From: Chuang Wang <nashuiliang@xxxxxxxxx> [ Upstream commit 685b64e4d6da4be8b4595654a57db663b3d1dfc2 ] list_for_each_entry_rcu() has built-in RCU and lock checking. Pass cond argument to list_for_each_entry_rcu() to silence false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled. Execute as follow: [tracing]# echo osnoise > current_tracer [tracing]# echo 1 > tracing_on [tracing]# echo 0 > tracing_on The trace_types_lock is held when osnoise_tracer_stop() or timerlat_tracer_stop() are called in the non-RCU read side section. So, pass lockdep_is_held(&trace_types_lock) to silence false lockdep warning. Link: https://lkml.kernel.org/r/20221227023036.784337-1-nashuiliang@xxxxxxxxx Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr") Acked-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> Signed-off-by: Chuang Wang <nashuiliang@xxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/trace/trace_osnoise.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index 4300c5dc4e5d..1c07efcb3d46 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -125,9 +125,8 @@ static void osnoise_unregister_instance(struct trace_array *tr) * register/unregister serialization is provided by trace's * trace_types_lock. */ - lockdep_assert_held(&trace_types_lock); - - list_for_each_entry_rcu(inst, &osnoise_instances, list) { + list_for_each_entry_rcu(inst, &osnoise_instances, list, + lockdep_is_held(&trace_types_lock)) { if (inst->tr == tr) { list_del_rcu(&inst->list); found = 1; -- 2.39.0
