mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-27 07:20:11 +00:00
97 lines
2.6 KiB
C
97 lines
2.6 KiB
C
/* Copyright (C) 1997-2000,2002,2003,2004 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
|
|
|
|
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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <endian.h>
|
|
#include <unistd.h>
|
|
|
|
#include <sysdep-cancel.h>
|
|
#include <sys/syscall.h>
|
|
#include <bp-checks.h>
|
|
|
|
#include "kernel-features.h"
|
|
|
|
#ifdef __NR_pread64 /* Newer kernels renamed but it's the same. */
|
|
# ifdef __NR_pread
|
|
# error "__NR_pread and __NR_pread64 both defined???"
|
|
# endif
|
|
# define __NR_pread __NR_pread64
|
|
#endif
|
|
|
|
#if defined __NR_pread || __ASSUME_PREAD_SYSCALL > 0
|
|
|
|
# if __ASSUME_PREAD_SYSCALL == 0
|
|
static ssize_t __emulate_pread (int fd, void *buf, size_t count,
|
|
off_t offset) internal_function;
|
|
# endif
|
|
|
|
|
|
static ssize_t
|
|
#ifdef NO_CANCELLATION
|
|
inline __attribute ((always_inline))
|
|
#endif
|
|
do_pread (int fd, void *buf, size_t count, off_t offset)
|
|
{
|
|
ssize_t result;
|
|
|
|
/* First try the syscall. */
|
|
assert (sizeof (offset) == 4);
|
|
result = INLINE_SYSCALL (pread, 5, fd, CHECK_N (buf, count), count,
|
|
__LONG_LONG_PAIR (offset >> 31, offset));
|
|
# if __ASSUME_PREAD_SYSCALL == 0
|
|
if (result == -1 && errno == ENOSYS)
|
|
/* No system call available. Use the emulation. */
|
|
result = __emulate_pread (fd, buf, count, offset);
|
|
# endif
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
ssize_t
|
|
__libc_pread (fd, buf, count, offset)
|
|
int fd;
|
|
void *buf;
|
|
size_t count;
|
|
off_t offset;
|
|
{
|
|
if (SINGLE_THREAD_P)
|
|
return do_pread (fd, buf, count, offset);
|
|
|
|
int oldtype = LIBC_CANCEL_ASYNC ();
|
|
|
|
ssize_t result = do_pread (fd, buf, count, offset);
|
|
|
|
LIBC_CANCEL_RESET (oldtype);
|
|
|
|
return result;
|
|
}
|
|
|
|
strong_alias (__libc_pread, __pread)
|
|
weak_alias (__libc_pread, pread)
|
|
|
|
# define __libc_pread(fd, buf, count, offset) \
|
|
static internal_function __emulate_pread (fd, buf, count, offset)
|
|
#endif
|
|
|
|
#if __ASSUME_PREAD_SYSCALL == 0
|
|
# include <sysdeps/posix/pread.c>
|
|
#endif
|