1 /* Definition for thread-local data handling. nptl/IA-64 version.
2 Copyright (C) 2003-2023 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 #ifndef _TLS_H
20 #define _TLS_H 1
21
22 #include <dl-sysdep.h>
23 #ifndef __ASSEMBLER__
24 # include <stdbool.h>
25 # include <stddef.h>
26 # include <stdint.h>
27 # include <stdlib.h>
28 # include <list.h>
29 # include <dl-dtv.h>
30
31 typedef struct
32 {
33 dtv_t *dtv;
34 void *__private;
35 } tcbhead_t;
36
37 register struct pthread *__thread_self __asm__("r13");
38
39 # define TLS_MULTIPLE_THREADS_IN_TCB 1
40
41 #else /* __ASSEMBLER__ */
42 # include <tcb-offsets.h>
43 #endif
44
45
46 /* Alignment requirement for the stack. */
47 #define STACK_ALIGN 16
48
49 #ifndef __ASSEMBLER__
50 /* Get system call information. */
51 # include <sysdep.h>
52
53 /* This is the size of the initial TCB. */
54 # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
55
56 /* This is the size of the TCB. */
57 # define TLS_TCB_SIZE sizeof (tcbhead_t)
58
59 /* This is the size we need before TCB.
60 If there is not any room for uintptr_t stack_guard and
61 uintptr_t pointer_guard in struct pthread's final padding,
62 we need to put struct pthread 16 byte slower. */
63 # define TLS_PRE_TCB_SIZE \
64 (sizeof (struct pthread) \
65 + (PTHREAD_STRUCT_END_PADDING < 2 * sizeof (uintptr_t) \
66 ? ((2 * sizeof (uintptr_t) + __alignof__ (struct pthread) - 1) \
67 & ~(__alignof__ (struct pthread) - 1)) \
68 : 0))
69
70 /* The DTV is allocated at the TP; the TCB is placed elsewhere. */
71 # define TLS_DTV_AT_TP 1
72 # define TLS_TCB_AT_TP 0
73
74 /* Get the thread descriptor definition. */
75 # include <nptl/descr.h>
76
77 /* Install the dtv pointer. The pointer passed is to the element with
78 index -1 which contain the length. */
79 # define INSTALL_DTV(descr, dtvp) \
80 ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
81
82 /* Install new dtv for current thread. */
83 # define INSTALL_NEW_DTV(DTV) \
84 (((tcbhead_t *)__thread_self)->dtv = (DTV))
85
86 /* Return dtv of given thread descriptor. */
87 # define GET_DTV(descr) \
88 (((tcbhead_t *) (descr))->dtv)
89
90 #define THREAD_SELF_SYSINFO (((tcbhead_t *) __thread_self)->__private)
91 #define THREAD_SYSINFO(pd) \
92 (((tcbhead_t *) ((char *) (pd) + TLS_PRE_TCB_SIZE))->__private)
93
94 #ifdef NEED_DL_SYSINFO
95 # define INIT_SYSINFO THREAD_SELF_SYSINFO = (void *) GLRO(dl_sysinfo)
96 # define SETUP_THREAD_SYSINFO(pd) \
97 (THREAD_SYSINFO (pd) = THREAD_SELF_SYSINFO)
98 # define CHECK_THREAD_SYSINFO(pd) \
99 assert (THREAD_SYSINFO (pd) == THREAD_SELF_SYSINFO)
100 #else
101 # define INIT_SYSINFO NULL
102 #endif
103
104 /* Code to initially initialize the thread pointer. This might need
105 special attention since 'errno' is not yet available and if the
106 operation can cause a failure 'errno' must not be touched. */
107 # define TLS_INIT_TP(thrdescr) \
108 (__thread_self = (thrdescr), INIT_SYSINFO, true)
109
110 /* Value passed to 'clone2' for initialization of the thread register. */
111 # define TLS_DEFINE_INIT_TP(tp, pd) \
112 void *tp = (char *) (pd) + TLS_PRE_TCB_SIZE
113
114 /* Return the address of the dtv for the current thread. */
115 # define THREAD_DTV() \
116 (((tcbhead_t *)__thread_self)->dtv)
117
118 /* Return the thread descriptor for the current thread. */
119 # define THREAD_SELF \
120 ((struct pthread *) ((char *) __thread_self - TLS_PRE_TCB_SIZE))
121
122 /* Magic for libthread_db to know how to do THREAD_SELF. */
123 # define DB_THREAD_SELF REGISTER (64, 64, 13 * 8, -TLS_PRE_TCB_SIZE)
124
125 # include <tcb-access.h>
126
127 /* Set the stack guard field in TCB head. */
128 #define THREAD_SET_STACK_GUARD(value) \
129 (((uintptr_t *) __thread_self)[-1] = (value))
130 #define THREAD_COPY_STACK_GUARD(descr) \
131 (((uintptr_t *) ((char *) (descr) + TLS_PRE_TCB_SIZE))[-1] \
132 = ((uintptr_t *) __thread_self)[-1])
133
134 /* Set the pointer guard field in TCB head. */
135 #define THREAD_GET_POINTER_GUARD() \
136 (((uintptr_t *) __thread_self)[-2])
137 #define THREAD_SET_POINTER_GUARD(value) \
138 (((uintptr_t *) __thread_self)[-2] = (value))
139 #define THREAD_COPY_POINTER_GUARD(descr) \
140 (((uintptr_t *) ((char *) (descr) + TLS_PRE_TCB_SIZE))[-2] \
141 = THREAD_GET_POINTER_GUARD ())
142
143 /* Get and set the global scope generation counter in struct pthread. */
144 #define THREAD_GSCOPE_FLAG_UNUSED 0
145 #define THREAD_GSCOPE_FLAG_USED 1
146 #define THREAD_GSCOPE_FLAG_WAIT 2
147 #define THREAD_GSCOPE_RESET_FLAG() \
148 do \
149 { int __res \
150 = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
151 THREAD_GSCOPE_FLAG_UNUSED); \
152 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
153 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
154 } \
155 while (0)
156 #define THREAD_GSCOPE_SET_FLAG() \
157 do \
158 { \
159 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
160 atomic_write_barrier (); \
161 } \
162 while (0)
163
164 #endif /* __ASSEMBLER__ */
165
166 #endif /* tls.h */