From patchwork Thu May 20 09:18:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 445755 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 90596C43603 for ; Thu, 20 May 2021 09:49:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 791B661465 for ; Thu, 20 May 2021 09:49:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234090AbhETJur (ORCPT ); Thu, 20 May 2021 05:50:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:47818 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234152AbhETJsl (ORCPT ); Thu, 20 May 2021 05:48:41 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DD1AB61476; Thu, 20 May 2021 09:34:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621503292; bh=fumZsiVBofI0RCCMA6zRsxo2n840tAab0nQ7pIhcE80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r4hDXhVkOo7ycZ2kcHG/voCumSx0wprZrl57T3lPXPE0OLybG2OFzIbYgXko3wSGs 57qPUn6+mft2/PMOeC8CBxR4iimEcltem/8Dp6hKPLB1pF/DdLldOi7Y5nyhlnx1rs cxM0VMBFuTFvzRtWeWaOS0wMa1FYRoZ3OQR9MYXA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Christopherson , Thomas Gleixner Subject: [PATCH 4.19 156/425] x86/cpu: Initialize MSR_TSC_AUX if RDTSCP *or* RDPID is supported Date: Thu, 20 May 2021 11:18:45 +0200 Message-Id: <20210520092136.563735779@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092131.308959589@linuxfoundation.org> References: <20210520092131.308959589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sean Christopherson commit b6b4fbd90b155a0025223df2c137af8a701d53b3 upstream. Initialize MSR_TSC_AUX with CPU node information if RDTSCP or RDPID is supported. This fixes a bug where vdso_read_cpunode() will read garbage via RDPID if RDPID is supported but RDTSCP is not. While no known CPU supports RDPID but not RDTSCP, both Intel's SDM and AMD's APM allow for RDPID to exist without RDTSCP, e.g. it's technically a legal CPU model for a virtual machine. Note, technically MSR_TSC_AUX could be initialized if and only if RDPID is supported since RDTSCP is currently not used to retrieve the CPU node. But, the cost of the superfluous WRMSR is negigible, whereas leaving MSR_TSC_AUX uninitialized is just asking for future breakage if someone decides to utilize RDTSCP. Fixes: a582c540ac1b ("x86/vdso: Use RDPID in preference to LSL when available") Signed-off-by: Sean Christopherson Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210504225632.1532621-2-seanjc@google.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/vdso/vma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -343,7 +343,7 @@ static void vgetcpu_cpu_init(void *arg) #ifdef CONFIG_NUMA node = cpu_to_node(cpu); #endif - if (static_cpu_has(X86_FEATURE_RDTSCP)) + if (boot_cpu_has(X86_FEATURE_RDTSCP) || boot_cpu_has(X86_FEATURE_RDPID)) write_rdtscp_aux((node << 12) | cpu); /*