tracing: Remove ftrace_stop/start() from reading the trace file

commit 099ed151675cd1d2dbeae1dac697975f6a68716d upstream.

Disabling reading and writing to the trace file should not be able to
disable all function tracing callbacks. There's other users today
(like kprobes and perf). Reading a trace file should not stop those
from happening.

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e916972c6d8726b9f5087f18a0494f3f5f51cade..1848dc6278b7bed999cb435d13adfc2744f10e91 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1367,7 +1367,6 @@ void tracing_start(void)
 
        arch_spin_unlock(&ftrace_max_lock);
 
-       ftrace_start();
  out:
        raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
 }
@@ -1414,7 +1413,6 @@ 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;