diff --git a/libc/Android.mk b/libc/Android.mk
index 0bb521fdb..056efd245 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -233,7 +233,6 @@ libc_upstream_freebsd_src_files := \
     upstream-freebsd/lib/libc/stdio/fwrite.c \
     upstream-freebsd/lib/libc/stdio/makebuf.c \
     upstream-freebsd/lib/libc/stdio/mktemp.c \
-    upstream-freebsd/lib/libc/stdio/putw.c \
     upstream-freebsd/lib/libc/stdio/setvbuf.c \
     upstream-freebsd/lib/libc/stdio/wsetup.c \
     upstream-freebsd/lib/libc/stdlib/abs.c \
@@ -352,6 +351,7 @@ libc_upstream_openbsd_src_files := \
     upstream-openbsd/lib/libc/stdio/putc.c \
     upstream-openbsd/lib/libc/stdio/putchar.c \
     upstream-openbsd/lib/libc/stdio/puts.c \
+    upstream-openbsd/lib/libc/stdio/putw.c \
     upstream-openbsd/lib/libc/stdio/refill.c \
     upstream-openbsd/lib/libc/stdio/remove.c \
     upstream-openbsd/lib/libc/stdio/rewind.c \
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index b790e2bd9..f6b3d6038 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -54,6 +54,8 @@ static pthread_mutex_t gPthreadStackCreationLock = PTHREAD_MUTEX_INITIALIZER;
 
 static pthread_mutex_t gDebuggerNotificationLock = PTHREAD_MUTEX_INITIALIZER;
 
+extern "C" int __isthreaded;
+
 // This code is used both by each new pthread and the code that initializes the main thread.
 void __init_tls(pthread_internal_t* thread) {
   // Zero-initialize all the slots after TLS_SLOT_SELF and TLS_SLOT_THREAD_ID.
@@ -169,11 +171,7 @@ int pthread_create(pthread_t* thread_out, pthread_attr_t const* attr,
                    void* (*start_routine)(void*), void* arg) {
   ErrnoRestorer errno_restorer;
 
-  // Inform the rest of the C library that at least one thread
-  // was created. This will enforce certain functions to acquire/release
-  // locks (e.g. atexit()) to protect shared global structures.
-  // This works because pthread_create() is not called by the C library
-  // initialization routine that sets up the main thread's data structures.
+  // Inform the rest of the C library that at least one thread was created.
   __isthreaded = 1;
 
   pthread_internal_t* thread = reinterpret_cast<pthread_internal_t*>(calloc(sizeof(*thread), 1));
diff --git a/libc/dns/net/reentrant.h b/libc/dns/net/reentrant.h
index 60bff089e..ddfa090c0 100644
--- a/libc/dns/net/reentrant.h
+++ b/libc/dns/net/reentrant.h
@@ -38,49 +38,49 @@
 
 /*
  * 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
@@ -212,8 +212,6 @@ void	__libc_thr_create(thr_t *, const thrattr_t *,
 void	__libc_thr_exit(void *) __attribute__((__noreturn__));
 int	*__libc_thr_errno(void);
 int	__libc_thr_setcancelstate(int, int *);
-
-extern int __isthreaded;
 __END_DECLS
 
 #define	thr_once(o, f)		__libc_thr_once((o), (f))
@@ -223,7 +221,6 @@ __END_DECLS
 #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_enabled()		(__isthreaded)
 #define thr_setcancelstate(n, o) __libc_thr_setcancelstate((n),(o))
 #endif /* __LIBC_THREAD_STUBS */
 
@@ -263,7 +260,7 @@ __END_DECLS
 #define	thr_self()
 #define	thr_errno()
 
-#define	FLOCKFILE(fp)		
-#define	FUNLOCKFILE(fp)		
+#define	FLOCKFILE(fp)
+#define	FUNLOCKFILE(fp)
 
 #endif /* _REENTRANT */
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
index c241d9456..6f8f92ef3 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -359,83 +359,6 @@ __END_DECLS
 #define	fwopen(cookie, fn) funopen(cookie, 0, fn, 0, 0)
 #endif /* __BSD_VISIBLE */
 
-/*
- * Functions internal to the implementation.
- */
-__BEGIN_DECLS
-int	__srget(FILE *);
-int	__swbuf(int, FILE *);
-__END_DECLS
-
-/*
- * The __sfoo macros are here so that we can
- * define function versions in the C library.
- */
-#define	__sgetc(p) (--(p)->_r < 0 ? __srget(p) : (int)(*(p)->_p++))
-#if defined(__GNUC__)
-static __inline int __sputc(int _c, FILE *_p) {
-	if (--_p->_w >= 0 || (_p->_w >= _p->_lbfsize && (char)_c != '\n'))
-		return (*_p->_p++ = _c);
-	else
-		return (__swbuf(_c, _p));
-}
-#else
-/*
- * This has been tuned to generate reasonable code on the vax using pcc.
- */
-#define	__sputc(c, p) \
-	(--(p)->_w < 0 ? \
-		(p)->_w >= (p)->_lbfsize ? \
-			(*(p)->_p = (c)), *(p)->_p != '\n' ? \
-				(int)*(p)->_p++ : \
-				__swbuf('\n', p) : \
-			__swbuf((int)(c), p) : \
-		(*(p)->_p = (c), (int)*(p)->_p++))
-#endif
-
-#define	__sfeof(p)	(((p)->_flags & __SEOF) != 0)
-#define	__sferror(p)	(((p)->_flags & __SERR) != 0)
-#define	__sclearerr(p)	((void)((p)->_flags &= ~(__SERR|__SEOF)))
-#define	__sfileno(p)	((p)->_file)
-
-extern	int __isthreaded;
-
-#define	feof(p)		(!__isthreaded ? __sfeof(p) : (feof)(p))
-#define	ferror(p)	(!__isthreaded ? __sferror(p) : (ferror)(p))
-#define	clearerr(p)	(!__isthreaded ? __sclearerr(p) : (clearerr)(p))
-
-#if __POSIX_VISIBLE
-#define	fileno(p)	(!__isthreaded ? __sfileno(p) : (fileno)(p))
-#endif
-
-#define	getc(fp)	(!__isthreaded ? __sgetc(fp) : (getc)(fp))
-
-#if __BSD_VISIBLE
-/*
- * The macro implementations of putc and putc_unlocked are not
- * fully POSIX compliant; they do not set errno on failure
- */
-#define putc(x, fp)	(!__isthreaded ? __sputc(x, fp) : (putc)(x, fp))
-#endif /* __BSD_VISIBLE */
-
-#ifndef lint
-#if __POSIX_VISIBLE >= 199506
-#define	getc_unlocked(fp)	__sgetc(fp)
-/*
- * The macro implementations of putc and putc_unlocked are not
- * fully POSIX compliant; they do not set errno on failure
- */
-#if __BSD_VISIBLE
-#define putc_unlocked(x, fp)	__sputc(x, fp)
-#endif /* __BSD_VISIBLE */
-#endif /* __POSIX_VISIBLE >= 199506 */
-#endif /* lint */
-
-#define	getchar()	getc(stdin)
-#define	putchar(x)	putc(x, stdout)
-#define	getchar_unlocked()	getc_unlocked(stdin)
-#define	putchar_unlocked(c)	putc_unlocked(c, stdout)
-
 #ifdef _GNU_SOURCE
 /*
  * glibc defines dprintf(int, const char*, ...), which is poorly named
diff --git a/libc/private/thread_private.h b/libc/private/thread_private.h
index b19ad09b9..f73118131 100644
--- a/libc/private/thread_private.h
+++ b/libc/private/thread_private.h
@@ -14,11 +14,6 @@
  * described functions for operation in a non-threaded environment.
  */
 
-/*
- * This variable is 0 until a second thread is created.
- */
-extern int __isthreaded;
-
 /*
  * helper macro to make unique names in the thread namespace
  */
@@ -39,13 +34,7 @@ struct __thread_private_tag_t {
 void	_thread_atexit_lock(void);
 void	_thread_atexit_unlock(void);
 
-#define _ATEXIT_LOCK()		do {					\
-					if (__isthreaded)		\
-						_thread_atexit_lock();	\
-				} while (0)
-#define _ATEXIT_UNLOCK()	do {					\
-					if (__isthreaded)		\
-						_thread_atexit_unlock();\
-				} while (0)
+#define _ATEXIT_LOCK() _thread_atexit_lock()
+#define _ATEXIT_UNLOCK() _thread_atexit_unlock()
 
 #endif /* _THREAD_PRIVATE_H_ */
diff --git a/libc/stdio/local.h b/libc/stdio/local.h
index a175d6fa0..facaa660f 100644
--- a/libc/stdio/local.h
+++ b/libc/stdio/local.h
@@ -91,7 +91,25 @@ extern int __sdidinit;
 	(fp)->_lb._base = NULL; \
 }
 
-#define FLOCKFILE(fp)   do { if (__isthreaded) flockfile(fp); } while (0)
-#define FUNLOCKFILE(fp) do { if (__isthreaded) funlockfile(fp); } while (0)
+#define FLOCKFILE(fp)   flockfile(fp)
+#define FUNLOCKFILE(fp) funlockfile(fp)
 
 #define FLOATING_POINT
+
+/* OpenBSD exposes these in <stdio.h>, but we only want them exposed to the implementation. */
+__BEGIN_DECLS
+int __srget(FILE*);
+int __swbuf(int, FILE*);
+__END_DECLS
+#define __sfeof(p)     (((p)->_flags & __SEOF) != 0)
+#define __sferror(p)   (((p)->_flags & __SERR) != 0)
+#define __sclearerr(p) ((void)((p)->_flags &= ~(__SERR|__SEOF)))
+#define __sfileno(p)   ((p)->_file)
+#define __sgetc(p) (--(p)->_r < 0 ? __srget(p) : (int)(*(p)->_p++))
+static __inline int __sputc(int _c, FILE* _p) {
+  if (--_p->_w >= 0 || (_p->_w >= _p->_lbfsize && (char)_c != '\n')) {
+    return (*_p->_p++ = _c);
+  } else {
+    return (__swbuf(_c, _p));
+  }
+}
diff --git a/libc/upstream-freebsd/libc_private.h b/libc/upstream-freebsd/libc_private.h
index ecdbb7ef5..c6a6433b1 100644
--- a/libc/upstream-freebsd/libc_private.h
+++ b/libc/upstream-freebsd/libc_private.h
@@ -17,9 +17,6 @@
 #ifndef _BIONIC_FREEBSD_LIBC_PRIVATE_H_included
 #define _BIONIC_FREEBSD_LIBC_PRIVATE_H_included
 
-#define FLOCKFILE(fp)   do { if (__isthreaded) flockfile(fp); } while (0)
-#define FUNLOCKFILE(fp) do { if (__isthreaded) funlockfile(fp); } while (0)
-
 #define STDIO_THREAD_LOCK()   /* TODO: until we have the FreeBSD findfp.c, this is useless. */
 #define STDIO_THREAD_UNLOCK() /* TODO: until we have the FreeBSD findfp.c, this is useless. */
 
diff --git a/libc/upstream-freebsd/lib/libc/stdio/putw.c b/libc/upstream-openbsd/lib/libc/stdio/putw.c
similarity index 85%
rename from libc/upstream-freebsd/lib/libc/stdio/putw.c
rename to libc/upstream-openbsd/lib/libc/stdio/putw.c
index 0360cafc4..47941a476 100644
--- a/libc/upstream-freebsd/lib/libc/stdio/putw.c
+++ b/libc/upstream-openbsd/lib/libc/stdio/putw.c
@@ -1,3 +1,4 @@
+/*	$OpenBSD: putw.c,v 1.10 2009/11/21 09:53:44 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -30,31 +31,24 @@
  * SUCH DAMAGE.
  */
 
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)putw.c	8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include "namespace.h"
 #include <stdio.h>
-#include "un-namespace.h"
+#include "local.h"
 #include "fvwrite.h"
-#include "libc_private.h"
 
 int
 putw(int w, FILE *fp)
 {
-	int retval;
 	struct __suio uio;
 	struct __siov iov;
+	int ret;
 
 	iov.iov_base = &w;
 	iov.iov_len = uio.uio_resid = sizeof(w);
 	uio.uio_iov = &iov;
 	uio.uio_iovcnt = 1;
 	FLOCKFILE(fp);
-	retval = __sfvwrite(fp, &uio);
+	_SET_ORIENTATION(fp, -1);
+	ret = __sfvwrite(fp, &uio);
 	FUNLOCKFILE(fp);
-	return (retval);
+	return (ret);
 }