sysdeps/mach/hurd/mlock.c

   1 /* mlock -- guarantee pages are resident in memory.  Mach/Hurd version.
   2    Copyright (C) 2001-2024 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 }