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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>
60 lines
2.2 KiB
C
60 lines
2.2 KiB
C
/* Copyright (C) 1993-2023 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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As a special exception, if you link the code in this file with
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files compiled with a GNU compiler to produce an executable,
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that does not cause the resulting executable to be covered by
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the GNU Lesser General Public License. This exception does not
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however invalidate any other reasons why the executable file
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might be covered by the GNU Lesser General Public License.
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This exception applies to code released by its copyright holders
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in files containing the exception. */
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#include "libioP.h"
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#include <stdio.h>
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#include <sys/param.h>
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char *
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__fgets_unlocked_chk (char *buf, size_t size, int n, FILE *fp)
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{
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size_t count;
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char *result;
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CHECK_FILE (fp, NULL);
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if (n <= 0)
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return NULL;
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/* This is very tricky since a file descriptor may be in the
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non-blocking mode. The error flag doesn't mean much in this
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case. We return an error only when there is a new error. */
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int old_error = fp->_flags & _IO_ERR_SEEN;
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fp->_flags &= ~_IO_ERR_SEEN;
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count = _IO_getline (fp, buf, MIN ((size_t) n - 1, size), '\n', 1);
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/* If we read in some bytes and errno is EAGAIN, that error will
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be reported for next read. */
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if (count == 0 || ((fp->_flags & _IO_ERR_SEEN) && errno != EAGAIN))
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result = NULL;
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else if (count >= size)
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__chk_fail ();
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else
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{
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buf[count] = '\0';
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result = buf;
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}
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fp->_flags |= old_error;
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return result;
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}
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libc_hidden_builtin_def (__fgets_unlocked_chk)
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