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Date:   Tue, 26 Apr 2022 14:18:25 +0200
From:   Heiko Carstens <hca@linux.ibm.com>
To:     Sven Schnelle <svens@linux.ibm.com>
Cc:     Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] s390: disable -Warray-bounds
Message-ID: <YmfjEeUqYoWS2rL2@osiris>
References: <20220425121742.3222133-1-svens@linux.ibm.com>
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On Mon, Apr 25, 2022 at 02:17:42PM +0200, Sven Schnelle wrote:
> gcc-12 shows a lot of array bound warnings on s390. This is caused
> by our S390_lowcore macro:
> 
> which uses an hardcoded address of 0. Wrapping that with
> absolute_pointer() works, but gcc no longer knows that a 12 bit
> instruction is sufficient to access lowcore. So it emits instructions
> like 'lghi %r1,0; l %rx,xxx(%r1)' instead of a single load/store
> instruction. As s390 stores variables often read/written in lowcore,
> this is considered problematic. Therefore disable -Warray-bounds on
> s390 when gcc-12 is used until there is a better real solution.
> 
> Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
> ---
> Changes in v2:
> - only remove -Warray-bounds for gcc-12
> 
>  arch/s390/Makefile | 10 ++++++++++
>  1 file changed, 10 insertions(+)

Applied, thanks!