launcher-util: Force all weston_launcher_open()s to use O_CLOEXEC

Really, there's pretty much no time we'd ever want O_CLOEXEC unset,
as it will likely result in leaking fds to processes that aren't
interested in them or shouldn't have them.

This also removes the (now unused) code from weston_logind_open() that
could drop O_CLOEXEC.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

src/launcher-util.c

@@ -114,11 +114,17 @@ weston_launcher_open(struct weston_launcher *launcher,
 	struct weston_launcher_open *message;
 	struct stat s;
 
+	/* We really don't want to be leaking fds to child processes so
+	 * we force this flag here.  If someone comes up with a legitimate
+	 * reason to not CLOEXEC they'll need to unset the flag manually.
+	 */
+	flags |= O_CLOEXEC;
+
 	if (launcher->logind)
 		return weston_logind_open(launcher->logind, path, flags);
 
 	if (launcher->fd == -1) {
-		fd = open(path, flags | O_CLOEXEC);
+		fd = open(path, flags);
 		if (fd == -1)
 			return -1;
 

src/logind-util.c

@@ -186,8 +186,8 @@ weston_logind_open(struct weston_logind *wl, const char *path,
 	 * directly. Instead, logind passes us an fd with sane default modes.
 	 * For DRM and evdev this means O_RDWR | O_CLOEXEC. If we want
 	 * something else, we need to change it afterwards. We currently
-	 * only support dropping FD_CLOEXEC and setting O_NONBLOCK. Changing
-	 * access-modes is not possible so accept whatever logind passes us. */
+	 * only support setting O_NONBLOCK. Changing access-modes is not
+	 * possible so accept whatever logind passes us. */
 
 	fl = fcntl(fd, F_GETFL);
 	if (fl < 0) {
@@ -203,22 +203,6 @@ weston_logind_open(struct weston_logind *wl, const char *path,
 		r = -errno;
 		goto err_close;
 	}
-
-	fl = fcntl(fd, F_GETFD);
-	if (fl < 0) {
-		r = -errno;
-		goto err_close;
-	}
-
-	if (!(flags & O_CLOEXEC))
-		fl &= ~FD_CLOEXEC;
-
-	r = fcntl(fd, F_SETFD, fl);
-	if (r < 0) {
-		r = -errno;
-		goto err_close;
-	}
-
 	return fd;
 
 err_close: