Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] powerpc: Avoid clang warnings around setjmp and longjmp
To:     Nathan Chancellor <natechancellor@gmail.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Nick Desaulniers <ndesaulniers@google.com>
Cc:     clang-built-linux@googlegroups.com, linuxppc-dev@lists.ozlabs.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org
References: <20190812023214.107817-1-natechancellor@gmail.com>
From:   Christophe Leroy <christophe.leroy@c-s.fr>
Message-ID: <5da5478f-9320-43bd-0f5e-430db2ee9195@c-s.fr>
Date:   Mon, 12 Aug 2019 07:37:51 +0200
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.8.0
MIME-Version: 1.0
In-Reply-To: <20190812023214.107817-1-natechancellor@gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: fr
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


Le 12/08/2019 à 04:32, Nathan Chancellor a écrit :
> Commit aea447141c7e ("powerpc: Disable -Wbuiltin-requires-header when
> setjmp is used") disabled -Wbuiltin-requires-header because of a warning
> about the setjmp and longjmp declarations.
> 
> r367387 in clang added another diagnostic around this, complaining that
> there is no jmp_buf declaration.
> 
[...]

> 
> Cc: stable@vger.kernel.org # 4.19+
> Link: https://github.com/ClangBuiltLinux/linux/issues/625
> Link: https://github.com/llvm/llvm-project/commit/3be25e79477db2d31ac46493d97eca8c20592b07
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> 
[...]

> 
>   arch/powerpc/kernel/Makefile | 5 +++--
>   arch/powerpc/xmon/Makefile   | 5 +++--

What about scripts/recordmcount.c and scripts/sortextable.c which 
contains calls to setjmp() and longjmp() ?

And arch/um/ ?

Christophe

>   2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index ea0c69236789..44e340ed4722 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -5,8 +5,9 @@
>   
>   CFLAGS_ptrace.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
>   
> -# Disable clang warning for using setjmp without setjmp.h header
> -CFLAGS_crash.o		+= $(call cc-disable-warning, builtin-requires-header)
> +# Avoid clang warnings about longjmp and setjmp built-ins (inclusion of setjmp.h and declaration of jmp_buf type)
> +CFLAGS_crash.o		+= $(call cc-disable-warning, builtin-requires-header) \
> +			   $(call cc-disable-warning, incomplete-setjmp-declaration)
>   
>   ifdef CONFIG_PPC64
>   CFLAGS_prom_init.o	+= $(NO_MINIMAL_TOC)
> diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
> index f142570ad860..53f341391210 100644
> --- a/arch/powerpc/xmon/Makefile
> +++ b/arch/powerpc/xmon/Makefile
> @@ -1,8 +1,9 @@
>   # SPDX-License-Identifier: GPL-2.0
>   # Makefile for xmon
>   
> -# Disable clang warning for using setjmp without setjmp.h header
> -subdir-ccflags-y := $(call cc-disable-warning, builtin-requires-header)
> +# Avoid clang warnings about longjmp and setjmp built-ins (inclusion of setjmp.h and declaration of jmp_buf type)
> +subdir-ccflags-y := $(call cc-disable-warning, builtin-requires-header) \
> +		    $(call cc-disable-warning, incomplete-setjmp-declaration)
>   
>   GCOV_PROFILE := n
>   KCOV_INSTRUMENT := n
>