1 files changed, 12 insertions, 0 deletions

diff --git a/lib/libc/stdio/fscanf.c b/lib/libc/stdio/fscanf.c
index f0e726af8490..bbb3155f94ad 100644
--- a/lib/libc/stdio/fscanf.c
+++ b/lib/libc/stdio/fscanf.c
@@ -44,14 +44,20 @@ static char sccsid[] = "@(#)fscanf.c	8.1 (Berkeley) 6/4/93";
 #else
 #include <varargs.h>
 #endif
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+#endif
 
 #if __STDC__
+int
 fscanf(FILE *fp, char const *fmt, ...) {
 	int ret;
 	va_list ap;
 
 	va_start(ap, fmt);
 #else
+int
 fscanf(fp, fmt, va_alist)
 	FILE *fp;
 	char *fmt;
@@ -62,7 +68,13 @@ fscanf(fp, fmt, va_alist)
 
 	va_start(ap);
 #endif
+#ifdef _THREAD_SAFE
+	_thread_flockfile(fp,__FILE__,__LINE__);
+#endif
 	ret = __svfscanf(fp, fmt, ap);
 	va_end(ap);
+#ifdef _THREAD_SAFE
+	_thread_funlockfile(fp);
+#endif
 	return (ret);
 }