mach/setup-thread.c

   1 /* Copyright (C) 1991-2016 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <mach.h>
  19 #include <thread_state.h>
  20 #include <string.h>
  21 #include <mach/machine/vm_param.h>
  22 #include "sysdep.h"             /* Defines stack direction.  */
  23
  24 #define STACK_SIZE      (16 * 1024 * 1024) /* 16MB, arbitrary.  */
  25
  26 /* Give THREAD a stack and set it to run at PC when resumed.
  27    If *STACK_SIZE is nonzero, that size of stack is allocated.
  28    If *STACK_BASE is nonzero, that stack location is used.
  29    If STACK_BASE is not null it is filled in with the chosen stack base.
  30    If STACK_SIZE is not null it is filled in with the chosen stack size.
  31    Regardless, an extra page of red zone is allocated off the end; this
  32    is not included in *STACK_SIZE.  */
  33
  34 kern_return_t
  35 __mach_setup_thread (task_t task, thread_t thread, void *pc,
  36                      vm_address_t *stack_base, vm_size_t *stack_size)
  37 {
  38   kern_return_t error;
  39   struct machine_thread_state ts;
  40   mach_msg_type_number_t tssize = MACHINE_THREAD_STATE_COUNT;
  41   vm_address_t stack;
  42   vm_size_t size;
  43   int anywhere;
  44
  45   size = stack_size ? *stack_size ? : STACK_SIZE : STACK_SIZE;
  46   stack = stack_base ? *stack_base ? : 0 : 0;
  47   anywhere = !stack_base || !*stack_base;
  48
  49   error = __vm_allocate (task, &stack, size + __vm_page_size, anywhere);
  50   if (error)
  51     return error;
  52
  53   if (stack_size)
  54     *stack_size = size;
  55
  56   memset (&ts, 0, sizeof (ts));
  57   MACHINE_THREAD_STATE_SET_PC (&ts, pc);
  58 #ifdef STACK_GROWTH_DOWN
  59   if (stack_base)
  60     *stack_base = stack + __vm_page_size;
  61   ts.SP = stack + __vm_page_size + size;
  62 #elif defined (STACK_GROWTH_UP)
  63   if (stack_base)
  64     *stack_base = stack;
  65   ts.SP = stack;
  66   stack += size;
  67 #else
  68   #error stack direction unknown
  69 #endif
  70
  71   /* Create the red zone.  */
  72   if (error = __vm_protect (task, stack, __vm_page_size, 0, VM_PROT_NONE))
  73     return error;
  74
  75   return __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR,
  76                              (natural_t *) &ts, tssize);
  77 }
  78
  79 weak_alias (__mach_setup_thread, mach_setup_thread)