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Date:   Tue, 7 Jan 2020 17:45:09 +0000
From:   Will Deacon <will@kernel.org>
To:     Christian Brauner <christian.brauner@ubuntu.com>
Cc:     Amanieu d'Antras <amanieu@gmail.com>,
        Will Deacon <will.deacon@arm.com>,
        linux-kernel@vger.kernel.org,
        Christian Brauner <christian@brauner.io>,
        "# 3.4.x" <stable@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        keescook@chromium.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH 2/7] arm64: Implement copy_thread_tls
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On Tue, Jan 07, 2020 at 10:02:27AM +0100, Christian Brauner wrote:
> [Cc Kees in case he knows something about where arch specific tests live
>  or whether we have a framework for this]
> 
> On Mon, Jan 06, 2020 at 07:03:32PM +0100, Amanieu d'Antras wrote:
> > On Mon, Jan 6, 2020 at 6:39 PM Will Deacon <will@kernel.org> wrote:
> > > I also ran the native and compat selftests but, unfortunately, they all
> > > pass even without this patch. Do you reckon it would be possible to update
> > > them to check the tls pointer?
> > 
> > Here's the program I used for testing on arm64. I considered adding it
> > to the selftests but there is no portable way of reading the TLS
> > register on all architectures.
> 
> I'm not saying you need to do this right now.

Agreed, these patches should be merged in their current state and my ack
stands for that.

> It feels like we must've run into the "this is architecture
> specific"-and-we-want-to-test-this issue before... Do we have a place
> where architecture specific selftests live?

For arch-specific selftests there are tools/testing/selftests/$ARCH
directories, although in this case maybe it's better to have an #ifdef
in a header so that architectures with __builtin_thread_pointer can use
that.

Will