diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -629,12 +629,10 @@
 	PGRP_LOCK_ASSERT(p->p_pgrp, MA_NOTOWNED);
 	SESS_LOCK_ASSERT(p->p_session, MA_NOTOWNED);
 	KASSERT(pgrp->pg_session == p->p_session,
-		("%s: pgrp's session %p, p->p_session %p.\n",
-		__func__,
-		pgrp->pg_session,
-		p->p_session));
+	    ("%s: pgrp's session %p, p->p_session %p proc %p\n",
+	    __func__, pgrp->pg_session, p->p_session, p));
 	KASSERT(pgrp != p->p_pgrp,
-		("%s: p belongs to pgrp.", __func__));
+	    ("%s: p %p belongs to pgrp %p", __func__, p, pgrp));
 
 	doenterpgrp(p, pgrp);
 
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -2227,9 +2227,9 @@
 		 * is default; don't stop the process below if sleeping,
 		 * and don't clear any pending SIGCONT.
 		 */
-		if ((prop & SIGPROP_TTYSTOP) &&
-		    (p->p_pgrp->pg_jobc == 0) &&
-		    (action == SIG_DFL)) {
+		if ((prop & SIGPROP_TTYSTOP) != 0 &&
+		    p->p_pgrp->pg_jobc == 0 &&
+		    action == SIG_DFL) {
 			if (ksi && (ksi->ksi_flags & KSI_INS))
 				ksiginfo_tryfree(ksi);
 			return (ret);
@@ -2984,10 +2984,10 @@
 			 * should ignore tty stops.
 			 */
 			if (prop & SIGPROP_STOP) {
-				if (p->p_flag &
-				    (P_TRACED | P_WEXIT | P_SINGLE_EXIT) ||
+				if ((p->p_flag & (P_TRACED | P_WEXIT |
+				    P_SINGLE_EXIT)) != 0 ||
 				    (p->p_pgrp->pg_jobc == 0 &&
-				     prop & SIGPROP_TTYSTOP))
+				    (prop & SIGPROP_TTYSTOP) != 0))
 					break;	/* == ignore */
 				if (TD_SBDRY_INTR(td)) {
 					KASSERT((td->td_flags & TDF_SBDRY) != 0,
diff --git a/sys/kern/tty.c b/sys/kern/tty.c
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -456,7 +456,7 @@
 		}
 
 		pg = p->p_pgrp;
-		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
+		if ((p->p_flag & P_PPWAIT) != 0 || pg->pg_jobc == 0) {
 			/* Don't allow the action to happen. */
 			PROC_UNLOCK(p);
 			return (EIO);