---

yaml
---
r: 100440
b: refs/heads/master
c: 60a1177
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e1c08bdd9fa73e44096e5a82c0d5928b04ab02c8
+refs/heads/master: 60a11774b38fef1ab90b18c5353bd1c7c4d311c8

trunk/kernel/trace/Kconfig

@@ -105,3 +105,16 @@ config DYNAMIC_FTRACE
 	 wakes up once a second and checks to see if any ftrace calls
 	 were made. If so, it runs stop_machine (stops all CPUS)
 	 and modifies the code to jump over the call to ftrace.
+
+config FTRACE_SELFTEST
+	bool
+
+config FTRACE_STARTUP_TEST
+	bool "Perform a startup test on ftrace"
+	depends on TRACING
+	select FTRACE_SELFTEST
+	help
+	  This option performs a series of startup tests on ftrace. On bootup
+	  a series of tests are made to verify that the tracer is
+	  functioning properly. It will do tests on all the configured
+	  tracers of ftrace.

trunk/kernel/trace/trace.c

@@ -32,6 +32,8 @@
 unsigned long __read_mostly	tracing_max_latency = (cycle_t)ULONG_MAX;
 unsigned long __read_mostly	tracing_thresh;
 
+static int tracing_disabled = 1;
+
 static long notrace
 ns2usecs(cycle_t nsec)
 {
@@ -217,11 +219,48 @@ int register_tracer(struct tracer *type)
 		}
 	}
 
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+	if (type->selftest) {
+		struct tracer *saved_tracer = current_trace;
+		struct trace_array_cpu *data;
+		struct trace_array *tr = &global_trace;
+		int saved_ctrl = tr->ctrl;
+		int i;
+		/*
+		 * Run a selftest on this tracer.
+		 * Here we reset the trace buffer, and set the current
+		 * tracer to be this tracer. The tracer can then run some
+		 * internal tracing to verify that everything is in order.
+		 * If we fail, we do not register this tracer.
+		 */
+		for_each_possible_cpu(i) {
+			if (!data->trace)
+				continue;
+			data = tr->data[i];
+			tracing_reset(data);
+		}
+		current_trace = type;
+		tr->ctrl = 0;
+		/* the test is responsible for initializing and enabling */
+		pr_info("Testing tracer %s: ", type->name);
+		ret = type->selftest(type, tr);
+		/* the test is responsible for resetting too */
+		current_trace = saved_tracer;
+		tr->ctrl = saved_ctrl;
+		if (ret) {
+			printk(KERN_CONT "FAILED!\n");
+			goto out;
+		}
+		printk(KERN_CONT "PASSED\n");
+	}
+#endif
+
 	type->next = trace_types;
 	trace_types = type;
 	len = strlen(type->name);
 	if (len > max_tracer_type_len)
 		max_tracer_type_len = len;
+
  out:
 	mutex_unlock(&trace_types_lock);
 
@@ -985,6 +1024,11 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
 {
 	struct trace_iterator *iter;
 
+	if (tracing_disabled) {
+		*ret = -ENODEV;
+		return NULL;
+	}
+
 	iter = kzalloc(sizeof(*iter), GFP_KERNEL);
 	if (!iter) {
 		*ret = -ENOMEM;
@@ -1023,6 +1067,9 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
 
 int tracing_open_generic(struct inode *inode, struct file *filp)
 {
+	if (tracing_disabled)
+		return -ENODEV;
+
 	filp->private_data = inode->i_private;
 	return 0;
 }
@@ -1128,6 +1175,9 @@ static int show_traces_open(struct inode *inode, struct file *file)
 {
 	int ret;
 
+	if (tracing_disabled)
+		return -ENODEV;
+
 	ret = seq_open(file, &show_traces_seq_ops);
 	if (!ret) {
 		struct seq_file *m = file->private_data;
@@ -1452,6 +1502,11 @@ struct dentry *tracing_init_dentry(void)
 	return d_tracer;
 }
 
+#ifdef CONFIG_FTRACE_SELFTEST
+/* Let selftest have access to static functions in this file */
+#include "trace_selftest.c"
+#endif
+
 static __init void tracer_init_debugfs(void)
 {
 	struct dentry *d_tracer;
@@ -1585,6 +1640,7 @@ __init static int tracer_alloc_buffers(void)
 	void *array;
 	struct page *page;
 	int pages = 0;
+	int ret = -ENOMEM;
 	int i;
 
 	/* Allocate the first page for all buffers */
@@ -1650,6 +1706,9 @@ __init static int tracer_alloc_buffers(void)
 	register_tracer(&no_tracer);
 	current_trace = &no_tracer;
 
+	/* All seems OK, enable tracing */
+	tracing_disabled = 0;
+
 	return 0;
 
  free_buffers:
@@ -1678,7 +1737,7 @@ __init static int tracer_alloc_buffers(void)
 		}
 #endif
 	}
-	return -ENOMEM;
+	return ret;
 }
 
-device_initcall(tracer_alloc_buffers);
+fs_initcall(tracer_alloc_buffers);

trunk/kernel/trace/trace.h

@@ -99,6 +99,10 @@ struct tracer {
 	void			(*start)(struct trace_iterator *iter);
 	void			(*stop)(struct trace_iterator *iter);
 	void			(*ctrl_update)(struct trace_array *tr);
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+	int			(*selftest)(struct tracer *trace,
+					    struct trace_array *tr);
+#endif
 	struct tracer		*next;
 	int			print_max;
 };
@@ -185,4 +189,31 @@ extern int unregister_tracer_switch(struct tracer_switch_ops *ops);
 extern unsigned long ftrace_update_tot_cnt;
 #endif
 
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+#ifdef CONFIG_FTRACE
+extern int trace_selftest_startup_function(struct tracer *trace,
+					   struct trace_array *tr);
+#endif
+#ifdef CONFIG_IRQSOFF_TRACER
+extern int trace_selftest_startup_irqsoff(struct tracer *trace,
+					  struct trace_array *tr);
+#endif
+#ifdef CONFIG_PREEMPT_TRACER
+extern int trace_selftest_startup_preemptoff(struct tracer *trace,
+					     struct trace_array *tr);
+#endif
+#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
+extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
+						 struct trace_array *tr);
+#endif
+#ifdef CONFIG_SCHED_TRACER
+extern int trace_selftest_startup_wakeup(struct tracer *trace,
+					 struct trace_array *tr);
+#endif
+#ifdef CONFIG_CONTEXT_SWITCH_TRACER
+extern int trace_selftest_startup_sched_switch(struct tracer *trace,
+					       struct trace_array *tr);
+#endif
+#endif /* CONFIG_FTRACE_STARTUP_TEST */
+
 #endif /* _LINUX_KERNEL_TRACE_H */

trunk/kernel/trace/trace_functions.c

@@ -63,6 +63,9 @@ static struct tracer function_trace __read_mostly =
 	.init	     = function_trace_init,
 	.reset	     = function_trace_reset,
 	.ctrl_update = function_trace_ctrl_update,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest    = trace_selftest_startup_function,
+#endif
 };
 
 static __init int init_function_trace(void)

trunk/kernel/trace/trace_irqsoff.c

@@ -432,6 +432,9 @@ static struct tracer irqsoff_tracer __read_mostly =
 	.close		= irqsoff_tracer_close,
 	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest    = trace_selftest_startup_irqsoff,
+#endif
 };
 # define register_irqsoff(trace) register_tracer(&trace)
 #else
@@ -455,6 +458,9 @@ static struct tracer preemptoff_tracer __read_mostly =
 	.close		= irqsoff_tracer_close,
 	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest    = trace_selftest_startup_preemptoff,
+#endif
 };
 # define register_preemptoff(trace) register_tracer(&trace)
 #else
@@ -480,6 +486,9 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
 	.close		= irqsoff_tracer_close,
 	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest    = trace_selftest_startup_preemptirqsoff,
+#endif
 };
 
 # define register_preemptirqsoff(trace) register_tracer(&trace)

trunk/kernel/trace/trace_sched_switch.c

@@ -107,6 +107,9 @@ static struct tracer sched_switch_trace __read_mostly =
 	.init		= sched_switch_trace_init,
 	.reset		= sched_switch_trace_reset,
 	.ctrl_update	= sched_switch_trace_ctrl_update,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest    = trace_selftest_startup_sched_switch,
+#endif
 };
 
 __init static int init_sched_switch_trace(void)

trunk/kernel/trace/trace_sched_wakeup.c

@@ -295,6 +295,9 @@ static struct tracer wakeup_tracer __read_mostly =
 	.close		= wakeup_tracer_close,
 	.ctrl_update	= wakeup_tracer_ctrl_update,
 	.print_max	= 1,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest    = trace_selftest_startup_wakeup,
+#endif
 };
 
 __init static int init_wakeup_tracer(void)