From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752961AbaJBQjO (ORCPT ); Thu, 2 Oct 2014 12:39:14 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:47744 "EHLO e06smtp13.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751445AbaJBQjK (ORCPT ); Thu, 2 Oct 2014 12:39:10 -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, 2 Oct 2014 20:38:56 +0400 Message-Id: <1412267936-19827-3-git-send-email-yarygin@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1412267936-19827-1-git-send-email-yarygin@linux.vnet.ibm.com> References: <1412267936-19827-1-git-send-email-yarygin@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14100216-2966-0000-0000-000001554F21 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. Since there is no place where the event can be safely consumed, 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..80efbfa 100644 --- a/tools/perf/builtin-kvm.c +++ b/tools/perf/builtin-kvm.c @@ -1370,6 +1370,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, } kvm->session->evlist = kvm->evlist; perf_session__set_id_hdr_size(kvm->session); + ordered_events__set_copy_on_queue(&kvm->session->ordered_events, true); machine__synthesize_threads(&kvm->session->machines.host, &kvm->opts.target, kvm->evlist->threads, false); err = kvm_live_open_events(kvm); -- 1.9.1