[PATCH v2 3/5] tracing: Make traceon, traceoff trigger affect the correct instance

From: Howard Cochran
Date: Fri Apr 15 2016 - 18:33:38 EST


Currently, the traceon & traceoff triggers always enable or disable
tracing in the top level buffer, even if it was triggered within an
instance. Fixed by using the trace_array associated with the
trace_event_file which fired the trigger.

Signed-off-by: Howard Cochran <hcochran@xxxxxxxxxxxxxxxx>
---
kernel/trace/trace.c | 6 +++---
kernel/trace/trace.h | 3 +++
kernel/trace/trace_events_trigger.c | 16 ++++++++--------
3 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5541517..c78fe42 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -498,7 +498,7 @@ static inline void ftrace_trace_stack(struct trace_array *tr,

#endif

-static void tracer_tracing_on(struct trace_array *tr)
+void tracer_tracing_on(struct trace_array *tr)
{
if (tr->trace_buffer.buffer)
ring_buffer_record_on(tr->trace_buffer.buffer);
@@ -764,7 +764,7 @@ void tracing_snapshot_alloc(void)
EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
#endif /* CONFIG_TRACER_SNAPSHOT */

-static void tracer_tracing_off(struct trace_array *tr)
+void tracer_tracing_off(struct trace_array *tr)
{
if (tr->trace_buffer.buffer)
ring_buffer_record_off(tr->trace_buffer.buffer);
@@ -807,7 +807,7 @@ void disable_trace_on_warning(void)
*
* Shows real state of the ring buffer if it is enabled or not.
*/
-static int tracer_tracing_is_on(struct trace_array *tr)
+int tracer_tracing_is_on(struct trace_array *tr)
{
if (tr->trace_buffer.buffer)
return ring_buffer_record_is_on(tr->trace_buffer.buffer);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 00a5419..d3bc0e8 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -717,6 +717,9 @@ enum print_line_t print_trace_line(struct trace_iterator *iter);
extern char trace_find_mark(unsigned long long duration);

void __trace_dump_stack(int skip, struct trace_array *tr);
+int tracer_tracing_is_on(struct trace_array *tr);
+void tracer_tracing_on(struct trace_array *tr);
+void tracer_tracing_off(struct trace_array *tr);

/* Standard output formatting function used for function return traces */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 670aa05..3595688 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -768,17 +768,17 @@ static void
traceon_trigger(struct event_trigger_data *data, void *rec,
struct trace_event_file *file)
{
- if (tracing_is_on())
+ if (tracer_tracing_is_on(file->tr))
return;

- tracing_on();
+ tracer_tracing_on(file->tr);
}

static void
traceon_count_trigger(struct event_trigger_data *data, void *rec,
struct trace_event_file *file)
{
- if (tracing_is_on())
+ if (tracer_tracing_is_on(file->tr))
return;

if (!data->count)
@@ -787,24 +787,24 @@ traceon_count_trigger(struct event_trigger_data *data, void *rec,
if (data->count != -1)
(data->count)--;

- tracing_on();
+ tracer_tracing_on(file->tr);
}

static void
traceoff_trigger(struct event_trigger_data *data, void *rec,
struct trace_event_file *file)
{
- if (!tracing_is_on())
+ if (!tracer_tracing_is_on(file->tr))
return;

- tracing_off();
+ tracer_tracing_off(file->tr);
}

static void
traceoff_count_trigger(struct event_trigger_data *data, void *rec,
struct trace_event_file *file)
{
- if (!tracing_is_on())
+ if (!tracer_tracing_is_on(file->tr))
return;

if (!data->count)
@@ -813,7 +813,7 @@ traceoff_count_trigger(struct event_trigger_data *data, void *rec,
if (data->count != -1)
(data->count)--;

- tracing_off();
+ tracer_tracing_off(file->tr);
}

static int
--
1.9.1