Commit a1cd6173 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

ftrace: Have ftrace_startup() return failure code 



The register_ftrace_function() returns an error code on failure
except if the call to ftrace_startup() fails. Add a error return to
ftrace_startup() if it fails to start, allowing register_ftrace_funtion()
to return a proper error value.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 7cbc5b8d

kernel/trace/ftrace.c

+8 −6
Original line number Diff line number Diff line
@@ -1638,12 +1638,12 @@ static void ftrace_startup_enable(int command) 
	ftrace_run_update_code(command);

}



static void ftrace_startup(struct ftrace_ops *ops, int command)

static int ftrace_startup(struct ftrace_ops *ops, int command)

{

	bool hash_enable = true;



	if (unlikely(ftrace_disabled))

		return;

		return -ENODEV;



	ftrace_start_up++;

	command |= FTRACE_ENABLE_CALLS;
@@ -1662,6 +1662,8 @@ static void ftrace_startup(struct ftrace_ops *ops, int command) 
		ftrace_hash_rec_enable(ops, 1);



	ftrace_startup_enable(command);



	return 0;

}



static void ftrace_shutdown(struct ftrace_ops *ops, int command)
@@ -2501,7 +2503,7 @@ static void __enable_ftrace_function_probe(void) 


	ret = __register_ftrace_function(&trace_probe_ops);

	if (!ret)

		ftrace_startup(&trace_probe_ops, 0);

		ret = ftrace_startup(&trace_probe_ops, 0);



	ftrace_probe_registered = 1;

}
@@ -3466,7 +3468,7 @@ device_initcall(ftrace_nodyn_init); 
static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }

static inline void ftrace_startup_enable(int command) { }

/* Keep as macros so we do not need to define the commands */

# define ftrace_startup(ops, command)	do { } while (0)

# define ftrace_startup(ops, command)	({0;})

# define ftrace_shutdown(ops, command)	do { } while (0)

# define ftrace_startup_sysctl()	do { } while (0)

# define ftrace_shutdown_sysctl()	do { } while (0)
@@ -3799,7 +3801,7 @@ int register_ftrace_function(struct ftrace_ops *ops) 


	ret = __register_ftrace_function(ops);

	if (!ret)

		ftrace_startup(ops, 0);

		ret = ftrace_startup(ops, 0);





 out_unlock:
@@ -4045,7 +4047,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc, 
	ftrace_graph_return = retfunc;

	ftrace_graph_entry = entryfunc;



	ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);

	ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);



out:

	mutex_unlock(&ftrace_lock);

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