glibc/sysdeps/unix/sysv/linux/lseek64.c
Joseph Myers 5c5c0dd747 Make llseek a compat symbol (bug 18471).
The llseek function name is an obsolete, Linux-specific, unprototyped
name for lseek64 with a link-time warning.  This patch completes the
obsoletion of this function name by making it into a compat symbol,
not available for newly linked programs and not included in the ABI
for new ports.

When a compat symbol is defined in syscalls.list, the code for that
function is not built at all for static linking unless some non-compat
symbol for that function is also defined with an explicit symbol
version, so an explicit symbol version for lseek64 is added to the
MIPS n32 syscalls.list.  The case in make-syscalls.sh that handles
such explicit non-compat symbol versions then needs to be changed to
use weak_alias instead of strong_alias when the syscall is built
outside of libc, to avoid linknamespace failures from a strong lseek64
symbol in static libpthread.

The x32 llseek.S was as far as I could tell already unused (nothing
builds an llseek.* source file, at least since the lseek / lseek64 /
llseek consolidation), so is removed in this patch as well.

Tested for x86_64 and x86, and with build-many-glibcs.py.

	[BZ #18471]
	* sysdeps/unix/make-syscalls.sh (emit_weak_aliases): Use weak
	aliases for non-libc case of versioned symbols.
	* sysdeps/unix/sysv/linux/lseek64.c: Include <shlib-compat.h>.
	(llseek): Define as compat symbol if
	[SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_28)], not as weak alias
	with link warning.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list (llseek):
	Make into a compat symbol, disabled for minimum symbol version
	GLIBC_2.28 and later.
	* sysdeps/unix/sysv/linux/x86_64/x32/llseek.S: Remove file.
2018-05-22 15:44:01 +00:00

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1.6 KiB
C

/* Linux lseek implementation, 64 bits off_t.
Copyright (C) 2016-2018 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
<http://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <stdint.h>
#include <sys/types.h>
#include <sysdep.h>
#include <errno.h>
#include <shlib-compat.h>
off64_t
__lseek64 (int fd, off64_t offset, int whence)
{
#ifdef __NR__llseek
loff_t res;
int rc = INLINE_SYSCALL_CALL (_llseek, fd,
(long) (((uint64_t) (offset)) >> 32),
(long) offset, &res, whence);
return rc ?: res;
#else
return INLINE_SYSCALL_CALL (lseek, fd, offset, whence);
#endif
}
#ifdef __OFF_T_MATCHES_OFF64_T
weak_alias (__lseek64, lseek)
weak_alias (__lseek64, __lseek)
strong_alias (__lseek64, __libc_lseek)
libc_hidden_def (__lseek)
#endif
strong_alias (__lseek64, __libc_lseek64)
weak_alias (__lseek64, lseek64)
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_28)
strong_alias (__lseek64, __compat_llseek)
compat_symbol (libc, __compat_llseek, llseek, GLIBC_2_0);
#endif