glibc/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsprintf_chk.c
Frédéric Bérat 505c884aeb stdio: Ensure *_chk routines have their hidden builtin definition available
If libc_hidden_builtin_{def,proto} isn't properly set for *_chk routines,
there are unwanted PLT entries in libc.so.

There is a special case with __asprintf_chk:
If ldbl_* macros are used for asprintf, ABI gets broken on s390x,
if it isn't, ppc64le isn't building due to multiple asm redirections.

This is due to the inclusion of bits/stdio-lbdl.h for ppc64le whereas it
isn't for s390x. This header creates redirections, which are not
compatible with the ones generated using libc_hidden_def.
Yet, we can't use libc_hidden_ldbl_proto on s390x since it will not
create a simple strong alias (e.g. as done on x86_64), but a versioned
alias, leading to ABI breakage.

This results in errors on s390x:
/usr/bin/ld: glibc/iconv/../libio/bits/stdio2.h:137: undefined reference
to `__asprintf_chk'

Original __asprintf_chk symbols:
00000000001395b0 T __asprintf_chk
0000000000177e90 T __nldbl___asprintf_chk

__asprintf_chk symbols with ldbl_* macros:
000000000012d590 t ___asprintf_chk
000000000012d590 t __asprintf_chk@@GLIBC_2.4
000000000012d590 t __GI___asprintf_chk
000000000012d590 t __GL____asprintf_chk___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk

__asprintf_chk symbols with the patch:
000000000012d590 t ___asprintf_chk
000000000012d590 T __asprintf_chk
000000000012d590 t __GI___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-07-05 16:59:48 +02:00

40 lines
1.4 KiB
C

/* Wrapper for __vsprintf_chk. IEEE128 version.
Copyright (C) 2019-2023 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, see
<https://www.gnu.org/licenses/>. */
#include <libio/libioP.h>
extern int
___ieee128___vsprintf_chk (char *string, int flag, size_t slen,
const char *format, va_list ap)
{
unsigned int mode = PRINTF_LDBL_USES_FLOAT128;
if (flag > 0)
mode |= PRINTF_FORTIFY;
/* Regardless of the value of flag, let __vsprintf_internal know that
this is a call from *printf_chk. */
mode |= PRINTF_CHK;
if (slen == 0)
__chk_fail ();
return __vsprintf_internal (string, slen, format, ap, mode);
}
hidden_def (___ieee128___vsprintf_chk)
strong_alias (___ieee128___vsprintf_chk, __vsprintf_chkieee128)