On Mon, 29 Nov 2021 11:13:31 +0100
Sven Schnelle <svens@xxxxxxxxxxxxx> wrote:
> This breaks the trigger-field-variable-support.tc from the ftrace test
> suite at least on s390:
>
> echo 'hist:keys=next_comm:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,sched.sched_waking.prio,next_comm) if next_comm=="ping"'
> linux/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc: line 15: echo: write error: Invalid argument
>
> I added a debugging line into check_synth_field():
>
> [ 44.091037] field->size 16, hist_field->size 16, field->is_signed 1, hist_field->is_signed 0
>
> Note the difference in the signed field.
That should not break on strings.
Does this fix it (if you keep the patch)?
-- Steve
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 9555b8e1d1e3..319f9c8ca7e7 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3757,7 +3757,7 @@ static int check_synth_field(struct synth_event *event,
if (strcmp(field->type, hist_field->type) != 0) {
if (field->size != hist_field->size ||
- field->is_signed != hist_field->is_signed)
+ (!field->is_string && field->is_signed != hist_field->is_signed))
return -EINVAL;
}
