sysdeps/unix/sysv/linux/mmap64.c

   1 /* Copyright (C) 1999,2000,2001,2002,2006 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>, 1999.
   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 <sys/mman.h>
  23
  24 #include <sysdep.h>
  25 #include <sys/syscall.h>
  26 #include <bp-checks.h>
  27
  28 #include <kernel-features.h>
  29
  30 #ifdef __NR_mmap2
  31
  32 /* This is always 12, even on architectures where PAGE_SHIFT != 12.  */
  33 # ifndef MMAP2_PAGE_SHIFT
  34 #  define MMAP2_PAGE_SHIFT 12
  35 # endif
  36
  37 # ifndef __ASSUME_MMAP2_SYSCALL
  38 static int have_no_mmap2;
  39 # endif
  40 #endif
  41
  42
  43 void *
  44 __mmap64 (void *addr, size_t len, int prot, int flags, int fd, off64_t offset)
  45 {
  46 #ifdef __NR_mmap2
  47   if (offset & ((1 << MMAP2_PAGE_SHIFT) - 1))
  48     {
  49       __set_errno (EINVAL);
  50       return MAP_FAILED;
  51     }
  52 # ifndef __ASSUME_MMAP2_SYSCALL
  53   if (! have_no_mmap2)
  54 # endif
  55     {
  56 # ifndef __ASSUME_MMAP2_SYSCALL
  57       int saved_errno = errno;
  58 # endif
  59       void *result;
  60       __ptrvalue (result) = (void *__unbounded)
  61         INLINE_SYSCALL (mmap2, 6, __ptrvalue (addr),
  62                         len, prot, flags, fd,
  63                         (off_t) (offset >> MMAP2_PAGE_SHIFT));
  64 # if __BOUNDED_POINTERS__
  65       __ptrlow (result) = __ptrvalue (result);
  66       __ptrhigh (result) = __ptrvalue (result) + len;
  67 # endif
  68 # ifndef __ASSUME_MMAP2_SYSCALL
  69       if (result != MAP_FAILED || errno != ENOSYS)
  70 # endif
  71         return result;
  72
  73 # ifndef __ASSUME_MMAP2_SYSCALL
  74       __set_errno (saved_errno);
  75       have_no_mmap2 = 1;
  76 # endif
  77     }
  78 #endif
  79 #ifndef __ASSUME_MMAP2_SYSCALL
  80   if (offset != (off_t) offset || (offset + len) != (off_t) (offset + len))
  81     {
  82       __set_errno (EINVAL);
  83       return MAP_FAILED;
  84     }
  85
  86   return __mmap (addr, len, prot, flags, fd, (off_t) offset);
  87 #endif
  88 }
  89 weak_alias (__mmap64, mmap64)