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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21FF3C46CA3 for ; Thu, 7 Dec 2023 13:55:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 850856B0085; Thu, 7 Dec 2023 08:55:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8006C6B0088; Thu, 7 Dec 2023 08:55:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6EF0A6B0089; Thu, 7 Dec 2023 08:55:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 60D536B0085 for ; Thu, 7 Dec 2023 08:55:40 -0500 (EST) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 431EC120213 for ; Thu, 7 Dec 2023 13:55:40 +0000 (UTC) X-FDA: 81540170040.20.C4A769E Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf05.hostedemail.com (Postfix) with ESMTP id 8E41E100009 for ; Thu, 7 Dec 2023 13:55:38 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of cmarinas@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1701957338; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=36wmC1nVWmwckcdr8ZViC6jbleGIKSPx3lYHjF1WIho=; b=npBWk7/4vHezGr+prEKRTIJiyhkpgtLml2z+Z+Mk8U3VCr6Z3SKAD+XeuPbfo4Eg7VfdIJ tnslK6S5FoOYaBAnwh5h9B66DOvzqi0SppBYj42lldfEvRs4C2GPy51DSt/x31vB68BPe6 Ft9eS9dOqP2AeeRcmZFQyC7+1w921Qw= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1701957338; a=rsa-sha256; cv=none; b=ax3HK4j9jO0al8tbUs/k3kn1vUAPtn9mjCiIhrZZ7tdsRKceP+Bsi4raheU5eOubvFzgLW xwiwmbxxfBtgD27tRO+QfIglevzX7jJkoV9lHmyEVFgO2Z6ubi5JaK7NsbYBK5i2NdsRXr AKVwY5EM032MgBTbMnQPb1DMmzCh1ig= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of cmarinas@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id C7AEBB826DA; Thu, 7 Dec 2023 13:55:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CF17C433C8; Thu, 7 Dec 2023 13:55:33 +0000 (UTC) Date: Thu, 7 Dec 2023 13:55:31 +0000 From: Catalin Marinas To: Mark Brown Cc: Joey Gouly , linux-arm-kernel@lists.infradead.org, akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, dave.hansen@linux.intel.com, maz@kernel.org, oliver.upton@linux.dev, shuah@kernel.org, will@kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, James Morse , Suzuki K Poulose , Zenghui Yu Subject: Re: [PATCH v3 05/25] arm64: context switch POR_EL0 register Message-ID: References: <20231124163510.1835740-1-joey.gouly@arm.com> <20231124163510.1835740-6-joey.gouly@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 8E41E100009 X-Rspam-User: X-Stat-Signature: usbekgzmw33a83yq1jau1ndft7qhe8mr X-Rspamd-Server: rspam03 X-HE-Tag: 1701957338-940242 X-HE-Meta: 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 Qf1rPzsg YLLyb5T4MQmK/5ouTau0kErhS88aP8RkGe3sKph1mQv4JgH/6LCZRIHDnA/SiAWgeii3DeI8YQ0ep9gLgw3b8+Sh1HtpVQnb82/C6U16v0byrFBpmOMM6+RNZWDj0GY3HnRJezpInOL5p4mprY8yHwihhV3IDdZslmTGawesULL7XVHzdIJDXByLEkoTyfstoC6FtJ7L1h8PZP+hNNoOtUmtHZn0H2lod8LPgakfk2CHM+XYZwaetQxO9dVt8+yp9+rtAnqNgc5LBWMGUWKj7EDb1bNaavUl6olEdyTwWxRLWtLDun8dWXmyY5dqtHCTWX5Gh3mBfhLeP4MKZ530u8/+RyKmIuZiEqu9mpZ3cfsNQdJw= 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: List-Subscribe: List-Unsubscribe: On Sat, Nov 25, 2023 at 12:02:49PM +0000, Mark Brown wrote: > On Fri, Nov 24, 2023 at 04:34:50PM +0000, Joey Gouly wrote: > > > +static void flush_poe(void) > > +{ > > + if (system_supports_poe()) > > + write_sysreg_s(POR_EL0_INIT, SYS_POR_EL0); > > +} > > Here we have no isb()... My immediate thought was that we'd not care about the ISB here since we'll have an ERET before getting to EL0. However, we may have some LDTR/STTR populating the new process args page on exec which may, in theory, pick up a stale POR_EL0. -- Catalin