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 f0831c2..fd21e60 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1355,7 +1355,6 @@ void tracing_start(void)
 
        arch_spin_unlock(&ftrace_max_lock);
 
-       ftrace_start();
  out:
        raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
 }
@@ -1402,7 +1401,6 @@ 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;