diff --git a/libc/Android.mk b/libc/Android.mk
index 056efd2..8cb85b7 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -400,7 +400,6 @@
 # Define some common cflags
 # ========================================================
 libc_common_cflags := \
-    -DANDROID_CHANGES \
     -D_LIBC=1 \
     -Wall -Wextra \
 
@@ -513,6 +512,7 @@
 LOCAL_SRC_FILES := $(call all-c-files-under,dns)
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
+    -DANDROID_CHANGES \
     -DINET6 \
     -I$(LOCAL_PATH)/dns/include \
     -I$(LOCAL_PATH)/private \
diff --git a/libc/dns/net/reentrant.h b/libc/dns/net/reentrant.h
deleted file mode 100644
index ddfa090..0000000
--- a/libc/dns/net/reentrant.h
+++ /dev/null
@@ -1,266 +0,0 @@
-/*	$NetBSD: reentrant.h,v 1.10 2004/12/14 00:23:19 nathanw Exp $	*/
-
-/*-
- * Copyright (c) 1997, 1998, 2003 The NetBSD Foundation, Inc.
- * All rights reserved.
- *
- * This code is derived from software contributed to The NetBSD Foundation
- * by J.T. Conklin, by Nathan J. Williams, and by Jason R. Thorpe.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *        This product includes software developed by the NetBSD
- *        Foundation, Inc. and its contributors.
- * 4. Neither the name of The NetBSD Foundation nor the names of its
- *    contributors may be used to endorse or promote products derived
- *    from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
- * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
- * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-/*
- * Requirements:
- *
- * 1. The thread safe mechanism should be lightweight so the library can
- *    be used by non-threaded applications without unreasonable overhead.
- *
- * 2. There should be no dependency on a thread engine for non-threaded
- *    applications.
- *
- * 3. There should be no dependency on any particular thread engine.
- *
- * 4. The library should be able to be compiled without support for thread
- *    safety.
- *
- *
- * Rationale:
- *
- * One approach for thread safety is to provide discrete versions of the
- * library: one thread safe, the other not.  The disadvantage of this is
- * that libc is rather large, and two copies of a library which are 99%+
- * identical is not an efficent use of resources.
- *
- * Another approach is to provide a single thread safe library.  However,
- * it should not add significant run time or code size overhead to non-
- * threaded applications.
- *
- * Since the NetBSD C library is used in other projects, it should be
- * easy to replace the mutual exclusion primitives with ones provided by
- * another system.  Similarly, it should also be easy to remove all
- * support for thread safety completely if the target environment does
- * not support threads.
- *
- *
- * Implementation Details:
- *
- * The thread primitives used by the library (mutex_t, mutex_lock, etc.)
- * are macros which expand to the cooresponding primitives provided by
- * the thread engine or to nothing.  The latter is used so that code is
- * not unreasonably cluttered with #ifdefs when all thread safe support
- * is removed.
- *
- * The thread macros can be directly mapped to the mutex primitives from
- * pthreads, however it should be reasonably easy to wrap another mutex
- * implementation so it presents a similar interface.
- *
- * The thread functions operate by dispatching to symbols which are, by
- * default, weak-aliased to no-op functions in thread-stub/thread-stub.c
- * (some uses of thread operations are conditional on __isthreaded, but
- * not all of them are).
- *
- * When the thread library is linked in, it provides strong-alias versions
- * of those symbols which dispatch to its own real thread operations.
- *
- */
-
-#ifdef _REENTRANT
-
-/*
- * Abtract thread interface for thread-safe libraries.  These routines
- * will use stubs in libc if the application is not linked against the
- * pthread library, and the real function in the pthread library if it
- * is.
- */
-
-#include <pthread.h>
-#include <signal.h>
-#include <sys/cdefs.h>
-
-#define	mutex_t			pthread_mutex_t
-#define	MUTEX_INITIALIZER	PTHREAD_MUTEX_INITIALIZER
-
-#define	mutexattr_t		pthread_mutexattr_t
-
-#define	MUTEX_TYPE_NORMAL	PTHREAD_MUTEX_NORMAL
-#define	MUTEX_TYPE_ERRORCHECK	PTHREAD_MUTEX_ERRORCHECK
-#define	MUTEX_TYPE_RECURSIVE	PTHREAD_MUTEX_RECURSIVE
-
-#define	cond_t			pthread_cond_t
-#define	COND_INITIALIZER	PTHREAD_COND_INITIALIZER
-
-#define	condattr_t		pthread_condattr_t
-
-#define	rwlock_t		pthread_rwlock_t
-#define	RWLOCK_INITIALIZER	PTHREAD_RWLOCK_INITIALIZER
-
-#define	rwlockattr_t		pthread_rwlockattr_t
-
-#define	thread_key_t		pthread_key_t
-
-#define	thr_t			pthread_t
-
-#define	thrattr_t		pthread_attr_t
-
-#define	once_t			pthread_once_t
-#define	ONCE_INITIALIZER	PTHREAD_ONCE_INIT
-
-#ifndef __LIBC_THREAD_STUBS
-
-__BEGIN_DECLS
-int	__libc_mutex_init(mutex_t *, const mutexattr_t *);
-int	__libc_mutex_lock(mutex_t *);
-int	__libc_mutex_trylock(mutex_t *);
-int	__libc_mutex_unlock(mutex_t *);
-int	__libc_mutex_destroy(mutex_t *);
-
-int	__libc_mutexattr_init(mutexattr_t *);
-int	__libc_mutexattr_settype(mutexattr_t *, int);
-int	__libc_mutexattr_destroy(mutexattr_t *);
-__END_DECLS
-
-#define	mutex_init(m, a)	__libc_mutex_init((m), (a))
-#define	mutex_lock(m)		__libc_mutex_lock((m))
-#define	mutex_trylock(m)	__libc_mutex_trylock((m))
-#define	mutex_unlock(m)		__libc_mutex_unlock((m))
-#define	mutex_destroy(m)	__libc_mutex_destroy((m))
-
-#define	mutexattr_init(ma)	__libc_mutexattr_init((ma))
-#define	mutexattr_settype(ma, t) __libc_mutexattr_settype((ma), (t))
-#define	mutexattr_destroy(ma)	__libc_mutexattr_destroy((ma))
-
-__BEGIN_DECLS
-int	__libc_cond_init(cond_t *, const condattr_t *);
-int	__libc_cond_signal(cond_t *);
-int	__libc_cond_broadcast(cond_t *);
-int	__libc_cond_wait(cond_t *, mutex_t *);
-int	__libc_cond_timedwait(cond_t *, mutex_t *, const struct timespec *);
-int	__libc_cond_destroy(cond_t *);
-__END_DECLS
-
-#define	cond_init(c, t, a)     	__libc_cond_init((c), (a))
-#define	cond_signal(c)		__libc_cond_signal((c))
-#define	cond_broadcast(c)	__libc_cond_broadcast((c))
-#define	cond_wait(c, m)		__libc_cond_wait((c), (m))
-#define	cond_timedwait(c, m, t)	__libc_cond_timedwait((c), (m), (t))
-#define	cond_destroy(c)		__libc_cond_destroy((c))
-
-__BEGIN_DECLS
-int	__libc_rwlock_init(rwlock_t *, const rwlockattr_t *);
-int	__libc_rwlock_rdlock(rwlock_t *);
-int	__libc_rwlock_wrlock(rwlock_t *);
-int	__libc_rwlock_tryrdlock(rwlock_t *);
-int	__libc_rwlock_trywrlock(rwlock_t *);
-int	__libc_rwlock_unlock(rwlock_t *);
-int	__libc_rwlock_destroy(rwlock_t *);
-__END_DECLS
-
-#define	rwlock_init(l, a)	__libc_rwlock_init((l), (a))
-#define	rwlock_rdlock(l)	__libc_rwlock_rdlock((l))
-#define	rwlock_wrlock(l)	__libc_rwlock_wrlock((l))
-#define	rwlock_tryrdlock(l)	__libc_rwlock_tryrdlock((l))
-#define	rwlock_trywrlock(l)	__libc_rwlock_trywrlock((l))
-#define	rwlock_unlock(l)	__libc_rwlock_unlock((l))
-#define	rwlock_destroy(l)	__libc_rwlock_destroy((l))
-
-__BEGIN_DECLS
-int	__libc_thr_keycreate(thread_key_t *, void (*)(void *));
-int	__libc_thr_setspecific(thread_key_t, const void *);
-void	*__libc_thr_getspecific(thread_key_t);
-int	__libc_thr_keydelete(thread_key_t);
-__END_DECLS
-
-#define	thr_keycreate(k, d)	__libc_thr_keycreate((k), (d))
-#define	thr_setspecific(k, p)	__libc_thr_setspecific((k), (p))
-#define	thr_getspecific(k)	__libc_thr_getspecific((k))
-#define	thr_keydelete(k)	__libc_thr_keydelete((k))
-
-__BEGIN_DECLS
-int	__libc_thr_once(once_t *, void (*)(void));
-int	__libc_thr_sigsetmask(int, const sigset_t *, sigset_t *);
-thr_t	__libc_thr_self(void);
-int	__libc_thr_yield(void);
-void	__libc_thr_create(thr_t *, const thrattr_t *,
-	    void *(*)(void *), void *);
-void	__libc_thr_exit(void *) __attribute__((__noreturn__));
-int	*__libc_thr_errno(void);
-int	__libc_thr_setcancelstate(int, int *);
-__END_DECLS
-
-#define	thr_once(o, f)		__libc_thr_once((o), (f))
-#define	thr_sigsetmask(f, n, o)	__libc_thr_sigsetmask((f), (n), (o))
-#define	thr_self()		__libc_thr_self()
-#define	thr_yield()		__libc_thr_yield()
-#define	thr_create(tp, ta, f, a) __libc_thr_create((tp), (ta), (f), (a))
-#define	thr_exit(v)		__libc_thr_exit((v))
-#define	thr_errno()		__libc_thr_errno()
-#define thr_setcancelstate(n, o) __libc_thr_setcancelstate((n),(o))
-#endif /* __LIBC_THREAD_STUBS */
-
-#define	FLOCKFILE(fp)		__flockfile_internal(fp, 1)
-#define	FUNLOCKFILE(fp)		__funlockfile_internal(fp, 1)
-
-#else /* _REENTRANT */
-
-#define	mutex_init(m, a)
-#define	mutex_lock(m)
-#define	mutex_trylock(m)
-#define	mutex_unlock(m)
-#define	mutex_destroy(m)
-
-#define	cond_init(c, t, a)
-#define	cond_signal(c)
-#define	cond_broadcast(c)
-#define	cond_wait(c, m)
-#define	cond_timedwait(c, m, t)
-#define	cond_destroy(c)
-
-#define	rwlock_init(l, a)
-#define	rwlock_rdlock(l)
-#define	rwlock_wrlock(l)
-#define	rwlock_tryrdlock(l)
-#define	rwlock_trywrlock(l)
-#define	rwlock_unlock(l)
-#define	rwlock_destroy(l)
-
-#define	thr_keycreate(k, d)
-#define	thr_setspecific(k, p)
-#define	thr_getspecific(k)
-#define	thr_keydelete(k)
-
-#define	thr_once(o, f)
-#define	thr_sigsetmask(f, n, o)
-#define	thr_self()
-#define	thr_errno()
-
-#define	FLOCKFILE(fp)
-#define	FUNLOCKFILE(fp)
-
-#endif /* _REENTRANT */
diff --git a/libc/include/locale.h b/libc/include/locale.h
index 65b5c7d..b6dbfdb 100644
--- a/libc/include/locale.h
+++ b/libc/include/locale.h
@@ -49,11 +49,13 @@
     LC_IDENTIFICATION = 12
 };
 
-extern char *setlocale(int category, const char *locale);
+extern char* setlocale(int, const char*);
 
-/* Make libstdc++-v3 happy.  */
+#if !defined(__LP64__)
+// TODO: LP32 had these bogus declarations but LP64 should have a real struct lconv and localeconv(3).
 struct lconv { };
-struct lconv *localeconv(void);
+struct lconv* localeconv(void);
+#endif
 
 __END_DECLS
 
diff --git a/libc/stdlib/strtod.c b/libc/stdlib/strtod.c
index 3934d9a..0a19446 100644
--- a/libc/stdlib/strtod.c
+++ b/libc/stdlib/strtod.c
@@ -91,12 +91,6 @@
  *	directly -- and assumed always to succeed.
  */
 
-#ifdef ANDROID_CHANGES
-#include <pthread.h>
-#define mutex_lock(x) pthread_mutex_lock(x)
-#define mutex_unlock(x) pthread_mutex_unlock(x)
-#endif
-
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
 __RCSID("$NetBSD: strtod.c,v 1.45.2.1 2005/04/19 13:35:54 tron Exp $");
@@ -151,18 +145,14 @@
 #ifndef KR_headers
 #include "stdlib.h"
 #include "string.h"
-#ifndef ANDROID_CHANGES
 #include "locale.h"
-#endif /* ANDROID_CHANGES */
 #else
 #include "malloc.h"
 #include "memory.h"
 #endif
 #endif
-#ifndef ANDROID_CHANGES
-#include "extern.h"
-#include "reentrant.h"
-#endif /* ANDROID_CHANGES */
+#include "../upstream-netbsd/extern.h" /* Android-changed. */
+#include "../upstream-netbsd/reentrant.h" /* Android-changed. */
 
 #ifdef MALLOC
 #ifdef KR_headers
@@ -370,13 +360,9 @@
 
  static Bigint *freelist[Kmax+1];
 
-#ifdef ANDROID_CHANGES
- static pthread_mutex_t freelist_mutex = PTHREAD_MUTEX_INITIALIZER;
-#else
 #ifdef _REENTRANT
  static mutex_t freelist_mutex = MUTEX_INITIALIZER;
 #endif
-#endif
 
 /* Special value used to indicate an invalid Bigint value,
  * e.g. when a memory allocation fails. The idea is that we
@@ -1346,16 +1332,14 @@
 	Bigint *bb1, *bd0;
 	Bigint *bb = NULL, *bd = NULL, *bs = NULL, *delta = NULL;/* pacify gcc */
 
-#ifdef ANDROID_CHANGES
 	CONST char decimal_point = '.';
-#else /* ANDROID_CHANGES */
+#if 0 /* BEGIN android-changed: no localeconv. */
 #ifndef KR_headers
 	CONST char decimal_point = localeconv()->decimal_point[0];
 #else
 	CONST char decimal_point = '.';
 #endif
-
-#endif /* ANDROID_CHANGES */
+#endif /* END android-changed */
 
 	sign = nz0 = nz = 0;
 	value(rv) = 0.;
diff --git a/libc/upstream-netbsd/reentrant.h b/libc/upstream-netbsd/reentrant.h
index e2945da..3ca8fd6 100644
--- a/libc/upstream-netbsd/reentrant.h
+++ b/libc/upstream-netbsd/reentrant.h
@@ -28,6 +28,8 @@
 
 #define MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
 #define mutex_t pthread_mutex_t
+#define mutex_lock(x) pthread_mutex_lock(x)
+#define mutex_unlock(x) pthread_mutex_unlock(x)
 
 #define RWLOCK_INITIALIZER PTHREAD_RWLOCK_INITIALIZER
 #define rwlock_t pthread_rwlock_t