From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 9 Apr 2012 15:02:42 +0000 (-0400)
Subject: Fix: ustctl need to send the second fd upon error of 1st fd
X-Git-Tag: v2.1.0-rc1~94
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=50be2fc41b02ee04860b5199d0ce2d346b1ea7c2;p=lttng-ust.git

Fix: ustctl need to send the second fd upon error of 1st fd

Otherwise cause protocol discrepancy between ust and sessiond upon send
error. The sessiond will wait for an fd that never arrives.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 099a6c85..0765c9b5 100644
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -320,14 +320,20 @@ end:
 	     || lum->cmd == LTTNG_UST_CHANNEL
 	     || lum->cmd == LTTNG_UST_METADATA)
 			&& lur.ret_code == USTCOMM_OK) {
+		int sendret = 0;
+
 		/* we also need to send the file descriptors. */
 		ret = ustcomm_send_fds_unix_sock(sock,
 			&shm_fd, &shm_fd,
 			1, sizeof(int));
 		if (ret < 0) {
 			perror("send shm_fd");
-			goto error;
+			sendret = ret;
 		}
+		/*
+		 * The sessiond expects 2 file descriptors, even upon
+		 * error.
+		 */
 		ret = ustcomm_send_fds_unix_sock(sock,
 			&wait_fd, &wait_fd,
 			1, sizeof(int));
@@ -335,6 +341,10 @@ end:
 			perror("send wait_fd");
 			goto error;
 		}
+		if (sendret) {
+			ret = sendret;
+			goto error;
+		}
 	}
 	/*
 	 * We still have the memory map reference, and the fds have been