From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932366AbaIRRIb (ORCPT ); Thu, 18 Sep 2014 13:08:31 -0400 Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:60700 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757161AbaIRRI2 (ORCPT ); Thu, 18 Sep 2014 13:08:28 -0400 From: Alexander Yarygin To: linux-kernel@vger.kernel.org Cc: Alexander Yarygin , Arnaldo Carvalho de Melo , Christian Borntraeger , David Ahern , Frederic Weisbecker , Ingo Molnar , Jiri Olsa , Mike Galbraith , Namhyung Kim , Paul Mackerras , Peter Zijlstra , Stephane Eranian Subject: [PATCH 2/2] perf kvm stat live: Enable events copying Date: Thu, 18 Sep 2014 21:07:39 +0400 Message-Id: <1411060059-23589-3-git-send-email-yarygin@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1411060059-23589-1-git-send-email-yarygin@linux.vnet.ibm.com> References: <1411060059-23589-1-git-send-email-yarygin@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14091817-5024-0000-0000-00000159B2A7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Process of analyzing events caused by 2 functions: mmap_read() and finished_round(). During mmap_read(), perf receives events from shared memory, queues their pointers for further processing in finished_round() and notifies the kernel that the events have been processed. By the time when finished_round() is invoked, queued events can be overwritten by the kernel, so the finished_round() occurs on potentially corrupted memory. Let's copy events when queueing. Signed-off-by: Alexander Yarygin Cc: Arnaldo Carvalho de Melo Cc: Christian Borntraeger Cc: David Ahern Cc: Ingo Molnar Cc: Jiri Olsa Cc: Paul Mackerras Cc: Peter Zijlstra --- tools/perf/builtin-kvm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c index f5d3ae4..c5b6d1d 100644 --- a/tools/perf/builtin-kvm.c +++ b/tools/perf/builtin-kvm.c @@ -1369,6 +1369,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, goto out; } kvm->session->evlist = kvm->evlist; + kvm->session->copy_on_queue = true; perf_session__set_id_hdr_size(kvm->session); machine__synthesize_threads(&kvm->session->machines.host, &kvm->opts.target, kvm->evlist->threads, false); -- 1.9.1