From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B2B5C33CA2 for ; Thu, 9 Jan 2020 22:02:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B1A942077B for ; Thu, 9 Jan 2020 22:02:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="RR5TIJx3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B1A942077B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 65AA78E0006; Thu, 9 Jan 2020 17:02:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 60AF68E0001; Thu, 9 Jan 2020 17:02:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5479D8E0006; Thu, 9 Jan 2020 17:02:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0106.hostedemail.com [216.40.44.106]) by kanga.kvack.org (Postfix) with ESMTP id 3BF808E0001 for ; Thu, 9 Jan 2020 17:02:05 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id D363D180AD804 for ; Thu, 9 Jan 2020 22:02:04 +0000 (UTC) X-FDA: 76359469368.10.boy29_2f398c6702141 X-HE-Tag: boy29_2f398c6702141 X-Filterd-Recvd-Size: 3019 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Thu, 9 Jan 2020 22:02:04 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3BF9F2075D; Thu, 9 Jan 2020 22:02:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578607323; bh=88y37HxDUMffX0HsWQMZbo0p/Dn1R5k39rJxWhAGkv8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RR5TIJx35kahaEVAxbdZSd2dD4wvvD8AygQIteNvGlhu412PcwBHI8AA++92FE7LS vzWA2mF2npuuF4AhWN+5xyBED2EGGDYnXNcNBvr/hY+Hz8EZplxNFIix9KXqE8N71x B3NTTHoTPXneC2tJYdwo7CNOgOrCKoT755DN3CLY= Date: Thu, 9 Jan 2020 14:02:02 -0800 From: Andrew Morton To: Masami Hiramatsu Cc: Arnd Bergmann , Oleksandr Natalenko , linux-mm@kvack.org, Arnaldo Carvalho de Melo , Will Deacon , Song Liu , Alexey Dobriyan , Marc Zyngier , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH] kallsyms: work around bogus -Wrestrict warning Message-Id: <20200109140202.fd5488a2ac02f81b25d83b88@linux-foundation.org> In-Reply-To: <20200108102602.43d4c5433eb495cdbf387e9b@kernel.org> References: <20200107214042.855757-1-arnd@arndb.de> <20200108102602.43d4c5433eb495cdbf387e9b@kernel.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 8 Jan 2020 10:26:02 +0900 Masami Hiramatsu wrote: > Hi Arnd, > > On Tue, 7 Jan 2020 22:40:26 +0100 > Arnd Bergmann wrote: > > > gcc -O3 produces some really odd warnings for this file: > > > > kernel/kallsyms.c: In function 'sprint_symbol': > > kernel/kallsyms.c:369:3: error: 'strcpy' source argument is the same as destination [-Werror=restrict] > > strcpy(buffer, name); > > ^~~~~~~~~~~~~~~~~~~~ > > kernel/kallsyms.c: In function 'sprint_symbol_no_offset': > > kernel/kallsyms.c:369:3: error: 'strcpy' source argument is the same as destination [-Werror=restrict] > > strcpy(buffer, name); > > ^~~~~~~~~~~~~~~~~~~~ > > kernel/kallsyms.c: In function 'sprint_backtrace': > > kernel/kallsyms.c:369:3: error: 'strcpy' source argument is the same as destination [-Werror=restrict] > > strcpy(buffer, name); > > ^~~~~~~~~~~~~~~~~~~~ > > > > This obviously cannot be since it is preceded by an 'if (name != buffer)' > > check. > > Hmm, this looks like a bug in gcc. Yes, we're getting a lot of such reports. I don't think current gcc is ready for this patch so I'll drop it, sorry.