Index: lib/libc/net/getaddrinfo.c
diff -u lib/libc/net/getaddrinfo.c.orig lib/libc/net/getaddrinfo.c
--- lib/libc/net/getaddrinfo.c.orig	Wed Oct  2 02:04:59 2002
+++ lib/libc/net/getaddrinfo.c	Wed Oct  2 02:09:01 2002
@@ -281,6 +281,15 @@
 static int	_hostconf_init_done;
 static void	_hostconf_init(void);
 
+/* Make getaddrinfo thread-safe in libc for use with kernel threads. */
+#include "libc_private.h"
+#include "spinlock.h"
+spinlock_t _getaddrinfo_thread_lock = _SPINLOCK_INITIALIZER;
+#define THREAD_LOCK() \
+	if (__isthreaded) _SPINLOCK(&_getaddrinfo_thread_lock);
+#define THREAD_UNLOCK() \
+	if (__isthreaded) _SPINUNLOCK(&_getaddrinfo_thread_lock);
+
 /* XXX macros that make external reference is BAD. */
 
 #define	GET_AI(ai, afd, addr) \
@@ -677,11 +686,15 @@
 	result = NULL;
 	*res = NULL;
 
+	THREAD_LOCK();
+
 	/*
 	 * if the servname does not match socktype/protocol, ignore it.
 	 */
-	if (get_portmatch(pai, servname) != 0)
+	if (get_portmatch(pai, servname) != 0) {
+		THREAD_UNLOCK();
 		return 0;
+	}
 
 	if (!_hostconf_init_done)
 		_hostconf_init();
@@ -696,11 +709,13 @@
 			GET_PORT(cur, servname);
 			/* canonname should be filled already */
 		}
+		THREAD_UNLOCK();
 		*res = result;
 		return 0;
 	}
 
 free:
+	THREAD_UNLOCK();
 	if (result)
 		freeaddrinfo(result);
 	return error;
Index: lib/libc/net/name6.c
diff -u lib/libc/net/name6.c.orig lib/libc/net/name6.c
--- lib/libc/net/name6.c.orig	Fri Sep 20 03:40:48 2002
+++ lib/libc/net/name6.c	Wed Oct  2 02:22:03 2002
@@ -185,6 +185,15 @@
 static struct	 hostent *_icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp);
 #endif /* ICMPNL */
 
+/* Make getipnodeby*() thread-safe in libc for use with kernel threads. */
+#include "libc_private.h"
+#include "spinlock.h"
+extern spinlock_t _getaddrinfo_thread_lock;
+#define THREAD_LOCK() \
+	if (__isthreaded) _SPINLOCK(&_getaddrinfo_thread_lock);
+#define THREAD_UNLOCK() \
+	if (__isthreaded) _SPINUNLOCK(&_getaddrinfo_thread_lock);
+
 /*
  * Select order host function.
  */
@@ -342,11 +351,15 @@
 		}
 	}
 
+	THREAD_LOCK();
 	for (i = 0; i < MAXHOSTCONF; i++) {
 		if (_hostconf[i].byname
-		 && (hp = (*_hostconf[i].byname)(name, af, errp)) != NULL)
+		    && (hp = (*_hostconf[i].byname)(name, af, errp)) != NULL) {
+			THREAD_UNLOCK();
 			return hp;
+		}
 	}
+	THREAD_UNLOCK();
 
 	return NULL;
 }
@@ -486,11 +499,15 @@
 
 	if (!_hostconf_init_done)
 		_hostconf_init();
+	THREAD_LOCK();
 	for (i = 0; i < MAXHOSTCONF; i++) {
 		if (_hostconf[i].byaddr
-		&&  (hp = (*_hostconf[i].byaddr)(src, len, af, errp)) != NULL)
+		&& (hp = (*_hostconf[i].byaddr)(src, len, af, errp)) != NULL) {
+			THREAD_UNLOCK();
 			return hp;
+		}
 	}
+	THREAD_UNLOCK();
 
 	return NULL;
 }