X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=lttng-events.c;h=2820a0e4d1f9045017dd772d08b7f9325be85cc9;hb=165eee701dce7f180d958125c1794459280fe64d;hp=0512a3f3ddfda66a72cf468f8f8c4730e2e4d4a1;hpb=309370e252e189867745fb31fe5c15c9ff494f34;p=lttng-modules.git

diff --git a/lttng-events.c b/lttng-events.c
index 0512a3f3..2820a0e4 100644
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -20,6 +20,12 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+/*
+ * This page_alloc.h wrapper needs to be included before gfpflags.h because it
+ * overrides a function with a define.
+ */
+#include "wrapper/page_alloc.h"
+
 #include <linux/module.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
@@ -98,6 +104,8 @@ struct lttng_session *lttng_session_create(void)
 	kref_init(&metadata_cache->refcount);
 	session->metadata_cache = metadata_cache;
 	INIT_LIST_HEAD(&metadata_cache->metadata_stream);
+	memcpy(&metadata_cache->uuid, &session->uuid,
+		sizeof(metadata_cache->uuid));
 	list_add(&session->list, &sessions);
 	mutex_unlock(&sessions_mutex);
 	return session;
@@ -377,8 +385,14 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 	 */
 	list_for_each_entry(event, &chan->session->events, list) {
 		if (!strcmp(event->desc->name, event_param->name)) {
-			ret = -EEXIST;
-			goto exist;
+			/*
+			 * Allow events with the same name to appear in
+			 * different channels.
+			 */
+			if (event->chan == chan) {
+				ret = -EEXIST;
+				goto exist;
+			}
 		}
 	}
 	event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
@@ -400,7 +414,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 			ret = -ENOENT;
 			goto register_error;
 		}
-		ret = kabi_2635_tracepoint_probe_register(event->desc->kname,
+		ret = lttng_wrapper_tracepoint_probe_register(event->desc->kname,
 				event->desc->probe_callback,
 				event);
 		if (ret) {
@@ -519,7 +533,7 @@ int _lttng_event_unregister(struct lttng_event *event)
 
 	switch (event->instrumentation) {
 	case LTTNG_KERNEL_TRACEPOINT:
-		ret = kabi_2635_tracepoint_probe_unregister(event->desc->kname,
+		ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
 						  event->desc->probe_callback,
 						  event);
 		if (ret)
@@ -597,16 +611,20 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 
 	/*
 	 * Ensure we support mutiple get_next / put sequences followed
-	 * by put_next.
+	 * by put_next. The metadata stream lock internally protects
+	 * reading the metadata cache. It can indeed be read
+	 * concurrently by "get_next_subbuf" and "flush" operations on
+	 * the buffer invoked by different processes.
 	 */
+	mutex_lock(&stream->lock);
 	WARN_ON(stream->metadata_in < stream->metadata_out);
 	if (stream->metadata_in != stream->metadata_out)
-		return 0;
+		goto end;
 
 	len = stream->metadata_cache->metadata_written -
 		stream->metadata_in;
 	if (!len)
-		return 0;
+		goto end;
 	reserve_len = min_t(size_t,
 			stream->transport->ops.packet_avail_size(chan),
 			len);
@@ -628,6 +646,7 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 	ret = reserve_len;
 
 end:
+	mutex_unlock(&stream->lock);
 	return ret;
 }
 
@@ -1255,15 +1274,34 @@ static int __init lttng_events_init(void)
 {
 	int ret;
 
+	ret = wrapper_lttng_fixup_sig(THIS_MODULE);
+	if (ret)
+		return ret;
+	ret = wrapper_get_pfnblock_flags_mask_init();
+	if (ret)
+		return ret;
+	ret = lttng_tracepoint_init();
+	if (ret)
+		return ret;
 	event_cache = KMEM_CACHE(lttng_event, 0);
-	if (!event_cache)
-		return -ENOMEM;
+	if (!event_cache) {
+		ret = -ENOMEM;
+		goto error_kmem;
+	}
 	ret = lttng_abi_init();
 	if (ret)
 		goto error_abi;
+	ret = lttng_logger_init();
+	if (ret)
+		goto error_logger;
 	return 0;
+
+error_logger:
+	lttng_abi_exit();
 error_abi:
 	kmem_cache_destroy(event_cache);
+error_kmem:
+	lttng_tracepoint_exit();
 	return ret;
 }
 
@@ -1273,10 +1311,12 @@ static void __exit lttng_events_exit(void)
 {
 	struct lttng_session *session, *tmpsession;
 
+	lttng_logger_exit();
 	lttng_abi_exit();
 	list_for_each_entry_safe(session, tmpsession, &sessions, list)
 		lttng_session_destroy(session);
 	kmem_cache_destroy(event_cache);
+	lttng_tracepoint_exit();
 }
 
 module_exit(lttng_events_exit);