[3.11.y.z extended stable] Patch "tracing: Remove ftrace_stop/start() from reading the trace file" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

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

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 2f5afda8ed1b1461b59ad7ac2b74df7a622bbb61 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Red Hat)" <rostedt at goodmis.org>
Date: Tue, 24 Jun 2014 23:50:09 -0400
Subject: 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 at hitachi.com>
Signed-off-by: Steven Rostedt <rostedt at goodmis.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 kernel/trace/trace.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5f22856fd02a..c8b8717afc23 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1323,7 +1323,6 @@ void tracing_start(void)

 	arch_spin_unlock(&ftrace_max_lock);

-	ftrace_start();
  out:
 	raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
 }
@@ -1370,7 +1369,6 @@ 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;
--
1.9.1