mach/setup-thread.c

   1 /* Copyright (C) 1991-2023 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <mach.h>
  19 #include <mach/setup-thread.h>
  20 #include <thread_state.h>
  21 #include <string.h>
  22 #include <mach/machine/vm_param.h>
  23 #include <ldsodefs.h>
  24 #include "sysdep.h"             /* Defines stack direction.  */
  25
  26 #define STACK_SIZE      (16 * 1024 * 1024) /* 16MB, arbitrary.  */
  27
  28 static kern_return_t
  29 mach_setup_thread_impl (task_t task, thread_t thread, int is_call,
  30                         void *pc, vm_address_t *stack_base,
  31                         vm_size_t *stack_size)
  32 {
  33   kern_return_t error;
  34   struct machine_thread_state ts;
  35   mach_msg_type_number_t tssize = MACHINE_THREAD_STATE_COUNT;
  36   vm_address_t stack, stack_start;
  37   vm_size_t size;
  38   int anywhere;
  39
  40   memset (&ts, 0, sizeof (ts));
  41
  42   size = stack_size ? *stack_size ? : STACK_SIZE : STACK_SIZE;
  43   stack = stack_base ? *stack_base ? : 0 : 0;
  44   anywhere = !stack_base || !*stack_base;
  45
  46   error = __vm_allocate (task, &stack, size + __vm_page_size, anywhere);
  47   if (error)
  48     return error;
  49
  50   if (stack_size)
  51     *stack_size = size;
  52
  53 #ifdef STACK_GROWTH_DOWN
  54   stack_start = stack + __vm_page_size;
  55 #elif defined (STACK_GROWTH_UP)
  56   stack_start = stack;
  57   stack += size;
  58 #else
  59   #error stack direction unknown
  60 #endif
  61   if (stack_base)
  62     *stack_base = stack_start;
  63
  64   if (is_call)
  65     MACHINE_THREAD_STATE_SETUP_CALL (&ts, stack_start, size, pc);
  66   else
  67     {
  68       MACHINE_THREAD_STATE_SET_PC (&ts, pc);
  69       MACHINE_THREAD_STATE_SET_SP (&ts, stack_start, size);
  70     }
  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_NEW_THREAD_STATE_FLAVOR,
  77                              (natural_t *) &ts, tssize);
  78 }
  79
  80 /* Give THREAD a stack and set it to run at PC when resumed.
  81    If *STACK_SIZE is nonzero, that size of stack is allocated.
  82    If *STACK_BASE is nonzero, that stack location is used.
  83    If STACK_BASE is not null it is filled in with the chosen stack base.
  84    If STACK_SIZE is not null it is filled in with the chosen stack size.
  85    Regardless, an extra page of red zone is allocated off the end; this
  86    is not included in *STACK_SIZE.  */
  87
  88 kern_return_t
  89 __mach_setup_thread (task_t task, thread_t thread, void *pc,
  90                      vm_address_t *stack_base, vm_size_t *stack_size)
  91 {
  92   return mach_setup_thread_impl (task, thread, 0, pc, stack_base, stack_size);
  93 }
  94
  95 weak_alias (__mach_setup_thread, mach_setup_thread)
  96
  97 kern_return_t
  98 __mach_setup_thread_call (task_t task, thread_t thread, void *pc,
  99                           vm_address_t *stack_base, vm_size_t *stack_size)
 100 {
 101   return mach_setup_thread_impl (task, thread, 1, pc, stack_base, stack_size);
 102 }
 103
 104 /* Give THREAD a TLS area.  */
 105 kern_return_t
 106 __mach_setup_tls (thread_t thread)
 107 {
 108   tcbhead_t *tcb = _dl_allocate_tls (NULL);
 109   if (tcb == NULL)
 110     return KERN_RESOURCE_SHORTAGE;
 111
 112   return _hurd_tls_new (thread, tcb);
 113 }
 114
 115 weak_alias (__mach_setup_tls, mach_setup_tls)