From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753068Ab3EHPI4 (ORCPT ); Wed, 8 May 2013 11:08:56 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:36988 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750774Ab3EHPIz (ORCPT ); Wed, 8 May 2013 11:08:55 -0400 From: David Ahern To: acme@ghostprotocols.net, linux-kernel@vger.kernel.org Cc: David Ahern , Ingo Molnar , Frederic Weisbecker , Peter Zijlstra , Jiri Olsa , Namhyung Kim , Stephane Eranian Subject: [PATCH] perf: detect when perf.data file not closed out properly Date: Wed, 8 May 2013 09:08:48 -0600 Message-Id: <1368025728-4669-1-git-send-email-dsahern@gmail.com> X-Mailer: git-send-email 1.7.10.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org perf-record updates the header in the perf.data file at termination. Without this update perf-report (and other processing builtins) cannot properly read events from the file -- the algorithm in __perf_session__process_events depends on the data_size which is read from the file header and that function loops if data_size is 0. Catch this condition when the file is opened and warn the user. Signed-off-by: David Ahern Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Frederic Weisbecker Cc: Peter Zijlstra Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian --- tools/perf/util/header.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 326068a..aa42c8c 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2802,6 +2802,18 @@ int perf_session__read_header(struct perf_session *session, int fd) if (perf_file_header__read(&f_header, header, fd) < 0) return -EINVAL; + /* + * sanity check that perf.data was written cleanly: data size + * is initialized to 0 and updated only if the on_exit function + * is run. If data size is still 0 then the file cannot be + * processed. + */ + if (f_header.data.size == 0) { + pr_err("data size is 0. " + "Was the record command properly terminated?\n"); + return -1; + } + nr_attrs = f_header.attrs.size / f_header.attr_size; lseek(fd, f_header.attrs.offset, SEEK_SET); -- 1.7.10.1