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=-18.9 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, 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 B154FC4743C for ; Mon, 14 Jun 2021 11:19:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E174610A0 for ; Mon, 14 Jun 2021 11:19:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235048AbhFNLVA (ORCPT ); Mon, 14 Jun 2021 07:21:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:42800 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234480AbhFNLJI (ORCPT ); Mon, 14 Jun 2021 07:09:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AB3EA6144F; Mon, 14 Jun 2021 10:46:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623667605; bh=cG4FSOO0beayRGoWvWbRpqmXB9IzjkrB44QsfWCBHYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=s0B/ZbTXw/FRl+iyFxSkB1Q6U+e/OHhPO82bre+O+H+P9vF/Q2E7Do3UQI9N/Gkc6 YvQ9Rp/qeE3btiOIwQC5TLPTpjS+NDd86SNXJtRU0JatMWjMYmR1XkeJUjl966Un3i gISwSKmGdRZNyEdVaCzYhZmZ8w83SErzGbL9OT1k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, CodyYao-oc , Ingo Molnar , "Peter Zijlstra (Intel)" Subject: [PATCH 5.10 117/131] x86/nmi_watchdog: Fix old-style NMI watchdog regression on old Intel CPUs Date: Mon, 14 Jun 2021 12:27:58 +0200 Message-Id: <20210614102656.994029648@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210614102652.964395392@linuxfoundation.org> References: <20210614102652.964395392@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: CodyYao-oc commit a8383dfb2138742a1bb77b481ada047aededa2ba upstream. The following commit: 3a4ac121c2ca ("x86/perf: Add hardware performance events support for Zhaoxin CPU.") Got the old-style NMI watchdog logic wrong and broke it for basically every Intel CPU where it was active. Which is only truly old CPUs, so few people noticed. On CPUs with perf events support we turn off the old-style NMI watchdog, so it was pretty pointless to add the logic for X86_VENDOR_ZHAOXIN to begin with ... :-/ Anyway, the fix is to restore the old logic and add a 'break'. [ mingo: Wrote a new changelog. ] Fixes: 3a4ac121c2ca ("x86/perf: Add hardware performance events support for Zhaoxin CPU.") Signed-off-by: CodyYao-oc Signed-off-by: Ingo Molnar Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210607025335.9643-1-CodyYao-oc@zhaoxin.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/perfctr-watchdog.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/cpu/perfctr-watchdog.c +++ b/arch/x86/kernel/cpu/perfctr-watchdog.c @@ -63,7 +63,7 @@ static inline unsigned int nmi_perfctr_m case 15: return msr - MSR_P4_BPU_PERFCTR0; } - fallthrough; + break; case X86_VENDOR_ZHAOXIN: case X86_VENDOR_CENTAUR: return msr - MSR_ARCH_PERFMON_PERFCTR0; @@ -96,7 +96,7 @@ static inline unsigned int nmi_evntsel_m case 15: return msr - MSR_P4_BSU_ESCR0; } - fallthrough; + break; case X86_VENDOR_ZHAOXIN: case X86_VENDOR_CENTAUR: return msr - MSR_ARCH_PERFMON_EVENTSEL0;