1  /* Common mmap definition for Linux implementation.
       2     Copyright (C) 2017-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       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, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef MMAP_INTERNAL_LINUX_H
      20  #define MMAP_INTERNAL_LINUX_H 1
      21  
      22  #include <stdint.h>
      23  
      24  /* This is the minimum mmap2 unit size accept by the kernel.  An architecture
      25     with multiple minimum page sizes (such as m68k) might define it as -1 and
      26     thus it will queried at runtime.  */
      27  #ifndef MMAP2_PAGE_UNIT
      28  # define MMAP2_PAGE_UNIT 4096ULL
      29  #endif
      30  
      31  #if MMAP2_PAGE_UNIT == -1ULL
      32  static uint64_t page_unit;
      33  # define MMAP_CHECK_PAGE_UNIT()			\
      34    if (page_unit == 0)				\
      35      page_unit = __getpagesize ();
      36  # undef MMAP2_PAGE_UNIT
      37  # define MMAP2_PAGE_UNIT page_unit
      38  #else
      39  # define MMAP_CHECK_PAGE_UNIT()
      40  #endif
      41  
      42  /* Do not accept offset not multiple of page size.  */
      43  #define MMAP_OFF_LOW_MASK  (MMAP2_PAGE_UNIT - 1)
      44  
      45  #include <mmap_call.h>
      46  
      47  #endif /* MMAP_INTERNAL_LINUX_H  */