diff --git a/libc/Android.mk b/libc/Android.mk
index c1a3dff..330bb6d 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -271,10 +271,12 @@
     upstream-netbsd/lib/libc/gen/psignal.c \
     upstream-netbsd/lib/libc/gen/utime.c \
     upstream-netbsd/lib/libc/gen/utmp.c \
+    upstream-netbsd/lib/libc/inet/nsap_addr.c \
     upstream-netbsd/lib/libc/regex/regcomp.c \
     upstream-netbsd/lib/libc/regex/regerror.c \
     upstream-netbsd/lib/libc/regex/regexec.c \
     upstream-netbsd/lib/libc/regex/regfree.c \
+    upstream-netbsd/lib/libc/resolv/mtctxres.c \
     upstream-netbsd/lib/libc/stdlib/bsearch.c \
     upstream-netbsd/lib/libc/stdlib/div.c \
     upstream-netbsd/lib/libc/stdlib/drand48.c \
diff --git a/libc/upstream-netbsd/lib/libc/include/resolv_mt.h b/libc/upstream-netbsd/lib/libc/include/resolv_mt.h
new file mode 100644
index 0000000..73a8dcc
--- /dev/null
+++ b/libc/upstream-netbsd/lib/libc/include/resolv_mt.h
@@ -0,0 +1,49 @@
+/*	$NetBSD: resolv_mt.h,v 1.1.1.3 2009/04/12 16:35:44 christos Exp $	*/
+
+#ifndef _RESOLV_MT_H
+#define _RESOLV_MT_H
+
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+
+/* Access functions for the libresolv private interface */
+
+int	__res_enable_mt(void);
+int	__res_disable_mt(void);
+
+/* Per-thread context */
+
+typedef struct {
+int	no_hosts_fallback_private;
+int	retry_save;
+int	retry_private;
+char	inet_nsap_ntoa_tmpbuf[255*3];
+char	sym_ntos_unname[20];
+char	sym_ntop_unname[20];
+char	p_option_nbuf[40];
+char	p_time_nbuf[40];
+char	precsize_ntoa_retbuf[sizeof "90000000.00"];
+char	loc_ntoa_tmpbuf[sizeof
+"1000 60 60.000 N 1000 60 60.000 W -12345678.00m 90000000.00m 90000000.00m 90000000.00m"];
+char	p_secstodate_output[15];
+} mtctxres_t;
+
+/* Thread-specific data (TSD) */
+
+mtctxres_t	*___mtctxres(void);
+#define mtctxres	(___mtctxres())
+
+/* Various static data that should be TSD */
+
+#define sym_ntos_unname		(mtctxres->sym_ntos_unname)
+#define sym_ntop_unname		(mtctxres->sym_ntop_unname)
+#define inet_nsap_ntoa_tmpbuf	(mtctxres->inet_nsap_ntoa_tmpbuf)
+#define p_option_nbuf		(mtctxres->p_option_nbuf)
+#define p_time_nbuf		(mtctxres->p_time_nbuf)
+#define precsize_ntoa_retbuf	(mtctxres->precsize_ntoa_retbuf)
+#define loc_ntoa_tmpbuf		(mtctxres->loc_ntoa_tmpbuf)
+#define p_secstodate_output	(mtctxres->p_secstodate_output)
+
+#endif /* _RESOLV_MT_H */
diff --git a/libc/dns/inet/nsap_addr.c b/libc/upstream-netbsd/lib/libc/inet/nsap_addr.c
similarity index 81%
rename from libc/dns/inet/nsap_addr.c
rename to libc/upstream-netbsd/lib/libc/inet/nsap_addr.c
index 4deabac..8633205 100644
--- a/libc/dns/inet/nsap_addr.c
+++ b/libc/upstream-netbsd/lib/libc/inet/nsap_addr.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: nsap_addr.c,v 1.2 2004/05/20 23:12:33 christos Exp $	*/
+/*	$NetBSD: nsap_addr.c,v 1.6 2009/04/12 17:07:17 christos Exp $	*/
 
 /*
  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
@@ -20,12 +20,15 @@
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
 #if 0
-static const char rcsid[] = "Id: nsap_addr.c,v 1.2.206.1 2004/03/09 08:33:33 marka Exp";
+static const char rcsid[] = "Id: nsap_addr.c,v 1.5 2005/07/28 06:51:48 marka Exp";
 #else
-__RCSID("$NetBSD: nsap_addr.c,v 1.2 2004/05/20 23:12:33 christos Exp $");
+__RCSID("$NetBSD: nsap_addr.c,v 1.6 2009/04/12 17:07:17 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
+#include "port_before.h"
+
+#include "namespace.h"
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/socket.h>
@@ -36,10 +39,14 @@
 
 #include <assert.h>
 #include <ctype.h>
-#ifdef ANDROID_CHANGES
-#include "resolv_private.h"
-#else
 #include <resolv.h>
+#include <resolv_mt.h>
+
+#include "port_after.h"
+
+#ifdef __weak_alias
+__weak_alias(inet_nsap_addr,_inet_nsap_addr)
+__weak_alias(inet_nsap_ntoa,_inet_nsap_ntoa)
 #endif
 
 static char
@@ -52,8 +59,8 @@
 	u_char c, nib;
 	u_int len = 0;
 
-	assert(ascii != NULL);
-	assert(binary != NULL);
+	_DIAGASSERT(ascii != NULL);
+	_DIAGASSERT(binary != NULL);
 
 	if (ascii[0] != '0' || (ascii[1] != 'x' && ascii[1] != 'X'))
 		return (0);
@@ -90,10 +97,10 @@
 inet_nsap_ntoa(int binlen, const u_char *binary, char *ascii) {
 	int nib;
 	int i;
-	static char tmpbuf[2+255*3];
+	char *tmpbuf = inet_nsap_ntoa_tmpbuf;
 	char *start;
 
-	assert(binary != NULL);
+	_DIAGASSERT(binary != NULL);
 
 	if (ascii)
 		start = ascii;
@@ -119,3 +126,5 @@
 	*ascii = '\0';
 	return (start);
 }
+
+/*! \file */
diff --git a/libc/upstream-netbsd/lib/libc/resolv/mtctxres.c b/libc/upstream-netbsd/lib/libc/resolv/mtctxres.c
new file mode 100644
index 0000000..6e3281a
--- /dev/null
+++ b/libc/upstream-netbsd/lib/libc/resolv/mtctxres.c
@@ -0,0 +1,130 @@
+/*	$NetBSD: mtctxres.c,v 1.4 2007/03/30 20:40:52 ghen Exp $	*/
+
+#include <port_before.h>
+#ifdef DO_PTHREADS
+#include <pthread.h>
+#endif
+#include <errno.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <string.h>
+#include <resolv_mt.h>
+#include <port_after.h>
+
+#ifdef DO_PTHREADS
+static pthread_key_t	key;
+static int		mt_key_initialized = 0;
+
+static int		__res_init_ctx(void);
+static void		__res_destroy_ctx(void *);
+
+#if defined(sun) && !defined(__GNUC__)
+#pragma init	(_mtctxres_init)
+#endif
+#endif
+
+static mtctxres_t	sharedctx;
+
+#ifdef DO_PTHREADS
+/*
+ * Initialize the TSD key. By doing this at library load time, we're
+ * implicitly running without interference from other threads, so there's
+ * no need for locking.
+ */
+static void
+_mtctxres_init(void) {
+	int pthread_keycreate_ret;
+
+	pthread_keycreate_ret = pthread_key_create(&key, __res_destroy_ctx);
+	if (pthread_keycreate_ret == 0)
+		mt_key_initialized = 1;
+}
+#endif
+
+/*
+ * To support binaries that used the private MT-safe interface in
+ * Solaris 8, we still need to provide the __res_enable_mt()
+ * and __res_disable_mt() entry points. They're do-nothing routines.
+ */
+int
+__res_enable_mt(void) {
+	return (-1);
+}
+
+int
+__res_disable_mt(void) {
+	return (0);
+}
+
+#ifdef DO_PTHREADS
+static int
+__res_init_ctx(void) {
+
+	mtctxres_t	*mt;
+	int		ret;
+
+
+	if (pthread_getspecific(key) != 0) {
+		/* Already exists */
+		return (0);
+	}
+
+	if ((mt = malloc(sizeof (mtctxres_t))) == 0) {
+		errno = ENOMEM;
+		return (-1);
+	}
+
+	memset(mt, 0, sizeof (mtctxres_t));
+
+	if ((ret = pthread_setspecific(key, mt)) != 0) {
+		free(mt);
+		errno = ret;
+		return (-1);
+	}
+
+	return (0);
+}
+
+static void
+__res_destroy_ctx(void *value) {
+
+	mtctxres_t	*mt = (mtctxres_t *)value;
+
+	if (mt != 0)
+		free(mt);
+}
+#endif
+
+mtctxres_t *
+___mtctxres(void) {
+#ifdef DO_PTHREADS
+	mtctxres_t	*mt;
+
+	/*
+	 * This if clause should only be executed if we are linking
+	 * statically.  When linked dynamically _mtctxres_init() should
+	 * be called at binding time due the #pragma above.
+	 */
+	if (!mt_key_initialized) {
+		static pthread_mutex_t keylock = PTHREAD_MUTEX_INITIALIZER;
+                if (pthread_mutex_lock(&keylock) == 0) {
+			_mtctxres_init();
+			(void) pthread_mutex_unlock(&keylock);
+		}
+	}
+
+	/*
+	 * If we have already been called in this thread return the existing
+	 * context.  Otherwise recreat a new context and return it.  If
+	 * that fails return a global context.
+	 */
+	if (mt_key_initialized) {
+		if (((mt = pthread_getspecific(key)) != 0) ||
+		    (__res_init_ctx() == 0 &&
+		     (mt = pthread_getspecific(key)) != 0)) {
+			return (mt);
+		}
+	}
+#endif
+	return (&sharedctx);
+}