markers: fix unregister bug and reenter bug, cleanup
Use the new rcu_read_lock_sched/unlock_sched() in marker code around the call
site instead of preempt_disable/enable(). It helps reviewing the code more
easily.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/marker.c b/kernel/marker.c
index 9f76c4a..fe5ca72 100644
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -100,11 +100,11 @@
char ptype;
/*
- * preempt_disable does two things : disabling preemption to make sure
- * the teardown of the callbacks can be done correctly when they are in
- * modules and they insure RCU read coherency.
+ * rcu_read_lock_sched does two things : disabling preemption to make
+ * sure the teardown of the callbacks can be done correctly when they
+ * are in modules and they insure RCU read coherency.
*/
- preempt_disable();
+ rcu_read_lock_sched();
ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
@@ -142,7 +142,7 @@
va_end(args);
}
}
- preempt_enable();
+ rcu_read_unlock_sched();
}
EXPORT_SYMBOL_GPL(marker_probe_cb);
@@ -159,7 +159,7 @@
va_list args; /* not initialized */
char ptype;
- preempt_disable();
+ rcu_read_lock_sched();
ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
@@ -192,7 +192,7 @@
multi[i].func(multi[i].probe_private, call_private,
mdata->format, &args);
}
- preempt_enable();
+ rcu_read_unlock_sched();
}
EXPORT_SYMBOL_GPL(marker_probe_cb_noarg);
@@ -539,7 +539,7 @@
* Disable a marker and its probe callback.
* Note: only waiting an RCU period after setting elem->call to the empty
* function insures that the original callback is not used anymore. This insured
- * by preempt_disable around the call site.
+ * by rcu_read_lock_sched around the call site.
*/
static void disable_marker(struct marker *elem)
{