diff -up nfs-utils-2.3.3/nfs.conf.orig nfs-utils-2.3.3/nfs.conf
--- nfs-utils-2.3.3/nfs.conf.orig	2021-07-19 09:45:40.441448059 -0400
+++ nfs-utils-2.3.3/nfs.conf	2021-07-19 12:08:55.314182838 -0400
@@ -22,6 +22,8 @@ use-gss-proxy=1
 # cred-cache-directory=
 # preferred-realm=
 # set-home=1
+# upcall-timeout=30
+# cancel-timed-out-upcalls=0
 #
 [lockd]
 # port=0
diff -up nfs-utils-2.3.3/utils/gssd/gssd.c.orig nfs-utils-2.3.3/utils/gssd/gssd.c
--- nfs-utils-2.3.3/utils/gssd/gssd.c.orig	2021-07-19 09:45:40.448448246 -0400
+++ nfs-utils-2.3.3/utils/gssd/gssd.c	2021-07-19 12:08:55.315182865 -0400
@@ -96,8 +96,29 @@ pthread_mutex_t clp_lock = PTHREAD_MUTEX
 static bool signal_received = false;
 static struct event_base *evbase = NULL;
 
+int upcall_timeout = DEF_UPCALL_TIMEOUT;
+static bool cancel_timed_out_upcalls = false;
+
 TAILQ_HEAD(topdir_list_head, topdir) topdir_list;
 
+/*
+ * active_thread_list:
+ *
+ * 	used to track upcalls for timeout purposes.
+ *
+ * 	protected by the active_thread_list_lock mutex.
+ *
+ * 	upcall_thread_info structures are added to the tail of the list
+ * 	by start_upcall_thread(), so entries closer to the head of the list
+ * 	will be closer to hitting the upcall timeout.
+ *
+ * 	upcall_thread_info structures are removed from the list upon a
+ * 	sucessful join of the upcall thread by the watchdog thread (via
+ * 	scan_active_thread_list().
+ */
+TAILQ_HEAD(active_thread_list_head, upcall_thread_info) active_thread_list;
+pthread_mutex_t active_thread_list_lock = PTHREAD_MUTEX_INITIALIZER;
+
 struct topdir {
 	TAILQ_ENTRY(topdir) list;
 	TAILQ_HEAD(clnt_list_head, clnt_info) clnt_list;
@@ -436,6 +457,138 @@ gssd_clnt_krb5_cb(int UNUSED(fd), short
 	handle_krb5_upcall(clp);
 }
 
+/*
+ * scan_active_thread_list:
+ *
+ * Walks the active_thread_list, trying to join as many upcall threads as
+ * possible.  For threads that have terminated, the corresponding
+ * upcall_thread_info will be removed from the list and freed.  Threads that
+ * are still busy and have exceeded the upcall_timeout will cause an error to
+ * be logged and may be canceled (depending on the value of
+ * cancel_timed_out_upcalls).
+ *
+ * Returns the number of seconds that the watchdog thread should wait before
+ * calling scan_active_thread_list() again.
+ */
+static int
+scan_active_thread_list(void)
+{
+	struct upcall_thread_info *info;
+	struct timespec now;
+	unsigned int sleeptime;
+	bool sleeptime_set = false;
+	int err;
+	void *tret, *saveprev;
+
+	sleeptime = upcall_timeout;
+	pthread_mutex_lock(&active_thread_list_lock);
+	clock_gettime(CLOCK_MONOTONIC, &now);
+	TAILQ_FOREACH(info, &active_thread_list, list) {
+		err = pthread_tryjoin_np(info->tid, &tret);
+		switch (err) {
+		case 0:
+			/*
+			 * The upcall thread has either completed successfully, or
+			 * has been canceled _and_ has acted on the cancellation request
+			 * (i.e. has hit a cancellation point).  We can now remove the
+			 * upcall_thread_info from the list and free it.
+			 */
+			if (tret == PTHREAD_CANCELED)
+				printerr(3, "watchdog: thread id 0x%lx cancelled successfully\n",
+						info->tid);
+			saveprev = info->list.tqe_prev;
+			TAILQ_REMOVE(&active_thread_list, info, list);
+			free(info);
+			info = saveprev;
+			break;
+		case EBUSY:
+			/*
+			 * The upcall thread is still running.  If the timeout has expired
+			 * then we either cancel the thread, log an error, and do an error
+			 * downcall to the kernel (cancel_timed_out_upcalls=true) or simply
+			 * log an error (cancel_timed_out_upcalls=false).  In either case,
+			 * the error is logged only once.
+			 */
+			if (now.tv_sec >= info->timeout.tv_sec) {
+				if (cancel_timed_out_upcalls && !(info->flags & UPCALL_THREAD_CANCELED)) {
+					printerr(0, "watchdog: thread id 0x%lx timed out\n",
+							info->tid);
+					pthread_cancel(info->tid);
+					info->flags |= (UPCALL_THREAD_CANCELED|UPCALL_THREAD_WARNED);
+					do_error_downcall(info->fd, info->uid, -ETIMEDOUT);
+				} else {
+					if (!(info->flags & UPCALL_THREAD_WARNED)) {
+						printerr(0, "watchdog: thread id 0x%lx running for %ld seconds\n",
+								info->tid,
+								now.tv_sec - info->timeout.tv_sec + upcall_timeout);
+						info->flags |= UPCALL_THREAD_WARNED;
+					}
+				}
+			} else if (!sleeptime_set) {
+			/*
+			 * The upcall thread is still running, but the timeout has not yet
+			 * expired.  Calculate the time remaining until the timeout will
+			 * expire.  This is the amount of time the watchdog thread will
+			 * wait before running again.  We only need to do this for the busy
+			 * thread closest to the head of the list - entries appearing later
+			 * in the list will time out later.
+			 */
+				sleeptime = info->timeout.tv_sec - now.tv_sec;
+				sleeptime_set = true;
+			}
+			break;
+		default:
+			/* EDEADLK, EINVAL, and ESRCH... none of which should happen! */
+			printerr(0, "watchdog: attempt to join thread id 0x%lx returned %d (%s)!\n",
+					info->tid, err, strerror(err));
+			break;
+		}
+	}
+	pthread_mutex_unlock(&active_thread_list_lock);
+
+	return sleeptime;
+}
+
+static void *
+watchdog_thread_fn(void *UNUSED(arg))
+{
+	unsigned int sleeptime;
+
+	for (;;) {
+		sleeptime = scan_active_thread_list();
+		printerr(4, "watchdog: sleeping %u secs\n", sleeptime);
+		sleep(sleeptime);
+	}
+	return (void *)0;
+}
+
+static int
+start_watchdog_thread(void)
+{
+	pthread_attr_t attr;
+	pthread_t th;
+	int ret;
+
+	ret = pthread_attr_init(&attr);
+	if (ret != 0) {
+		printerr(0, "ERROR: failed to init pthread attr: ret %d: %s\n",
+			 ret, strerror(errno));
+		return ret;
+	}
+	ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+	if (ret != 0) {
+		printerr(0, "ERROR: failed to create pthread attr: ret %d: %s\n",
+			 ret, strerror(errno));
+		return ret;
+	}
+	ret = pthread_create(&th, &attr, watchdog_thread_fn, NULL);
+	if (ret != 0) {
+		printerr(0, "ERROR: pthread_create failed: ret %d: %s\n",
+			 ret, strerror(errno));
+	}
+	return ret;
+}
+
 static struct clnt_info *
 gssd_get_clnt(struct topdir *tdi, const char *name)
 {
@@ -810,7 +963,7 @@ sig_die(int signal)
 static void
 usage(char *progname)
 {
-	fprintf(stderr, "usage: %s [-f] [-l] [-M] [-n] [-v] [-r] [-p pipefsdir] [-k keytab] [-d ccachedir] [-t timeout] [-R preferred realm] [-D] [-H]\n",
+	fprintf(stderr, "usage: %s [-f] [-l] [-M] [-n] [-v] [-r] [-p pipefsdir] [-k keytab] [-d ccachedir] [-t timeout] [-R preferred realm] [-D] [-H] [-U upcall timeout] [-C]\n",
 		progname);
 	exit(1);
 }
@@ -831,6 +984,9 @@ read_gss_conf(void)
 #endif
 	context_timeout = conf_get_num("gssd", "context-timeout", context_timeout);
 	rpc_timeout = conf_get_num("gssd", "rpc-timeout", rpc_timeout);
+	upcall_timeout = conf_get_num("gssd", "upcall-timeout", upcall_timeout);
+	cancel_timed_out_upcalls = conf_get_bool("gssd", "cancel-timed-out-upcalls",
+						cancel_timed_out_upcalls);
 	s = conf_get_str("gssd", "pipefs-directory");
 	if (!s)
 		s = conf_get_str("general", "pipefs-directory");
@@ -872,7 +1028,7 @@ main(int argc, char *argv[])
 	verbosity = conf_get_num("gssd", "verbosity", verbosity);
 	rpc_verbosity = conf_get_num("gssd", "rpc-verbosity", rpc_verbosity);
 
-	while ((opt = getopt(argc, argv, "HDfvrlmnMp:k:d:t:T:R:")) != -1) {
+	while ((opt = getopt(argc, argv, "HDfvrlmnMp:k:d:t:T:R:U:C")) != -1) {
 		switch (opt) {
 			case 'f':
 				fg = 1;
@@ -923,6 +1079,12 @@ main(int argc, char *argv[])
 			case 'H':
 				set_home = false;
 				break;
+			case 'U':
+				upcall_timeout = atoi(optarg);
+				break;
+			case 'C':
+				cancel_timed_out_upcalls = true;
+				break;
 			default:
 				usage(argv[0]);
 				break;
@@ -995,6 +1157,11 @@ main(int argc, char *argv[])
 	else
 		progname = argv[0];
 
+	if (upcall_timeout > MAX_UPCALL_TIMEOUT)
+		upcall_timeout = MAX_UPCALL_TIMEOUT;
+	else if (upcall_timeout < MIN_UPCALL_TIMEOUT)
+		upcall_timeout = MIN_UPCALL_TIMEOUT;
+
 	initerr(progname, verbosity, fg);
 #ifdef HAVE_LIBTIRPC_SET_DEBUG
 	/*
@@ -1045,6 +1212,14 @@ main(int argc, char *argv[])
 			       gssd_inotify_cb, NULL);
 	event_add(inotify_ev, NULL);
 
+	TAILQ_INIT(&active_thread_list);
+
+	rc = start_watchdog_thread();
+	if (rc != 0) {
+		printerr(0, "ERROR: failed to start watchdog thread: %d\n", rc);
+		exit(EXIT_FAILURE);
+	}
+
 	TAILQ_INIT(&topdir_list);
 	gssd_scan();
 	daemon_ready();
diff -up nfs-utils-2.3.3/utils/gssd/gssd.h.orig nfs-utils-2.3.3/utils/gssd/gssd.h
--- nfs-utils-2.3.3/utils/gssd/gssd.h.orig	2021-07-19 09:45:40.449448272 -0400
+++ nfs-utils-2.3.3/utils/gssd/gssd.h	2021-07-19 12:08:55.315182865 -0400
@@ -50,6 +50,12 @@
 #define GSSD_DEFAULT_KEYTAB_FILE		"/etc/krb5.keytab"
 #define GSSD_SERVICE_NAME			"nfs"
 #define RPC_CHAN_BUF_SIZE			32768
+
+/* timeouts are in seconds */
+#define MIN_UPCALL_TIMEOUT			5
+#define DEF_UPCALL_TIMEOUT			30
+#define MAX_UPCALL_TIMEOUT			600
+
 /*
  * The gss mechanisms that we can handle
  */
@@ -91,10 +97,22 @@ struct clnt_upcall_info {
 	char			*service;
 };
 
+struct upcall_thread_info {
+	TAILQ_ENTRY(upcall_thread_info) list;
+	pthread_t		tid;
+	struct timespec		timeout;
+	uid_t			uid;
+	int			fd;
+	unsigned short		flags;
+#define UPCALL_THREAD_CANCELED	0x0001
+#define UPCALL_THREAD_WARNED	0x0002
+};
+
 void handle_krb5_upcall(struct clnt_info *clp);
 void handle_gssd_upcall(struct clnt_info *clp);
 void free_upcall_info(struct clnt_upcall_info *info);
 void gssd_free_client(struct clnt_info *clp);
+int do_error_downcall(int k5_fd, uid_t uid, int err);
 
 
 #endif /* _RPC_GSSD_H_ */
diff -up nfs-utils-2.3.3/utils/gssd/gssd.man.orig nfs-utils-2.3.3/utils/gssd/gssd.man
--- nfs-utils-2.3.3/utils/gssd/gssd.man.orig	2021-07-19 09:45:40.443448112 -0400
+++ nfs-utils-2.3.3/utils/gssd/gssd.man	2021-07-19 12:08:55.315182865 -0400
@@ -8,7 +8,7 @@
 rpc.gssd \- RPCSEC_GSS daemon
 .SH SYNOPSIS
 .B rpc.gssd
-.RB [ \-DfMnlvrH ]
+.RB [ \-DfMnlvrHC ]
 .RB [ \-k
 .IR keytab ]
 .RB [ \-p
@@ -17,6 +17,10 @@ rpc.gssd \- RPCSEC_GSS daemon
 .IR ccachedir ]
 .RB [ \-t
 .IR timeout ]
+.RB [ \-T
+.IR timeout ]
+.RB [ \-U
+.IR timeout ]
 .RB [ \-R
 .IR realm ]
 .SH INTRODUCTION
@@ -290,7 +294,7 @@ seconds, which allows changing Kerberos
 The default is no explicit timeout, which means the kernel context will live
 the lifetime of the Kerberos service ticket used in its creation.
 .TP
-.B -T timeout
+.BI "-T " timeout
 Timeout, in seconds, to create an RPC connection with a server while
 establishing an authenticated gss context for a user.
 The default timeout is set to 5 seconds.
@@ -298,6 +302,18 @@ If you get messages like "WARNING: can't
 %servername% for user with uid %uid%: RPC: Remote system error -
 Connection timed out", you should consider an increase of this timeout.
 .TP
+.BI "-U " timeout
+Timeout, in seconds, for upcall threads.  Threads executing longer than
+.I timeout
+seconds will cause an error message to be logged.  The default
+.I timeout
+is 30 seconds.  The minimum is 5 seconds.  The maximum is 600 seconds.
+.TP
+.B -C
+In addition to logging an error message for threads that have timed out,
+the thread will be canceled and an error of -ETIMEDOUT will be reported
+to the kernel.
+.TP
 .B -H
 Avoids setting $HOME to "/". This allows rpc.gssd to read per user k5identity
 files versus trying to read /.k5identity for each user.
@@ -365,6 +381,17 @@ Equivalent to
 Equivalent to
 .BR -R .
 .TP
+.B upcall-timeout
+Equivalent to
+.BR -U .
+.TP
+.B cancel-timed-out-upcalls
+Setting to
+.B true
+is equivalent to providing the
+.B -C
+flag.
+.TP
 .B set-home
 Setting to
 .B false
diff -up nfs-utils-2.3.3/utils/gssd/gssd_proc.c.orig nfs-utils-2.3.3/utils/gssd/gssd_proc.c
--- nfs-utils-2.3.3/utils/gssd/gssd_proc.c.orig	2021-07-19 09:45:40.449448272 -0400
+++ nfs-utils-2.3.3/utils/gssd/gssd_proc.c	2021-07-19 12:08:55.316182891 -0400
@@ -81,11 +81,24 @@
 #include "gss_names.h"
 
 extern pthread_mutex_t clp_lock;
+extern pthread_mutex_t active_thread_list_lock;
+extern int upcall_timeout;
+extern TAILQ_HEAD(active_thread_list_head, upcall_thread_info) active_thread_list;
 
 /* Encryption types supported by the kernel rpcsec_gss code */
 int num_krb5_enctypes = 0;
 krb5_enctype *krb5_enctypes = NULL;
 
+/* Args for the cleanup_handler() */
+struct cleanup_args  {
+	OM_uint32 	*min_stat;
+	gss_buffer_t	acceptor;
+	gss_buffer_t	token;
+	struct authgss_private_data *pd;
+	AUTH		**auth;
+	CLIENT		**rpc_clnt;
+};
+
 /*
  * Parse the supported encryption type information
  */
@@ -184,7 +197,7 @@ out_err:
 	return;
 }
 
-static int
+int
 do_error_downcall(int k5_fd, uid_t uid, int err)
 {
 	char	buf[1024];
@@ -604,27 +617,66 @@ out:
 }
 
 /*
+ * cleanup_handler:
+ *
+ * Free any resources allocated by process_krb5_upcall().
+ *
+ * Runs upon normal termination of process_krb5_upcall as well as if the
+ * thread is canceled.
+ */
+static void
+cleanup_handler(void *arg)
+{
+	struct cleanup_args *args = (struct cleanup_args *)arg;
+
+	gss_release_buffer(args->min_stat, args->acceptor);
+	if (args->token->value)
+		free(args->token->value);
+#ifdef HAVE_AUTHGSS_FREE_PRIVATE_DATA
+	if (args->pd->pd_ctx_hndl.length != 0 || args->pd->pd_ctx != 0)
+		authgss_free_private_data(args->pd);
+#endif
+	if (*args->auth)
+		AUTH_DESTROY(*args->auth);
+	if (*args->rpc_clnt)
+		clnt_destroy(*args->rpc_clnt);
+}
+
+/*
+ * process_krb5_upcall:
+ *
  * this code uses the userland rpcsec gss library to create a krb5
  * context on behalf of the kernel
+ *
+ * This is the meat of the upcall thread.  Note that cancelability is disabled
+ * and enabled at various points to ensure that any resources reserved by the
+ * lower level libraries are released safely.
  */
 static void
-process_krb5_upcall(struct clnt_info *clp, uid_t uid, int fd, char *srchost,
-		    char *tgtname, char *service)
+process_krb5_upcall(struct clnt_upcall_info *info)
 {
+	struct clnt_info	*clp = info->clp;
+	uid_t			uid = info->uid;
+	int			fd = info->fd;
+	char			*srchost = info->srchost;
+	char			*tgtname = info->target;
+	char			*service = info->service;
 	CLIENT			*rpc_clnt = NULL;
 	AUTH			*auth = NULL;
 	struct authgss_private_data pd;
 	gss_buffer_desc		token;
-	int			err, downcall_err = -EACCES;
+	int			err, downcall_err;
 	OM_uint32		maj_stat, min_stat, lifetime_rec;
 	gss_name_t		gacceptor = GSS_C_NO_NAME;
 	gss_OID			mech;
 	gss_buffer_desc		acceptor  = {0};
+	struct cleanup_args cleanup_args = {&min_stat, &acceptor, &token, &pd, &auth, &rpc_clnt};
 
 	token.length = 0;
 	token.value = NULL;
 	memset(&pd, 0, sizeof(struct authgss_private_data));
 
+	pthread_cleanup_push(cleanup_handler, &cleanup_args);
 	/*
 	 * If "service" is specified, then the kernel is indicating that
 	 * we must use machine credentials for this request.  (Regardless
@@ -646,6 +698,8 @@ process_krb5_upcall(struct clnt_info *cl
 	 * used for this case is not important.
 	 *
 	 */
+	downcall_err = -EACCES;
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
 	if (uid != 0 || (uid == 0 && root_uses_machine_creds == 0 &&
 				service == NULL)) {
 
@@ -666,15 +720,21 @@ process_krb5_upcall(struct clnt_info *cl
 			goto out_return_error;
 		}
 	}
+	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+	pthread_testcancel();
 
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
 	if (!authgss_get_private_data(auth, &pd)) {
 		printerr(1, "WARNING: Failed to obtain authentication "
 			    "data for user with uid %d for server %s\n",
 			 uid, clp->servername);
 		goto out_return_error;
 	}
+	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+	pthread_testcancel();
 
 	/* Grab the context lifetime and acceptor name out of the ctx. */
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
 	maj_stat = gss_inquire_context(&min_stat, pd.pd_ctx, NULL, &gacceptor,
 				       &lifetime_rec, &mech, NULL, NULL, NULL);
 
@@ -686,37 +746,35 @@ process_krb5_upcall(struct clnt_info *cl
 		get_hostbased_client_buffer(gacceptor, mech, &acceptor);
 		gss_release_name(&min_stat, &gacceptor);
 	}
+	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+	pthread_testcancel();
 
 	/*
 	 * The serialization can mean turning pd.pd_ctx into a lucid context. If
 	 * that happens then the pd.pd_ctx will be unusable, so we must never
 	 * try to use it after this point.
 	 */
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
 	if (serialize_context_for_kernel(&pd.pd_ctx, &token, &krb5oid, NULL)) {
 		printerr(1, "WARNING: Failed to serialize krb5 context for "
 			    "user with uid %d for server %s\n",
 			 uid, clp->servername);
 		goto out_return_error;
 	}
+	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+	pthread_testcancel();
 
 	do_downcall(fd, uid, &pd, &token, lifetime_rec, &acceptor);
 
 out:
-	gss_release_buffer(&min_stat, &acceptor);
-	if (token.value)
-		free(token.value);
-#ifdef HAVE_AUTHGSS_FREE_PRIVATE_DATA
-	if (pd.pd_ctx_hndl.length != 0 || pd.pd_ctx != 0)
-		authgss_free_private_data(&pd);
-#endif
-	if (auth)
-		AUTH_DESTROY(auth);
-	if (rpc_clnt)
-		clnt_destroy(rpc_clnt);
+	pthread_cleanup_pop(1);
 
 	return;
 
 out_return_error:
+	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+	pthread_testcancel();
+
 	do_error_downcall(fd, uid, downcall_err);
 	goto out;
 }
@@ -782,36 +840,69 @@ void free_upcall_info(struct clnt_upcall
 }
 
 static void
-gssd_work_thread_fn(struct clnt_upcall_info *info)
+cleanup_clnt_upcall_info(void *arg)
 {
-	process_krb5_upcall(info->clp, info->uid, info->fd, info->srchost, info->target, info->service);
+	struct clnt_upcall_info *info = (struct clnt_upcall_info *)arg;
+
 	free_upcall_info(info);
 }
 
+static void
+gssd_work_thread_fn(struct clnt_upcall_info *info)
+{
+	pthread_cleanup_push(cleanup_clnt_upcall_info, info);
+	process_krb5_upcall(info);
+	pthread_cleanup_pop(1);
+}
+
+static struct upcall_thread_info *
+alloc_upcall_thread_info(void)
+{
+	struct upcall_thread_info *info;
+
+	info = malloc(sizeof(struct upcall_thread_info));
+	if (info == NULL)
+		return NULL;
+	memset(info, 0, sizeof(*info));
+	return info;
+}
+
 static int
-start_upcall_thread(void (*func)(struct clnt_upcall_info *), void *info)
+start_upcall_thread(void (*func)(struct clnt_upcall_info *), struct clnt_upcall_info *info)
 {
 	pthread_attr_t attr;
 	pthread_t th;
+	struct upcall_thread_info *tinfo;
 	int ret;
 
+	tinfo = alloc_upcall_thread_info();
+	if (!tinfo)
+		return -ENOMEM;
+	tinfo->fd = info->fd;
+	tinfo->uid = info->uid;
+
 	ret = pthread_attr_init(&attr);
 	if (ret != 0) {
 		printerr(0, "ERROR: failed to init pthread attr: ret %d: %s\n",
 			 ret, strerror(errno));
-		return ret;
-	}
-	ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
-	if (ret != 0) {
-		printerr(0, "ERROR: failed to create pthread attr: ret %d: "
-			 "%s\n", ret, strerror(errno));
+		free(tinfo);
 		return ret;
 	}
 
 	ret = pthread_create(&th, &attr, (void *)func, (void *)info);
-	if (ret != 0)
+	if (ret != 0) {
 		printerr(0, "ERROR: pthread_create failed: ret %d: %s\n",
 			 ret, strerror(errno));
+		free(tinfo);
+		return ret;
+	}
+	tinfo->tid = th;
+	pthread_mutex_lock(&active_thread_list_lock);
+	clock_gettime(CLOCK_MONOTONIC, &tinfo->timeout);
+	tinfo->timeout.tv_sec += upcall_timeout;
+	TAILQ_INSERT_TAIL(&active_thread_list, tinfo, list);
+	pthread_mutex_unlock(&active_thread_list_lock);
+
 	return ret;
 }