Merge branch 'linus' into tracing/core

[firefly-linux-kernel-4.4.55.git] / kernel / trace / ftrace.c

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index c7f4a4be05dc0f96c35fec5163c23f7761d081fd..678e3d6caf85ad4dc32879fffbc066cb45fb4181 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -928,9 +928,14 @@ void ftrace_release(void *start, unsigned long size)
 
        mutex_lock(&ftrace_lock);
        do_for_each_ftrace_rec(pg, rec) {
-               if ((rec->ip >= s) && (rec->ip < e) &&
-                   !(rec->flags & FTRACE_FL_FREE))
+               if ((rec->ip >= s) && (rec->ip < e)) {
+                       /*
+                        * rec->ip is changed in ftrace_free_rec()
+                        * It should not between s and e if record was freed.
+                        */
+                       FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
                        ftrace_free_rec(rec);
+               }
        } while_for_each_ftrace_rec();
        mutex_unlock(&ftrace_lock);
 }
@@ -3287,6 +3292,9 @@ void unregister_ftrace_graph(void)
 {
        mutex_lock(&ftrace_lock);
 
+       if (!unlikely(atomic_read(&ftrace_graph_active)))
+               goto out;
+
        atomic_dec(&ftrace_graph_active);
        unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
        ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
@@ -3294,6 +3302,7 @@ void unregister_ftrace_graph(void)
        ftrace_shutdown(FTRACE_STOP_FUNC_RET);
        unregister_pm_notifier(&ftrace_suspend_notifier);
 
+ out:
        mutex_unlock(&ftrace_lock);
 }