tracing: Move locking of trace_cmdline_lock into start/stop seq calls
authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>
Fri, 30 May 2014 14:49:46 +0000 (10:49 -0400)
committerSteven Rostedt <rostedt@goodmis.org>
Fri, 30 May 2014 17:03:40 +0000 (13:03 -0400)
commit4c27e756bc019ec1c11232893af036fdae720a97
tree799c598208d828e343422d73cb70b74e22f64608
parent379cfdac37923653c9d4242d10052378b7563005
tracing: Move locking of trace_cmdline_lock into start/stop seq calls

With the conversion of the saved_cmdlines output to use seq_read, there
is now a race between accessing the values of the saved_cmdlines and
the writing to them. The trace_cmdline_lock needs to be taken at
the start and stop of the seq calls.

A new __trace_find_cmdline() call is created to allow for the look up
to happen without taking the lock.

Fixes: 42584c81c5ad tracing: Have saved_cmdlines use the seq_read infrastructure
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
kernel/trace/trace.c