From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755189AbdKBM0D (ORCPT ); Thu, 2 Nov 2017 08:26:03 -0400 Received: from foss.arm.com ([217.140.101.70]:59330 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752607AbdKBM0B (ORCPT ); Thu, 2 Nov 2017 08:26:01 -0400 Subject: Re: [PATCH] ARM: NOMMU: work around maybe-uninitialized warning To: Arnd Bergmann , Russell King Cc: Nicolas Pitre , afzal mohammed , Laura Abbott , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20171102092155.737712-1-arnd@arndb.de> From: Vladimir Murzin Message-ID: <681a1757-ddbe-c9a7-6945-fa72600cf172@arm.com> Date: Thu, 2 Nov 2017 12:25:47 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20171102092155.737712-1-arnd@arndb.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/11/17 09:21, Arnd Bergmann wrote: > The reworked MPU code produces a new warning in some configurations, > presumably starting with the code move after the compiler now makes > different inlining decisions: > > arch/arm/mm/pmsa-v7.c: In function 'adjust_lowmem_bounds_mpu': > arch/arm/mm/pmsa-v7.c:310:5: error: 'specified_mem_size' may be used uninitialized in this function [-Werror=maybe-uninitialized] > > This appears to be harmless, as we know that there is always at > least one memblock, and the only way this could get triggered is > if the for_each_memblock() loop was never entered. > > I could not come up with a better workaround than initializing > the specified_mem_size to zero, but at least that is the value > that the variable would have in the hypothetical case of no > memblocks. > > Fixes: 877ec119dbbf ("ARM: 8706/1: NOMMU: Move out MPU setup in separate module") > Signed-off-by: Arnd Bergmann > --- > Vladimir, if this looks good to you, can you forward it to Russell's > patch tracker, or otherwise suggest a different fix? Accepted as patch 8719/1. Not sure if Russell will pick it up or not... anyway, thanks for the patch! Vladimir > --- > arch/arm/mm/pmsa-v7.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/mm/pmsa-v7.c b/arch/arm/mm/pmsa-v7.c > index 106ae1c435a3..976df60ac426 100644 > --- a/arch/arm/mm/pmsa-v7.c > +++ b/arch/arm/mm/pmsa-v7.c > @@ -234,7 +234,7 @@ static int __init allocate_region(phys_addr_t base, phys_addr_t size, > /* MPU initialisation functions */ > void __init adjust_lowmem_bounds_mpu(void) > { > - phys_addr_t specified_mem_size, total_mem_size = 0; > + phys_addr_t specified_mem_size = 0, total_mem_size = 0; > struct memblock_region *reg; > bool first = true; > phys_addr_t mem_start; >