Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-android

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

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4c41e22f162b5dea8d1253ce15a4140716c09372..bb9c36de8bfbe1d425caa3d8c48cc701d1b6c343 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1308,7 +1308,6 @@ void tracing_start(void)
 
        arch_spin_unlock(&ftrace_max_lock);
 
-       ftrace_start();
  out:
        raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
 }
@@ -1355,7 +1354,6 @@ void tracing_stop(void)
        struct ring_buffer *buffer;
        unsigned long flags;
 
-       ftrace_stop();
        raw_spin_lock_irqsave(&global_trace.start_lock, flags);
        if (global_trace.stop_count++)
                goto out;
@@ -1402,12 +1400,12 @@ static void tracing_stop_tr(struct trace_array *tr)
 
 void trace_stop_cmdline_recording(void);
 
-static void trace_save_cmdline(struct task_struct *tsk)
+static int trace_save_cmdline(struct task_struct *tsk)
 {
        unsigned pid, idx;
 
        if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
-               return;
+               return 0;
 
        /*
         * It's not the end of the world if we don't get
@@ -1416,7 +1414,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
         * so if we miss here, then better luck next time.
         */
        if (!arch_spin_trylock(&trace_cmdline_lock))
-               return;
+               return 0;
 
        idx = map_pid_to_cmdline[tsk->pid];
        if (idx == NO_CMDLINE_MAP) {
@@ -1442,6 +1440,8 @@ static void trace_save_cmdline(struct task_struct *tsk)
        saved_tgids[idx] = tsk->tgid;
 
        arch_spin_unlock(&trace_cmdline_lock);
+
+       return 1;
 }
 
 void trace_find_cmdline(int pid, char comm[])
@@ -1502,9 +1502,8 @@ void tracing_record_cmdline(struct task_struct *tsk)
        if (!__this_cpu_read(trace_cmdline_save))
                return;
 
-       __this_cpu_write(trace_cmdline_save, false);
-
-       trace_save_cmdline(tsk);
+       if (trace_save_cmdline(tsk))
+               __this_cpu_write(trace_cmdline_save, false);
 }
 
 void