Fix REALLOC_ZERO_BYTES_FREES comment to match C17

[thirdparty/glibc.git] / debug / swprintf_chk.c

diff --git a/debug/swprintf_chk.c b/debug/swprintf_chk.c
index 554cbe66a3272cb4965336f40cf3f4d761709bd0..7cfe766816214506d7f9665668014a8eb8172787 100644 (file)
--- a/debug/swprintf_chk.c
+++ b/debug/swprintf_chk.c
@@ -1,5 +1,4 @@
-/* Copyright (C) 1991,1995,1997,1998,1999,2000,2003,2005
-       Free Software Foundation, Inc.
+/* Copyright (C) 1991-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -13,25 +12,31 @@
    Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
+   License along with the GNU C Library; if not, see
+   <https://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;
 }