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,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 E414BC47247 for ; Thu, 30 Apr 2020 14:01:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1DC62063A for ; Thu, 30 Apr 2020 14:01:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588255305; bh=jlxp6bHqaL5SLGNE4+p8W1vuvAGZv7qXffR7022qqeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zLp4VWdbkxG8HLPbTIz0v7NIF192mYTb+orrhLiKDgaVsNfIr0wyfaOX0LdAnq+dM jUKtwbRLr2ZEDAXCNnqZnHYF11KqqHQlclZJCFpaXQZ/9upElSdj206GdDefg7Woqs 3k55gFeEbdHEfAGZ3JiBcZIxXucp/TAe07jTmXPs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729424AbgD3OBo (ORCPT ); Thu, 30 Apr 2020 10:01:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:35888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728831AbgD3Nxx (ORCPT ); Thu, 30 Apr 2020 09:53:53 -0400 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 4DE622063A; Thu, 30 Apr 2020 13:53:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588254833; bh=jlxp6bHqaL5SLGNE4+p8W1vuvAGZv7qXffR7022qqeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e9wfXrY01SXVQljBfVr5OZ3anAfjHWJ0ZpCVJdyQjmg10b5TX5NrT75C3R103HzCZ zbW+/vWqbZHdC4cTDiIvLarf+62WuajRhKOjoZkAWuA0lkYTHWJ/X4srcKqIX6swhN CO19Oxu6me/dCRKSJAbZCnLWyhrjJXkJQvyjZ3t0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Philipp Rudo , Vasily Gorbik , Sasha Levin , linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 24/30] s390/ftrace: fix potential crashes when switching tracers Date: Thu, 30 Apr 2020 09:53:19 -0400 Message-Id: <20200430135325.20762-24-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200430135325.20762-1-sashal@kernel.org> References: <20200430135325.20762-1-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: Philipp Rudo [ Upstream commit 8ebf6da9db1b2a20bb86cc1bee2552e894d03308 ] Switching tracers include instruction patching. To prevent that a instruction is patched while it's read the instruction patching is done in stop_machine 'context'. This also means that any function called during stop_machine must not be traced. Thus add 'notrace' to all functions called within stop_machine. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Fixes: 38f2c691a4b3 ("s390: improve wait logic of stop_machine") Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield") Signed-off-by: Philipp Rudo Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- arch/s390/kernel/diag.c | 2 +- arch/s390/kernel/smp.c | 4 ++-- arch/s390/kernel/trace.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/s390/kernel/diag.c b/arch/s390/kernel/diag.c index 35c842aa87058..4c7cf8787a848 100644 --- a/arch/s390/kernel/diag.c +++ b/arch/s390/kernel/diag.c @@ -128,7 +128,7 @@ void diag_stat_inc(enum diag_stat_enum nr) } EXPORT_SYMBOL(diag_stat_inc); -void diag_stat_inc_norecursion(enum diag_stat_enum nr) +void notrace diag_stat_inc_norecursion(enum diag_stat_enum nr) { this_cpu_inc(diag_stat.counter[nr]); trace_s390_diagnose_norecursion(diag_map[nr].code); diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index ecd24711f3aa9..8e31dfd85de32 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -393,7 +393,7 @@ int smp_find_processor_id(u16 address) return -1; } -bool arch_vcpu_is_preempted(int cpu) +bool notrace arch_vcpu_is_preempted(int cpu) { if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu)) return false; @@ -403,7 +403,7 @@ bool arch_vcpu_is_preempted(int cpu) } EXPORT_SYMBOL(arch_vcpu_is_preempted); -void smp_yield_cpu(int cpu) +void notrace smp_yield_cpu(int cpu) { if (MACHINE_HAS_DIAG9C) { diag_stat_inc_norecursion(DIAG_STAT_X09C); diff --git a/arch/s390/kernel/trace.c b/arch/s390/kernel/trace.c index 490b52e850145..11a669f3cc93c 100644 --- a/arch/s390/kernel/trace.c +++ b/arch/s390/kernel/trace.c @@ -14,7 +14,7 @@ EXPORT_TRACEPOINT_SYMBOL(s390_diagnose); static DEFINE_PER_CPU(unsigned int, diagnose_trace_depth); -void trace_s390_diagnose_norecursion(int diag_nr) +void notrace trace_s390_diagnose_norecursion(int diag_nr) { unsigned long flags; unsigned int *depth; -- 2.20.1