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, 2 insertions, 4 deletions

diff --git a/include/linux/module.h b/include/linux/module.h
index 5e869ffd34aa..393ec39b580a 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -460,8 +460,7 @@ static inline void __module_get(struct module *module)
         if (module) {
                 preempt_disable();
                 __this_cpu_inc(module->refptr->count);
-                trace_module_get(module, _THIS_IP_,
-                                 __this_cpu_read(module->refptr->count));
+                trace_module_get(module, _THIS_IP_);
                 preempt_enable();
         }
 }
@@ -475,8 +474,7 @@ static inline int try_module_get(struct module *module)
 
                 if (likely(module_is_live(module))) {
                         __this_cpu_inc(module->refptr->count);
-                        trace_module_get(module, _THIS_IP_,
-                                __this_cpu_read(module->refptr->count));
+                        trace_module_get(module, _THIS_IP_);
                 }
                 else
                         ret = 0;