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

[Kamal Mostafa]

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-3.13.y-queue branch of the 3.13.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-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.6.

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

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 2ba3474dad6aa125628da5949451a8e3cbec99af 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: Kamal Mostafa <kamal 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 0a360ce..9250479 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1328,7 +1328,6 @@ void tracing_start(void)

 	arch_spin_unlock(&ftrace_max_lock);

-	ftrace_start();
  out:
 	raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
 }
@@ -1375,7 +1374,6 @@ 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