ftrace: let function tracing and function return run together
Impact: feature
This patch enables function tracing and function return to run together.
I've tested this by enabling the stack tracer and return tracer, where
both the function entry and function return are used together with
dynamic ftrace.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 5f7c864..cbf8b09 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -53,9 +53,6 @@
/* Quick disabling of function tracer. */
int function_trace_stop;
-/* By default, current tracing type is normal tracing. */
-enum ftrace_tracing_type_t ftrace_tracing_type = FTRACE_TYPE_ENTER;
-
/*
* ftrace_disabled is set when an anomaly is discovered.
* ftrace_disabled is much stronger than ftrace_enabled.
@@ -1576,15 +1573,9 @@
mutex_lock(&ftrace_sysctl_lock);
- if (ftrace_tracing_type == FTRACE_TYPE_RETURN) {
- ret = -EBUSY;
- goto out;
- }
-
ret = __register_ftrace_function(ops);
ftrace_startup(0);
-out:
mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
@@ -1731,23 +1722,16 @@
mutex_lock(&ftrace_sysctl_lock);
- /*
- * Don't launch return tracing if normal function
- * tracing is already running.
- */
- if (ftrace_trace_function != ftrace_stub) {
- ret = -EBUSY;
- goto out;
- }
atomic_inc(&ftrace_graph_active);
ret = start_graph_tracing();
if (ret) {
atomic_dec(&ftrace_graph_active);
goto out;
}
- ftrace_tracing_type = FTRACE_TYPE_RETURN;
+
ftrace_graph_return = retfunc;
ftrace_graph_entry = entryfunc;
+
ftrace_startup(FTRACE_START_FUNC_RET);
out:
@@ -1763,8 +1747,6 @@
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub;
ftrace_shutdown(FTRACE_STOP_FUNC_RET);
- /* Restore normal tracing type */
- ftrace_tracing_type = FTRACE_TYPE_ENTER;
mutex_unlock(&ftrace_sysctl_lock);
}