From patchwork Tue May 25 15:14:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12279331 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=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 E2B20C2B9F8 for ; Tue, 25 May 2021 15:38:05 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 A0F9061360 for ; Tue, 25 May 2021 15:38:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A0F9061360 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=kI1FIPlUYinp2lRaz9x6a2/dBkIT29yQ07d+sx83g5I=; b=GwyuosghQQFcJ+ TVSK8JU4/0pTrcQD+6XA+jN62brp8VYwLFN1M6f8gVHwE4piRqPgjs+z1aO0akUnqnDz9Xc3v8Bz4 0rZxWrsJCbd2xzxto1SQkprmdTbnS88kzClG2o3ASMdIH5WiA0byI0DL1OAHI3rzEeJ91RIqCLQ24 mB0FS/BfbMS/87Q8ycbFX7/7NMhSWonaf9dQ8OlSUPZLFexEWrQDbZG3+DfetO0NuPooCvMeIqtG5 vQjD6pcUCdrq6kRL6j6jKt934KDE8b/Te9MbayV8uNsAvIM7SJx2o9gHGV7je1bocWxrX1zfnFiLe b7skGHlV7gyrFk8ZRSFw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1llZ5u-0062zQ-HQ; Tue, 25 May 2021 15:35:47 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1llYnH-005u69-3f for linux-arm-kernel@lists.infradead.org; Tue, 25 May 2021 15:16:32 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 72E906141D; Tue, 25 May 2021 15:16:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621955790; bh=+/Imnr+Lo2MHpB6ujnUBakmFLkmdTTKNQf8pvMFeGqo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CMsDJnKhwUnXSsyJXLrzpp4HjoVRD3S63OQWe/qSC1xxp0FfgSlshU7VAV4lB9tlt a2vKC55LaHtqUTG6HPX6i/f5m0GoX3SN0/oQLTYycrccS+Fupt6spRFqHE+Pt2EbjX FJq2oAMDuRRmqfNNAVfjZQ3z3HbiBJvKzlYQByFCIufApdE3+dSHaEGEfhZ9Fs4rvL uQCF2tZy0dn4c8gKG04jjh1j0A/J4NEjcGRrqVTBdO8zPVKJY72c55iJLAlH+ItyGp mbJFmQPr363ErKG6rJp88QUrdbCb+P7oZvK5ih329JPQZLYse5jjOQk5mcQyB2Kf1s KpMZm+8xwHQkA== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon , Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Quentin Perret , Tejun Heo , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , "Rafael J. Wysocki" , Dietmar Eggemann , Daniel Bristot de Oliveira , kernel-team@android.com Subject: [PATCH v7 20/22] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Date: Tue, 25 May 2021 16:14:30 +0100 Message-Id: <20210525151432.16875-21-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210525151432.16875-1-will@kernel.org> References: <20210525151432.16875-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210525_081631_220931_628A1910 X-CRM114-Status: GOOD ( 12.50 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Allow systems with mismatched 32-bit support at EL0 to run 32-bit applications based on a new kernel parameter. Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- Documentation/admin-guide/kernel-parameters.txt | 8 ++++++++ arch/arm64/kernel/cpufeature.c | 7 +++++++ 2 files changed, 15 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb89dbdedc46..a2e453919bb6 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -287,6 +287,14 @@ do not want to use tracing_snapshot_alloc() as it needs to be done where GFP_KERNEL allocations are allowed. + allow_mismatched_32bit_el0 [ARM64] + Allow execve() of 32-bit applications and setting of the + PER_LINUX32 personality on systems where only a strict + subset of the CPUs support 32-bit EL0. When this + parameter is present, the set of CPUs supporting 32-bit + EL0 is indicated by /sys/devices/system/cpu/aarch32_el0 + and hot-unplug operations may be restricted. + amd_iommu= [HW,X86-64] Pass parameters to the AMD IOMMU driver in the system. Possible values are: diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 72efdc611b14..f2c97baa050f 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1298,6 +1298,13 @@ const struct cpumask *system_32bit_el0_cpumask(void) return cpu_possible_mask; } +static int __init parse_32bit_el0_param(char *str) +{ + allow_mismatched_32bit_el0 = true; + return 0; +} +early_param("allow_mismatched_32bit_el0", parse_32bit_el0_param); + static ssize_t aarch32_el0_show(struct device *dev, struct device_attribute *attr, char *buf) {