1 files changed, 70 insertions, 0 deletions
diff --git a/debug/vsnprintf_chk.c b/debug/vsnprintf_chk.c
new file mode 100644
index 0000000000..850cd5af5a
--- /dev/null
+++ b/debug/vsnprintf_chk.c
@@ -0,0 +1,70 @@
+/* Copyright (C) 1991, 1995, 1997, 1998, 2004 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   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.  */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include "../libio/libioP.h"
+#include "../libio/strfile.h"
+
+extern const struct _IO_jump_t _IO_strn_jumps attribute_hidden;
+
+/* Write formatted output into S, according to the format
+   string FORMAT, writing no more than MAXLEN characters.  */
+/* VARARGS5 */
+int
+__vsnprintf_chk (char *s, size_t maxlen, int flags, size_t slen,
+		 const char *format, va_list args)
+{
+  /* XXX Maybe for less strict version do not fail immediately.
+     Though, maxlen is supposed to be the size of buffer pointed
+     to by s, so a conforming program can't pass such maxlen
+     to *snprintf.  */
+  if (__builtin_expect (slen < maxlen, 0))
+    __chk_fail ();
+
+  _IO_strnfile sf;
+  int ret;
+#ifdef _IO_MTSAFE_IO
+  sf.f._sbf._f._lock = NULL;
+#endif
+
+  /* We need to handle the special case where MAXLEN is 0.  Use the
+     overflow buffer right from the start.  */
+  if (maxlen == 0)
+    {
+      s = sf.overflow_buf;
+      maxlen = sizeof (sf.overflow_buf);
+    }
+
+  _IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
+  _IO_JUMPS ((struct _IO_FILE_plus *) &sf.f._sbf) = &_IO_strn_jumps;
+  s[0] = '\0';
+
+  /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
+     can only come from read-only format strings.  */
+  if (flags > 0)
+    sf.f._sbf._f._flags2 |= _IO_FLAGS2_CHECK_PERCENT_N;
+
+  _IO_str_init_static_internal (&sf.f, s, maxlen - 1, s);
+  ret = INTUSE(_IO_vfprintf) ((_IO_FILE *) &sf.f._sbf, format, args);
+
+  if (sf.f._sbf._f._IO_buf_base != sf.overflow_buf)
+    *sf.f._sbf._f._IO_write_ptr = '\0';
+  return ret;
+}
+libc_hidden_def (__vsnprintf_chk)