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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, 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 B269AC2BBCD for ; Thu, 3 Dec 2020 14:51:32 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 5A48222C7C for ; Thu, 3 Dec 2020 14:43:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5A48222C7C 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=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject: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=vrIZSljv4S3G7Ps8e6jEeoPg3gVjnZWIc9XEQA4TgOg=; b=PSTZuW6VEqtb1QxOrHDIsPPo2 pEFrlxMIOXg8ME1nPhNnAJ8XSnPJ4a0e0tAvSVgtloaduxqlmDBTaIFodYf9cD6qsY1BYMoFFyEhg 910PE3/3JhLL4HbC6+E6yDMYPuDdHWAXF8LqXyhzZ85uv/mZkzab3keBIonwj++GmRRud/NSBlDDF S5HiCE+Ym22fGIPG6wf+4nRq/D1w6cp7D3Piv/sbdP7dMX/WyzEws65a2uC/UeqM4aRBMZNRVKvQn IcSXuhEB2pdRbvinUDkXqigHCzIIFH0MBWqjY2PHnPwEE1+l3Eg3h9N7jWLxJJhcX1saIzxFNHXT0 WLhw2nMFQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kkpnU-0001yS-UH; Thu, 03 Dec 2020 14:41:29 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kkpnR-0001xX-TO for linux-arm-kernel@lists.infradead.org; Thu, 03 Dec 2020 14:41:26 +0000 Date: Thu, 3 Dec 2020 14:41:21 +0000 From: Catalin Marinas To: Peter Collingbourne Subject: Re: [PATCH] arm64: mte: remove an ISB on kernel exit Message-ID: <20201203144120.GA2830@gaia> References: <20201203073458.2675400-1-pcc@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201203073458.2675400-1-pcc@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-20201203_094126_050472_72F6F188 X-CRM114-Status: GOOD ( 13.75 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrey Konovalov , Linux ARM 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 Wed, Dec 02, 2020 at 11:34:58PM -0800, Peter Collingbourne wrote: > This ISB is unnecessary because we will soon do an ERET. > > Signed-off-by: Peter Collingbourne > Link: https://linux-review.googlesource.com/id/I69f1ee6bb09b1372dd744a0e01cedaf090c8d448 > --- > arch/arm64/kernel/entry.S | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 07646ef4f184..f8ad8d7fb1a2 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -182,7 +182,6 @@ alternative_else_nop_endif > mrs_s \tmp2, SYS_GCR_EL1 > bfi \tmp2, \tmp, #0, #16 > msr_s SYS_GCR_EL1, \tmp2 > - isb > #endif > .endm > > @@ -194,6 +193,7 @@ alternative_else_nop_endif > ldr_l \tmp, gcr_kernel_excl > > mte_set_gcr \tmp, \tmp2 > + isb > 1: > #endif > .endm It makes sense. I'll apply it after -rc1 once the MTE+kasan patches go in. Thanks. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel