From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751886AbcGLWmT (ORCPT ); Tue, 12 Jul 2016 18:42:19 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:45281 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752439AbcGLWlC (ORCPT ); Tue, 12 Jul 2016 18:41:02 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Jiri Olsa , David Ahern , Namhyung Kim , Peter Zijlstra , Arnaldo Carvalho de Melo Subject: [PATCH 60/66] perf python: Fix pyrf_evlist__read_on_cpu event consuming Date: Tue, 12 Jul 2016 19:40:35 -0300 Message-Id: <1468363241-14555-61-git-send-email-acme@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1468363241-14555-1-git-send-email-acme@kernel.org> References: <1468363241-14555-1-git-send-email-acme@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiri Olsa We can't consume the event before parsing it. Under heavy load we could get caught by kernel writer overwriting the event we're trying to parse. Signed-off-by: Jiri Olsa Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1468148882-10362-5-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/python.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c index d0c1267741ee..c68ef0319114 100644 --- a/tools/perf/util/python.c +++ b/tools/perf/util/python.c @@ -865,12 +865,14 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist, PyObject *pyevent = pyrf_event__new(event); struct pyrf_event *pevent = (struct pyrf_event *)pyevent; - perf_evlist__mmap_consume(evlist, cpu); - if (pyevent == NULL) return PyErr_NoMemory(); err = perf_evlist__parse_sample(evlist, event, &pevent->sample); + + /* Consume the even only after we parsed it out. */ + perf_evlist__mmap_consume(evlist, cpu); + if (err) return PyErr_Format(PyExc_OSError, "perf: can't parse sample, err=%d", err); -- 2.7.4