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Date:   Wed, 15 Dec 2021 14:43:25 +0000
From:   Mark Rutland <mark.rutland@arm.com>
To:     Marco Elver <elver@google.com>
Cc:     Alexander Potapenko <glider@google.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
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        Eric Dumazet <edumazet@google.com>,
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Subject: Re: [PATCH 12/43] kcsan: clang: retire CONFIG_KCSAN_KCOV_BROKEN
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On Wed, Dec 15, 2021 at 02:39:43PM +0100, Marco Elver wrote:
> On Wed, 15 Dec 2021 at 14:33, Mark Rutland <mark.rutland@arm.com> wrote:
> >
> > On Tue, Dec 14, 2021 at 05:20:19PM +0100, Alexander Potapenko wrote:
> > > kcov used to be broken prior to Clang 11, but right now that version is
> > > already the minimum required to build with KCSAN, that is why we don't
> > > need KCSAN_KCOV_BROKEN anymore.
> >
> > Just to check, how is that requirement enforced?
> 
> HAVE_KCSAN_COMPILER will only be true with Clang 11 or later, due to
> no prior compiler having "-tsan-distinguish-volatile=1".

I see -- could we add wording to that effect into the commit messge?

> > I see the core Makefiles enforce 10.0.1+, but I couldn't spot an explicit
> > version dependency in Kconfig.kcsan.
> >
> > Otherwise, this looks good to me!
> 
> I think 5.17 will be Clang 11 only, so we could actually revert
> ea91a1d45d19469001a4955583187b0d75915759:
> https://lkml.kernel.org/r/Yao86FeC2ybOobLO@archlinux-ax161
> 
> I should resend that to be added to the -kbuild tree.

FWIW, that also works for me.

Thanks,
Mark.