perf cs-etm: Support unknown_thread in cs_etm_auxtrace

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@linaro.org>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1525924920-4381-1-git-send-email-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Leo Yan 2018-05-10 12:01:59 +08:00 committed by Arnaldo Carvalho de Melo
parent 04d2600ab6
commit 46d5362004
1 changed files with 22 additions and 2 deletions

View File

@ -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);
}
@ -1357,6 +1358,23 @@ 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;
@ -1371,16 +1389,18 @@ 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;