1/* System dependent pthreads code. Hurd version.
2 Copyright (C) 2000-2024 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 <https://www.gnu.org/licenses/>. */
18
19#include <assert.h>
20#include <stddef.h>
21#include <stdint.h>
22
23#include <mach.h>
24#include <mach/mig_support.h>
25
26#include <pt-internal.h>
27#include <pthreadP.h>
28
29/* Initial thread structure used temporarily during initialization, so various
30 * functions can already work at least basically. */
31static struct __pthread init_thread;
32
33static void
34reset_pthread_total (void)
35{
36 /* Only current thread remains */
37 __pthread_total = 1;
38}
39
40/* This function is called from the Hurd-specific startup code. It
41 should return a new stack pointer for the main thread. The caller
42 will switch to this new stack before doing anything serious. */
43static void
44_init_routine (void *stack)
45{
46 struct __pthread *thread;
47 int err;
48 pthread_attr_t attr, *attrp = 0;
49
50 if (GL (dl_pthread_threads) != NULL)
51 /* Already initialized */
52 return;
53
54 /* Initialize early thread structure. */
55 init_thread.thread = 1;
56 ___pthread_self = &init_thread;
57
58 /* Initialize the library. */
59 ___pthread_init ();
60
61 if (stack != NULL)
62 {
63 /* We are given a stack, use it. */
64
65 /* Get the stack area information */
66 vm_address_t addr = (vm_address_t) stack;
67 vm_size_t vm_size;
68 vm_prot_t prot, max_prot;
69 vm_inherit_t inherit;
70 boolean_t is_shared;
71 memory_object_name_t obj;
72 vm_offset_t offset;
73
74 if (__vm_region (__mach_task_self (), &addr,
75 &vm_size, &prot, &max_prot, &inherit, &is_shared,
76 &obj, &offset) == KERN_SUCCESS)
77 __mach_port_deallocate (__mach_task_self (), obj);
78 else
79 {
80 /* Uh. Assume at least a page. */
81 vm_size = __vm_page_size;
82#if _STACK_GROWS_DOWN
83 addr = (vm_address_t) stack - vm_size;
84#else
85 addr = (vm_address_t) stack + vm_size;
86#endif
87 }
88
89 /* Avoid allocating another stack */
90 attrp = &attr;
91 __pthread_attr_init (attr: attrp);
92 __pthread_attr_setstack (attrp, (void *) addr, vm_size);
93 }
94
95 /* Create the pthread structure for the main thread (i.e. us). */
96 err = __pthread_create_internal (&thread, attrp, 0, 0);
97 assert_perror (err);
98
99 /* XXX The caller copies the command line arguments and the environment
100 to the new stack. Pretend it wasn't allocated so that it remains
101 valid if the main thread terminates. */
102 thread->stack = 0;
103 thread->tcb = THREAD_SELF;
104
105#ifndef PAGESIZE
106 __pthread_default_attr.__guardsize = __vm_page_size;
107#endif
108
109 /* Copy over the thread-specific state */
110 assert (!init_thread.thread_specifics);
111 memcpy (dest: &thread->static_thread_specifics,
112 src: &init_thread.static_thread_specifics,
113 n: sizeof (thread->static_thread_specifics));
114
115 ___pthread_self = thread;
116
117 /* Decrease the number of threads, to take into account that the
118 signal thread (which will be created by the glibc startup code
119 when we return from here) shouldn't be seen as a user thread. */
120 __pthread_total--;
121
122 __pthread_atfork (NULL, NULL, child: reset_pthread_total);
123
124 GL(dl_init_static_tls) = &__pthread_init_static_tls;
125
126 /* Make MiG code thread aware. */
127 __mig_init (thread->stackaddr);
128}
129
130void
131__pthread_initialize_minimal (void)
132{
133 _init_routine (stack: __libc_stack_end);
134}
135
136#ifdef SHARED
137__attribute__ ((constructor))
138static void
139dynamic_init_routine (void)
140{
141 _init_routine (__libc_stack_end);
142}
143#endif
144

source code of glibc/sysdeps/mach/hurd/htl/pt-sysdep.c