debug/vsprintf_chk.c

   1 /* Copyright (C) 1994-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <libio/libioP.h>
  19
  20 int
  21 ___vsprintf_chk (char *s, int flag, size_t slen, const char *format,
  22                  va_list ap)
  23 {
  24   /* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
  25      can only come from read-only format strings.  */
  26   unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
  27
  28   /* Regardless of the value of flag, let __vsprintf_internal know that
  29      this is a call from *printf_chk.  */
  30   mode |= PRINTF_CHK;
  31
  32   if (slen == 0)
  33     __chk_fail ();
  34
  35   return __vsprintf_internal (s, slen, format, ap, mode);
  36 }
  37 ldbl_hidden_def (___vsprintf_chk, __vsprintf_chk)
  38 ldbl_strong_alias (___vsprintf_chk, __vsprintf_chk)