-kbuild-owner@vger.kernel.org>
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On Fri, Mar 17, 2017 at 8:29 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Mar 17, 2017 at 08:26:42PM +0100, Peter Zijlstra wrote:
>> On Fri, Mar 17, 2017 at 08:05:16PM +0100, Dmitry Vyukov wrote:
>> > You can also find some reasons in the Why section of LLVM-Linux project:
>> > http://llvm.linuxfoundation.org/index.php/Main_Page
>>
>> From that:
>>
>>  - LLVM/Clang is a fast moving project with many things fixed quickly
>>    and features added.
>>
>> So what's the deal with that 5 year old bug you want us to work around?
>>
>> Also, clang doesn't support asm cc flags output and a few other
>> extensions last time I checked.
>>
>
> Another great one:
>
>  - BSD License (some people prefer this license to the GPL)
>
> Seems a very weak argument to make when talking about the Linux Kernel
> which is very explicitly GPLv2 (and not later).

OK, I guess should not have referenced the llvm-linux page.
So here are reasons on our side that I am ready to vouch:

 - clang make it possible to implement KMSAN (dynamic detection of
uses of uninit memory)
 - better code coverage for fuzzing
 - why simpler and faster development (e.g. we can port our user-space
hardening technologies -- CFI and SafeStack)

Michael is on a different team and has own reasons to do this.