NetBSD/lib/libc/sys/pread.c

70 lines
2.5 KiB
C

/* $NetBSD: pread.c,v 1.8 2006/11/10 17:37:39 christos Exp $ */
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: pread.c,v 1.8 2006/11/10 17:37:39 christos Exp $");
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <sys/syscall.h>
#include <unistd.h>
#ifdef __weak_alias
__weak_alias(pread,_sys_pread)
__weak_alias(_pread,_sys_pread)
#endif
#ifdef __lint__
#define _sys_pread pread
#endif
ssize_t _sys_pread(int, void *, size_t, off_t);
/*
* This function provides 64-bit offset padding that
* is not supplied by GCC 1.X but is supplied by GCC 2.X.
*/
ssize_t
_sys_pread(int fd, void *buf, size_t nbyte, off_t offset)
{
quad_t q;
int rv;
q = __syscall((quad_t)SYS_pread, fd, buf, nbyte, 0, offset);
if (/* LINTED constant */ sizeof (quad_t) == sizeof (register_t) ||
/* LINTED constant */ BYTE_ORDER == LITTLE_ENDIAN)
rv = (int)q;
else
rv = (int)((u_quad_t)q >> 32);
return rv;
}