X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fmarker.c;h=e9c6b2bc9400627cf183382ee55933333f0ee83b;hb=d2441183dc222d12961ff2201f5086c846505d93;hp=7d1faecd7a51bd643cc1e10f0f2048765136bf16;hpb=83bd6998b04fc1bb7280b14f16b2bdbdc07c914b;p=linux-2.6-omap-h63xx.git

diff --git a/kernel/marker.c b/kernel/marker.c
index 7d1faecd7a5..e9c6b2bc940 100644
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -62,7 +62,7 @@ struct marker_entry {
 	int refcount;	/* Number of times armed. 0 if disarmed. */
 	struct rcu_head rcu;
 	void *oldptr;
-	unsigned char rcu_pending:1;
+	int rcu_pending;
 	unsigned char ptype:1;
 	char name[0];	/* Contains name'\0'format'\0' */
 };
@@ -103,11 +103,11 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
 	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;
@@ -145,7 +145,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
 			va_end(args);
 		}
 	}
-	preempt_enable();
+	rcu_read_unlock_sched();
 }
 EXPORT_SYMBOL_GPL(marker_probe_cb);
 
@@ -162,7 +162,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
 	va_list args;	/* not initialized */
 	char ptype;
 
-	preempt_disable();
+	rcu_read_lock_sched();
 	ptype = mdata->ptype;
 	if (likely(!ptype)) {
 		marker_probe_func *func;
@@ -195,7 +195,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
 			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);
 
@@ -560,7 +560,7 @@ static int set_marker(struct marker_entry **entry, struct marker *elem,
  * 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)
 {
@@ -653,11 +653,17 @@ int marker_probe_register(const char *name, const char *format,
 	entry = get_marker(name);
 	if (!entry) {
 		entry = add_marker(name, format);
-		if (IS_ERR(entry)) {
+		if (IS_ERR(entry))
 			ret = PTR_ERR(entry);
-			goto end;
-		}
+	} else if (format) {
+		if (!entry->format)
+			ret = marker_set_format(&entry, format);
+		else if (strcmp(entry->format, format))
+			ret = -EPERM;
 	}
+	if (ret)
+		goto end;
+
 	/*
 	 * If we detect that a call_rcu is pending for this marker,
 	 * make sure it's executed now.
@@ -674,6 +680,8 @@ int marker_probe_register(const char *name, const char *format,
 	mutex_lock(&markers_mutex);
 	entry = get_marker(name);
 	WARN_ON(!entry);
+	if (entry->rcu_pending)
+		rcu_barrier_sched();
 	entry->oldptr = old;
 	entry->rcu_pending = 1;
 	/* write rcu_pending before calling the RCU callback */
@@ -717,6 +725,8 @@ int marker_probe_unregister(const char *name,
 	entry = get_marker(name);
 	if (!entry)
 		goto end;
+	if (entry->rcu_pending)
+		rcu_barrier_sched();
 	entry->oldptr = old;
 	entry->rcu_pending = 1;
 	/* write rcu_pending before calling the RCU callback */
@@ -795,6 +805,8 @@ int marker_probe_unregister_private_data(marker_probe_func *probe,
 	mutex_lock(&markers_mutex);
 	entry = get_marker_from_private_data(probe, probe_private);
 	WARN_ON(!entry);
+	if (entry->rcu_pending)
+		rcu_barrier_sched();
 	entry->oldptr = old;
 	entry->rcu_pending = 1;
 	/* write rcu_pending before calling the RCU callback */