[PATCH] tracing: Do not use PERF enums when perf is not defined

From: Steven Rostedt
Date: Sun Mar 23 2025 - 15:22:00 EST


From: Steven Rostedt <rostedt@xxxxxxxxxxx>

An update was made to up the module ref count when a synthetic event is
registered for both trace and perf events. But if perf is not configured
in, the perf enums used will cause the kernel to fail to build.

Fixes: a1e3ad43115e ("tracing: Ensure module defining synth event cannot be unloaded while tracing")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202503232230.TeREVy8R-lkp@xxxxxxxxx/
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_events_synth.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index d91205bc9f61..5976545403ea 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -859,8 +859,10 @@ static int synth_event_reg(struct trace_event_call *call,
struct synth_event *event = container_of(call, struct synth_event, call);

switch (type) {
- case TRACE_REG_REGISTER:
+#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
+#endif
+ case TRACE_REG_REGISTER:
if (!try_module_get(event->mod))
return -EBUSY;
break;
@@ -871,8 +873,10 @@ static int synth_event_reg(struct trace_event_call *call,
int ret = trace_event_reg(call, type, data);

switch (type) {
- case TRACE_REG_UNREGISTER:
+#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_UNREGISTER:
+#endif
+ case TRACE_REG_UNREGISTER:
module_put(event->mod);
break;
default:
--
2.47.2