Index: libkse/sys/lock.c
===================================================================
RCS file: /home/ncvs/src/lib/libkse/sys/lock.c,v
retrieving revision 1.11
diff -u -r1.11 lock.c
--- libkse/sys/lock.c	9 Oct 2007 13:42:26 -0000	1.11
+++ libkse/sys/lock.c	31 Jan 2008 18:37:42 -0000
@@ -117,14 +117,23 @@
 {
 	if (lu == NULL)
 		return (-1);
-	/*
-	 * All lockusers keep their watch request and drop their
-	 * own (lu_myreq) request.  Their own request is either
-	 * some other lockuser's watch request or is the head of
-	 * the lock.
-	 */
-	lu->lu_myreq = lu->lu_watchreq;
-	if (lu->lu_myreq == NULL)
+
+	if (lu->lu_watchreq != NULL) {
+		/*
+		 * In this case the lock is active.  All lockusers
+		 * keep their watch request and drop their own
+		 * (lu_myreq) request.  Their own request is either
+		 * some other lockuser's watch request or is the
+		 * head of the lock.
+		 */
+		lu->lu_myreq = lu->lu_watchreq;
+		lu->lu_watchreq = NULL;
+       }
+       if (lu->lu_myreq == NULL)
+		/*
+		 * Oops, something isn't quite right.  Try to
+		 * allocate one.
+		 */
 		return (_lockuser_init(lu, priv));
 	else {
 		lu->lu_myreq->lr_locked = 1;
Index: libkse/thread/thr_kern.c
===================================================================
RCS file: /home/ncvs/src/lib/libkse/thread/thr_kern.c,v
retrieving revision 1.125
diff -u -r1.125 thr_kern.c
--- libkse/thread/thr_kern.c	9 Oct 2007 13:42:28 -0000	1.125
+++ libkse/thread/thr_kern.c	31 Jan 2008 18:37:42 -0000
@@ -342,6 +342,17 @@
 		_LCK_SET_PRIVATE2(&curthread->kse->k_lockusers[i], NULL);
 	}
 	curthread->kse->k_locklevel = 0;
+
+	/*
+	 * Reinitialize the thread and signal locks so that
+	 * sigaction() will work after a fork().
+	 */
+	_lock_reinit(&curthread->lock, LCK_ADAPTIVE, _thr_lock_wait,
+	    _thr_lock_wakeup);
+	_lock_reinit(&_thread_signal_lock, LCK_ADAPTIVE, _kse_lock_wait,
+	    _kse_lock_wakeup);
+
+ 
 	_thr_spinlock_init();
 	if (__isthreaded) {
 		_thr_rtld_fini();
@@ -351,6 +362,20 @@
 	curthread->kse->k_kcb->kcb_kmbx.km_curthread = NULL;
 	curthread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
 
+	/*
+	 * After a fork, it is possible that an upcall occurs in
+	 * the parent KSE that fork()'d before the child process
+	 * is fully created and before its vm space is copied.
+	 * During the upcall, the tcb is set to null or to another
+	 * thread, and this is what gets copied in the child process
+	 * when the vm space is cloned sometime after the upcall
+	 * occurs.  Note that we shouldn't have to set the kcb, but
+	 * we do it for completeness.
+	 */
+	_kcb_set(curthread->kse->k_kcb);
+	_tcb_set(curthread->kse->k_kcb, curthread->tcb);
+ 
+
 	/* After a fork(), there child should have no pending signals. */
 	sigemptyset(&curthread->sigpend);