From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754208AbeCGI0f (ORCPT ); Wed, 7 Mar 2018 03:26:35 -0500 Received: from terminus.zytor.com ([198.137.202.136]:42535 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751055AbeCGI0c (ORCPT ); Wed, 7 Mar 2018 03:26:32 -0500 Date: Wed, 7 Mar 2018 00:26:11 -0800 From: tip-bot for Jiri Olsa Message-ID: Cc: jolsa@kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, namhyung@kernel.org, hpa@zytor.com, alexander.shishkin@linux.intel.com, acme@redhat.com, tglx@linutronix.de, dsahern@gmail.com, mingo@kernel.org Reply-To: mingo@kernel.org, dsahern@gmail.com, alexander.shishkin@linux.intel.com, tglx@linutronix.de, acme@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, jolsa@kernel.org, namhyung@kernel.org, peterz@infradead.org In-Reply-To: <20180302161354.30192-1-jolsa@kernel.org> References: <20180302161354.30192-1-jolsa@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf record: Fix crash in pipe mode Git-Commit-ID: cfacbabd1d9c35d2a179650b2911f17a8d8620b8 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: cfacbabd1d9c35d2a179650b2911f17a8d8620b8 Gitweb: https://git.kernel.org/tip/cfacbabd1d9c35d2a179650b2911f17a8d8620b8 Author: Jiri Olsa AuthorDate: Fri, 2 Mar 2018 17:13:54 +0100 Committer: Arnaldo Carvalho de Melo CommitDate: Mon, 5 Mar 2018 11:52:41 -0300 perf record: Fix crash in pipe mode Currently we can crash perf record when running in pipe mode, like: $ perf record ls | perf report # To display the perf.data header info, please use --header/--header-only options. # perf: Segmentation fault Error: The - file has no samples! The callstack of the crash is: 0x0000000000515242 in perf_event__synthesize_event_update_name 3513 ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->id[0]); (gdb) bt #0 0x0000000000515242 in perf_event__synthesize_event_update_name #1 0x00000000005158a4 in perf_event__synthesize_extra_attr #2 0x0000000000443347 in record__synthesize #3 0x00000000004438e3 in __cmd_record #4 0x000000000044514e in cmd_record #5 0x00000000004cbc95 in run_builtin #6 0x00000000004cbf02 in handle_internal_command #7 0x00000000004cc054 in run_argv #8 0x00000000004cc422 in main The reason of the crash is that the evsel does not have ids array allocated and the pipe's synthesize code tries to access it. We don't force evsel ids allocation when we have single event, because it's not needed. However we need it when we are in pipe mode even for single event as a key for evsel update event. Fixing this by forcing evsel ids allocation event for single event, when we are in pipe mode. Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20180302161354.30192-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 9 +++++++++ tools/perf/perf.h | 1 + tools/perf/util/record.c | 8 ++++++-- 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index bf4ca749d1ac..a217623fec2e 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -881,6 +881,15 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) } } + /* + * If we have just single event and are sending data + * through pipe, we need to force the ids allocation, + * because we synthesize event name through the pipe + * and need the id for that. + */ + if (data->is_pipe && rec->evlist->nr_entries == 1) + rec->opts.sample_id = true; + if (record__open(rec) != 0) { err = -1; goto out_child; diff --git a/tools/perf/perf.h b/tools/perf/perf.h index cfe46236a5e5..57b9b342d533 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -61,6 +61,7 @@ struct record_opts { bool tail_synthesize; bool overwrite; bool ignore_missing_thread; + bool sample_id; unsigned int freq; unsigned int mmap_pages; unsigned int auxtrace_mmap_pages; diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c index 1e97937b03a9..6f09e4962dad 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -137,6 +137,7 @@ void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts, struct perf_evsel *evsel; bool use_sample_identifier = false; bool use_comm_exec; + bool sample_id = opts->sample_id; /* * Set the evsel leader links before we configure attributes, @@ -163,8 +164,7 @@ void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts, * match the id. */ use_sample_identifier = perf_can_sample_identifier(); - evlist__for_each_entry(evlist, evsel) - perf_evsel__set_sample_id(evsel, use_sample_identifier); + sample_id = true; } else if (evlist->nr_entries > 1) { struct perf_evsel *first = perf_evlist__first(evlist); @@ -174,6 +174,10 @@ void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts, use_sample_identifier = perf_can_sample_identifier(); break; } + sample_id = true; + } + + if (sample_id) { evlist__for_each_entry(evlist, evsel) perf_evsel__set_sample_id(evsel, use_sample_identifier); }