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=-10.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 61FADC433DB for ; Mon, 8 Mar 2021 17:00:22 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EC21365236 for ; Mon, 8 Mar 2021 17:00:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC21365236 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=MyXfrYnhOP5Vvu/pHxchBHwMjYr/7feYX03w9YYlueM=; b=PxT0ymixF71Klqn0x08AcvexR SkgF/vUfjTCrT6C7FSiST+01N1Tkhty/zA3izfXsIyvtewwSm2Ce7kxAC4LnZV5MoHrug6RSwHa3+ 2cnupzTVbGT5/5orYmkg2AQgY8p1msVBlaou4BO1LmxRKQcbPHlF3af9a0LkqEfcvsIln7ES8VdBK jPzJMPXmjNBDuIezWv2J/6jmqiHKXjhox6RLIFhFW80NXq9YIvIGnnUpZkhU5K6bFE1q2I6md/mtH 7VXgF9KjDzs/n5hLMh1KXDl6EEcg/XySDbWkGvJm6mA72YT9kVqKClsa7CLVQTlu0l1YHCini+4Jm Wmq52vwVg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lJJDf-001DwS-To; Mon, 08 Mar 2021 16:59:00 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lJJDa-001Du0-A2 for linux-arm-kernel@lists.infradead.org; Mon, 08 Mar 2021 16:58:56 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id E424E6522C; Mon, 8 Mar 2021 16:58:49 +0000 (UTC) Date: Mon, 8 Mar 2021 16:58:47 +0000 From: Catalin Marinas To: Andrey Konovalov Cc: Vincenzo Frascino , Alexander Potapenko , Marco Elver , Andrew Morton , Will Deacon , Dmitry Vyukov , Andrey Ryabinin , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/5] arm64: kasan: allow to init memory when setting tags Message-ID: <20210308165847.GF15644@arm.com> References: <755161094eac5b0fc15273d609c78a459d4d07b9.1615218180.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <755161094eac5b0fc15273d609c78a459d4d07b9.1615218180.git.andreyknvl@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210308_165854_538038_40A7109E X-CRM114-Status: GOOD ( 10.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Mar 08, 2021 at 04:55:14PM +0100, Andrey Konovalov wrote: > @@ -68,10 +69,16 @@ static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag) > * 'asm volatile' is required to prevent the compiler to move > * the statement outside of the loop. > */ > - asm volatile(__MTE_PREAMBLE "stg %0, [%0]" > - : > - : "r" (curr) > - : "memory"); > + if (init) > + asm volatile(__MTE_PREAMBLE "stzg %0, [%0]" > + : > + : "r" (curr) > + : "memory"); > + else > + asm volatile(__MTE_PREAMBLE "stg %0, [%0]" > + : > + : "r" (curr) > + : "memory"); > > curr += MTE_GRANULE_SIZE; > } while (curr != end); Is 'init' always a built-in constant here? If not, checking it once outside the loop may be better (or check the code generation, maybe the compiler is smart enough). -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel