debug/asprintf_chk.c

   1 /* Copyright (C) 1991-2023 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 from FORMAT to a string which is
  23    allocated with malloc and stored in *STRING_PTR.  */
  24 int
  25 ___asprintf_chk (char **result_ptr, int flag, const char *format, ...)
  26 {
  27   /* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
  28      can only come from read-only format strings.  */
  29   unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
  30   va_list ap;
  31   int ret;
  32
  33   va_start (ap, format);
  34   ret = __vasprintf_internal (result_ptr, format, ap, mode);
  35   va_end (ap);
  36
  37   return ret;
  38 }
  39 #if defined __LDBL_COMPAT || __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
  40 /* This is needed since <bits/stdio-lbdl.h> is included in this case, leading to
  41  * multiple asm redirection of the same symbol
  42  */
  43 ldbl_hidden_def (___asprintf_chk, __asprintf_chk)
  44 ldbl_strong_alias (___asprintf_chk, __asprintf_chk)
  45 #else
  46 /* On some systems introduction of ldbl_* macros lead to ABI breakage due to the
  47  * long_double_symbol aliasing, e.g. on s390x:
  48  * /usr/bin/ld: glibc/iconv/../libio/bits/stdio2.h:137: undefined reference to
  49  * `__asprintf_chk'
  50  * Due to __asprintf_chk@@GLIBC_2.4 alias replacing __asprintf_chk.
  51  */
  52 strong_alias (___asprintf_chk, __asprintf_chk)
  53 libc_hidden_def (__asprintf_chk)
  54 #endif