lkml.org 
[lkml]   [2013]   [Aug]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[ 20/99] tracing: Kill the unbalanced tr->ref++ in tracing_buffers_open()
Date
3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Oleg Nesterov <oleg@redhat.com>

commit e70e78e3c83b536730e31231dd9b979768d8df3c upstream.

tracing_buffers_open() does trace_array_get() and then it wrongly
inrcements tr->ref again under trace_types_lock. This means that
every caller leaks trace_array:

# cd /sys/kernel/debug/tracing/
# mkdir instances/X
# true < instances/X/per_cpu/cpu0/trace_pipe_raw
# rmdir instances/X
rmdir: failed to remove `instances/X': Device or resource busy

Link: http://lkml.kernel.org/r/20130719153644.GA18899@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
kernel/trace/trace.c | 2 --
1 file changed, 2 deletions(-)

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4907,8 +4907,6 @@ static int tracing_buffers_open(struct i

mutex_lock(&trace_types_lock);

- tr->ref++;
-
info->iter.tr = tr;
info->iter.cpu_file = tc->cpu;
info->iter.trace = tr->current_trace;



\
 
 \ /
  Last update: 2013-08-02 13:01    [W:0.363 / U:0.856 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site