From patchwork Fri May 8 12:35:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226159 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=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,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 C1743C38A2A for ; Fri, 8 May 2020 13:03:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 971C8206D6 for ; Fri, 8 May 2020 13:03:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588942999; bh=LTRsRa4wOMiSn/uoTzJ5hVuhRHAn+clpoI749rHtK7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YoGbe5XS502gkCkiH1qS1yWnrvcMGlN9htQ+CLJsHRWXmxAdVP0I5xTxZj9XvWH/s NJEVqnJ4Zz5WGQmeWzWu/1V3UWd3xM82UyLoAZn+nvybKxtZpssTLOXzQGBIKiNGir eLu8W9N8V6ooCrE3RYePUBdVdqibCc1vHQkhvXLU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728330AbgEHNDS (ORCPT ); Fri, 8 May 2020 09:03:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:57700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727123AbgEHMuQ (ORCPT ); Fri, 8 May 2020 08:50:16 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 458F1218AC; Fri, 8 May 2020 12:50:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588942215; bh=LTRsRa4wOMiSn/uoTzJ5hVuhRHAn+clpoI749rHtK7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o+KP2wiwUxqKYaYhjTDkniVzStddqB3Nyc/NZBwby9D3Y63qKdl/U/gtA1fwz9EHN C8fqD9Xh++kX4HgxIsFXV7UlqcNSNElR+U5AJkNL5NB7nfJmqBR43NNSeK1KeY+OPw mGlnKZs8j8IJZj4bD/mN+Ai9zbR28xOMTr5ZmWGo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Philipp Rudo , Vasily Gorbik , Sasha Levin Subject: [PATCH 4.14 12/22] s390/ftrace: fix potential crashes when switching tracers Date: Fri, 8 May 2020 14:35:24 +0200 Message-Id: <20200508123035.392899555@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200508123033.915895060@linuxfoundation.org> References: <20200508123033.915895060@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 b649a6538350d..808f4fbe869e7 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -406,7 +406,7 @@ 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; @@ -416,7 +416,7 @@ 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;