[RFC PATCH v3 10/19] tracing: Add NULL trace-array check in print_synth_event()

From: Masami Hiramatsu
Date: Sun Aug 25 2019 - 23:17:45 EST


Add NULL trace-array check in print_synth_event(), because
if we enable tp_printk option, iter->tr can be NULL.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
kernel/trace/trace_events_hist.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index a7f447195143..db973928e580 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -822,7 +822,7 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter,
fmt = synth_field_fmt(se->fields[i]->type);

/* parameter types */
- if (tr->trace_flags & TRACE_ITER_VERBOSE)
+ if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)
trace_seq_printf(s, "%s ", fmt);

snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);