Fix the handle locking in stdio to use flockfile/funlockfile

internally when and where required.  Macros in <stdio.h> are updated
to automatically call the underlying functions when the process is
threaded to obtain the necessary locking.  A private mutex is added
to protect __sglue, the internal list of FILE handles, and another
to protect the one-time initialization.  Some routines in libc that
use getc() change to use getc_unlocked() as they're either protected
by their own lock or aren't thread-safe routines anyway.

ok kurt@, earlier version tested by sthen@ and jj@

47 files changed, 283 insertions, 139 deletions

diff --git a/lib/libc/gen/getgrent.c b/lib/libc/gen/getgrent.c
index d64b04cde1d..13ca99b8fc4 100644
--- a/lib/libc/gen/getgrent.c
+++ b/lib/libc/gen/getgrent.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getgrent.c,v 1.32 2009/06/07 03:52:54 schwarze Exp $ */
+/*	$OpenBSD: getgrent.c,v 1.33 2009/10/21 16:04:23 guenther Exp $ */
 /*
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -319,7 +319,8 @@ grscan(int search, gid_t gid, const char *name, struct group *p_gr,
 		if (!strchr(line, '\n')) {
 			int ch;
 
-			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
+			while ((ch = getc_unlocked(_gr_fp)) != '\n' &&
+			    ch != EOF)
 				;
 			continue;
 		}
diff --git a/lib/libc/gen/getgrouplist.c b/lib/libc/gen/getgrouplist.c
index d8dff264d8a..564ca8fb3c1 100644
--- a/lib/libc/gen/getgrouplist.c
+++ b/lib/libc/gen/getgrouplist.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getgrouplist.c,v 1.18 2009/06/23 18:52:43 schwarze Exp $ */
+/*	$OpenBSD: getgrouplist.c,v 1.19 2009/10/21 16:04:23 guenther Exp $ */
 /*
  * Copyright (c) 2008 Ingo Schwarze <schwarze@usta.de>
  * Copyright (c) 1991, 1993
@@ -123,7 +123,7 @@ _read_netid(const char *key, uid_t uid, gid_t *groups, int *ngroups,
 			*p = '\0';
 		else { /* Skip lines that are too long. */
 			int ch;
-			while ((ch = getc(fp)) != '\n' && ch != EOF)
+			while ((ch = getc_unlocked(fp)) != '\n' && ch != EOF)
 				;
 			continue;
 		}
diff --git a/lib/libc/gen/getttyent.c b/lib/libc/gen/getttyent.c
index 38b57feee91..081b56f6665 100644
--- a/lib/libc/gen/getttyent.c
+++ b/lib/libc/gen/getttyent.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getttyent.c,v 1.9 2005/08/08 08:05:34 espie Exp $ */
+/*	$OpenBSD: getttyent.c,v 1.10 2009/10/21 16:04:23 guenther Exp $ */
 /*
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -68,7 +68,7 @@ getttyent(void)
 			return (NULL);
 		/* skip lines that are too big */
 		if (!strchr(p, '\n')) {
-			while ((c = getc(tf)) != '\n' && c != EOF)
+			while ((c = getc_unlocked(tf)) != '\n' && c != EOF)
 				;
 			continue;
 		}
diff --git a/lib/libc/stdio/asprintf.c b/lib/libc/stdio/asprintf.c
index de6404ecb4f..b3b037a1fb2 100644
--- a/lib/libc/stdio/asprintf.c
+++ b/lib/libc/stdio/asprintf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: asprintf.c,v 1.15 2005/10/10 12:00:52 espie Exp $	*/
+/*	$OpenBSD: asprintf.c,v 1.16 2009/10/21 16:04:23 guenther Exp $	*/
 
 /*
  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -40,7 +40,7 @@ asprintf(char **str, const char *fmt, ...)
 		goto err;
 	f._bf._size = f._w = 127;		/* Leave room for the NUL */
 	va_start(ap, fmt);
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	va_end(ap);
 	if (ret == -1)
 		goto err;
diff --git a/lib/libc/stdio/clrerr.c b/lib/libc/stdio/clrerr.c
index 20f19945193..8286305c5be 100644
--- a/lib/libc/stdio/clrerr.c
+++ b/lib/libc/stdio/clrerr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: clrerr.c,v 1.6 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: clrerr.c,v 1.7 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -32,12 +32,13 @@
  */
 
 #include <stdio.h>
+#include "local.h"
 #undef	clearerr
 
 void
 clearerr(FILE *fp)
 {
-	flockfile(fp);
+	FLOCKFILE(fp);
 	__sclearerr(fp);
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 }
diff --git a/lib/libc/stdio/fclose.c b/lib/libc/stdio/fclose.c
index bdf6e52fc77..3d0c7b97dd8 100644
--- a/lib/libc/stdio/fclose.c
+++ b/lib/libc/stdio/fclose.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fclose.c,v 1.6 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fclose.c,v 1.7 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -45,6 +45,7 @@ fclose(FILE *fp)
 		errno = EBADF;
 		return (EOF);
 	}
+	FLOCKFILE(fp);
 	WCIO_FREE(fp);
 	r = fp->_flags & __SWR ? __sflush(fp) : 0;
 	if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0)
@@ -55,7 +56,8 @@ fclose(FILE *fp)
 		FREEUB(fp);
 	if (HASLB(fp))
 		FREELB(fp);
-	fp->_flags = 0;		/* Release this FILE for reuse. */
 	fp->_r = fp->_w = 0;	/* Mess up if reaccessed. */
+	fp->_flags = 0;		/* Release this FILE for reuse. */
+	FUNLOCKFILE(fp);
 	return (r);
 }
diff --git a/lib/libc/stdio/feof.c b/lib/libc/stdio/feof.c
index eb742da7efd..d381a29c4f7 100644
--- a/lib/libc/stdio/feof.c
+++ b/lib/libc/stdio/feof.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: feof.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: feof.c,v 1.6 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -32,6 +32,7 @@
  */
 
 #include <stdio.h>
+#include "local.h"
 
 /*
  * A subroutine version of the macro feof.
@@ -41,5 +42,10 @@
 int
 feof(FILE *fp)
 {
-	return (__sfeof(fp));
+	int	ret;
+
+	FLOCKFILE(fp);
+	ret = __sfeof(fp);
+	FUNLOCKFILE(fp);
+	return (ret);
 }
diff --git a/lib/libc/stdio/ferror.c b/lib/libc/stdio/ferror.c
index 0d2cf01a1bc..29b08d3642a 100644
--- a/lib/libc/stdio/ferror.c
+++ b/lib/libc/stdio/ferror.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ferror.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: ferror.c,v 1.6 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -32,6 +32,7 @@
  */
 
 #include <stdio.h>
+#include "local.h"
 
 /*
  * A subroutine version of the macro ferror.
@@ -41,5 +42,10 @@
 int
 ferror(FILE *fp)
 {
-	return (__sferror(fp));
+	int     ret;
+
+	FLOCKFILE(fp);
+	ret = __sferror(fp);
+	FUNLOCKFILE(fp);
+	return (ret);
 }
diff --git a/lib/libc/stdio/fflush.c b/lib/libc/stdio/fflush.c
index 3f72ad8d99b..554f531e7e0 100644
--- a/lib/libc/stdio/fflush.c
+++ b/lib/libc/stdio/fflush.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fflush.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fflush.c,v 1.6 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -39,14 +39,18 @@
 int
 fflush(FILE *fp)
 {
+	int	r;
 
 	if (fp == NULL)
-		return (_fwalk(__sflush));
+		return (_fwalk(__sflush_locked));
+	FLOCKFILE(fp);
 	if ((fp->_flags & (__SWR | __SRW)) == 0) {
 		errno = EBADF;
-		return (EOF);
-	}
-	return (__sflush(fp));
+		r = EOF;
+	} else
+		r = __sflush(fp);
+	FUNLOCKFILE(fp);
+	return (r);
 }
 
 int
@@ -80,3 +84,14 @@ __sflush(FILE *fp)
 	}
 	return (0);
 }
+
+int
+__sflush_locked(FILE *fp)
+{
+	int	r;
+
+	FLOCKFILE(fp);
+	r = __sflush(fp);
+	FUNLOCKFILE(fp);
+	return (r);
+}
diff --git a/lib/libc/stdio/fgetc.c b/lib/libc/stdio/fgetc.c
index 53e2948813e..d5a08a9abf3 100644
--- a/lib/libc/stdio/fgetc.c
+++ b/lib/libc/stdio/fgetc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fgetc.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fgetc.c,v 1.6 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -36,5 +36,5 @@
 int
 fgetc(FILE *fp)
 {
-	return (__sgetc(fp));
+	return (getc(fp));
 }
diff --git a/lib/libc/stdio/fgetln.c b/lib/libc/stdio/fgetln.c
index f97cfb97e60..8723f7982ac 100644
--- a/lib/libc/stdio/fgetln.c
+++ b/lib/libc/stdio/fgetln.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fgetln.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fgetln.c,v 1.8 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -71,19 +71,18 @@ char *
 fgetln(FILE *fp, size_t *lenp)
 {
 	unsigned char *p;
+	char *ret;
 	size_t len;
 	size_t off;
 
+	FLOCKFILE(fp);
+
 	/* make sure there is input */
-	if (fp->_r <= 0 && __srefill(fp)) {
-		*lenp = 0;
-		return (NULL);
-	}
+	if (fp->_r <= 0 && __srefill(fp))
+		goto error;
 
 	/* look for a newline in the input */
 	if ((p = memchr((void *)fp->_p, '\n', fp->_r)) != NULL) {
-		char *ret;
-
 		/*
 		 * Found one.  Flag buffer as modified to keep fseek from
 		 * `optimising' a backward seek, in case the user stomps on
@@ -95,6 +94,7 @@ fgetln(FILE *fp, size_t *lenp)
 		fp->_flags |= __SMOD;
 		fp->_r -= len;
 		fp->_p = p;
+		FUNLOCKFILE(fp);
 		return (ret);
 	}
 
@@ -139,12 +139,15 @@ fgetln(FILE *fp, size_t *lenp)
 		break;
 	}
 	*lenp = len;
+	ret = (char *)fp->_lb._base;
 #ifdef notdef
-	fp->_lb._base[len] = '\0';
+	ret[len] = '\0';
 #endif
-	return ((char *)fp->_lb._base);
+	FUNLOCKFILE(fp);
+	return (ret);
 
 error:
 	*lenp = 0;		/* ??? */
+	FUNLOCKFILE(fp);
 	return (NULL);		/* ??? */
 }
diff --git a/lib/libc/stdio/fgets.c b/lib/libc/stdio/fgets.c
index 536935256be..66ba159509c 100644
--- a/lib/libc/stdio/fgets.c
+++ b/lib/libc/stdio/fgets.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fgets.c,v 1.11 2009/06/02 22:28:18 ray Exp $ */
+/*	$OpenBSD: fgets.c,v 1.12 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -54,6 +54,7 @@ fgets(char *buf, int n, FILE *fp)
 		return (NULL);
 	}
 
+	FLOCKFILE(fp);
 	_SET_ORIENTATION(fp, -1);
 	s = buf;
 	n--;			/* leave space for NUL */
@@ -64,8 +65,10 @@ fgets(char *buf, int n, FILE *fp)
 		if (fp->_r <= 0) {
 			if (__srefill(fp)) {
 				/* EOF/error: stop with partial or no line */
-				if (s == buf)
+				if (s == buf) {
+					FUNLOCKFILE(fp);
 					return (NULL);
+				}
 				break;
 			}
 		}
@@ -87,6 +90,7 @@ fgets(char *buf, int n, FILE *fp)
 			fp->_p = t;
 			(void)memcpy((void *)s, (void *)p, len);
 			s[len] = '\0';
+			FUNLOCKFILE(fp);
 			return (buf);
 		}
 		fp->_r -= len;
@@ -96,5 +100,6 @@ fgets(char *buf, int n, FILE *fp)
 		n -= len;
 	}
 	*s = '\0';
+	FUNLOCKFILE(fp);
 	return (buf);
 }
diff --git a/lib/libc/stdio/fgetwc.c b/lib/libc/stdio/fgetwc.c
index 8da50877264..0ab5cb78200 100644
--- a/lib/libc/stdio/fgetwc.c
+++ b/lib/libc/stdio/fgetwc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fgetwc.c,v 1.1 2005/06/17 20:40:32 espie Exp $	*/
+/*	$OpenBSD: fgetwc.c,v 1.2 2009/10/21 16:04:23 guenther Exp $	*/
 /* $NetBSD: fgetwc.c,v 1.3 2003/03/07 07:11:36 tshiozak Exp $ */
 
 /*-
@@ -82,9 +82,9 @@ fgetwc(FILE *fp)
 {
 	wint_t r;
 
-	flockfile(fp);
+	FLOCKFILE(fp);
 	r = __fgetwc_unlock(fp);
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 
 	return (r);
 }
diff --git a/lib/libc/stdio/fgetws.c b/lib/libc/stdio/fgetws.c
index 783ff919b09..5716021f430 100644
--- a/lib/libc/stdio/fgetws.c
+++ b/lib/libc/stdio/fgetws.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fgetws.c,v 1.2 2005/08/08 08:05:36 espie Exp $	*/
+/*	$OpenBSD: fgetws.c,v 1.3 2009/10/21 16:04:23 guenther Exp $	*/
 /* $NetBSD: fgetws.c,v 1.1 2003/03/07 07:11:37 tshiozak Exp $ */
 
 /*-
@@ -45,7 +45,7 @@ fgetws(ws, n, fp)
 	wchar_t *wsp;
 	wint_t wc;
 
-	flockfile(fp);
+	FLOCKFILE(fp);
 	_SET_ORIENTATION(fp, 1);
 
 	if (n <= 0) {
@@ -72,11 +72,11 @@ fgetws(ws, n, fp)
 	}
 
 	*wsp++ = L'\0';
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 
 	return (ws);
 
 error:
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 	return (NULL);
 }
diff --git a/lib/libc/stdio/fileno.c b/lib/libc/stdio/fileno.c
index 0fd985b23e7..7237beb84dc 100644
--- a/lib/libc/stdio/fileno.c
+++ b/lib/libc/stdio/fileno.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fileno.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fileno.c,v 1.6 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -32,6 +32,7 @@
  */
 
 #include <stdio.h>
+#include "local.h"
 
 /*
  * A subroutine version of the macro fileno.
@@ -41,5 +42,10 @@
 int
 fileno(FILE *fp)
 {
-	return (__sfileno(fp));
+	int     ret;
+
+	FLOCKFILE(fp);
+	ret = __sfileno(fp);
+	FUNLOCKFILE(fp);
+	return (ret);
 }
diff --git a/lib/libc/stdio/findfp.c b/lib/libc/stdio/findfp.c
index 27d19843208..f3e000c3591 100644
--- a/lib/libc/stdio/findfp.c
+++ b/lib/libc/stdio/findfp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: findfp.c,v 1.9 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: findfp.c,v 1.10 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -39,6 +39,7 @@
 #include <string.h>
 #include "local.h"
 #include "glue.h"
+#include "thread_private.h"
 
 int	__sdidinit;
 
@@ -54,6 +55,8 @@ int	__sdidinit;
 static FILE usual[FOPEN_MAX - 3];
 static struct __sfileext usualext[FOPEN_MAX - 3];
 static struct glue uglue = { 0, FOPEN_MAX - 3, usual };
+static struct glue *lastglue = &uglue;
+_THREAD_PRIVATE_MUTEX(__sfp_mutex);
 
 struct __sfileext __sFext[3];
 FILE __sF[3] = {
@@ -104,16 +107,25 @@ __sfp(void)
 
 	if (!__sdidinit)
 		__sinit();
-	for (g = &__sglue;; g = g->next) {
+
+	_THREAD_PRIVATE_MUTEX_LOCK(__sfp_mutex);
+	for (g = &__sglue; g != NULL; g = g->next) {
 		for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
 			if (fp->_flags == 0)
 				goto found;
-		if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL)
-			break;
 	}
-	return (NULL);
+
+	/* release lock while mallocing */
+	_THREAD_PRIVATE_MUTEX_UNLOCK(__sfp_mutex);
+	if ((g = moreglue(NDYNAMIC)) == NULL)
+		return (NULL);
+	_THREAD_PRIVATE_MUTEX_LOCK(__sfp_mutex);
+	lastglue->next = g;
+	lastglue = g;
+	fp = g->iobs;
 found:
 	fp->_flags = 1;		/* reserve this slot; caller sets real flags */
+	_THREAD_PRIVATE_MUTEX_UNLOCK(__sfp_mutex);
 	fp->_p = NULL;		/* no current pointer */
 	fp->_w = 0;		/* nothing to read or write */
 	fp->_r = 0;
@@ -143,8 +155,12 @@ f_prealloc(void)
 	n = getdtablesize() - FOPEN_MAX + 20;		/* 20 for slop. */
 	for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
 		/* void */;
-	if (n > 0)
-		g->next = moreglue(n);
+	if (n > 0 && ((g = moreglue(n)) != NULL)) {
+		_THREAD_PRIVATE_MUTEX_LOCK(__sfp_mutex);
+		lastglue->next = g;
+		lastglue = g;
+		_THREAD_PRIVATE_MUTEX_UNLOCK(__sfp_mutex);
+	}
 }
 
 /*
@@ -168,12 +184,18 @@ _cleanup(void)
 void
 __sinit(void)
 {
+	_THREAD_PRIVATE_MUTEX(__sinit_mutex);
 	int i;
 
+	_THREAD_PRIVATE_MUTEX_LOCK(__sinit_mutex);
+	if (__sdidinit)
+		goto out;	/* bail out if caller lost the race */
 	for (i = 0; i < FOPEN_MAX - 3; i++) {
 		_FILEEXT_SETUP(usual+i, usualext+i);
 	}
 	/* make sure we clean up on exit */
 	__atexit_register_cleanup(_cleanup); /* conservative */
 	__sdidinit = 1;
+out: 
+	_THREAD_PRIVATE_MUTEX_UNLOCK(__sinit_mutex);
 }
diff --git a/lib/libc/stdio/fpurge.c b/lib/libc/stdio/fpurge.c
index fa0213ac7b7..4a0988e8479 100644
--- a/lib/libc/stdio/fpurge.c
+++ b/lib/libc/stdio/fpurge.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fpurge.c,v 1.6 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fpurge.c,v 1.7 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -43,7 +43,9 @@
 int
 fpurge(FILE *fp)
 {
+	FLOCKFILE(fp);
 	if (!fp->_flags) {
+		FUNLOCKFILE(fp);
 		errno = EBADF;
 		return(EOF);
 	}
@@ -54,5 +56,6 @@ fpurge(FILE *fp)
 	fp->_p = fp->_bf._base;
 	fp->_r = 0;
 	fp->_w = fp->_flags & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
+	FUNLOCKFILE(fp);
 	return (0);
 }
diff --git a/lib/libc/stdio/fputc.c b/lib/libc/stdio/fputc.c
index 2a6e7b7456f..275e0398411 100644
--- a/lib/libc/stdio/fputc.c
+++ b/lib/libc/stdio/fputc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fputc.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fputc.c,v 1.8 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -33,14 +33,9 @@
 
 #include <stdio.h>
 #include <errno.h>
-#include "local.h"
 
 int
 fputc(int c, FILE *fp)
 {
-	if (cantwrite(fp)) {
-		errno = EBADF;
-		return (EOF);
-	}
 	return (putc(c, fp));
 }
diff --git a/lib/libc/stdio/fputs.c b/lib/libc/stdio/fputs.c
index 7434ca86d64..4a861fa66b9 100644
--- a/lib/libc/stdio/fputs.c
+++ b/lib/libc/stdio/fputs.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fputs.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fputs.c,v 1.8 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -44,11 +44,15 @@ fputs(const char *s, FILE *fp)
 {
 	struct __suio uio;
 	struct __siov iov;
+	int ret;
 
 	iov.iov_base = (void *)s;
 	iov.iov_len = uio.uio_resid = strlen(s);
 	uio.uio_iov = &iov;
 	uio.uio_iovcnt = 1;
+	FLOCKFILE(fp);
 	_SET_ORIENTATION(fp, -1);
-	return (__sfvwrite(fp, &uio));
+	ret = __sfvwrite(fp, &uio);
+	FUNLOCKFILE(fp);
+	return (ret);
 }
diff --git a/lib/libc/stdio/fputwc.c b/lib/libc/stdio/fputwc.c
index 4b54cfa4dd5..4d399730440 100644
--- a/lib/libc/stdio/fputwc.c
+++ b/lib/libc/stdio/fputwc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fputwc.c,v 1.1 2005/06/17 20:40:32 espie Exp $	*/
+/*	$OpenBSD: fputwc.c,v 1.2 2009/10/21 16:04:23 guenther Exp $	*/
 /* $NetBSD: fputwc.c,v 1.3 2003/03/07 07:11:37 tshiozak Exp $ */
 
 /*-
@@ -80,9 +80,9 @@ fputwc(wchar_t wc, FILE *fp)
 {
 	wint_t r;
 
-	flockfile(fp);
+	FLOCKFILE(fp);
 	r = __fputwc_unlock(wc, fp);
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 
 	return (r);
 }
diff --git a/lib/libc/stdio/fputws.c b/lib/libc/stdio/fputws.c
index a54ee669608..d2163affc36 100644
--- a/lib/libc/stdio/fputws.c
+++ b/lib/libc/stdio/fputws.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fputws.c,v 1.2 2005/08/08 08:05:36 espie Exp $	*/
+/*	$OpenBSD: fputws.c,v 1.3 2009/10/21 16:04:23 guenther Exp $	*/
 /* $NetBSD: fputws.c,v 1.1 2003/03/07 07:11:37 tshiozak Exp $ */
 
 /*-
@@ -40,17 +40,17 @@ fputws(ws, fp)
 	const wchar_t * __restrict ws;
 	FILE * __restrict fp;
 {
-	flockfile(fp);
+	FLOCKFILE(fp);
 	_SET_ORIENTATION(fp, 1);
 
 	while (*ws != '\0') {
 		if (__fputwc_unlock(*ws++, fp) == WEOF) {
-			funlockfile(fp);
+			FUNLOCKFILE(fp);
 			return (-1);
 		}
 	}
 
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 
 	return (0);
 }
diff --git a/lib/libc/stdio/fread.c b/lib/libc/stdio/fread.c
index c7389e76ed6..572be07160f 100644
--- a/lib/libc/stdio/fread.c
+++ b/lib/libc/stdio/fread.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fread.c,v 1.7 2009/07/12 18:45:21 millert Exp $ */
+/*	$OpenBSD: fread.c,v 1.8 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -48,6 +48,7 @@ fread(void *buf, size_t size, size_t count, FILE *fp)
 	 */
 	if ((resid = count * size) == 0)
 		return (0);
+	FLOCKFILE(fp);
 	if (fp->_r < 0)
 		fp->_r = 0;
 	total = resid;
@@ -60,11 +61,13 @@ fread(void *buf, size_t size, size_t count, FILE *fp)
 		resid -= r;
 		if (__srefill(fp)) {
 			/* no more input: return partial result */
+			FUNLOCKFILE(fp);
 			return ((total - resid) / size);
 		}
 	}
 	(void)memcpy((void *)p, (void *)fp->_p, resid);
 	fp->_r -= resid;
 	fp->_p += resid;
+	FUNLOCKFILE(fp);
 	return (count);
 }
diff --git a/lib/libc/stdio/freopen.c b/lib/libc/stdio/freopen.c
index cd2d833846b..b5dbc3096d4 100644
--- a/lib/libc/stdio/freopen.c
+++ b/lib/libc/stdio/freopen.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: freopen.c,v 1.10 2008/04/21 12:28:35 otto Exp $ */
+/*	$OpenBSD: freopen.c,v 1.11 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -60,6 +60,8 @@ freopen(const char *file, const char *mode, FILE *fp)
 	if (!__sdidinit)
 		__sinit();
 
+	FLOCKFILE(fp);
+
 	/*
 	 * There are actually programs that depend on being able to "freopen"
 	 * descriptors that weren't originally open.  Keep this from breaking.
@@ -121,6 +123,7 @@ freopen(const char *file, const char *mode, FILE *fp)
 
 	if (f < 0) {			/* did not get it after all */
 		fp->_flags = 0;		/* set it free */
+		FUNLOCKFILE(fp);
 		errno = sverrno;	/* restore in case _close clobbered */
 		return (NULL);
 	}
@@ -140,6 +143,7 @@ freopen(const char *file, const char *mode, FILE *fp)
 	/* _file is only a short */
 	if (f > SHRT_MAX) {
 		fp->_flags = 0;		/* set it free */
+		FUNLOCKFILE(fp);
 		errno = EMFILE;
 		return (NULL);
 	}
@@ -162,5 +166,6 @@ freopen(const char *file, const char *mode, FILE *fp)
 	 */
 	if (oflags & O_APPEND)
 		(void) __sseek((void *)fp, (fpos_t)0, SEEK_END);
+	FUNLOCKFILE(fp);
 	return (fp);
 }
diff --git a/lib/libc/stdio/fseek.c b/lib/libc/stdio/fseek.c
index 4f5014d6e0c..525c095f895 100644
--- a/lib/libc/stdio/fseek.c
+++ b/lib/libc/stdio/fseek.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fseek.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fseek.c,v 1.8 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -70,6 +70,7 @@ fseeko(FILE *fp, off_t offset, int whence)
 	 * Change any SEEK_CUR to SEEK_SET, and check `whence' argument.
 	 * After this, whence is either SEEK_SET or SEEK_END.
 	 */
+	FLOCKFILE(fp);
 	switch (whence) {
 
 	case SEEK_CUR:
@@ -83,8 +84,10 @@ fseeko(FILE *fp, off_t offset, int whence)
 			curoff = fp->_offset;
 		else {
 			curoff = (*seekfn)(fp->_cookie, (fpos_t)0, SEEK_CUR);
-			if (curoff == (fpos_t)-1)
+			if (curoff == (fpos_t)-1) {
+				FUNLOCKFILE(fp);
 				return (EOF);
+			}
 		}
 		if (fp->_flags & __SRD) {
 			curoff -= fp->_r;
@@ -105,6 +108,7 @@ fseeko(FILE *fp, off_t offset, int whence)
 		break;
 
 	default:
+		FUNLOCKFILE(fp);
 		errno = EINVAL;
 		return (EOF);
 	}
@@ -189,6 +193,7 @@ fseeko(FILE *fp, off_t offset, int whence)
 		if (HASUB(fp))
 			FREEUB(fp);
 		fp->_flags &= ~__SEOF;
+		FUNLOCKFILE(fp);
 		return (0);
 	}
 
@@ -215,6 +220,7 @@ fseeko(FILE *fp, off_t offset, int whence)
 		fp->_p += n;
 		fp->_r -= n;
 	}
+	FUNLOCKFILE(fp);
 	return (0);
 
 	/*
@@ -224,6 +230,7 @@ fseeko(FILE *fp, off_t offset, int whence)
 dumb:
 	if (__sflush(fp) ||
 	    (*seekfn)(fp->_cookie, (fpos_t)offset, whence) == POS_ERR) {
+		FUNLOCKFILE(fp);
 		return (EOF);
 	}
 	/* success: clear EOF indicator and discard ungetc() data */
@@ -233,6 +240,7 @@ dumb:
 	fp->_r = 0;
 	/* fp->_w = 0; */	/* unnecessary (I think...) */
 	fp->_flags &= ~__SEOF;
+	FUNLOCKFILE(fp);
 	return (0);
 }
 
diff --git a/lib/libc/stdio/ftell.c b/lib/libc/stdio/ftell.c
index b7d449e187d..9d4d54628ac 100644
--- a/lib/libc/stdio/ftell.c
+++ b/lib/libc/stdio/ftell.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ftell.c,v 1.6 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: ftell.c,v 1.7 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -45,20 +45,22 @@ ftello(FILE *fp)
 
 	if (fp->_seek == NULL) {
 		errno = ESPIPE;			/* historic practice */
-		return ((off_t)-1);
+		pos = -1;
+		goto out;
 	}
 
 	/*
 	 * Find offset of underlying I/O object, then
 	 * adjust for buffered bytes.
 	 */
+	FLOCKFILE(fp);
 	__sflush(fp);		/* may adjust seek offset on append stream */
 	if (fp->_flags & __SOFF)
 		pos = fp->_offset;
 	else {
 		pos = (*fp->_seek)(fp->_cookie, (fpos_t)0, SEEK_CUR);
-		if (pos == -1L)
-			return (pos);
+		if (pos == -1)
+			goto out;
 	}
 	if (fp->_flags & __SRD) {
 		/*
@@ -77,6 +79,7 @@ ftello(FILE *fp)
 		 */
 		pos += fp->_p - fp->_bf._base;
 	}
+out:	FUNLOCKFILE(fp);
 	return (pos);
 }
 
diff --git a/lib/libc/stdio/fvwrite.c b/lib/libc/stdio/fvwrite.c
index e70ff3490ad..d16db977329 100644
--- a/lib/libc/stdio/fvwrite.c
+++ b/lib/libc/stdio/fvwrite.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fvwrite.c,v 1.14 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fvwrite.c,v 1.15 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -134,7 +134,7 @@ __sfvwrite(FILE *fp, struct __suio *uio)
 				COPY(w);
 				/* fp->_w -= w; */ /* unneeded */
 				fp->_p += w;
-				if (fflush(fp))
+				if (__sflush(fp))
 					goto err;
 			} else if (len >= (w = fp->_bf._size)) {
 				/* write directly */
@@ -174,7 +174,7 @@ __sfvwrite(FILE *fp, struct __suio *uio)
 				COPY(w);
 				/* fp->_w -= w; */
 				fp->_p += w;
-				if (fflush(fp))
+				if (__sflush(fp))
 					goto err;
 			} else if (s >= (w = fp->_bf._size)) {
 				w = (*fp->_write)(fp->_cookie, p, w);
@@ -188,7 +188,7 @@ __sfvwrite(FILE *fp, struct __suio *uio)
 			}
 			if ((nldist -= w) == 0) {
 				/* copied the newline: flush and forget */
-				if (fflush(fp))
+				if (__sflush(fp))
 					goto err;
 				nlknown = 0;
 			}
diff --git a/lib/libc/stdio/fwalk.c b/lib/libc/stdio/fwalk.c
index 5606cf1e002..0f1c1b6e32f 100644
--- a/lib/libc/stdio/fwalk.c
+++ b/lib/libc/stdio/fwalk.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fwalk.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: fwalk.c,v 1.8 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -45,8 +45,9 @@ _fwalk(int (*function)(FILE *))
 
 	ret = 0;
 	for (g = &__sglue; g != NULL; g = g->next)
-		for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
-			if (fp->_flags != 0)
+		for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) {
+			if ((fp->_flags != 0) && ((fp->_flags & __SIGN) == 0))
 				ret |= (*function)(fp);
+		}
 	return (ret);
 }
diff --git a/lib/libc/stdio/fwide.c b/lib/libc/stdio/fwide.c
index 6fd31b0e73e..b15a14f2375 100644
--- a/lib/libc/stdio/fwide.c
+++ b/lib/libc/stdio/fwide.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fwide.c,v 1.1 2005/06/17 20:40:32 espie Exp $	*/
+/*	$OpenBSD: fwide.c,v 1.2 2009/10/21 16:04:23 guenther Exp $	*/
 /* $NetBSD: fwide.c,v 1.2 2003/01/18 11:29:54 thorpej Exp $ */
 
 /*-
@@ -49,7 +49,7 @@ fwide(FILE *fp, int mode)
 	else if (mode < 0)
 		mode = -1;
 
-	flockfile(fp);
+	FLOCKFILE(fp);
 	wcio = WCIO_GET(fp);
 	if (!wcio)
 		return 0; /* XXX */
@@ -58,7 +58,7 @@ fwide(FILE *fp, int mode)
 		wcio->wcio_mode = mode;
 	else
 		mode = wcio->wcio_mode;
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 
 	return mode;
 }
diff --git a/lib/libc/stdio/fwrite.c b/lib/libc/stdio/fwrite.c
index a60f9e0807a..8e7ae01e096 100644
--- a/lib/libc/stdio/fwrite.c
+++ b/lib/libc/stdio/fwrite.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fwrite.c,v 1.6 2009/07/12 18:45:21 millert Exp $ */
+/*	$OpenBSD: fwrite.c,v 1.7 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -45,6 +45,7 @@ fwrite(const void *buf, size_t size, size_t count, FILE *fp)
 	size_t n;
 	struct __suio uio;
 	struct __siov iov;
+	int ret;
 
 	/*
 	 * ANSI and SUSv2 require a return value of 0 if size or count are 0.
@@ -62,7 +63,10 @@ fwrite(const void *buf, size_t size, size_t count, FILE *fp)
 	 * skip the divide if this happens, since divides are
 	 * generally slow and since this occurs whenever size==0.
 	 */
-	if (__sfvwrite(fp, &uio) == 0)
+	FLOCKFILE(fp);
+	ret = __sfvwrite(fp, &uio);
+	FUNLOCKFILE(fp);
+	if (ret == 0)
 		return (count);
 	return ((n - uio.uio_resid) / size);
 }
diff --git a/lib/libc/stdio/getc.c b/lib/libc/stdio/getc.c
index cdd572215bd..8a1f8c9e510 100644
--- a/lib/libc/stdio/getc.c
+++ b/lib/libc/stdio/getc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getc.c,v 1.6 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: getc.c,v 1.7 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -32,6 +32,7 @@
  */
 
 #include <stdio.h>
+#include "local.h"
 
 /*
  * A subroutine version of the macro getc_unlocked.
@@ -54,8 +55,8 @@ getc(FILE *fp)
 {
 	int c;
 
-	flockfile(fp);
+	FLOCKFILE(fp);
 	c = __sgetc(fp);
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 	return (c);
 }
diff --git a/lib/libc/stdio/gets.c b/lib/libc/stdio/gets.c
index 004eb99f487..30cd712e035 100644
--- a/lib/libc/stdio/gets.c
+++ b/lib/libc/stdio/gets.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gets.c,v 1.9 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: gets.c,v 1.10 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -32,6 +32,7 @@
  */
 
 #include <stdio.h>
+#include "local.h"
 
 __warn_references(gets,
     "warning: gets() is very unsafe; consider using fgets()");
@@ -42,14 +43,17 @@ gets(char *buf)
 	int c;
 	char *s;
 
-	for (s = buf; (c = getchar()) != '\n';)
+	FLOCKFILE(stdin);
+	for (s = buf; (c = getchar_unlocked()) != '\n';)
 		if (c == EOF)
-			if (s == buf)
+			if (s == buf) {
+				FUNLOCKFILE(stdin);
 				return (NULL);
-			else
+			} else
 				break;
 		else
 			*s++ = c;
 	*s = '\0';
+	FUNLOCKFILE(stdin);
 	return (buf);
 }
diff --git a/lib/libc/stdio/local.h b/lib/libc/stdio/local.h
index e5863e5a604..5c5e878841f 100644
--- a/lib/libc/stdio/local.h
+++ b/lib/libc/stdio/local.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: local.h,v 1.12 2005/10/10 17:37:44 espie Exp $	*/
+/*	$OpenBSD: local.h,v 1.13 2009/10/21 16:04:23 guenther Exp $	*/
 
 /*-
  * Copyright (c) 1990, 1993
@@ -42,6 +42,7 @@
 #include "fileext.h"
 
 int	__sflush(FILE *);
+int	__sflush_locked(FILE *);
 FILE	*__sfp(void);
 int	__srefill(FILE *);
 int	__sread(void *, char *, int);
@@ -56,6 +57,7 @@ int	_fwalk(int (*)(FILE *));
 int	__swsetup(FILE *);
 int	__sflags(const char *, int *);
 wint_t __fgetwc_unlock(FILE *);
+int	__vfprintf(FILE *, const char *, __va_list);
 
 extern void __atexit_register_cleanup(void (*)(void));
 extern int __sdidinit;
@@ -86,3 +88,6 @@ extern int __sdidinit;
 	free((char *)(fp)->_lb._base); \
 	(fp)->_lb._base = NULL; \
 }
+
+#define FLOCKFILE(fp)	do { if (__isthreaded) flockfile(fp); } while (0)
+#define FUNLOCKFILE(fp)	do { if (__isthreaded) funlockfile(fp); } while (0)
diff --git a/lib/libc/stdio/putc.c b/lib/libc/stdio/putc.c
index 925021549fb..571c7a70538 100644
--- a/lib/libc/stdio/putc.c
+++ b/lib/libc/stdio/putc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: putc.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: putc.c,v 1.8 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -60,8 +60,8 @@ putc(int c, FILE *fp)
 {
 	int ret;
 
-	flockfile(fp);
+	FLOCKFILE(fp);
 	ret = putc_unlocked(c, fp);
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 	return (ret);
 }
diff --git a/lib/libc/stdio/puts.c b/lib/libc/stdio/puts.c
index c6ecc24f1a8..a3957b3b234 100644
--- a/lib/libc/stdio/puts.c
+++ b/lib/libc/stdio/puts.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: puts.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: puts.c,v 1.8 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -33,6 +33,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include "local.h"
 #include "fvwrite.h"
 
 /*
@@ -44,6 +45,7 @@ puts(const char *s)
 	size_t c = strlen(s);
 	struct __suio uio;
 	struct __siov iov[2];
+	int ret;
 
 	iov[0].iov_base = (void *)s;
 	iov[0].iov_len = c;
@@ -52,5 +54,8 @@ puts(const char *s)
 	uio.uio_resid = c + 1;
 	uio.uio_iov = &iov[0];
 	uio.uio_iovcnt = 2;
-	return (__sfvwrite(stdout, &uio) ? EOF : '\n');
+	FLOCKFILE(stdout);
+	ret = __sfvwrite(stdout, &uio);
+	FUNLOCKFILE(stdout);
+	return (ret ? EOF : '\n');
 }
diff --git a/lib/libc/stdio/putw.c b/lib/libc/stdio/putw.c
index 12955fec848..b47d87cb21f 100644
--- a/lib/libc/stdio/putw.c
+++ b/lib/libc/stdio/putw.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: putw.c,v 1.6 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: putw.c,v 1.7 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -32,6 +32,7 @@
  */
 
 #include <stdio.h>
+#include "local.h"
 #include "fvwrite.h"
 
 int
@@ -39,10 +40,14 @@ putw(int w, FILE *fp)
 {
 	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;
-	return (__sfvwrite(fp, &uio));
+	FLOCKFILE(fp);
+	ret = __sfvwrite(fp, &uio);
+	FUNLOCKFILE(fp);
+	return (ret);
 }
diff --git a/lib/libc/stdio/refill.c b/lib/libc/stdio/refill.c
index 74b378e1488..a559ca9b320 100644
--- a/lib/libc/stdio/refill.c
+++ b/lib/libc/stdio/refill.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: refill.c,v 1.8 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: refill.c,v 1.9 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -39,9 +39,8 @@
 static int
 lflush(FILE *fp)
 {
-
 	if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
-		return (__sflush(fp));
+		return (__sflush_locked(fp));	/* ignored... */
 	return (0);
 }
 
@@ -103,8 +102,16 @@ __srefill(FILE *fp)
 	 * flush all line buffered output files, per the ANSI C
 	 * standard.
 	 */
-	if (fp->_flags & (__SLBF|__SNBF))
+	if (fp->_flags & (__SLBF|__SNBF)) {
+		/* Ignore this file in _fwalk to avoid potential deadlock. */
+		fp->_flags |= __SIGN;
 		(void) _fwalk(lflush);
+		fp->_flags &= ~__SIGN;
+
+		/* Now flush this file without locking it. */
+		if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
+			__sflush(fp);
+	}
 	fp->_p = fp->_bf._base;
 	fp->_r = (*fp->_read)(fp->_cookie, (char *)fp->_p, fp->_bf._size);
 	fp->_flags &= ~__SMOD;	/* buffer contents are again pristine */
diff --git a/lib/libc/stdio/setvbuf.c b/lib/libc/stdio/setvbuf.c
index 9b92bf08113..21db80dbbdb 100644
--- a/lib/libc/stdio/setvbuf.c
+++ b/lib/libc/stdio/setvbuf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: setvbuf.c,v 1.8 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: setvbuf.c,v 1.9 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -61,6 +61,7 @@ setvbuf(FILE *fp, char *buf, int mode, size_t size)
 	 * malloc()ed.  We also clear any eof condition, as if this were
 	 * a seek.
 	 */
+	FLOCKFILE(fp);
 	ret = 0;
 	(void)__sflush(fp);
 	if (HASUB(fp))
@@ -107,6 +108,7 @@ nbf:
 			fp->_w = 0;
 			fp->_bf._base = fp->_p = fp->_nbuf;
 			fp->_bf._size = 1;
+			FUNLOCKFILE(fp);
 			return (ret);
 		}
 		flags |= __SMBF;
@@ -145,6 +147,7 @@ nbf:
 		/* begin/continue reading, or stay in intermediate state */
 		fp->_w = 0;
 	}
+	FUNLOCKFILE(fp);
 	__atexit_register_cleanup(_cleanup);
 
 	return (ret);
diff --git a/lib/libc/stdio/snprintf.c b/lib/libc/stdio/snprintf.c
index 45ef7eb676a..56f3b612c37 100644
--- a/lib/libc/stdio/snprintf.c
+++ b/lib/libc/stdio/snprintf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: snprintf.c,v 1.14 2005/10/10 12:00:52 espie Exp $ */
+/*	$OpenBSD: snprintf.c,v 1.15 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -60,7 +60,7 @@ snprintf(char *str, size_t n, const char *fmt, ...)
 	f._bf._base = f._p = (unsigned char *)str;
 	f._bf._size = f._w = n - 1;
 	va_start(ap, fmt);
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	va_end(ap);
 	*f._p = '\0';
 	return (ret);
diff --git a/lib/libc/stdio/sprintf.c b/lib/libc/stdio/sprintf.c
index 67f924b27e8..c26d0e3930e 100644
--- a/lib/libc/stdio/sprintf.c
+++ b/lib/libc/stdio/sprintf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sprintf.c,v 1.13 2005/10/10 12:00:52 espie Exp $ */
+/*	$OpenBSD: sprintf.c,v 1.14 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -56,7 +56,7 @@ sprintf(char *str, const char *fmt, ...)
 	f._bf._base = f._p = (unsigned char *)str;
 	f._bf._size = f._w = INT_MAX;
 	va_start(ap, fmt);
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	va_end(ap);
 	*f._p = '\0';
 	return (ret);
diff --git a/lib/libc/stdio/ungetc.c b/lib/libc/stdio/ungetc.c
index fe05258a84e..9c4296df053 100644
--- a/lib/libc/stdio/ungetc.c
+++ b/lib/libc/stdio/ungetc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ungetc.c,v 1.9 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: ungetc.c,v 1.10 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -82,17 +82,20 @@ ungetc(int c, FILE *fp)
 		return (EOF);
 	if (!__sdidinit)
 		__sinit();
+	FLOCKFILE(fp);
 	_SET_ORIENTATION(fp, -1);
 	if ((fp->_flags & __SRD) == 0) {
 		/*
 		 * Not already reading: no good unless reading-and-writing.
 		 * Otherwise, flush any current write stuff.
 		 */
-		if ((fp->_flags & __SRW) == 0)
+		if ((fp->_flags & __SRW) == 0) {
+error:			FUNLOCKFILE(fp);
 			return (EOF);
+		}
 		if (fp->_flags & __SWR) {
 			if (__sflush(fp))
-				return (EOF);
+				goto error;
 			fp->_flags &= ~__SWR;
 			fp->_w = 0;
 			fp->_lbfsize = 0;
@@ -107,9 +110,10 @@ ungetc(int c, FILE *fp)
 	 */
 	if (HASUB(fp)) {
 		if (fp->_r >= _UB(fp)._size && __submore(fp))
-			return (EOF);
+			goto error;
 		*--fp->_p = c;
-		fp->_r++;
+inc_ret:	fp->_r++;
+		FUNLOCKFILE(fp);
 		return (c);
 	}
 	fp->_flags &= ~__SEOF;
@@ -122,8 +126,7 @@ ungetc(int c, FILE *fp)
 	if (fp->_bf._base != NULL && fp->_p > fp->_bf._base &&
 	    fp->_p[-1] == c) {
 		fp->_p--;
-		fp->_r++;
-		return (c);
+		goto inc_ret;
 	}
 
 	/*
@@ -137,5 +140,6 @@ ungetc(int c, FILE *fp)
 	fp->_ubuf[sizeof(fp->_ubuf) - 1] = c;
 	fp->_p = &fp->_ubuf[sizeof(fp->_ubuf) - 1];
 	fp->_r = 1;
+	FUNLOCKFILE(fp);
 	return (c);
 }
diff --git a/lib/libc/stdio/ungetwc.c b/lib/libc/stdio/ungetwc.c
index 8bd30168130..20d953e79e8 100644
--- a/lib/libc/stdio/ungetwc.c
+++ b/lib/libc/stdio/ungetwc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ungetwc.c,v 1.1 2005/06/17 20:40:32 espie Exp $	*/
+/*	$OpenBSD: ungetwc.c,v 1.2 2009/10/21 16:04:23 guenther Exp $	*/
 /* $NetBSD: ungetwc.c,v 1.2 2003/01/18 11:29:59 thorpej Exp $ */
 
 /*-
@@ -42,7 +42,7 @@ ungetwc(wint_t wc, FILE *fp)
 	if (wc == WEOF)
 		return WEOF;
 
-	flockfile(fp);
+	FLOCKFILE(fp);
 	_SET_ORIENTATION(fp, 1);
 	/*
 	 * XXX since we have no way to transform a wchar string to
@@ -52,19 +52,19 @@ ungetwc(wint_t wc, FILE *fp)
 
 	wcio = WCIO_GET(fp);
 	if (wcio == 0) {
-		funlockfile(fp);
+		FUNLOCKFILE(fp);
 		errno = ENOMEM; /* XXX */
 		return WEOF;
 	}
 
 	if (wcio->wcio_ungetwc_inbuf >= WCIO_UNGETWC_BUFSIZE) {
-		funlockfile(fp);
+		FUNLOCKFILE(fp);
 		return WEOF;
 	}
 
 	wcio->wcio_ungetwc_buf[wcio->wcio_ungetwc_inbuf++] = wc;
 	__sclearerr(fp);
-	funlockfile(fp);
+	FUNLOCKFILE(fp);
 
 	return wc;
 }
diff --git a/lib/libc/stdio/vasprintf.c b/lib/libc/stdio/vasprintf.c
index c3280c9fcd3..65c15c038f2 100644
--- a/lib/libc/stdio/vasprintf.c
+++ b/lib/libc/stdio/vasprintf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vasprintf.c,v 1.13 2006/01/06 18:53:04 millert Exp $	*/
+/*	$OpenBSD: vasprintf.c,v 1.14 2009/10/21 16:04:23 guenther Exp $	*/
 
 /*
  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -37,7 +37,7 @@ vasprintf(char **str, const char *fmt, __va_list ap)
 	if (f._bf._base == NULL)
 		goto err;
 	f._bf._size = f._w = 127;		/* Leave room for the NUL */
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	if (ret == -1)
 		goto err;
 	*f._p = '\0';
diff --git a/lib/libc/stdio/vfprintf.c b/lib/libc/stdio/vfprintf.c
index 7d7958b69df..2d3fb3ebe13 100644
--- a/lib/libc/stdio/vfprintf.c
+++ b/lib/libc/stdio/vfprintf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfprintf.c,v 1.54 2009/10/16 12:15:03 martynas Exp $	*/
+/*	$OpenBSD: vfprintf.c,v 1.55 2009/10/21 16:04:23 guenther Exp $	*/
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -130,8 +130,8 @@ __sbprintf(FILE *fp, const char *fmt, va_list ap)
 	fake._lbfsize = 0;	/* not actually used, but Just In Case */
 
 	/* do the work, then copy any error status */
-	ret = vfprintf(&fake, fmt, ap);
-	if (ret >= 0 && fflush(&fake))
+	ret = __vfprintf(&fake, fmt, ap);
+	if (ret >= 0 && __sflush(&fake))
 		ret = EOF;
 	if (fake._flags & __SERR)
 		fp->_flags |= __SERR;
@@ -190,6 +190,17 @@ static int exponent(char *, int, int);
 int
 vfprintf(FILE *fp, const char *fmt0, __va_list ap)
 {
+	int ret;
+
+	FLOCKFILE(fp);
+	ret = __vfprintf(fp, fmt0, ap);
+	FUNLOCKFILE(fp);
+	return (ret);
+}
+
+int
+__vfprintf(FILE *fp, const char *fmt0, __va_list ap)
+{
 	char *fmt;		/* format string */
 	int ch;			/* character from fmt */
 	int n, n2;		/* handy integers (short term usage) */
diff --git a/lib/libc/stdio/vfscanf.c b/lib/libc/stdio/vfscanf.c
index 7e05f1ac567..3a579b19a02 100644
--- a/lib/libc/stdio/vfscanf.c
+++ b/lib/libc/stdio/vfscanf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfscanf.c,v 1.22 2009/04/05 19:29:28 martynas Exp $ */
+/*	$OpenBSD: vfscanf.c,v 1.23 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -117,6 +117,7 @@ VFSCANF(FILE *fp, const char *fmt0, __va_list ap)
 	static short basefix[17] =
 		{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
 
+	FLOCKFILE(fp);
 	_SET_ORIENTATION(fp, -1);
 
 	nassigned = 0;
@@ -124,8 +125,10 @@ VFSCANF(FILE *fp, const char *fmt0, __va_list ap)
 	base = 0;		/* XXX just to keep gcc happy */
 	for (;;) {
 		c = *fmt++;
-		if (c == 0)
+		if (c == 0) {
+			FUNLOCKFILE(fp);
 			return (nassigned);
+		}
 		if (isspace(c)) {
 			while ((fp->_r > 0 || __srefill(fp) == 0) &&
 			    isspace(*fp->_p))
@@ -293,6 +296,7 @@ literal:
 		 * Disgusting backwards compatibility hacks.	XXX
 		 */
 		case '\0':	/* compat */
+			FUNLOCKFILE(fp);
 			return (EOF);
 
 		default:	/* compat */
@@ -690,8 +694,10 @@ literal:
 		}
 	}
 input_failure:
-	return (nassigned ? nassigned : -1);
+	if (nassigned == 0)
+		nassigned = -1;
 match_failure:
+	FUNLOCKFILE(fp);
 	return (nassigned);
 }
 
diff --git a/lib/libc/stdio/vsnprintf.c b/lib/libc/stdio/vsnprintf.c
index e6dd009d106..5a08714075e 100644
--- a/lib/libc/stdio/vsnprintf.c
+++ b/lib/libc/stdio/vsnprintf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vsnprintf.c,v 1.12 2006/01/06 18:53:04 millert Exp $ */
+/*	$OpenBSD: vsnprintf.c,v 1.13 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -58,7 +58,7 @@ vsnprintf(char *str, size_t n, const char *fmt, __va_list ap)
 	f._flags = __SWR | __SSTR;
 	f._bf._base = f._p = (unsigned char *)str;
 	f._bf._size = f._w = n - 1;
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	*f._p = '\0';
 	return (ret);
 }
diff --git a/lib/libc/stdio/vsprintf.c b/lib/libc/stdio/vsprintf.c
index 67a53a1bd5d..720adb32f4c 100644
--- a/lib/libc/stdio/vsprintf.c
+++ b/lib/libc/stdio/vsprintf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vsprintf.c,v 1.13 2006/01/06 18:53:04 millert Exp $ */
+/*	$OpenBSD: vsprintf.c,v 1.14 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -53,7 +53,7 @@ vsprintf(char *str, const char *fmt, __va_list ap)
 	f._flags = __SWR | __SSTR;
 	f._bf._base = f._p = (unsigned char *)str;
 	f._bf._size = f._w = INT_MAX;
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	*f._p = '\0';
 	return (ret);
 }
diff --git a/lib/libc/stdio/wbuf.c b/lib/libc/stdio/wbuf.c
index c757799d47c..8d181a66f30 100644
--- a/lib/libc/stdio/wbuf.c
+++ b/lib/libc/stdio/wbuf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: wbuf.c,v 1.9 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: wbuf.c,v 1.10 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -65,20 +65,20 @@ __swbuf(int c, FILE *fp)
 	 * stuff c into the buffer.  If this causes the buffer to fill
 	 * completely, or if c is '\n' and the file is line buffered,
 	 * flush it (perhaps a second time).  The second flush will always
-	 * happen on unbuffered streams, where _bf._size==1; fflush()
+	 * happen on unbuffered streams, where _bf._size==1; __sflush()
 	 * guarantees that putc() will always call wbuf() by setting _w
 	 * to 0, so we need not do anything else.
 	 */
 	n = fp->_p - fp->_bf._base;
 	if (n >= fp->_bf._size) {
-		if (fflush(fp))
+		if (__sflush(fp))
 			return (EOF);
 		n = 0;
 	}
 	fp->_w--;
 	*fp->_p++ = c;
 	if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n'))
-		if (fflush(fp))
+		if (__sflush(fp))
 			return (EOF);
 	return (c);
 }