22 files changed, 261 insertions, 104 deletions

diff --git a/lib/libc/gen/_pthread_stubs.c b/lib/libc/gen/_pthread_stubs.c
index 87b0ad2..be6dab7 100644
--- a/lib/libc/gen/_pthread_stubs.c
+++ b/lib/libc/gen/_pthread_stubs.c
@@ -49,8 +49,14 @@
 #pragma weak	_pthread_mutexattr_destroy=_pthread_mutexattr_destroy_stub
 #pragma weak	_pthread_mutexattr_settype=_pthread_mutexattr_settype_stub
 #pragma weak	_pthread_once=_pthread_once_stub
+#pragma weak	_pthread_self=_pthread_self_stub
 #pragma weak	_pthread_setspecific=_pthread_setspecific_stub
 
+struct pthread {
+};
+
+static struct pthread	main_thread;
+
 
 void *
 _pthread_getspecific_stub(pthread_key_t key)
@@ -124,6 +130,12 @@ _pthread_once_stub(pthread_once_t *once_control, void (*init_routine) (void))
 	return (0);
 }
 
+pthread_t
+_pthread_self_stub(void)
+{
+	return (&main_thread);
+}
+
 int
 _pthread_setspecific_stub(pthread_key_t key, const void *value)
 {
diff --git a/lib/libc/include/namespace.h b/lib/libc/include/namespace.h
index 95acce4..ddffa82 100644
--- a/lib/libc/include/namespace.h
+++ b/lib/libc/include/namespace.h
@@ -70,6 +70,7 @@
 #define		pthread_mutexattr_destroy	_pthread_mutexattr_destroy
 #define		pthread_mutexattr_settype	_pthread_mutexattr_settype
 #define		pthread_once			_pthread_once
+#define		pthread_self			_pthread_self
 #define		pthread_setspecific		_pthread_setspecific
 #define		read				_read
 #define		readv				_readv
@@ -115,7 +116,6 @@
 #define		pthread_rwlock_wrlock		_pthread_rwlock_wrlock
 #define		pthread_rwlockattr_init		_pthread_rwlockattr_init
 #define		pthread_rwlockattr_destroy	_pthread_rwlockattr_destroy
-#define		pthread_self			_pthread_self
 #define		sched_yield			_sched_yield
 #define		sendfile			_sendfile
 #define		shutdown			_shutdown
diff --git a/lib/libc/include/un-namespace.h b/lib/libc/include/un-namespace.h
index 4d2e8bd..76ba625 100644
--- a/lib/libc/include/un-namespace.h
+++ b/lib/libc/include/un-namespace.h
@@ -65,6 +65,7 @@
 #undef		pthread_mutexattr_destroy
 #undef		pthread_mutexattr_settype
 #undef		pthread_once
+#undef		pthread_self
 #undef		pthread_setspecific
 #undef		read
 #undef		readv
@@ -102,7 +103,6 @@
 #undef		pthread_rwlock_wrlock
 #undef		pthread_rwlockattr_init
 #undef		pthread_rwlockattr_destroy
-#undef		pthread_self
 #undef		sched_yield
 #undef		sendfile
 #undef		shutdown
diff --git a/lib/libc/stdio/_flock_stub.c b/lib/libc/stdio/_flock_stub.c
index 83a3e86..8bea66d 100644
--- a/lib/libc/stdio/_flock_stub.c
+++ b/lib/libc/stdio/_flock_stub.c
@@ -33,49 +33,155 @@
  *
  */
 
+/*
+ * POSIX stdio FILE locking functions. These assume that the locking
+ * is only required at FILE structure level, not at file descriptor
+ * level too.
+ *
+ */
+
+#include "namespace.h"
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include "un-namespace.h"
+
+/*
+ * Weak symbols for externally visible functions in this file:
+ */
+#pragma weak	flockfile=_flockfile
+#pragma weak	_flockfile_debug=_flockfile_debug_stub
+#pragma weak	ftrylockfile=_ftrylockfile
+#pragma weak	funlockfile=_funlockfile
+
+static int	init_lock(FILE *);
 
 /*
- * Declare weak references in case the application is not linked
- * with libpthread.
+ * The FILE lock structure. The FILE *fp is locked when the mutex
+ * is locked.
  */
-#pragma weak flockfile=_flockfile_stub
-#pragma weak _flockfile=_flockfile_stub
-#pragma weak _flockfile_debug=_flockfile_debug_stub
-#pragma weak ftrylockfile=_ftrylockfile_stub
-#pragma weak _ftrylockfile=_ftrylockfile_stub
-#pragma weak funlockfile=_funlockfile_stub
-#pragma weak _funlockfile=_funlockfile_stub
+struct	__file_lock {
+	pthread_mutex_t	fl_mutex;
+	pthread_t	fl_owner;	/* current owner */
+	int		fl_count;	/* recursive lock count */
+};
 
 /*
- * This function is a stub for the _flockfile function in libpthread.
+ * Allocate and initialize a file lock.
  */
+static int
+init_lock(FILE *fp)
+{
+	struct __file_lock *p;
+	int	ret;
+
+	if ((p = malloc(sizeof(struct __file_lock))) == NULL)
+		ret = -1;
+	else {
+		p->fl_mutex = PTHREAD_MUTEX_INITIALIZER;
+		p->fl_owner = NULL;
+		p->fl_count = 0;
+		fp->_lock = p;
+		ret = 0;
+	}
+	return (ret);
+}
+
 void
-_flockfile_stub(FILE *fp)
+_flockfile(FILE *fp)
 {
+	pthread_t curthread = _pthread_self();
+
+	/*
+	 * Check if this is a real file with a valid lock, creating
+	 * the lock if needed:
+	 */
+	if ((fp->_file >= 0) &&
+	    ((fp->_lock != NULL) || (init_lock(fp) == 0))) {
+		if (fp->_lock->fl_owner == curthread)
+			fp->_lock->fl_count++;
+		else {
+			/*
+			 * Make sure this mutex is treated as a private
+			 * internal mutex:
+			 */
+			_pthread_mutex_lock(&fp->_lock->fl_mutex);
+			fp->_lock->fl_owner = curthread;
+			fp->_lock->fl_count = 1;
+		}
+	}
 }
 
 /*
- * This function is a stub for the _flockfile_debug function in libpthread.
+ * This can be overriden by the threads library if it is linked in.
  */
 void
 _flockfile_debug_stub(FILE *fp, char *fname, int lineno)
 {
+	_flockfile(fp);
 }
 
-/*
- * This function is a stub for the _ftrylockfile function in libpthread.
- */
 int
-_ftrylockfile_stub(FILE *fp)
+_ftrylockfile(FILE *fp)
 {
-	return(0);
+	pthread_t curthread = _pthread_self();
+	int	ret = 0;
+
+	/*
+	 * Check if this is a real file with a valid lock, creating
+	 * the lock if needed:
+	 */
+	if ((fp->_file >= 0) &&
+	    ((fp->_lock != NULL) || (init_lock(fp) == 0))) {
+		if (fp->_lock->fl_owner == curthread)
+			fp->_lock->fl_count++;
+		/*
+		 * Make sure this mutex is treated as a private
+		 * internal mutex:
+		 */
+		else if (_pthread_mutex_trylock(&fp->_lock->fl_mutex) == 0) {
+			fp->_lock->fl_owner = curthread;
+			fp->_lock->fl_count = 1;
+		}
+		else
+			ret = -1;
+	}
+	else
+		ret = -1;
+	return (ret);
 }
 
-/*
- * This function is a stub for the _funlockfile function in libpthread.
- */
-void
-_funlockfile_stub(FILE *fp)
+void 
+_funlockfile(FILE *fp)
 {
+	pthread_t	curthread = _pthread_self();
+
+	/*
+	 * Check if this is a real file with a valid lock owned
+	 * by the current thread:
+	 */
+	if ((fp->_file >= 0) && (fp->_lock != NULL) &&
+	    (fp->_lock->fl_owner == curthread)) {
+		/*
+		 * Check if this thread has locked the FILE
+		 * more than once:
+		 */
+		if (fp->_lock->fl_count > 1)
+			/*
+			 * Decrement the count of the number of
+			 * times the running thread has locked this
+			 * file:
+			 */
+			fp->_lock->fl_count--;
+		else {
+			/*
+			 * The running thread will release the
+			 * lock now:
+			 */
+			fp->_lock->fl_count = 0;
+			fp->_lock->fl_owner = NULL;
+			_pthread_mutex_unlock(&fp->_lock->fl_mutex);
+		}
+	}
 }
diff --git a/lib/libc/stdio/asprintf.c b/lib/libc/stdio/asprintf.c
index e125bfc..cf4fb3c 100644
--- a/lib/libc/stdio/asprintf.c
+++ b/lib/libc/stdio/asprintf.c
@@ -40,6 +40,8 @@ static char rcsid[] = "$FreeBSD$";
 #include <varargs.h>
 #endif
 
+#include "local.h"
+
 int
 #if __STDC__
 asprintf(char **str, char const *fmt, ...)
@@ -68,7 +70,7 @@ asprintf(str, fmt, va_alist)
 		return (-1);
 	}
 	f._bf._size = f._w = 127;		/* Leave room for the NULL */
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);		/* Use unlocked __vfprintf */
 	*f._p = '\0';
 	va_end(ap);
 	f._bf._base = reallocf(f._bf._base, f._bf._size + 1);
diff --git a/lib/libc/stdio/fclose.c b/lib/libc/stdio/fclose.c
index 0d6fd80..e70a2da 100644
--- a/lib/libc/stdio/fclose.c
+++ b/lib/libc/stdio/fclose.c
@@ -51,8 +51,7 @@ static const char rcsid[] =
 #include "local.h"
 
 int
-fclose(fp)
-	FILE *fp;
+fclose(FILE *fp)
 {
 	int r;
 
@@ -70,15 +69,9 @@ fclose(fp)
 		FREEUB(fp);
 	if (HASLB(fp))
 		FREELB(fp);
-	FUNLOCKFILE(fp);
 	fp->_file = -1;
 	fp->_r = fp->_w = 0;	/* Mess up if reaccessed. */
-#if 0
-	if (fp->_lock != NULL) {
-		_pthread_mutex_destroy((pthread_mutex_t *)&fp->_lock);
-		fp->_lock = NULL;
-	}
-#endif
 	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 3581100..60cad53 100644
--- a/lib/libc/stdio/feof.c
+++ b/lib/libc/stdio/feof.c
@@ -42,16 +42,24 @@ static const char rcsid[] =
   "$FreeBSD$";
 #endif /* LIBC_SCCS and not lint */
 
+#include "namespace.h"
 #include <stdio.h>
+#include "un-namespace.h"
+#include "libc_private.h"
 
 /*
- * A subroutine version of the macro feof.
+ * feof has traditionally been a macro in <stdio.h>.  That is no
+ * longer true because it needs to be thread-safe.
+ *
+ * #undef feof
  */
-#undef feof
-
 int
-feof(fp)
-	FILE *fp;
+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 2311926..c4424c6 100644
--- a/lib/libc/stdio/ferror.c
+++ b/lib/libc/stdio/ferror.c
@@ -42,16 +42,24 @@ static const char rcsid[] =
   "$FreeBSD$";
 #endif /* LIBC_SCCS and not lint */
 
+#include "namespace.h"
 #include <stdio.h>
+#include "un-namespace.h"
+#include "libc_private.h"
 
 /*
- * A subroutine version of the macro ferror.
+ * ferror has traditionally been a macro in <stdio.h>.  That is no
+ * longer true because it needs to be thread-safe.
+ *
+ * #undef ferror
  */
-#undef ferror
-
 int
-ferror(fp)
-	FILE *fp;
+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 09d346b..5c1eaa1 100644
--- a/lib/libc/stdio/fflush.c
+++ b/lib/libc/stdio/fflush.c
@@ -49,6 +49,8 @@ static const char rcsid[] =
 #include "libc_private.h"
 #include "local.h"
 
+static int	sflush_locked(FILE *);
+
 /*
  * Flush a single file, or (if fp is NULL) all files.
  * MT-safe version
@@ -59,7 +61,7 @@ fflush(FILE *fp)
 	int retval;
 
 	if (fp == NULL)
-		return (_fwalk(__sflush));
+		return (_fwalk(sflush_locked));
 	FLOCKFILE(fp);
 	if ((fp->_flags & (__SWR | __SRW)) == 0) {
 		errno = EBADF;
@@ -80,7 +82,7 @@ __fflush(FILE *fp)
 	int retval;
 
 	if (fp == NULL)
-		return (_fwalk(__sflush));
+		return (_fwalk(sflush_locked));
 	if ((fp->_flags & (__SWR | __SRW)) == 0) {
 		errno = EBADF;
 		retval = EOF;
@@ -120,3 +122,14 @@ __sflush(FILE *fp)
 	}
 	return (0);
 }
+
+static int
+sflush_locked(FILE *fp)
+{
+	int	ret;
+
+	FLOCKFILE(fp);
+	ret = __sflush(fp);
+	FUNLOCKFILE(fp);
+	return (ret);
+}
diff --git a/lib/libc/stdio/fgetc.c b/lib/libc/stdio/fgetc.c
index a367af3..684da00 100644
--- a/lib/libc/stdio/fgetc.c
+++ b/lib/libc/stdio/fgetc.c
@@ -46,6 +46,7 @@ static const char rcsid[] =
 #include <stdio.h>
 #include "un-namespace.h"
 #include "libc_private.h"
+#include "local.h"
 
 int
 fgetc(fp)
diff --git a/lib/libc/stdio/fgetln.c b/lib/libc/stdio/fgetln.c
index 3987b0d..c607a9c 100644
--- a/lib/libc/stdio/fgetln.c
+++ b/lib/libc/stdio/fgetln.c
@@ -42,9 +42,12 @@ static const char rcsid[] =
   "$FreeBSD$";
 #endif /* LIBC_SCCS and not lint */
 
+#include "namespace.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include "un-namespace.h"
+#include "libc_private.h"
 #include "local.h"
 
 /*
@@ -54,10 +57,8 @@ static const char rcsid[] =
  * so we add 1 here.
 #endif
  */
-int
-__slbexpand(fp, newsize)
-	FILE *fp;
-	size_t newsize;
+static int
+slbexpand(FILE *fp, size_t newsize)
 {
 	void *p;
 
@@ -81,23 +82,23 @@ __slbexpand(fp, newsize)
  * it if they wish.  Thus, we set __SMOD in case the caller does.
  */
 char *
-fgetln(fp, lenp)
-	register FILE *fp;
-	size_t *lenp;
+fgetln(FILE *fp, size_t *lenp)
 {
-	register unsigned char *p;
-	register size_t len;
+	unsigned char *p;
+	size_t len;
 	size_t off;
 
+	FLOCKFILE(fp);
 	/* make sure there is input */
 	if (fp->_r <= 0 && __srefill(fp)) {
 		*lenp = 0;
+		FUNLOCKFILE(fp);
 		return (NULL);
 	}
 
 	/* look for a newline in the input */
 	if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) != NULL) {
-		register char *ret;
+		char *ret;
 
 		/*
 		 * Found one.  Flag buffer as modified to keep fseek from
@@ -110,6 +111,7 @@ fgetln(fp, lenp)
 		fp->_flags |= __SMOD;
 		fp->_r -= len;
 		fp->_p = p;
+		FUNLOCKFILE(fp);
 		return (ret);
 	}
 
@@ -124,14 +126,14 @@ fgetln(fp, lenp)
 #define OPTIMISTIC 80
 
 	for (len = fp->_r, off = 0;; len += fp->_r) {
-		register size_t diff;
+		size_t diff;
 
 		/*
 		 * Make sure there is room for more bytes.  Copy data from
 		 * file buffer to line buffer, refill file and look for
 		 * newline.  The loop stops only when we find a newline.
 		 */
-		if (__slbexpand(fp, len + OPTIMISTIC))
+		if (slbexpand(fp, len + OPTIMISTIC))
 			goto error;
 		(void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
 		    len - off);
@@ -145,7 +147,7 @@ fgetln(fp, lenp)
 		p++;
 		diff = p - fp->_p;
 		len += diff;
-		if (__slbexpand(fp, len))
+		if (slbexpand(fp, len))
 			goto error;
 		(void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
 		    diff);
@@ -157,9 +159,11 @@ fgetln(fp, lenp)
 #ifdef notdef
 	fp->_lb._base[len] = 0;
 #endif
+	FUNLOCKFILE(fp);
 	return ((char *)fp->_lb._base);
 
 error:
 	*lenp = 0;		/* ??? */
+	FUNLOCKFILE(fp);
 	return (NULL);		/* ??? */
 }
diff --git a/lib/libc/stdio/fgetpos.c b/lib/libc/stdio/fgetpos.c
index 239f6d1..51f14ef 100644
--- a/lib/libc/stdio/fgetpos.c
+++ b/lib/libc/stdio/fgetpos.c
@@ -42,19 +42,16 @@ static const char rcsid[] =
   "$FreeBSD$";
 #endif /* LIBC_SCCS and not lint */
 
-#include "namespace.h"
 #include <stdio.h>
-#include "un-namespace.h"
-#include "libc_private.h"
 
 int
-fgetpos(fp, pos)
-	FILE *fp;
-	fpos_t *pos;
+fgetpos(FILE *fp, fpos_t *pos)
 {
-	int retval;
-	FLOCKFILE(fp);
-	retval = (*pos = ftello(fp)) == (fpos_t)-1;
-	FUNLOCKFILE(fp);
-	return(retval);
+	/*
+	 * ftello is thread-safe; no need to lock fp.
+	 */
+	if ((*pos = ftello(fp)) == (fpos_t)-1)
+		return (-1);
+	else
+		return (0);
 }
diff --git a/lib/libc/stdio/fileno.c b/lib/libc/stdio/fileno.c
index 0c3a8dc..b8f500e 100644
--- a/lib/libc/stdio/fileno.c
+++ b/lib/libc/stdio/fileno.c
@@ -45,13 +45,14 @@ static const char rcsid[] =
 #include <stdio.h>
 
 /*
- * A subroutine version of the macro fileno.
+ * fileno has traditionally been a macro in <stdio.h>.  That is
+ * no longer true because it needs to be thread-safe.
+ *
+ * #undef fileno
  */
-#undef fileno
-
 int
-fileno(fp)
-	FILE *fp;
+fileno(FILE *fp)
 {
+	/* ??? - Should probably use atomic_read. */
 	return (__sfileno(fp));
 }
diff --git a/lib/libc/stdio/findfp.c b/lib/libc/stdio/findfp.c
index 30e8f90..f307e3e 100644
--- a/lib/libc/stdio/findfp.c
+++ b/lib/libc/stdio/findfp.c
@@ -82,7 +82,7 @@ static spinlock_t thread_lock = _SPINLOCK_INITIALIZER;
 #define THREAD_UNLOCK()	if (__isthreaded) _SPINUNLOCK(&thread_lock)
 
 #if NOT_YET
-#define	SET_GLUE_PTR(ptr, val)	atomic_set_ptr(&(ptr), (uintptr_t)(val))
+#define	SET_GLUE_PTR(ptr, val)	atomic_set_rel_ptr(&(ptr), (uintptr_t)(val))
 #else
 #define	SET_GLUE_PTR(ptr, val)	ptr = val
 #endif
@@ -150,7 +150,7 @@ found:
 	fp->_ub._size = 0;
 	fp->_lb._base = NULL;	/* no line buffer */
 	fp->_lb._size = 0;
-	/* fp->_lock = NULL; */
+/*	fp->_lock = NULL; */	/* once set always set (reused) */
 	return (fp);
 }
 
@@ -203,7 +203,7 @@ _cleanup()
 void
 __sinit()
 {
-	/* make sure we clean up on exit */
+	/* Make sure we clean up on exit. */
 	__cleanup = _cleanup;		/* conservative */
 	__sdidinit = 1;
 }
diff --git a/lib/libc/stdio/fopen.c b/lib/libc/stdio/fopen.c
index 4ea2eb9..aca314c 100644
--- a/lib/libc/stdio/fopen.c
+++ b/lib/libc/stdio/fopen.c
@@ -74,7 +74,6 @@ fopen(file, mode)
 	fp->_write = __swrite;
 	fp->_seek = __sseek;
 	fp->_close = __sclose;
-	/* fp->_lock = NULL; */
 	/*
 	 * When opening in append mode, even though we use O_APPEND,
 	 * we need to seek to the end so that ftell() gets the right
diff --git a/lib/libc/stdio/freopen.c b/lib/libc/stdio/freopen.c
index fd8612c..a434d5a 100644
--- a/lib/libc/stdio/freopen.c
+++ b/lib/libc/stdio/freopen.c
@@ -62,9 +62,9 @@ static const char rcsid[] =
 FILE *
 freopen(file, mode, fp)
 	const char *file, *mode;
-	register FILE *fp;
+	FILE *fp;
 {
-	register int f;
+	int f;
 	int flags, isopen, oflags, sverrno, wantfd;
 
 	if ((flags = __sflags(mode, &oflags)) == 0) {
diff --git a/lib/libc/stdio/fwalk.c b/lib/libc/stdio/fwalk.c
index 17cb5ce..b943be4 100644
--- a/lib/libc/stdio/fwalk.c
+++ b/lib/libc/stdio/fwalk.c
@@ -61,10 +61,13 @@ _fwalk(function)
 	 * It should be safe to walk the list without locking it;
 	 * new nodes are only added to the end and none are ever
 	 * removed.
+	 *
+	 * Avoid locking this list while walking it or else you will
+	 * introduce a potential deadlock in [at least] refill.c.
 	 */
 	for (g = &__sglue; g != NULL; g = g->next)
 		for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
-			if (fp->_flags != 0)
+			if ((fp->_flags != 0) && ((fp->_flags & __SIGN) == 0))
 				ret |= (*function)(fp);
 	return (ret);
 }
diff --git a/lib/libc/stdio/getc.c b/lib/libc/stdio/getc.c
index 1668407..cabc40c 100644
--- a/lib/libc/stdio/getc.c
+++ b/lib/libc/stdio/getc.c
@@ -46,11 +46,10 @@ static const char rcsid[] =
 #include <stdio.h>
 #include "un-namespace.h"
 #include "libc_private.h"
+#include "local.h"
 
-#undef getc
 int
-getc(fp)
-	register FILE *fp;
+getc(FILE *fp)
 {
 	int retval;
 	FLOCKFILE(fp);
diff --git a/lib/libc/stdio/refill.c b/lib/libc/stdio/refill.c
index 2db485bba..b597f97 100644
--- a/lib/libc/stdio/refill.c
+++ b/lib/libc/stdio/refill.c
@@ -42,22 +42,28 @@ static const char rcsid[] =
   "$FreeBSD$";
 #endif /* LIBC_SCCS and not lint */
 
+#include "namespace.h"
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include "un-namespace.h"
 
+#include "libc_private.h"
 #include "local.h"
 
 static int lflush __P((FILE *));
 
 static int
-lflush(fp)
-	FILE *fp;
+lflush(FILE *fp)
 {
+	int	ret = 0;
 
-	if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
-		return (__sflush(fp));
-	return (0);
+	if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR)) {
+		FLOCKFILE(fp);
+		ret = __sflush(fp);
+		FUNLOCKFILE(fp);
+	}
+	return (ret);
 }
 
 /*
@@ -65,10 +71,8 @@ lflush(fp)
  * Return EOF on eof or error, 0 otherwise.
  */
 int
-__srefill(fp)
-	register FILE *fp;
+__srefill(FILE *fp)
 {
-
 	/* make sure stdio is set up */
 	if (!__sdidinit)
 		__sinit();
@@ -119,8 +123,16 @@ __srefill(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/rget.c b/lib/libc/stdio/rget.c
index 45d817d..4ec796f 100644
--- a/lib/libc/stdio/rget.c
+++ b/lib/libc/stdio/rget.c
@@ -39,22 +39,19 @@
 static char sccsid[] = "@(#)rget.c	8.1 (Berkeley) 6/4/93";
 #endif
 static const char rcsid[] =
-	"$Id";
+	"$FreeBSD$";
 #endif /* LIBC_SCCS and not lint */
 
 #include <stdio.h>
 #include "local.h"
 
-int 
-__srefill(FILE *);
-
 /*
  * Handle getc() when the buffer ran out:
  * Refill, then return the first character
  * in the newly-filled buffer.
  */
-int __srget(fp)
-	register FILE *fp;
+int
+__srget(FILE *fp)
 {
 	if (__srefill(fp) == 0) {
 		fp->_r--;
diff --git a/lib/libc/stdio/snprintf.c b/lib/libc/stdio/snprintf.c
index bedf98d..fe21129 100644
--- a/lib/libc/stdio/snprintf.c
+++ b/lib/libc/stdio/snprintf.c
@@ -50,6 +50,8 @@ static const char rcsid[] =
 #include <varargs.h>
 #endif
 
+#include "local.h"
+
 #if __STDC__
 int
 snprintf(char *str, size_t n, char const *fmt, ...)
@@ -81,7 +83,7 @@ snprintf(str, n, fmt, va_alist)
 	f._flags = __SWR | __SSTR;
 	f._bf._base = f._p = (unsigned char *)str;
 	f._bf._size = f._w = n;
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	if (on > 0)
 		*f._p = '\0';
 	va_end(ap);
diff --git a/lib/libc/stdio/sprintf.c b/lib/libc/stdio/sprintf.c
index 10e73f0..a810096 100644
--- a/lib/libc/stdio/sprintf.c
+++ b/lib/libc/stdio/sprintf.c
@@ -74,7 +74,7 @@ sprintf(str, fmt, va_alist)
 #else
 	va_start(ap);
 #endif
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	va_end(ap);
 	*f._p = 0;
 	return (ret);