glibc/sysdeps/unix/sysv/linux/mmap64.c
2012-02-09 23:18:22 +00:00

102 lines
2.6 KiB
C

/* Copyright (C) 1999,2000,2001,2002,2006,2010 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>, 1999.
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, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sysdep.h>
#include <sys/syscall.h>
#include <bp-checks.h>
#include <kernel-features.h>
#ifdef __NR_mmap2
/* This is always 12, even on architectures where PAGE_SHIFT != 12. */
# if MMAP2_PAGE_SHIFT == -1
static int page_shift;
# else
# ifndef MMAP2_PAGE_SHIFT
# define MMAP2_PAGE_SHIFT 12
# endif
# define page_shift MMAP2_PAGE_SHIFT
# endif
# ifndef __ASSUME_MMAP2_SYSCALL
static int have_no_mmap2;
# endif
#endif
void *
__mmap64 (void *addr, size_t len, int prot, int flags, int fd, off64_t offset)
{
#ifdef __NR_mmap2
# if MMAP2_PAGE_SHIFT == -1
if (page_shift == 0)
{
int page_size = getpagesize ();
while ((1 << ++page_shift) != page_size)
;
}
# endif
if (offset & ((1 << page_shift) - 1))
{
__set_errno (EINVAL);
return MAP_FAILED;
}
# ifndef __ASSUME_MMAP2_SYSCALL
if (! have_no_mmap2)
# endif
{
# ifndef __ASSUME_MMAP2_SYSCALL
int saved_errno = errno;
# endif
void *result;
__ptrvalue (result) = (void *__unbounded)
INLINE_SYSCALL (mmap2, 6, __ptrvalue (addr),
len, prot, flags, fd,
(off_t) (offset >> MMAP2_PAGE_SHIFT));
# if __BOUNDED_POINTERS__
__ptrlow (result) = __ptrvalue (result);
__ptrhigh (result) = __ptrvalue (result) + len;
# endif
# ifndef __ASSUME_MMAP2_SYSCALL
if (result != MAP_FAILED || errno != ENOSYS)
# endif
return result;
# ifndef __ASSUME_MMAP2_SYSCALL
__set_errno (saved_errno);
have_no_mmap2 = 1;
# endif
}
#endif
#ifndef __ASSUME_MMAP2_SYSCALL
if (offset != (off_t) offset || (offset + len) != (off_t) (offset + len))
{
__set_errno (EINVAL);
return MAP_FAILED;
}
return __mmap (addr, len, prot, flags, fd, (off_t) offset);
#endif
}
weak_alias (__mmap64, mmap64)