sysdeps/mach/htl/pt-stack-alloc.c

   1 /* Allocate a new stack.  Mach version.
   2    Copyright (C) 2000-2018 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20
  21 #include <mach.h>
  22 #include <mach/machine/vm_param.h>
  23
  24 #include <pt-internal.h>
  25
  26 /* The next address to use for stack allocation.  */
  27 static vm_address_t next_stack_base = VM_MIN_ADDRESS;
  28
  29
  30 /* Allocate a new stack of size STACKSIZE.  If successful, store the
  31    address of the newly allocated stack in *STACKADDR and return 0.
  32    Otherwise return an error code (EINVAL for an invalid stack size,
  33    EAGAIN if the system lacked the necessary resources to allocate a
  34    new stack).  */
  35 int
  36 __pthread_stack_alloc (void **stackaddr, size_t stacksize)
  37 {
  38   vm_offset_t base;
  39   int i = 0;
  40
  41 get_stack:
  42   i++;
  43   for (base = next_stack_base;
  44        base < VM_MAX_ADDRESS
  45        && __vm_allocate (__mach_task_self (), &base,
  46                          stacksize, FALSE) != KERN_SUCCESS; base += stacksize)
  47     ;
  48
  49   if (base >= VM_MAX_ADDRESS)
  50     {
  51       if (i == 1)
  52         {
  53           next_stack_base = VM_MIN_ADDRESS;
  54           goto get_stack;
  55         }
  56       else
  57         return EAGAIN;
  58     }
  59
  60   if (base >= VM_MAX_ADDRESS)
  61     return EAGAIN;
  62
  63   next_stack_base = base + stacksize;
  64
  65   (*stackaddr) = (void *) base;
  66   return 0;
  67 }