X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=ltt-sessiond%2Fmain.c;h=720d23439c99b855546617f503ad2fc609373b46;hp=56266db3ce429bb6074bf34af85391ce6e7b865e;hb=ce3d728cd9bfcc0f7d43e08275a92cf04e898662;hpb=d4a2a84a5533017c9d0aa9fe66e7677a6b36b521

diff --git a/ltt-sessiond/main.c b/ltt-sessiond/main.c
index 56266db3c..720d23439 100644
--- a/ltt-sessiond/main.c
+++ b/ltt-sessiond/main.c
@@ -322,6 +322,42 @@ error:
 	return ret;
 }
 
+/*
+ *  ust_start_trace
+ *
+ *  Start a trace. This trace, identified by the pid, must be
+ *  in the current session ust_traces list.
+ */
+static int ust_start_trace(pid_t pid)
+{
+	int sock, ret;
+	struct ltt_ust_trace *trace;
+
+	DBG("Starting trace for pid %d", pid);
+
+	trace = find_session_ust_trace_by_pid(current_session, pid);
+	if (trace == NULL) {
+		ret = LTTCOMM_NO_TRACE;
+		goto error;
+	}
+
+	/* Connect to app using ustctl API */
+	sock = connect_app(pid);
+	if (sock < 0) {
+		ret = LTTCOMM_NO_TRACEABLE;
+		goto error;
+	}
+
+	ret = ustctl_start_trace(sock, "auto");
+	if (ret < 0) {
+		ret = LTTCOMM_START_FAIL;
+		goto error;
+	}
+
+error:
+	return ret;
+}
+
 /*
  *  copy_common_data
  *
@@ -453,7 +489,10 @@ static int process_client_msg(int sock, struct lttcomm_session_msg *lsm)
 		{
 			ret = ust_create_trace(lsm->pid);
 			if (ret < 0) {
-				ret = LTTCOMM_CREATE_FAIL;
+				/* If -1 is returned from ust_create_trace, malloc
+				 * failed so it's pretty much a fatal error.
+				 */
+				ret = LTTCOMM_FATAL;
 				goto end;
 			}
 
@@ -481,6 +520,13 @@ static int process_client_msg(int sock, struct lttcomm_session_msg *lsm)
 
 			break;
 		}
+		case UST_START_TRACE:
+		{
+			ret = ust_start_trace(lsm->pid);
+
+			/* No auxiliary data so only send the llm struct. */
+			goto end;
+		}
 		case LTTNG_LIST_SESSIONS:
 		{
 			unsigned int session_count = get_session_count();