From patchwork Tue May 28 21:31:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Kosina X-Patchwork-Id: 10965839 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 36F1676 for ; Tue, 28 May 2019 21:31:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1EEA22887B for ; Tue, 28 May 2019 21:31:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 121E828898; Tue, 28 May 2019 21:31:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 914F12887B for ; Tue, 28 May 2019 21:31:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728034AbfE1Vbu (ORCPT ); Tue, 28 May 2019 17:31:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:39990 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727144AbfE1Vbu (ORCPT ); Tue, 28 May 2019 17:31:50 -0400 Received: from pobox.suse.cz (prg-ext-pat.suse.com [213.151.95.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E323C2075B; Tue, 28 May 2019 21:31:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559079109; bh=B3o8n9SYmJUHF3FbOoAq6ElBxC4Irv0C7SwxfW0q6xM=; h=Date:From:To:cc:Subject:From; b=WUGHTvBWnKfY4zuHnA2yGwugqnDj8KRilM6MCZy2qP0sWTxds0Dprg8EWhOaJEwu3 FvNMjV2PbIGEkSXGybFZh8W7JwcdwYUmdGR+hD2j0s7OBtNf9CjTl+s8n1QuQmhY2Q AKmsOTHF9VF33eLsC9dzKzy0Oy61Ve2jniQ8kcAs= Date: Tue, 28 May 2019 23:31:45 +0200 (CEST) From: Jiri Kosina To: "Rafael J. Wysocki" , Pavel Machek , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Josh Poimboeuf cc: x86@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] x86/power: Fix 'nosmt' vs. hibernation triple fault during resume Message-ID: User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jiri Kosina As explained in 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") we always, no matter what, have to bring up x86 HT siblings during boot at least once in order to avoid first MCE bringing the system to its knees. That means that whenever 'nosmt' is supplied on the kernel command-line, all the HT siblings are as a result sitting in mwait or cpudile after going through the online-offline cycle at least once. This causes a serious issue though when a kernel, which saw 'nosmt' on its commandline, is going to perform resume from hibernation: if the resume from the hibernated image is successful, cr3 is flipped in order to point to the address space of the kernel that is being resumed, which in turn means that all the HT siblings are all of a sudden mwaiting on address which is no longer valid. That results in triple fault shortly after cr3 is switched, and machine reboots. Fix this by always waking up all the SMT siblings before initiating the 'restore from hibernation' process; this guarantees that all the HT siblings will be properly carried over to the resumed kernel waiting in resume_play_dead(), and acted upon accordingly afterwards, based on the target kernel configuration. Cc: stable@vger.kernel.org # v4.19+ Debugged-by: Thomas Gleixner Fixes: 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") Signed-off-by: Jiri Kosina Acked-by: Rafael J. Wysocki --- arch/x86/power/cpu.c | 11 +++++++++++ include/linux/cpu.h | 2 ++ kernel/cpu.c | 2 +- 3 files changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index a7d966964c6f..bde8ce1f6c6c 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -299,9 +299,20 @@ int hibernate_resume_nonboot_cpu_disable(void) * address in its instruction pointer may not be possible to resolve * any more at that point (the page tables used by it previously may * have been overwritten by hibernate image data). + * + * First, make sure that we wake up all the potentially disabled SMT + * threads which have been initially brought up and then put into + * mwait/cpuidle sleep. + * Those will be put to proper (not interfering with hibernation + * resume) sleep afterwards, and the resumed kernel will decide itself + * what to do with them. */ smp_ops.play_dead = resume_play_dead; + ret = cpuhp_smt_enable(); + if (ret) + goto out; ret = disable_nonboot_cpus(); +out: smp_ops.play_dead = play_dead; return ret; } diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 3813fe45effd..b5523552a607 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -201,10 +201,12 @@ enum cpuhp_smt_control { extern enum cpuhp_smt_control cpu_smt_control; extern void cpu_smt_disable(bool force); extern void cpu_smt_check_topology(void); +extern int cpuhp_smt_enable(void); #else # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) static inline void cpu_smt_disable(bool force) { } static inline void cpu_smt_check_topology(void) { } +static inline int cpuhp_smt_enable(void) { return 0; } #endif /* diff --git a/kernel/cpu.c b/kernel/cpu.c index f2ef10460698..3ff5ce0e4132 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2093,7 +2093,7 @@ static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) return ret; } -static int cpuhp_smt_enable(void) +int cpuhp_smt_enable(void) { int cpu, ret = 0;