[PATCH] ftrace: Have stacktrace option work with func-args

[PATCH] ftrace: Have stacktrace option work with func-args

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

When both the func_stack_trace option is enabled first, the func-args
option can not be enabled. Same if the func-args option is enabled first,
the func_stack_trace option can not be enabled.

Allow the two to work together. The stack trace is already slow and
testing the current tracer flags should be in the noise of overhead.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_functions.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index cd37f2013758..5604cf3ac78f 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -121,6 +121,7 @@ static ftrace_func_t select_trace_function(u32 flags_val)
 	case TRACE_FUNC_OPT_ARGS:
 		return function_args_trace_call;
 	case TRACE_FUNC_OPT_STACK:
+	case TRACE_FUNC_OPT_STACK | TRACE_FUNC_OPT_ARGS:
 		return function_stack_trace_call;
 	case TRACE_FUNC_OPT_NO_REPEATS:
 		return function_no_repeats_trace_call;
@@ -295,7 +296,9 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
 
 	if (likely(disabled == 1)) {
 		trace_ctx = tracing_gen_ctx_flags(flags);
-		trace_function(tr, ip, parent_ip, trace_ctx, NULL);
+		if (!(tr->current_trace_flags->val & TRACE_FUNC_OPT_ARGS))
+			fregs = NULL;
+		trace_function(tr, ip, parent_ip, trace_ctx, fregs);
 #ifdef CONFIG_UNWINDER_FRAME_POINTER
 		if (ftrace_pids_enabled(op))
 			skip++;
-- 
2.53.0