mach/setup-thread.c

   1 /* Copyright (C) 1991, 1994, 1995, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <mach.h>
  20 #include "thread_state.h"
  21 #include <string.h>
  22 #include <mach/machine/vm_param.h>
  23 #include "sysdep.h"             /* Defines stack direction.  */
  24
  25 #define STACK_SIZE      (16 * 1024 * 1024) /* 16MB, arbitrary.  */
  26
  27 /* Give THREAD a stack and set it to run at PC when resumed.
  28    If *STACK_SIZE is nonzero, that size of stack is allocated.
  29    If *STACK_BASE is nonzero, that stack location is used.
  30    If STACK_BASE is not null it is filled in with the chosen stack base.
  31    If STACK_SIZE is not null it is filled in with the chosen stack size.
  32    Regardless, an extra page of red zone is allocated off the end; this
  33    is not included in *STACK_SIZE.  */
  34
  35 kern_return_t
  36 __mach_setup_thread (task_t task, thread_t thread, void *pc,
  37                      vm_address_t *stack_base, vm_size_t *stack_size)
  38 {
  39   kern_return_t error;
  40   struct machine_thread_state ts;
  41   mach_msg_type_number_t tssize = MACHINE_THREAD_STATE_COUNT;
  42   vm_address_t stack;
  43   vm_size_t size;
  44   int anywhere;
  45
  46   size = stack_size ? *stack_size ? : STACK_SIZE : STACK_SIZE;
  47   stack = stack_base ? *stack_base ? : 0 : 0;
  48   anywhere = !stack_base || !*stack_base;
  49
  50   error = __vm_allocate (task, &stack, size + __vm_page_size, anywhere);
  51   if (error)
  52     return error;
  53
  54   if (stack_size)
  55     *stack_size = size;
  56
  57   memset (&ts, 0, sizeof (ts));
  58   MACHINE_THREAD_STATE_SET_PC (&ts, pc);
  59 #ifdef STACK_GROWTH_DOWN
  60   if (stack_base)
  61     *stack_base = stack + __vm_page_size;
  62   ts.SP = stack + __vm_page_size + size;
  63 #elif defined (STACK_GROWTH_UP)
  64   if (stack_base)
  65     *stack_base = stack;
  66   ts.SP = stack;
  67   stack += size;
  68 #else
  69   #error stack direction unknown
  70 #endif
  71
  72   /* Create the red zone.  */
  73   if (error = __vm_protect (task, stack, __vm_page_size, 0, VM_PROT_NONE))
  74     return error;
  75
  76   return __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR,
  77                              (int *) &ts, tssize);
  78 }
  79
  80 weak_alias (__mach_setup_thread, mach_setup_thread)