From: Masami Hiramatsu (Google) <[email protected]>
When unloading module, the tprobe events are not correctly cleaned
up. Thus it becomes `fprobe-event` and never be enabled again even
if loading the same module again.
For example;
# cd /sys/kernel/tracing
# modprobe trace_events_sample
# echo 't:my_tprobe foo_bar' >> dynamic_events
# cat dynamic_events
t:tracepoints/my_tprobe foo_bar
# rmmod trace_events_sample
# cat dynamic_events
f:tracepoints/my_tprobe foo_bar
As you can see, the second time my_tprobe starts with 'f' instead
of 't'.
This unregisters the fprobe and tracepoint callback when module is
unloaded but marks the fprobe-event is tprobe-event.
Fixes: 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded
modules")
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
---
Changes in v2:
- Do not use unregister_trace_fprobe() but directly unregister
fprobe and tracepoint in the callback.
---
kernel/trace/trace_fprobe.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index e27305d31fc5..88a80953ae5e 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -1008,10 +1008,13 @@ static int __tracepoint_probe_module_cb(struct
notifier_block *self,
reenable_trace_fprobe(tf);
}
} else if (val == MODULE_STATE_GOING && tp_mod->mod == tf->mod)
{
- tracepoint_probe_unregister(tf->tpoint,
+ unregister_fprobe(&tf->fp);
+ if (trace_fprobe_is_tracepoint(tf)) {
+ tracepoint_probe_unregister(tf->tpoint,
tf->tpoint->probestub, NULL);
- tf->tpoint = NULL;
- tf->mod = NULL;
+ tf->tpoint = TRACEPOINT_STUB;
+ tf->mod = NULL;
+ }
}
}
mutex_unlock(&event_mutex);
