From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Date: Thu, 23 Dec 2010 16:43:52 +0000 (-0500)
Subject: Interface ABI with probe list
X-Git-Tag: v2.0-pre1~182
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=dda6a249b86e7f06e82fb18a26e981522d9e852d;p=lttng-modules.git

Interface ABI with probe list

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/ltt-debugfs-abi.c b/ltt-debugfs-abi.c
index 9043759f..0ac88611 100644
--- a/ltt-debugfs-abi.c
+++ b/ltt-debugfs-abi.c
@@ -241,8 +241,11 @@ int lttng_abi_open_stream(struct file *channel_file)
 		goto file_error;
 	}
 	fd_install(stream_fd, stream_file);
-	/* The stream holds a reference on the channel */
-	atomic_long_inc(&channel_file->f_count);
+	/*
+	 * The stream holds a reference to the channel within the generic ring
+	 * buffer library, so no need to hold a refcount on the channel and
+	 * session files here.
+	 */
 	return stream_fd;
 
 file_error:
@@ -262,6 +265,7 @@ int lttng_abi_create_event(struct file *channel_file,
 	struct lttng_event event_param;
 	int event_fd, ret;
 	struct file *event_file;
+	void *probe;
 
 	if (copy_from_user(&event_param, uevent_param, sizeof(event_param)))
 		return -EFAULT;
@@ -273,6 +277,12 @@ int lttng_abi_create_event(struct file *channel_file,
 		goto name_error;
 	}
 	event_name[PATH_MAX - 1] = '\0';
+
+	probe = ltt_probe_get(event_name);
+	if (!probe) {
+		ret = -ENOENT;
+		goto probe_error;
+	}
 	event_fd = get_unused_fd();
 	if (event_fd < 0) {
 		ret = event_fd;
@@ -290,7 +300,7 @@ int lttng_abi_create_event(struct file *channel_file,
 	 * invariant for the rest of the session.
 	 */
 	event = ltt_event_create(channel, event_name, event_param.itype,
-				 (void *) 0x1, NULL);	/* TODO connect real probe */
+				 probe, NULL);
 	if (!event) {
 		goto event_error;
 		ret = -EEXIST;
@@ -307,6 +317,8 @@ event_error:
 file_error:
 	put_unused_fd(event_fd);
 fd_error:
+	ltt_probe_put(probe);
+probe_error:
 name_error:
 	kfree(event_name);
 	return ret;
diff --git a/ltt-events.c b/ltt-events.c
index 0e34f6f8..c2a6a920 100644
--- a/ltt-events.c
+++ b/ltt-events.c
@@ -46,9 +46,14 @@ void ltt_session_destroy(struct ltt_session *session)
 {
 	struct ltt_channel *chan, *tmpchan;
 	struct ltt_event *event, *tmpevent;
+	int ret;
 
 	mutex_lock(&sessions_mutex);
 	session->active = 0;
+	list_for_each_entry(event, &session->events, list) {
+		ret = _ltt_event_unregister(event);
+		WARN_ON(ret);
+	}
 	synchronize_trace();	/* Wait for in-flight events to complete */
 	list_for_each_entry_safe(event, tmpevent, &session->events, list)
 		_ltt_event_destroy(event);
@@ -172,8 +177,8 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name,
 	if (chan->free_event_id == -1UL)
 		goto full;
 	/*
-	 * This is O(n^2) (for each event loop called at event creation).
-	 * Might require a hash if we have lots of events.
+	 * This is O(n^2) (for each event, the loop is called at event
+	 * creation). Might require a hash if we have lots of events.
 	 */
 	list_for_each_entry(event, &chan->session->events, list)
 		if (!strcmp(event->name, name))
@@ -201,6 +206,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name,
 	default:
 		WARN_ON_ONCE(1);
 	}
+	list_add(&event->list, &chan->session->events);
 	mutex_unlock(&sessions_mutex);
 	return event;
 
@@ -218,7 +224,7 @@ full:
 /*
  * Only used internally at session destruction.
  */
-int _ltt_event_destroy(struct ltt_event *event)
+int _ltt_event_unregister(struct ltt_event *event)
 {
 	int ret = -EINVAL;
 
@@ -232,9 +238,17 @@ int _ltt_event_destroy(struct ltt_event *event)
 	default:
 		WARN_ON_ONCE(1);
 	}
+	return ret;
+}
+
+/*
+ * Only used internally at session destruction.
+ */
+void _ltt_event_destroy(struct ltt_event *event)
+{
 	kfree(event->name);
+	list_del(&event->list);
 	kmem_cache_free(event_cache, event);
-	return ret;
 }
 
 /**
diff --git a/ltt-events.h b/ltt-events.h
index b888dd2b..e8171b03 100644
--- a/ltt-events.h
+++ b/ltt-events.h
@@ -88,7 +88,8 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 				   char *name,
 				   enum instrum_type itype,
 				   void *probe, void *filter);
-int _ltt_event_destroy(struct ltt_event *event);
+int _ltt_event_unregister(struct ltt_event *event);
+void _ltt_event_destroy(struct ltt_event *event);
 
 void ltt_transport_register(struct ltt_transport *transport);
 void ltt_transport_unregister(struct ltt_transport *transport);
diff --git a/ltt-probes.c b/ltt-probes.c
index 9870b9d8..f8f1ef22 100644
--- a/ltt-probes.c
+++ b/ltt-probes.c
@@ -21,13 +21,13 @@ static LIST_HEAD(probe_list);
 static DEFINE_MUTEX(probe_mutex);
 static struct kmem_cache *probe_cache;
 
-static void *find_probe(const char *name)
+static struct ltt_probe *find_probe(const char *name)
 {
 	struct ltt_probe *probe;
 
 	list_for_each_entry(probe, &probe_list, list) {
 		if (!strcmp(probe->name, name))
-			return probe->cb;
+			return probe;
 	}
 	return NULL;
 }