sysdeps/unix/sysv/linux/powerpc/powerpc32/pread64.c

   1 /* Copyright (C) 1997,1998,1999,2000,2002,2003,2006
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <unistd.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 #if defined __NR_pread || __ASSUME_PREAD_SYSCALL > 0
  31
  32 # if __ASSUME_PREAD_SYSCALL == 0
  33 static ssize_t __emulate_pread64 (int fd, void *buf, size_t count,
  34                                   off64_t offset) internal_function;
  35 # endif
  36
  37
  38 ssize_t
  39 __libc_pread64 (fd, buf, count, offset)
  40      int fd;
  41      void *buf;
  42      size_t count;
  43      off64_t offset;
  44 {
  45   ssize_t result;
  46
  47   if (SINGLE_THREAD_P)
  48     {
  49       /* On PPC32 64bit values are aligned in odd/even register pairs.  */
  50       result = INLINE_SYSCALL (pread, 6, fd, CHECK_N (buf, count), count,
  51                                0, (long) (offset >> 32),
  52                                (long) offset);
  53 # if __ASSUME_PREAD_SYSCALL == 0
  54       if (result == -1 && errno == ENOSYS)
  55         /* No system call available.  Use the emulation.  */
  56         result = __emulate_pread64 (fd, buf, count, offset);
  57 # endif
  58
  59       return result;
  60     }
  61
  62   int oldtype = LIBC_CANCEL_ASYNC ();
  63
  64   /* On PPC32 64bit values are aligned in odd/even register pairs.  */
  65   result = INLINE_SYSCALL (pread, 6, fd, CHECK_N (buf, count), count,
  66                            0, (long) (offset >> 32),
  67                            (long) offset);
  68 # if __ASSUME_PREAD_SYSCALL == 0
  69   if (result == -1 && errno == ENOSYS)
  70     /* No system call available.  Use the emulation.  */
  71     result = __emulate_pread64 (fd, buf, count, offset);
  72 # endif
  73
  74   LIBC_CANCEL_RESET (oldtype);
  75
  76   return result;
  77 }
  78
  79 weak_alias (__libc_pread64, __pread64)
  80 weak_alias (__libc_pread64, pread64)
  81
  82 # define __libc_pread64(fd, buf, count, offset) \
  83      static internal_function __emulate_pread64 (fd, buf, count, offset)
  84 #endif
  85
  86 # if __ASSUME_PREAD_SYSCALL == 0
  87 # include <sysdeps/posix/pread64.c>
  88 #endif