X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust-ctl%2Fustctl.c;h=fc7f57ca265173439fd4277e9ccbdf2107240ee2;hb=75c5ad79cbdc0b7d0579ccd1c97902ded5bdc08a;hp=5405418ccab632e204d1a2603413fa2a4a903a89;hpb=2be0e72cf5e765e859c639daf37886ebd9640818;p=lttng-ust.git

diff --git a/liblttng-ust-ctl/ustctl.c b/liblttng-ust-ctl/ustctl.c
index 5405418c..fc7f57ca 100644
--- a/liblttng-ust-ctl/ustctl.c
+++ b/liblttng-ust-ctl/ustctl.c
@@ -63,8 +63,6 @@ int ustctl_release_handle(int sock, int handle)
  */
 int ustctl_release_object(int sock, struct lttng_ust_object_data *data)
 {
-	struct ustcomm_ust_msg lum;
-	struct ustcomm_ust_reply lur;
 	int ret;
 
 	if (data->shm_fd >= 0) {
@@ -137,7 +135,7 @@ int ustctl_open_metadata(int sock, int session_handle,
 	struct ustcomm_ust_msg lum;
 	struct ustcomm_ust_reply lur;
 	struct lttng_ust_object_data *metadata_data;
-	int ret;
+	int ret, err = 0;
 
 	metadata_data = malloc(sizeof(*metadata_data));
 	if (!metadata_data)
@@ -168,13 +166,21 @@ int ustctl_open_metadata(int sock, int session_handle,
 	/* get shm fd */
 	ret = ustcomm_recv_fd(sock);
 	if (ret < 0)
-		goto error;
-	metadata_data->shm_fd = ret;
+		err = 1;
+	else
+		metadata_data->shm_fd = ret;
+	/*
+	 * We need to get the second FD even if the first fails, because
+	 * libust expects us to read the two FDs.
+	 */
 	/* get wait fd */
 	ret = ustcomm_recv_fd(sock);
 	if (ret < 0)
+		err = 1;
+	else
+		metadata_data->wait_fd = ret;
+	if (err)
 		goto error;
-	metadata_data->wait_fd = ret;
 	*_metadata_data = metadata_data;
 	return 0;
 
@@ -191,7 +197,7 @@ int ustctl_create_channel(int sock, int session_handle,
 	struct ustcomm_ust_msg lum;
 	struct ustcomm_ust_reply lur;
 	struct lttng_ust_object_data *channel_data;
-	int ret;
+	int ret, err = 0;
 
 	channel_data = malloc(sizeof(*channel_data));
 	if (!channel_data)
@@ -222,13 +228,21 @@ int ustctl_create_channel(int sock, int session_handle,
 	/* get shm fd */
 	ret = ustcomm_recv_fd(sock);
 	if (ret < 0)
-		goto error;
-	channel_data->shm_fd = ret;
+		err = 1;
+	else
+		channel_data->shm_fd = ret;
+	/*
+	 * We need to get the second FD even if the first fails, because
+	 * libust expects us to read the two FDs.
+	 */
 	/* get wait fd */
 	ret = ustcomm_recv_fd(sock);
 	if (ret < 0)
+		err = 1;
+	else
+		channel_data->wait_fd = ret;
+	if (err)
 		goto error;
-	channel_data->wait_fd = ret;
 	*_channel_data = channel_data;
 	return 0;
 
@@ -249,7 +263,7 @@ int ustctl_create_stream(int sock, struct lttng_ust_object_data *channel_data,
 	struct ustcomm_ust_msg lum;
 	struct ustcomm_ust_reply lur;
 	struct lttng_ust_object_data *stream_data;
-	int ret, fd;
+	int ret, fd, err = 0;
 
 	stream_data = malloc(sizeof(*stream_data));
 	if (!stream_data)
@@ -274,13 +288,21 @@ int ustctl_create_stream(int sock, struct lttng_ust_object_data *channel_data,
 	/* get shm fd */
 	fd = ustcomm_recv_fd(sock);
 	if (fd < 0)
-		goto error;
-	stream_data->shm_fd = fd;
+		err = 1;
+	else
+		stream_data->shm_fd = fd;
+	/*
+	 * We need to get the second FD even if the first fails, because
+	 * libust expects us to read the two FDs.
+	 */
 	/* get wait fd */
 	fd = ustcomm_recv_fd(sock);
 	if (fd < 0)
+		err = 1;
+	else
+		stream_data->wait_fd = fd;
+	if (err)
 		goto error;
-	stream_data->wait_fd = fd;
 	*_stream_data = stream_data;
 	return ret;
 
@@ -509,12 +531,24 @@ struct lttng_ust_shm_handle *ustctl_map_channel(struct lttng_ust_object_data *ch
 		return NULL;
 	}
 	/*
-	 * Set to -1 because the lttng_ust_shm_handle destruction will take care
-	 * of closing shm_fd and wait_fd.
+	 * Set to -1, and then close the shm fd, and set the handle shm
+	 * fd to -1 too. We don't need the shm fds after they have been
+	 * mapped.
+	 * The wait_fd is set to -1 in chan_data because it is now owned
+	 * by the handle.
 	 */
 	chan_data->shm_fd = -1;
 	chan_data->wait_fd = -1;
 
+	/* chan is object 0. This is hardcoded. */
+	if (handle->table->objects[0].shm_fd >= 0) {
+		ret = close(handle->table->objects[0].shm_fd);
+		if (ret) {
+			perror("Error closing shm_fd");
+		}
+		handle->table->objects[0].shm_fd = -1;
+	}
+
 	/*
 	 * TODO: add consistency checks to be resilient if the
 	 * application try to feed us with incoherent channel structure
@@ -598,12 +632,15 @@ void ustctl_unmap_channel(struct lttng_ust_shm_handle *handle)
 	channel_destroy(chan, handle, 1);
 }
 
+/*
+ * ustctl closes the shm_fd fds after mapping it.
+ */
 struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_handle *handle,
 	int cpu)
 {
 	struct channel *chan = handle->shadow_chan;
-	int shm_fd, wait_fd;
-	uint64_t memory_map_size;
+	int *shm_fd, *wait_fd;
+	uint64_t *memory_map_size;
 	struct lttng_ust_lib_ring_buffer *buf;
 	int ret;
 
@@ -614,6 +651,16 @@ struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_h
 	ret = lib_ring_buffer_open_read(buf, handle, 1);
 	if (ret)
 		return NULL;
+	/*
+	 * We can close shm_fd early, right after is has been mapped.
+	 */
+	if (*shm_fd >= 0) {
+		ret = close(*shm_fd);
+		if (ret) {
+			perror("Error closing shm_fd");
+		}
+		*shm_fd = -1;
+	}
 	return buf;
 }