tracing: Remove side effect from module tracepoints that caused a GPF

Remove the @refcnt argument, because it has side-effects, and arguments with
side-effects are not skipped by the jump over disabled instrumentation and are
executed even when the tracepoint is disabled.

This was also causing a GPF as found by Randy Dunlap:

Subject: 2.6.33 GP fault only when built with tracing
LKML-Reference: <4BA2B69D.3000309@oracle.com>

Note, the current 2.6.34-rc has a fix for the actual cause of the GPF,
but this fixes one of its triggers.

Tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BA97FA7.6040406@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/kernel/module.c b/kernel/module.c
index c968d3606dca..21591ad921f3 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -800,8 +800,7 @@ void module_put(struct module *module)
                 preempt_disable();
                 __this_cpu_dec(module->refptr->count);
 
-                trace_module_put(module, _RET_IP_,
-                                 __this_cpu_read(module->refptr->count));
+                trace_module_put(module, _RET_IP_);
                 /* Maybe they're waiting for us to drop reference? */
                 if (unlikely(!module_is_live(module)))
                         wake_up_process(module->waiter);