Version 2.4.4

[lttng-modules.git] / lttng-events.c

diff --git a/lttng-events.c b/lttng-events.c
index 97d82a297b911d9ad945cc6b88e484d87d2d8fb3..39e04e51dd0918559b03f35f1f4a215726abb95c 100644 (file)
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -98,6 +98,8 @@ 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;
@@ -368,7 +370,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 
        mutex_lock(&sessions_mutex);
        if (chan->free_event_id == -1U) {
-               event = ERR_PTR(-EMFILE);
+               ret = -EMFILE;
                goto full;
        }
        /*
@@ -377,13 +379,13 @@ 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)) {
-                       event = ERR_PTR(-EEXIST);
+                       ret = -EEXIST;
                        goto exist;
                }
        }
        event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
        if (!event) {
-               event = ERR_PTR(-ENOMEM);
+               ret = -ENOMEM;
                goto cache_error;
        }
        event->chan = chan;
@@ -397,14 +399,14 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
        case LTTNG_KERNEL_TRACEPOINT:
                event->desc = lttng_event_get(event_param->name);
                if (!event->desc) {
-                       event = ERR_PTR(-ENOENT);
+                       ret = -ENOENT;
                        goto register_error;
                }
-               ret = kabi_2635_tracepoint_probe_register(event_param->name,
+               ret = kabi_2635_tracepoint_probe_register(event->desc->kname,
                                event->desc->probe_callback,
                                event);
                if (ret) {
-                       event = ERR_PTR(-EINVAL);
+                       ret = -EINVAL;
                        goto register_error;
                }
                break;
@@ -415,7 +417,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
                                event_param->u.kprobe.addr,
                                event);
                if (ret) {
-                       event = ERR_PTR(-EINVAL);
+                       ret = -EINVAL;
                        goto register_error;
                }
                ret = try_module_get(event->desc->owner);
@@ -429,7 +431,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
                event_return =
                        kmem_cache_zalloc(event_cache, GFP_KERNEL);
                if (!event_return) {
-                       event = ERR_PTR(-ENOMEM);
+                       ret = -ENOMEM;
                        goto register_error;
                }
                event_return->chan = chan;
@@ -448,7 +450,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
                                event, event_return);
                if (ret) {
                        kmem_cache_free(event_cache, event_return);
-                       event = ERR_PTR(-EINVAL);
+                       ret = -EINVAL;
                        goto register_error;
                }
                /* Take 2 refs on the module: one per event. */
@@ -463,7 +465,6 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
                        kmem_cache_free(event_cache, event_return);
                        module_put(event->desc->owner);
                        module_put(event->desc->owner);
-                       event = ERR_PTR(ret);
                        goto statedump_error;
                }
                list_add(&event_return->list, &chan->session->events);
@@ -474,7 +475,6 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
                                event_param->u.ftrace.symbol_name,
                                event);
                if (ret) {
-                       event = ERR_PTR(ret);
                        goto register_error;
                }
                ret = try_module_get(event->desc->owner);
@@ -483,19 +483,18 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
        case LTTNG_KERNEL_NOOP:
                event->desc = internal_desc;
                if (!event->desc) {
-                       event = ERR_PTR(-EINVAL);
+                       ret = -EINVAL;
                        goto register_error;
                }
                break;
        default:
                WARN_ON_ONCE(1);
-               event = ERR_PTR(-EINVAL);
+               ret = -EINVAL;
                goto register_error;
        }
        ret = _lttng_event_metadata_statedump(chan->session, chan, event);
        WARN_ON_ONCE(ret > 0);
        if (ret) {
-               event = ERR_PTR(ret);
                goto statedump_error;
        }
        list_add(&event->list, &chan->session->events);
@@ -510,7 +509,7 @@ cache_error:
 exist:
 full:
        mutex_unlock(&sessions_mutex);
-       return event;
+       return ERR_PTR(ret);
 }
 
 /*
@@ -522,7 +521,7 @@ int _lttng_event_unregister(struct lttng_event *event)
 
        switch (event->instrumentation) {
        case LTTNG_KERNEL_TRACEPOINT:
-               ret = kabi_2635_tracepoint_probe_unregister(event->desc->name,
+               ret = kabi_2635_tracepoint_probe_unregister(event->desc->kname,
                                                  event->desc->probe_callback,
                                                  event);
                if (ret)
@@ -600,16 +599,20 @@ 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);
@@ -631,6 +634,7 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
        ret = reserve_len;
 
 end:
+       mutex_unlock(&stream->lock);
        return ret;
 }
 
@@ -1289,4 +1293,5 @@ MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
 MODULE_DESCRIPTION("LTTng Events");
 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
        __stringify(LTTNG_MODULES_MINOR_VERSION) "."
-       __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION));
+       __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
+       LTTNG_MODULES_EXTRAVERSION);