upstream: tweak proctitle to include sshd arguments, as these are

frequently used to distinguish between multiple independent instances of the
server. New proctitle looks like this:

$ pgrep -lf sshd
12844 sshd: /usr/sbin/sshd -f /etc/ssh/sshd_config [listener] 0 of 10-100 startups

requested by sthen@ and aja@; ok aja@

OpenBSD-Commit-ID: cf235a561c655a3524a82003cf7244ecb48ccc1e

sshd.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.544 2020/01/23 07:10:22 dtucker Exp $ */
+/* $OpenBSD: sshd.c,v 1.545 2020/01/24 23:56:01 djm Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -262,6 +262,8 @@ void destroy_sensitive_data(void);
 void demote_sensitive_data(void);
 static void do_ssh2_kex(struct ssh *);
 
+static char *listener_proctitle;
+
 /*
  * Close all listening sockets
  */
@@ -1087,9 +1089,9 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
 	 */
 	for (;;) {
 		if (ostartups != startups) {
-			setproctitle("[listener] %d of %d-%d startups",
-			    startups, options.max_startups_begin,
-			    options.max_startups);
+			setproctitle("%s [listener] %d of %d-%d startups",
+			    listener_proctitle, startups,
+			    options.max_startups_begin, options.max_startups);
 			ostartups = startups;
 		}
 		if (received_sighup) {
@@ -1435,6 +1437,17 @@ accumulate_host_timing_secret(struct sshbuf *server_cfg,
 	sshbuf_free(buf);
 }
 
+static char *
+prepare_proctitle(int ac, char **av)
+{
+	char *ret = NULL;
+	int i;
+
+	for (i = 0; i < ac; i++)
+		xextendf(&ret, " ", "%s", av[i]);
+	return ret;
+}
+
 /*
  * Main program for the daemon.
  */
@@ -1911,6 +1924,7 @@ main(int ac, char **av)
 		rexec_argv[rexec_argc] = "-R";
 		rexec_argv[rexec_argc + 1] = NULL;
 	}
+	listener_proctitle = prepare_proctitle(ac, av);
 
 	/* Ensure that umask disallows at least group and world write */
 	new_umask = umask(0077) | 0022;