X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=8892e76dc144f7963be7813647df05e5f9006da1;hb=cafc2c60ea4893d837fe0e9cb0bbe92c02b8cc46;hp=e478499336896f5d739e087c8ee91e3a395886cd;hpb=1cfb4b98d79d3dd709037ee6827f238a5616832a;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index e47849933..8892e76dc 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -36,6 +36,8 @@
 
 /*
  * Add context on a kernel channel.
+ *
+ * Assumes the ownership of ctx.
  */
 int kernel_add_channel_context(struct ltt_kernel_channel *chan,
 		struct ltt_kernel_context *ctx)
@@ -63,12 +65,16 @@ int kernel_add_channel_context(struct ltt_kernel_channel *chan,
 			goto error;
 		}
 	}
+	ret = 0;
 
 end:
 	cds_list_add_tail(&ctx->list, &chan->ctx_list);
-	return 0;
-
+	ctx->in_list = true;
+	ctx = NULL;
 error:
+	if (ctx) {
+		trace_kernel_destroy_context(ctx);
+	}
 	return ret;
 }
 
@@ -1023,12 +1029,10 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 
 		/* For each channel, ask the consumer to snapshot it. */
 		cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
-			pthread_mutex_lock(socket->lock);
 			ret = consumer_snapshot_channel(socket, chan->fd, output, 0,
 					ksess->uid, ksess->gid,
 					DEFAULT_KERNEL_TRACE_DIR, wait,
 					nb_packets_per_stream);
-			pthread_mutex_unlock(socket->lock);
 			if (ret < 0) {
 				ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 				(void) kernel_consumer_destroy_metadata(socket,
@@ -1038,11 +1042,9 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 		}
 
 		/* Snapshot metadata, */
-		pthread_mutex_lock(socket->lock);
 		ret = consumer_snapshot_channel(socket, ksess->metadata->fd, output,
 				1, ksess->uid, ksess->gid,
 				DEFAULT_KERNEL_TRACE_DIR, wait, 0);
-		pthread_mutex_unlock(socket->lock);
 		if (ret < 0) {
 			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 			goto error_consumer;
@@ -1088,3 +1090,35 @@ int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits)
 
 	return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits);
 }
+
+/*
+ * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS via abi
+ * version number.
+ *
+ * Return 1 on success, 0 when feature is not supported, negative value in case
+ * of errors.
+ */
+int kernel_supports_ring_buffer_snapshot_sample_positions(int tracer_fd)
+{
+	int ret = 0; // Not supported by default
+	struct lttng_kernel_tracer_abi_version abi;
+
+	ret = kernctl_tracer_abi_version(tracer_fd, &abi);
+	if (ret < 0) {
+		ERR("Failed to retrieve lttng-modules ABI version");
+		goto error;
+	}
+
+	/*
+	 * RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS was introduced in 2.3
+	 */
+	if (abi.major >= 2 && abi.minor >= 3) {
+		/* Supported */
+		ret = 1;
+	} else {
+		/* Not supported */
+		ret = 0;
+	}
+error:
+	return ret;
+}