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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 85F53C432C0 for ; Fri, 22 Nov 2019 06:08:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E7E52068F for ; Fri, 22 Nov 2019 06:08:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402933; bh=bn7fpoGbsr5yYxne9+e9O//N48LFYLbM1CQiyWwEfes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fAxGMu88tg9NowDKuD6lha+th1FQGTQevMU0aT9UWe/kpnDR3tpj1GKANQmM7oWiT eGv1uuVTlGO//yf1UzWarpDUHFZKDmyV+BbL6jvTI3Qbj8qs3SxBuFkdazO4IlrPgo lsYclWOCuFr31EnxSJGJtJSV8x2RBGyHnfqj/z4A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727208AbfKVGIw (ORCPT ); Fri, 22 Nov 2019 01:08:52 -0500 Received: from mail.kernel.org ([198.145.29.99]:39822 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728945AbfKVGBg (ORCPT ); Fri, 22 Nov 2019 01:01:36 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CE8DD2070B; Fri, 22 Nov 2019 06:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402495; bh=bn7fpoGbsr5yYxne9+e9O//N48LFYLbM1CQiyWwEfes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SmIfM/4BYSV6ivc/n8G7zKhe+pz3B/8YyABlnChdG/3LGtOtAx1LIsBd8MVMIUZ/S aahLMdYCu+f9oKNcuTM6uJw0r0Rc0ZhmIg/ATdRq4ODB/OwqxmlFVHL+xedHmotmaS lZqN9VJFsQQocIJEOUozY6+zowLWUXfaWqEMOc9U= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Steve Capper , Will Deacon , Sasha Levin , linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 4.9 06/91] arm64: mm: Prevent mismatched 52-bit VA support Date: Fri, 22 Nov 2019 01:00:04 -0500 Message-Id: <20191122060129.4239-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122060129.4239-1-sashal@kernel.org> References: <20191122060129.4239-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steve Capper [ Upstream commit a96a33b1ca57dbea4285893dedf290aeb8eb090b ] For cases where there is a mismatch in ARMv8.2-LVA support between CPUs we have to be careful in allowing secondary CPUs to boot if 52-bit virtual addresses have already been enabled on the boot CPU. This patch adds code to the secondary startup path. If the boot CPU has enabled 52-bit VAs then ID_AA64MMFR2_EL1 is checked to see if the secondary can also enable 52-bit support. If not, the secondary is prevented from booting and an error message is displayed indicating why. Technically this patch could be implemented using the cpufeature code when considering 52-bit userspace support. However, we employ low level checks here as the cpufeature code won't be able to run if we have mismatched 52-bit kernel va support. Signed-off-by: Steve Capper Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/kernel/head.S | 26 ++++++++++++++++++++++++++ arch/arm64/kernel/smp.c | 5 +++++ 2 files changed, 31 insertions(+) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index db6ff1944c412..3b10b93959607 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -686,6 +686,7 @@ secondary_startup: /* * Common entry point for secondary CPUs. */ + bl __cpu_secondary_check52bitva bl __cpu_setup // initialise processor bl __enable_mmu ldr x8, =__secondary_switched @@ -759,6 +760,31 @@ ENTRY(__enable_mmu) ret ENDPROC(__enable_mmu) +ENTRY(__cpu_secondary_check52bitva) +#ifdef CONFIG_ARM64_52BIT_VA + ldr_l x0, vabits_user + cmp x0, #52 + b.ne 2f + + mrs_s x0, SYS_ID_AA64MMFR2_EL1 + and x0, x0, #(0xf << ID_AA64MMFR2_LVA_SHIFT) + cbnz x0, 2f + + adr_l x0, va52mismatch + mov w1, #1 + strb w1, [x0] + dmb sy + dc ivac, x0 // Invalidate potentially stale cache line + + update_early_cpu_boot_status CPU_STUCK_IN_KERNEL, x0, x1 +1: wfe + wfi + b 1b + +#endif +2: ret +ENDPROC(__cpu_secondary_check52bitva) + __no_granule_support: /* Indicate that this CPU can't boot and is stuck in the kernel */ update_early_cpu_boot_status CPU_STUCK_IN_KERNEL, x1, x2 diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index cfd33f18f4378..f0c41524b052f 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -136,6 +136,7 @@ static int boot_secondary(unsigned int cpu, struct task_struct *idle) } static DECLARE_COMPLETION(cpu_running); +bool va52mismatch __ro_after_init; int __cpu_up(unsigned int cpu, struct task_struct *idle) { @@ -164,6 +165,10 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) if (!cpu_online(cpu)) { pr_crit("CPU%u: failed to come online\n", cpu); + + if (IS_ENABLED(CONFIG_ARM64_52BIT_VA) && va52mismatch) + pr_crit("CPU%u: does not support 52-bit VAs\n", cpu); + ret = -EIO; } } else { -- 2.20.1