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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 0BD92C55179 for ; Tue, 3 Nov 2020 20:49:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5DFE2242A for ; Tue, 3 Nov 2020 20:49:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436543; bh=ahjbn9H70hPUckCaDcElCvVnZe3GnTqMRqR5U/J3N8c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BRo6iHaW5pVW6nYsjRuObjvu76G/TXJ/bQK6pvM0iGSUixCrnEHm3f9ZcdBLBcmi/ G03AxUqMAeI3OZ6J9l9N+KffWb4zXN+Ec8x4yw6xQA0KOGzkCA2mnbtbpu1aAtysQ/ vXuuFImOAKujgY6JUddlTS496oKeSoSX8v6pw0zA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731691AbgKCUtB (ORCPT ); Tue, 3 Nov 2020 15:49:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:41158 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731673AbgKCUsz (ORCPT ); Tue, 3 Nov 2020 15:48:55 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 BF9D520719; Tue, 3 Nov 2020 20:48:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436535; bh=ahjbn9H70hPUckCaDcElCvVnZe3GnTqMRqR5U/J3N8c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JBcNyaTtUVGIQGV0RbKxP9qEmIjNrIalwr+NET8NMgDi6k/NNBrq3unC+4jGEZKxN b//WZZtCpoeZ/n6hGsjeb9Vtfgc3w6e4Xx//Z6YBH+4VKozj0RgVPvzokh3MBhaGuS JiHYZeT9jpLw9DDgvQsP+ql3804jngXwDtyn1mDc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ganesh Goudar , Michael Ellerman Subject: [PATCH 5.9 291/391] powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash Date: Tue, 3 Nov 2020 21:35:42 +0100 Message-Id: <20201103203406.705455782@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203348.153465465@linuxfoundation.org> References: <20201103203348.153465465@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: Ganesh Goudar commit 8d0e2101274358d9b6b1f27232b40253ca48bab5 upstream. Use of nmi_enter/exit in real mode handler causes the kernel to panic and reboot on injecting SLB mutihit on pseries machine running in hash MMU mode, because these calls try to accesses memory outside RMO region in real mode handler where translation is disabled. Add check to not to use these calls on pseries machine running in hash MMU mode. Fixes: 116ac378bb3f ("powerpc/64s: machine check interrupt update NMI accounting") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Ganesh Goudar Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201009064005.19777-2-ganeshgr@linux.ibm.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/mce.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/arch/powerpc/kernel/mce.c +++ b/arch/powerpc/kernel/mce.c @@ -591,12 +591,11 @@ EXPORT_SYMBOL_GPL(machine_check_print_ev long notrace machine_check_early(struct pt_regs *regs) { long handled = 0; - bool nested = in_nmi(); u8 ftrace_enabled = this_cpu_get_ftrace_enabled(); this_cpu_set_ftrace_enabled(0); - - if (!nested) + /* Do not use nmi_enter/exit for pseries hpte guest */ + if (radix_enabled() || !firmware_has_feature(FW_FEATURE_LPAR)) nmi_enter(); hv_nmi_check_nonrecoverable(regs); @@ -607,7 +606,7 @@ long notrace machine_check_early(struct if (ppc_md.machine_check_early) handled = ppc_md.machine_check_early(regs); - if (!nested) + if (radix_enabled() || !firmware_has_feature(FW_FEATURE_LPAR)) nmi_exit(); this_cpu_set_ftrace_enabled(ftrace_enabled);