| Message ID | 1525924920-4381-1-git-send-email-leo.yan@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Em Thu, May 10, 2018 at 12:01:59PM +0800, Leo Yan escreveu: > 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 <leo.yan@linaro.org> > Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> Thanks, applied to perf/urgent. And please use a more descriptive, eye catching summary, something like: perf cs-etm: Fix segfault when accessing NULL unknown_thread variable :-) - Arnaldo
On Fri, May 11, 2018 at 10:48:00AM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, May 10, 2018 at 12:01:59PM +0800, Leo Yan escreveu: > > 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 <leo.yan@linaro.org> > > Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > Thanks, applied to perf/urgent. > > And please use a more descriptive, eye catching summary, something like: > > perf cs-etm: Fix segfault when accessing NULL unknown_thread variable > > :-) Thanks for suggestion. Indeed, this patch is a fix rather than a new feature, subject should reflect it. Thanks, Leo Yan
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 6533b1a..69f21de 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); } @@ -1355,6 +1356,23 @@ 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 +1387,18 @@ 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;