From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753915AbeCYSTM (ORCPT ); Sun, 25 Mar 2018 14:19:12 -0400 Received: from mail.kmu-office.ch ([178.209.48.109]:54954 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753700AbeCYSTL (ORCPT ); Sun, 25 Mar 2018 14:19:11 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Date: Sun, 25 Mar 2018 20:19:09 +0200 From: Stefan Agner To: Nicolas Pitre Cc: linux@armlinux.org.uk, ard.biesheuvel@linaro.org, arnd@arndb.de, robin.murphy@arm.com, marc.zyngier@arm.com, behanw@converseincode.com, keescook@chromium.org, Bernhard.Rosenkranzer@linaro.org, mka@chromium.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/6] bus: arm-cci: use asm unreachable In-Reply-To: References: <20180325180959.28008-1-stefan@agner.ch> <20180325180959.28008-2-stefan@agner.ch> Message-ID: User-Agent: Roundcube Webmail/1.3.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25.03.2018 20:14, Nicolas Pitre wrote: > On Sun, 25 Mar 2018, Stefan Agner wrote: > >> Mixing asm and C code is not recommended in a naked function by >> gcc and leads to an error when using clang: >> drivers/bus/arm-cci.c:2107:2: error: non-ASM statement in naked >> function is not supported >> unreachable(); >> ^ >> >> While the function is marked __naked it actually properly return >> in asm. There is no need for the unreachable() call. >> >> Suggested-by: Russell King >> Signed-off-by: Stefan Agner > > If that doesn't introduce any warning with gcc then I'm fine with it. > At least with GCC 6.2 it did not introduce a new warning with gcc. > Acked-by: Nicolas Pitre Thanks! -- Stefan > > >> --- >> Changes in v2: >> - Don't add assembly ASM_UNREACHABLE, just drop unreachable() >> >> drivers/bus/arm-cci.c | 2 -- >> 1 file changed, 2 deletions(-) >> >> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c >> index 5426c04fe24b..fc2da3a617ac 100644 >> --- a/drivers/bus/arm-cci.c >> +++ b/drivers/bus/arm-cci.c >> @@ -2103,8 +2103,6 @@ asmlinkage void __naked cci_enable_port_for_self(void) >> [sizeof_struct_cpu_port] "i" (sizeof(struct cpu_port)), >> [sizeof_struct_ace_port] "i" (sizeof(struct cci_ace_port)), >> [offsetof_port_phys] "i" (offsetof(struct cci_ace_port, phys)) ); >> - >> - unreachable(); >> } >> >> /** >> -- >> 2.16.2 >> >> From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan@agner.ch (Stefan Agner) Date: Sun, 25 Mar 2018 20:19:09 +0200 Subject: [PATCH v2 1/6] bus: arm-cci: use asm unreachable In-Reply-To: References: <20180325180959.28008-1-stefan@agner.ch> <20180325180959.28008-2-stefan@agner.ch> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 25.03.2018 20:14, Nicolas Pitre wrote: > On Sun, 25 Mar 2018, Stefan Agner wrote: > >> Mixing asm and C code is not recommended in a naked function by >> gcc and leads to an error when using clang: >> drivers/bus/arm-cci.c:2107:2: error: non-ASM statement in naked >> function is not supported >> unreachable(); >> ^ >> >> While the function is marked __naked it actually properly return >> in asm. There is no need for the unreachable() call. >> >> Suggested-by: Russell King >> Signed-off-by: Stefan Agner > > If that doesn't introduce any warning with gcc then I'm fine with it. > At least with GCC 6.2 it did not introduce a new warning with gcc. > Acked-by: Nicolas Pitre Thanks! -- Stefan > > >> --- >> Changes in v2: >> - Don't add assembly ASM_UNREACHABLE, just drop unreachable() >> >> drivers/bus/arm-cci.c | 2 -- >> 1 file changed, 2 deletions(-) >> >> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c >> index 5426c04fe24b..fc2da3a617ac 100644 >> --- a/drivers/bus/arm-cci.c >> +++ b/drivers/bus/arm-cci.c >> @@ -2103,8 +2103,6 @@ asmlinkage void __naked cci_enable_port_for_self(void) >> [sizeof_struct_cpu_port] "i" (sizeof(struct cpu_port)), >> [sizeof_struct_ace_port] "i" (sizeof(struct cci_ace_port)), >> [offsetof_port_phys] "i" (offsetof(struct cci_ace_port, phys)) ); >> - >> - unreachable(); >> } >> >> /** >> -- >> 2.16.2 >> >>