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505c884aeb
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>
55 lines
2.0 KiB
C
55 lines
2.0 KiB
C
/* Copyright (C) 1991-2023 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <stdarg.h>
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#include <libio/libioP.h>
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/* Write formatted output from FORMAT to a string which is
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allocated with malloc and stored in *STRING_PTR. */
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int
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___asprintf_chk (char **result_ptr, int flag, const char *format, ...)
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{
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/* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
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can only come from read-only format strings. */
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unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
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va_list ap;
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int ret;
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va_start (ap, format);
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ret = __vasprintf_internal (result_ptr, format, ap, mode);
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va_end (ap);
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return ret;
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}
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#if defined __LDBL_COMPAT || __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
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/* This is needed since <bits/stdio-lbdl.h> is included in this case, leading to
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* multiple asm redirection of the same symbol
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*/
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ldbl_hidden_def (___asprintf_chk, __asprintf_chk)
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ldbl_strong_alias (___asprintf_chk, __asprintf_chk)
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#else
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/* On some systems introduction of ldbl_* macros lead to ABI breakage due to the
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* long_double_symbol aliasing, e.g. on s390x:
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* /usr/bin/ld: glibc/iconv/../libio/bits/stdio2.h:137: undefined reference to
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* `__asprintf_chk'
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* Due to __asprintf_chk@@GLIBC_2.4 alias replacing __asprintf_chk.
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*/
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strong_alias (___asprintf_chk, __asprintf_chk)
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libc_hidden_def (__asprintf_chk)
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#endif
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