[PATCH 2/3] tracing: Don't return -EINVAL when tracing soft disabled synth events

From: Tom Zanussi
Date: Mon Feb 10 2020 - 18:07:08 EST


There's no reason to return -EINVAL when tracing a synthetic event if
it's soft disabled - treat it the same as if it were hard disabled and
return normally.

Have synth_event_trace() and synth_event_trace_array() just return
normally, and have synth_event_trace_start set the trace state to
disabled and return.

Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
kernel/trace/trace_events_hist.c | 20 ++++++--------------
1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index a546ffa14785..99a02168599b 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1828,7 +1828,8 @@ int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
* called directly by the user, we don't have that but we
* still need to honor not logging when disabled.
*/
- if (!(file->flags & EVENT_FILE_FL_ENABLED))
+ if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
+ trace_trigger_soft_disabled(file))
return 0;

event = file->event_call->data;
@@ -1836,9 +1837,6 @@ int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
if (n_vals != event->n_fields)
return -EINVAL;

- if (trace_trigger_soft_disabled(file))
- return -EINVAL;
-
fields_size = event->n_u64 * sizeof(u64);

/*
@@ -1918,7 +1916,8 @@ int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
* called directly by the user, we don't have that but we
* still need to honor not logging when disabled.
*/
- if (!(file->flags & EVENT_FILE_FL_ENABLED))
+ if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
+ trace_trigger_soft_disabled(file))
return 0;

event = file->event_call->data;
@@ -1926,9 +1925,6 @@ int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
if (n_vals != event->n_fields)
return -EINVAL;

- if (trace_trigger_soft_disabled(file))
- return -EINVAL;
-
fields_size = event->n_u64 * sizeof(u64);

/*
@@ -2017,7 +2013,8 @@ int synth_event_trace_start(struct trace_event_file *file,
* trace case, we save the enabed state upon start and just
* ignore the following data calls.
*/
- if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
+ if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
+ trace_trigger_soft_disabled(file)) {
trace_state->enabled = false;
goto out;
}
@@ -2026,11 +2023,6 @@ int synth_event_trace_start(struct trace_event_file *file,

trace_state->event = file->event_call->data;

- if (trace_trigger_soft_disabled(file)) {
- ret = -EINVAL;
- goto out;
- }
-
fields_size = trace_state->event->n_u64 * sizeof(u64);

/*
--
2.14.1