Index: sys/miscfs/procfs/procfs_subr.c
===================================================================
RCS file: /cvsroot/src/sys/miscfs/procfs/procfs_subr.c,v
retrieving revision 1.91
diff -u -p -u -r1.91 procfs_subr.c
--- sys/miscfs/procfs/procfs_subr.c	2 Jul 2008 19:49:58 -0000	1.91
+++ sys/miscfs/procfs/procfs_subr.c	5 Sep 2008 13:42:49 -0000
@@ -372,8 +372,17 @@ procfs_rw(v)
 #undef	M2K
 
 	mutex_enter(p->p_lock);
-	l = LIST_FIRST(&p->p_lwps);
-	KASSERT(l != NULL);
+	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
+		if (l->l_stat != LSZOMB)
+			break;
+	}
+	/* Process is exiting if no-LWPS or all LWPs are LSZOMB */
+	if (l == NULL) {
+		mutex_exit(p->p_lock);
+		procfs_proc_unlock(p);
+		return ESRCH;
+	}
+
 	lwp_addref(l);
 	mutex_exit(p->p_lock);
 
Index: sys/miscfs/procfs/procfs_vnops.c
===================================================================
RCS file: /cvsroot/src/sys/miscfs/procfs/procfs_vnops.c,v
retrieving revision 1.171
diff -u -p -u -r1.171 procfs_vnops.c
--- sys/miscfs/procfs/procfs_vnops.c	5 Sep 2008 13:21:12 -0000	1.171
+++ sys/miscfs/procfs/procfs_vnops.c	5 Sep 2008 13:42:51 -0000
@@ -974,6 +974,7 @@ procfs_lookup(void *v)
 	pid_t pid, vnpid;
 	struct pfsnode *pfs;
 	struct proc *p = NULL;
+	struct lwp *plwp;
 	int i, error;
 	pfstype type;
 
@@ -1053,23 +1054,33 @@ procfs_lookup(void *v)
 		if (procfs_proc_lock(pfs->pfs_pid, &p, ESRCH) != 0)
 			break;
 
+		mutex_enter(p->p_lock);
+		LIST_FOREACH(plwp, &p->p_lwps, l_sibling) {
+			if (plwp->l_stat != LSZOMB)
+				break;
+		}
+		/* Process is exiting if no-LWPS or all LWPs are LSZOMB */
+		if (plwp == NULL) {
+			mutex_exit(p->p_lock);
+			procfs_proc_unlock(p);
+			return ESRCH;
+		}
+
+		lwp_addref(plwp);
+		mutex_exit(p->p_lock);
+
 		for (pt = proc_targets, i = 0; i < nproc_targets; pt++, i++) {
-			struct lwp *plwp;
 			int found;
 
-			mutex_enter(p->p_lock);
-			plwp = LIST_FIRST(&p->p_lwps);
-			KASSERT(plwp != NULL);
-			lwp_addref(plwp);
-			mutex_exit(p->p_lock);
 			found = cnp->cn_namelen == pt->pt_namlen &&
 			    memcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 &&
 			    (pt->pt_valid == NULL
 			      || (*pt->pt_valid)(plwp, dvp->v_mount));
-			lwp_delref(plwp);
 			if (found)
 				break;
 		}
+		lwp_delref(plwp);
+
 		if (i == nproc_targets) {
 			procfs_proc_unlock(p);
 			break;