From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755500AbdKBNL3 (ORCPT ); Thu, 2 Nov 2017 09:11:29 -0400 Received: from foss.arm.com ([217.140.101.70]:59860 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751974AbdKBNL0 (ORCPT ); Thu, 2 Nov 2017 09:11:26 -0400 Subject: Re: [PATCH] ARM: NOMMU: work around maybe-uninitialized warning To: Russell King - ARM Linux Cc: Arnd Bergmann , Nicolas Pitre , afzal mohammed , Laura Abbott , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20171102092155.737712-1-arnd@arndb.de> <681a1757-ddbe-c9a7-6945-fa72600cf172@arm.com> <20171102130734.GZ9463@n2100.armlinux.org.uk> From: Vladimir Murzin Message-ID: Date: Thu, 2 Nov 2017 13:11:23 +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: <20171102130734.GZ9463@n2100.armlinux.org.uk> 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 13:07, Russell King - ARM Linux wrote: > On Thu, Nov 02, 2017 at 12:25:47PM +0000, Vladimir Murzin wrote: >> 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! > > I'd prefer not to at this stage. Same things that apply that I said > in the "ARM: early_printk: use printascii() rather than printch()" > thread - I need to ensure that what I have is stable before 4.14 is > released, so I'm not accepting anything further unless it is _really_ > urgent. Yes, I saw that thread, it is why that "not sure" thing. > > This isn't urgent. > Should I resubmit after -rc1 or you'll apply it directly from patch tracker? Thanks Vladimir