From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Wed, 30 Sep 2015 20:48:12 +0000 (-0400)
Subject: Fix: Remove dependency on glibc 2.12 caused by pthread_setname_np
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=b8090274814e5f6a22cff0dd656e14769cc7a7df

Fix: Remove dependency on glibc 2.12 caused by pthread_setname_np

prctl() can be used to set the same attribute set by
pthread_setname_np, but doesn't introduce a dependency on a newer
glibc. Using prctl(PR_SET_NAME) introduces a soft dependency on
Linux 2.6.9. However, the worker won't fail to launch if the call
fails as it is set out of convenience (debugger output).

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/common/runas.c b/src/common/runas.c
index 3826c6175..bc7356b6a 100644
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -31,6 +31,7 @@
 #include <sched.h>
 #include <sys/signal.h>
 #include <assert.h>
+#include <sys/prctl.h>
 
 #include <common/common.h>
 #include <common/utils.h>
@@ -322,12 +323,11 @@ int run_as_worker(struct run_as_worker *worker)
 	memset(worker->procname, 0, proc_orig_len);
 	strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len);
 
-	ret = pthread_setname_np(pthread_self(), DEFAULT_RUN_AS_WORKER_NAME);
+	ret = prctl(PR_SET_NAME, DEFAULT_RUN_AS_WORKER_NAME, 0, 0, 0);
 	if (ret) {
-		errno = ret;
-		ret = -1;
-		PERROR("pthread_setname_np");
-		return EXIT_FAILURE;
+		/* Don't fail as this is not essential. */
+		PERROR("prctl PR_SET_NAME");
+		ret = 0;
 	}
 
 	sendret.ret = 0;