From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751268AbeECPSo (ORCPT ); Thu, 3 May 2018 11:18:44 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:32950 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751088AbeECPSm (ORCPT ); Thu, 3 May 2018 11:18:42 -0400 X-Google-Smtp-Source: AB8JxZruLGpwlTHLzkosggcV+Ar8l/IashJMWCcaG/W/3VgMfI0ckr5x3YP/FfYXQkMNCTtFp58zhw== From: Leo Yan To: Mathieu Poirier , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org Cc: Leo Yan Subject: [PATCH 1/2] perf cs-etm: Support unknown_thread in cs_etm_auxtrace Date: Thu, 3 May 2018 23:18:22 +0800 Message-Id: <1525360703-26159-1-git-send-email-leo.yan@linaro.org> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org CoreSight doesn't allocate thread structure for unknown_thread in etm auxtrace, so unknown_thread is NULL pointer. If the perf data doesn't contain valid tid and then cs_etm__mem_access() uses unknown_thread instead as thread handler, this results in segmentation fault when thread__find_addr_map() accesses thread handler. This commit creates new thread data which is used by unknown_thread, so CoreSight tracing can roll back to use unknown_thread if perf data doesn't include valid thread info. This commit also releases thread data for initialization failure case and for normal auxtrace free flow. Signed-off-by: Leo Yan --- tools/perf/util/cs-etm.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 6533b1a..417302c 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -239,6 +239,7 @@ static void cs_etm__free(struct perf_session *session) for (i = 0; i < aux->num_cpu; i++) zfree(&aux->metadata[i]); + thread__zput(aux->unknown_thread); zfree(&aux->metadata); zfree(&aux); } @@ -266,6 +267,7 @@ static u32 cs_etm__mem_access(struct cs_etm_queue *etmq, u64 address, if (!thread) { if (cpumode != PERF_RECORD_MISC_KERNEL) return -EINVAL; + thread = etmq->etm->unknown_thread; } @@ -1355,6 +1357,23 @@ int cs_etm__process_auxtrace_info(union perf_event *event, etm->auxtrace.free = cs_etm__free; session->auxtrace = &etm->auxtrace; + etm->unknown_thread = thread__new(999999999, 999999999); + if (!etm->unknown_thread) + goto err_free_queues; + + /* + * Initialize list node so that at thread__zput() we can avoid + * segmentation fault at list_del_init(). + */ + INIT_LIST_HEAD(&etm->unknown_thread->node); + + err = thread__set_comm(etm->unknown_thread, "unknown", 0); + if (err) + goto err_delete_thread; + + if (thread__init_map_groups(etm->unknown_thread, etm->machine)) + goto err_delete_thread; + if (dump_trace) { cs_etm__print_auxtrace_info(auxtrace_info->priv, num_cpu); return 0; @@ -1369,16 +1388,18 @@ int cs_etm__process_auxtrace_info(union perf_event *event, err = cs_etm__synth_events(etm, session); if (err) - goto err_free_queues; + goto err_delete_thread; err = auxtrace_queues__process_index(&etm->queues, session); if (err) - goto err_free_queues; + goto err_delete_thread; etm->data_queued = etm->queues.populated; return 0; +err_delete_thread: + thread__zput(etm->unknown_thread); err_free_queues: auxtrace_queues__free(&etm->queues); session->auxtrace = NULL; -- 2.7.4