[PATCH 1/2] perf cs-etm: Support unknown_thread in cs_etm_auxtrace

[PATCH 1/2] perf cs-etm: Support unknown_thread in cs_etm_auxtrace

[Leo Yan]

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>
---
 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

[PATCH 2/2] perf cs-etm: Remove redundant space

[Leo Yan]

There have two spaces ahead function name cs_etm__set_pid_tid_cpu(), so
remove one space and correct indentation.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 tools/perf/util/cs-etm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 417302c..3137fbe 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -612,8 +612,8 @@ cs_etm__get_trace(struct cs_etm_buffer *buff, struct cs_etm_queue *etmq)
 	return buff->len;
 }
 
-static void  cs_etm__set_pid_tid_cpu(struct cs_etm_auxtrace *etm,
-				     struct auxtrace_queue *queue)
+static void cs_etm__set_pid_tid_cpu(struct cs_etm_auxtrace *etm,
+				    struct auxtrace_queue *queue)
 {
 	struct cs_etm_queue *etmq = queue->priv;
 
-- 
2.7.4

Re: [PATCH 2/2] perf cs-etm: Remove redundant space

[Mathieu Poirier]

On 3 May 2018 at 09:18, Leo Yan <leo.yan@linaro.org> wrote:
> There have two spaces ahead function name cs_etm__set_pid_tid_cpu(), so
> remove one space and correct indentation.
>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>

Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> ---
>  tools/perf/util/cs-etm.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index 417302c..3137fbe 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -612,8 +612,8 @@ cs_etm__get_trace(struct cs_etm_buffer *buff, struct cs_etm_queue *etmq)
>         return buff->len;
>  }
>
> -static void  cs_etm__set_pid_tid_cpu(struct cs_etm_auxtrace *etm,
> -                                    struct auxtrace_queue *queue)
> +static void cs_etm__set_pid_tid_cpu(struct cs_etm_auxtrace *etm,
> +                                   struct auxtrace_queue *queue)
>  {
>         struct cs_etm_queue *etmq = queue->priv;
>
> --
> 2.7.4
>

Re: [PATCH 1/2] perf cs-etm: Support unknown_thread in cs_etm_auxtrace

[Mathieu Poirier]

On 3 May 2018 at 09:18, Leo Yan <leo.yan@linaro.org> wrote:
> 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>
> ---
>  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;
> +

Extra line, please remove.

With this change:

Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>

>                 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
>

Re: [PATCH 1/2] perf cs-etm: Support unknown_thread in cs_etm_auxtrace

[Leo Yan]

On Tue, May 08, 2018 at 11:01:30AM -0600, Mathieu Poirier wrote:
> On 3 May 2018 at 09:18, Leo Yan <leo.yan@linaro.org> wrote:
> > 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>
> > ---
> >  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;
> > +
> 
> Extra line, please remove.
> 
> With this change:
> 
> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Thanks for reviewing, Mathieu.  Will spin new patches and send out.

[...]

Thanks,
Leo Yan