tracing: Kill the unbalanced tr->ref++ in tracing_buffers_open()
authorOleg Nesterov <oleg@redhat.com>
Fri, 19 Jul 2013 15:36:44 +0000 (17:36 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 4 Aug 2013 08:50:43 +0000 (16:50 +0800)
commite55679914313bbfc003dcdf8ff74a16dec2fe24d
tree202596b1d2f367a3c1fa82ef845fbed1b176cb72
parente45ccd09b53e4cd60941891ad6992579ebc78024
tracing: Kill the unbalanced tr->ref++ in tracing_buffers_open()

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