mach/setup-thread.c

   1 /* Copyright (C) 1991-2024 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 <ldsodefs.h>
  23 #include "sysdep.h"             /* Defines stack direction.  */
  24
  25 #define STACK_SIZE      (16 * 1024 * 1024) /* 16MB, arbitrary.  */
  26
  27 static kern_return_t
  28 mach_setup_thread_impl (task_t task, thread_t thread, int is_call,
  29                         void *pc, vm_address_t *stack_base,
  30                         vm_size_t *stack_size)
  31 {
  32   kern_return_t error;
  33   struct machine_thread_state ts;
  34   mach_msg_type_number_t tssize = MACHINE_THREAD_STATE_COUNT;
  35   vm_address_t stack, stack_start;
  36   vm_size_t size;
  37   int anywhere;
  38
  39   memset (&ts, 0, sizeof (ts));
  40
  41   size = stack_size ? *stack_size ? : STACK_SIZE : STACK_SIZE;
  42   stack = stack_base ? *stack_base ? : 0 : 0;
  43   anywhere = !stack_base || !*stack_base;
  44
  45   error = __vm_allocate (task, &stack, size + __vm_page_size, anywhere);
  46   if (error)
  47     return error;
  48
  49   if (stack_size)
  50     *stack_size = size;
  51
  52 #ifdef STACK_GROWTH_DOWN
  53   stack_start = stack + __vm_page_size;
  54 #elif defined (STACK_GROWTH_UP)
  55   stack_start = stack;
  56   stack += size;
  57 #else
  58   #error stack direction unknown
  59 #endif
  60   if (stack_base)
  61     *stack_base = stack_start;
  62
  63   if (is_call)
  64     MACHINE_THREAD_STATE_SETUP_CALL (&ts, stack_start, size, pc);
  65   else
  66     {
  67       MACHINE_THREAD_STATE_SET_PC (&ts, pc);
  68       MACHINE_THREAD_STATE_SET_SP (&ts, stack_start, size);
  69     }
  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_NEW_THREAD_STATE_FLAVOR,
  76                              (natural_t *) &ts, tssize);
  77 }
  78
  79 /* Give THREAD a stack and set it to run at PC when resumed.
  80    If *STACK_SIZE is nonzero, that size of stack is allocated.
  81    If *STACK_BASE is nonzero, that stack location is used.
  82    If STACK_BASE is not null it is filled in with the chosen stack base.
  83    If STACK_SIZE is not null it is filled in with the chosen stack size.
  84    Regardless, an extra page of red zone is allocated off the end; this
  85    is not included in *STACK_SIZE.  */
  86
  87 kern_return_t
  88 __mach_setup_thread (task_t task, thread_t thread, void *pc,
  89                      vm_address_t *stack_base, vm_size_t *stack_size)
  90 {
  91   return mach_setup_thread_impl (task, thread, 0, pc, stack_base, stack_size);
  92 }
  93
  94 weak_alias (__mach_setup_thread, mach_setup_thread)
  95
  96 kern_return_t
  97 __mach_setup_thread_call (task_t task, thread_t thread, void *pc,
  98                           vm_address_t *stack_base, vm_size_t *stack_size)
  99 {
 100   return mach_setup_thread_impl (task, thread, 1, pc, stack_base, stack_size);
 101 }
 102
 103 /* Give THREAD a TLS area.  */
 104 kern_return_t
 105 __mach_setup_tls (thread_t thread)
 106 {
 107   tcbhead_t *tcb = _dl_allocate_tls (NULL);
 108   if (tcb == NULL)
 109     return KERN_RESOURCE_SHORTAGE;
 110
 111   return _hurd_tls_new (thread, tcb);
 112 }
 113
 114 weak_alias (__mach_setup_tls, mach_setup_tls)