1 files changed, 36 insertions, 5 deletions

diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 9c74071c10e0..a87a20fa3fc6 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -353,15 +353,28 @@ void trace_preempt_off(unsigned long a0, unsigned long a1)
 }
 #endif /* CONFIG_PREEMPT_TRACER */
 
+/*
+ * save_tracer_enabled is used to save the state of the tracer_enabled
+ * variable when we disable it when we open a trace output file.
+ */
+static int save_tracer_enabled;
+
 static void start_irqsoff_tracer(struct trace_array *tr)
 {
         register_ftrace_function(&trace_ops);
-        tracer_enabled = 1;
+        if (tracing_is_enabled()) {
+                tracer_enabled = 1;
+                save_tracer_enabled = 1;
+        } else {
+                tracer_enabled = 0;
+                save_tracer_enabled = 0;
+        }
 }
 
 static void stop_irqsoff_tracer(struct trace_array *tr)
 {
         tracer_enabled = 0;
+        save_tracer_enabled = 0;
         unregister_ftrace_function(&trace_ops);
 }
 
@@ -389,17 +402,29 @@ static void irqsoff_tracer_ctrl_update(struct trace_array *tr)
                 stop_irqsoff_tracer(tr);
 }
 
+static void irqsoff_tracer_start(struct trace_array *tr)
+{
+        irqsoff_tracer_reset(tr);
+        tracer_enabled = 1;
+        save_tracer_enabled = 1;
+}
+
+static void irqsoff_tracer_stop(struct trace_array *tr)
+{
+        tracer_enabled = 0;
+        save_tracer_enabled = 0;
+}
+
 static void irqsoff_tracer_open(struct trace_iterator *iter)
 {
         /* stop the trace while dumping */
-        if (iter->tr->ctrl)
-                stop_irqsoff_tracer(iter->tr);
+        tracer_enabled = 0;
 }
 
 static void irqsoff_tracer_close(struct trace_iterator *iter)
 {
-        if (iter->tr->ctrl)
-                start_irqsoff_tracer(iter->tr);
+        /* restart tracing */
+        tracer_enabled = save_tracer_enabled;
 }
 
 #ifdef CONFIG_IRQSOFF_TRACER
@@ -414,6 +439,8 @@ static struct tracer irqsoff_tracer __read_mostly =
         .name           = "irqsoff",
         .init           = irqsoff_tracer_init,
         .reset          = irqsoff_tracer_reset,
+        .start          = irqsoff_tracer_start,
+        .stop           = irqsoff_tracer_stop,
         .open           = irqsoff_tracer_open,
         .close          = irqsoff_tracer_close,
         .ctrl_update    = irqsoff_tracer_ctrl_update,
@@ -440,6 +467,8 @@ static struct tracer preemptoff_tracer __read_mostly =
         .name           = "preemptoff",
         .init           = preemptoff_tracer_init,
         .reset          = irqsoff_tracer_reset,
+        .start          = irqsoff_tracer_start,
+        .stop           = irqsoff_tracer_stop,
         .open           = irqsoff_tracer_open,
         .close          = irqsoff_tracer_close,
         .ctrl_update    = irqsoff_tracer_ctrl_update,
@@ -468,6 +497,8 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
         .name           = "preemptirqsoff",
         .init           = preemptirqsoff_tracer_init,
         .reset          = irqsoff_tracer_reset,
+        .start          = irqsoff_tracer_start,
+        .stop           = irqsoff_tracer_stop,
         .open           = irqsoff_tracer_open,
         .close          = irqsoff_tracer_close,
         .ctrl_update    = irqsoff_tracer_ctrl_update,