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/* mmap - map files or devices into memory. Linux version.
Copyright (C) 1999-2020 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sysdep.h>
#include <mmap_internal.h>
#ifdef __NR_mmap2
/* To avoid silent truncation of offset when using mmap2, do not accept
offset larger than 1 << (page_shift + off_t bits). For archictures with
32 bits off_t and page size of 4096 it would be 1^44. */
# define MMAP_OFF_HIGH_MASK \
((-(MMAP2_PAGE_UNIT << 1) << (8 * sizeof (off_t) - 1)))
#else
/* Some ABIs might use __NR_mmap while having sizeof (off_t) smaller than
sizeof (off64_t) (currently only MIPS64n32). For this case just set
zero the higher bits so mmap with large offset does not fail. */
# define MMAP_OFF_HIGH_MASK 0x0
#endif
#define MMAP_OFF_MASK (MMAP_OFF_HIGH_MASK | MMAP_OFF_LOW_MASK)
/* An architecture may override this. */
#ifndef MMAP_PREPARE
# define MMAP_PREPARE(addr, len, prot, flags, fd, offset)
#endif
void *
__mmap64 (void *addr, size_t len, int prot, int flags, int fd, off64_t offset)
{
MMAP_CHECK_PAGE_UNIT ();
if (offset & MMAP_OFF_MASK)
return (void *) INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
MMAP_PREPARE (addr, len, prot, flags, fd, offset);
#ifdef __NR_mmap2
return (void *) MMAP_CALL (mmap2, addr, len, prot, flags, fd,
(off_t) (offset / MMAP2_PAGE_UNIT));
#else
return (void *) MMAP_CALL (mmap, addr, len, prot, flags, fd, offset);
#endif
}
weak_alias (__mmap64, mmap64)
libc_hidden_def (__mmap64)
#ifdef __OFF_T_MATCHES_OFF64_T
weak_alias (__mmap64, mmap)
weak_alias (__mmap64, __mmap)
libc_hidden_def (__mmap)
#endif
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