glibc/sysdeps/unix/sysv/linux/mmap64.c

58 lines
1.7 KiB
C

/* Copyright (C) 1999-2016 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 <string.h>
#include <sysdep.h>
#include <sys/syscall.h>
/* This is always 12, even on architectures where PAGE_SHIFT != 12. */
#ifndef MMAP2_PAGE_SHIFT
# define MMAP2_PAGE_SHIFT 12
#endif
#if MMAP2_PAGE_SHIFT == -1
static int page_shift;
#else
#define page_shift MMAP2_PAGE_SHIFT
#endif
void *
__mmap64 (void *addr, size_t len, int prot, int flags, int fd, off64_t offset)
{
#if MMAP2_PAGE_SHIFT == -1
if (page_shift == 0)
{
int page_size = __getpagesize ();
page_shift = __ffs (page_size) - 1;
}
#endif
if (offset & ((1 << page_shift) - 1))
return (void *) INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
void *result;
result = (void *)
INLINE_SYSCALL (mmap2, 6, addr,
len, prot, flags, fd,
(off_t) (offset >> page_shift));
return result;
}
weak_alias (__mmap64, mmap64)