2 files changed, 9 insertions, 10 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 6893d5a2bf08..926ebfb74936 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -66,7 +66,7 @@
 
 static struct ftrace_ops ftrace_list_end __read_mostly = {
         .func           = ftrace_stub,
-        .flags          = FTRACE_OPS_FL_RECURSION_SAFE,
+        .flags          = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
 };
 
 /* ftrace_enabled is a method to turn ftrace on or off */
@@ -694,7 +694,6 @@ int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
                 free_page(tmp);
         }
 
-        free_page((unsigned long)stat->pages);
         stat->pages = NULL;
         stat->start = NULL;
 
@@ -4131,7 +4130,8 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
         preempt_disable_notrace();
         trace_recursion_set(TRACE_CONTROL_BIT);
         do_for_each_ftrace_op(op, ftrace_control_list) {
-                if (!ftrace_function_local_disabled(op) &&
+                if (!(op->flags & FTRACE_OPS_FL_STUB) &&
+                    !ftrace_function_local_disabled(op) &&
                     ftrace_ops_test(op, ip))
                         op->func(ip, parent_ip, op, regs);
         } while_for_each_ftrace_op(op);
@@ -4555,12 +4555,8 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
                 ftrace_startup_sysctl();
 
                 /* we are starting ftrace again */
-                if (ftrace_ops_list != &ftrace_list_end) {
-                        if (ftrace_ops_list->next == &ftrace_list_end)
-                                ftrace_trace_function = ftrace_ops_list->func;
-                        else
-                                ftrace_trace_function = ftrace_ops_list_func;
-                }
+                if (ftrace_ops_list != &ftrace_list_end)
+                        update_ftrace_function();
 
         } else {
                 /* stopping ftrace calls (just send to ftrace_stub) */
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4f1dade56981..7ba7fc76f9eb 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -744,8 +744,11 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
                 return;
 
         WARN_ON_ONCE(!irqs_disabled());
-        if (WARN_ON_ONCE(!current_trace->allocated_snapshot))
+        if (!current_trace->allocated_snapshot) {
+                /* Only the nop tracer should hit this when disabling */
+                WARN_ON_ONCE(current_trace != &nop_trace);
                 return;
+        }
 
         arch_spin_lock(&ftrace_max_lock);