1 files changed, 6 insertions, 2 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2074e5b7766b..d6973dfadb36 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -599,7 +599,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip)
         local_irq_save(flags);
 
         stat = &__get_cpu_var(ftrace_profile_stats);
-        if (!stat->hash)
+        if (!stat->hash || !ftrace_profile_enabled)
                 goto out;
 
         rec = ftrace_find_profiled_func(stat, ip);
@@ -630,7 +630,7 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
 
         local_irq_save(flags);
         stat = &__get_cpu_var(ftrace_profile_stats);
-        if (!stat->hash)
+        if (!stat->hash || !ftrace_profile_enabled)
                 goto out;
 
         calltime = trace->rettime - trace->calltime;
@@ -724,6 +724,10 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf,
                         ftrace_profile_enabled = 1;
                 } else {
                         ftrace_profile_enabled = 0;
+                        /*
+                         * unregister_ftrace_profiler calls stop_machine
+                         * so this acts like an synchronize_sched.
+                         */
                         unregister_ftrace_profiler();
                 }
         }