From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35666 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753248AbdCTReU (ORCPT ); Mon, 20 Mar 2017 13:34:20 -0400 Subject: Patch "x86/perf: Fix CR4.PCE propagation to use active_mm instead of mm" has been added to the 4.4-stable tree To: luto@kernel.org, acme@redhat.com, alexander.shishkin@linux.intel.com, bpetkov@suse.de, eranian@google.com, gregkh@linuxfoundation.org, hpa@zytor.com, jolsa@redhat.com, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, vincent.weaver@maine.edu Cc: , From: Date: Mon, 20 Mar 2017 18:34:00 +0100 Message-ID: <1490031240198186@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/perf: Fix CR4.PCE propagation to use active_mm instead of mm to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-perf-fix-cr4.pce-propagation-to-use-active_mm-instead-of-mm.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 5dc855d44c2ad960a86f593c60461f1ae1566b6d Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 16 Mar 2017 12:59:39 -0700 Subject: x86/perf: Fix CR4.PCE propagation to use active_mm instead of mm From: Andy Lutomirski commit 5dc855d44c2ad960a86f593c60461f1ae1566b6d upstream. If one thread mmaps a perf event while another thread in the same mm is in some context where active_mm != mm (which can happen in the scheduler, for example), refresh_pce() would write the wrong value to CR4.PCE. This broke some PAPI tests. Reported-and-tested-by: Vince Weaver Signed-off-by: Andy Lutomirski Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: 7911d3f7af14 ("perf/x86: Only allow rdpmc if a perf_event is mapped") Link: http://lkml.kernel.org/r/0c5b38a76ea50e405f9abe07a13dfaef87c173a1.1489694270.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/perf_event.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1996,8 +1996,8 @@ static int x86_pmu_event_init(struct per static void refresh_pce(void *ignored) { - if (current->mm) - load_mm_cr4(current->mm); + if (current->active_mm) + load_mm_cr4(current->active_mm); } static void x86_pmu_event_mapped(struct perf_event *event) Patches currently in stable-queue which might be from luto@kernel.org are queue-4.4/x86-perf-fix-cr4.pce-propagation-to-use-active_mm-instead-of-mm.patch