4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Leo Yan <leo.yan@xxxxxxxxxx> [ Upstream commit 46d53620044f7b574c0f3216f8b4f2ce3559ce31 ] 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 a segmentation fault when thread__find_addr_map() accesses the thread handler. This commit creates a 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 <leo.yan@xxxxxxxxxx> Acked-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/1525924920-4381-1-git-send-email-leo.yan@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/perf/util/cs-etm.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -212,6 +212,7 @@ static void cs_etm__free(struct perf_ses for (i = 0; i < aux->num_cpu; i++) zfree(&aux->metadata[i]); + thread__zput(aux->unknown_thread); zfree(&aux->metadata); zfree(&aux); } @@ -980,6 +981,23 @@ int cs_etm__process_auxtrace_info(union 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; @@ -994,16 +1012,18 @@ int cs_etm__process_auxtrace_info(union 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;
