1  /* mlock -- guarantee pages are resident in memory.  Mach/Hurd version.
       2     Copyright (C) 2001-2023 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  #include <sys/types.h>
      20  #include <sys/mman.h>
      21  #include <errno.h>
      22  #include <hurd.h>
      23  #include <mach/mach_host.h>
      24  
      25  /* Guarantee all whole pages mapped by the range [ADDR,ADDR+LEN) to
      26     be memory resident.  */
      27  
      28  int
      29  mlock (const void *addr, size_t len)
      30  {
      31    mach_port_t host;
      32    vm_address_t page;
      33    error_t err;
      34  
      35    err = __get_privileged_ports (&host, NULL);
      36    if (err)
      37      host = __mach_host_self();
      38  
      39    page = trunc_page ((vm_address_t) addr);
      40    len = round_page ((vm_address_t) addr + len) - page;
      41  
      42    err = __vm_wire (host, __mach_task_self (), page, len, VM_PROT_READ);
      43    if (host != __mach_host_self())
      44      __mach_port_deallocate (__mach_task_self (), host);
      45  
      46    return err ? __hurd_fail (err) : 0;
      47  }