1 files changed, 17 insertions, 10 deletions
diff --git a/debug/swprintf_chk.c b/debug/swprintf_chk.c
index 35887e48e2..186c17751c 100644
--- a/debug/swprintf_chk.c
+++ b/debug/swprintf_chk.c
@@ -16,20 +16,27 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdarg.h>
-#include <wchar.h>
+#include <libio/libioP.h>
 
-/* Write formatted output into S, according to the format string FORMAT.  */
-/* VARARGS5 */
+
+/* Write formatted output into S, according to the format string FORMAT,
+   writing no more than MAXLEN characters.  */
 int
-__swprintf_chk (wchar_t *s, size_t n, int flag, size_t s_len,
+__swprintf_chk (wchar_t *s, size_t maxlen, int flag, size_t slen,
 		const wchar_t *format, ...)
 {
-  va_list arg;
-  int done;
+  if (__glibc_unlikely (slen < maxlen))
+    __chk_fail ();
+
+  /* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
+     can only come from read-only format strings.  */
+  unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
+  va_list ap;
+  int ret;
 
-  va_start (arg, format);
-  done = __vswprintf_chk (s, n, flag, s_len, format, arg);
-  va_end (arg);
+  va_start (ap, format);
+  ret = __vswprintf_internal (s, maxlen, format, ap, mode);
+  va_end (ap);
 
-  return done;
+  return ret;
 }