1/* Copyright (C) 1991-2022 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 <stdarg.h>
19#include <libio/libioP.h>
20
21
22/* Write formatted output into S, according to the format string FORMAT. */
23int
24___sprintf_chk (char *s, int flag, size_t slen, const char *format, ...)
25{
26 /* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
27 can only come from read-only format strings. */
28 unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
29 va_list ap;
30 int ret;
31
32 /* Regardless of the value of flag, let __vsprintf_internal know that
33 this is a call from *printf_chk. */
34 mode |= PRINTF_CHK;
35
36 if (slen == 0)
37 __chk_fail ();
38
39 va_start (ap, format);
40 ret = __vsprintf_internal (string: s, maxlen: slen, format, ap, mode_flags: mode);
41 va_end (ap);
42
43 return ret;
44}
45ldbl_strong_alias (___sprintf_chk, __sprintf_chk)
46

source code of glibc/debug/sprintf_chk.c