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From:   Olof Johansson <olof@lixom.net>
Date:   Wed, 7 Nov 2018 08:23:38 -0800
Message-ID: <CAOesGMgHxsgRcc6BvWFztZ6ypK6bxrh8CNsXRUusx=iL7TH0vA@mail.gmail.com>
Subject: Re: [PATCH v2] ubsan: don't mark __ubsan_handle_builtin_unreachable
 as noreturn
To:     aryabinin@virtuozzo.com
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>
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On Wed, Nov 7, 2018 at 6:45 AM Andrey Ryabinin <aryabinin@virtuozzo.com> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> gcc-8 complains about the prototype for this function:
>
> lib/ubsan.c:432:1: error: ignoring attribute 'noreturn' in declaration of a built-in function '__ubsan_handle_builtin_unreachable' because it conflicts with attribute 'const' [-Werror=attributes]
>
> This is actually a GCC's bug. In GCC internals
> __ubsan_handle_builtin_unreachable() declared with both 'noreturn' and
> 'const' attributes instead of only 'noreturn':
>    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84210
>
> Workaround this by removing the noreturn attribute.
>
> [aryabinin: Add information about GCC bug in changelog]
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>

Acked-by: Olof Johansson <olof@lixom.net>

While it's a GCC bug, it's there in official releases now and it makes
warnings noisy so we'd rather silence it.


-Olof