sysdeps/unix/sysv/linux/mips/pread64.c

   1 /* Copyright (C) 1997, 1998, 2000, 2002, 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <endian.h>
  23
  24 #include <sysdep-cancel.h>
  25 #include <sys/syscall.h>
  26 #include <bp-checks.h>
  27
  28 #include <kernel-features.h>
  29
  30 #ifdef __NR_pread64             /* Newer kernels renamed but it's the same.  */
  31 # ifdef __NR_pread
  32 #  error "__NR_pread and __NR_pread64 both defined???"
  33 # endif
  34 # define __NR_pread __NR_pread64
  35 #endif
  36
  37 #if defined __NR_pread || __ASSUME_PREAD_SYSCALL > 0
  38
  39 # if __ASSUME_PREAD_SYSCALL == 0
  40 static ssize_t __emulate_pread64 (int fd, void *buf, size_t count,
  41                                   off64_t offset) internal_function;
  42 # endif
  43
  44 ssize_t
  45 __libc_pread64 (fd, buf, count, offset)
  46      int fd;
  47      void *buf;
  48      size_t count;
  49      off64_t offset;
  50 {
  51   ssize_t result;
  52
  53
  54   if (SINGLE_THREAD_P)
  55     {
  56      /* First try the syscall.  */
  57 #if (defined _ABIN32 && _MIPS_SIM == _ABIN32) || (defined _ABI64 && _MIPS_SIM == _ABI64)
  58       result = INLINE_SYSCALL (pread, 4, fd, CHECK_N (buf, count), count,
  59                                offset);
  60 #else
  61      result = INLINE_SYSCALL (pread, 6, fd, CHECK_N (buf, count), count, 0,
  62                               __LONG_LONG_PAIR ((off_t) (offset >> 32),
  63                               (off_t) (offset & 0xffffffff)));
  64 #endif
  65 # if __ASSUME_PREAD_SYSCALL == 0
  66      if (result == -1 && errno == ENOSYS)
  67      /* No system call available.  Use the emulation.  */
  68      result = __emulate_pread64 (fd, buf, count, offset);
  69 # endif
  70      return result;
  71     }
  72
  73   int oldtype = LIBC_CANCEL_ASYNC ();
  74
  75   /* First try the syscall.  */
  76 #if (defined _ABIN32 && _MIPS_SIM == _ABIN32) || (defined _ABI64 && _MIPS_SIM == _ABI64)
  77   result = INLINE_SYSCALL (pread, 4, fd, CHECK_N (buf, count), count, offset);
  78 #else
  79   result = INLINE_SYSCALL (pread, 6, fd, CHECK_N (buf, count), count, 0,
  80                            __LONG_LONG_PAIR ((off_t) (offset >> 32),
  81                                              (off_t) (offset & 0xffffffff)));
  82 #endif
  83 # if __ASSUME_PREAD_SYSCALL == 0
  84   if (result == -1 && errno == ENOSYS)
  85     /* No system call available.  Use the emulation.  */
  86     result = __emulate_pread64 (fd, buf, count, offset);
  87 # endif
  88
  89   LIBC_CANCEL_RESET (oldtype);
  90
  91   return result;
  92 }
  93
  94 weak_alias (__libc_pread64, __pread64)
  95 weak_alias (__libc_pread64, pread64)
  96
  97 # define __libc_pread64(fd, buf, count, offset) \
  98      static internal_function __emulate_pread64 (fd, buf, count, offset)
  99 #endif
 100
 101 #if __ASSUME_PREAD_SYSCALL == 0
 102 # include <sysdeps/posix/pread64.c>
 103 #endif