1 /* Definition for thread-local data handling. NPTL/SH 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
21
22 # include <dl-sysdep.h>
23
24 #ifndef __ASSEMBLER__
25 # include <stdbool.h>
26 # include <stddef.h>
27 # include <stdint.h>
28 # include <stdlib.h>
29 # include <list.h>
30 # include <sysdep.h>
31 # include <dl-dtv.h>
32
33 typedef struct
34 {
35 dtv_t *dtv;
36 uintptr_t pointer_guard;
37 } tcbhead_t;
38
39 # define TLS_MULTIPLE_THREADS_IN_TCB 1
40
41 #else /* __ASSEMBLER__ */
42 # include <tcb-offsets.h>
43 #endif /* __ASSEMBLER__ */
44
45
46 #ifndef __ASSEMBLER__
47
48 /* Get system call information. */
49 # include <sysdep.h>
50
51 /* This is the size of the initial TCB. */
52 # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
53
54 /* This is the size of the TCB. */
55 # define TLS_TCB_SIZE sizeof (tcbhead_t)
56
57 /* This is the size we need before TCB. */
58 # define TLS_PRE_TCB_SIZE sizeof (struct pthread)
59
60 /* The TLS blocks start right after the TCB. */
61 # define TLS_DTV_AT_TP 1
62 # define TLS_TCB_AT_TP 0
63
64 /* Get the thread descriptor definition. */
65 # include <nptl/descr.h>
66
67 /* Install the dtv pointer. The pointer passed is to the element with
68 index -1 which contain the length. */
69 # define INSTALL_DTV(tcbp, dtvp) \
70 ((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1
71
72 /* Install new dtv for current thread. */
73 # define INSTALL_NEW_DTV(dtv) \
74 ({ tcbhead_t *__tcbp; \
75 __asm __volatile ("stc gbr,%0" : "=r" (__tcbp)); \
76 __tcbp->dtv = (dtv);})
77
78 /* Return dtv of given thread descriptor. */
79 # define GET_DTV(tcbp) \
80 (((tcbhead_t *) (tcbp))->dtv)
81
82 /* Code to initially initialize the thread pointer. This might need
83 special attention since 'errno' is not yet available and if the
84 operation can cause a failure 'errno' must not be touched. */
85 # define TLS_INIT_TP(tcbp) \
86 ({ __asm __volatile ("ldc %0,gbr" : : "r" (tcbp)); true; })
87
88 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
89
90 /* Return the address of the dtv for the current thread. */
91 # define THREAD_DTV() \
92 ({ tcbhead_t *__tcbp; \
93 __asm __volatile ("stc gbr,%0" : "=r" (__tcbp)); \
94 __tcbp->dtv;})
95
96 /* Return the thread descriptor for the current thread.
97 The contained asm must *not* be marked volatile since otherwise
98 assignments like
99 struct pthread *self = thread_self();
100 do not get optimized away. */
101 # define THREAD_SELF \
102 ({ struct pthread *__self; \
103 __asm ("stc gbr,%0" : "=r" (__self)); \
104 __self - 1;})
105
106 /* Magic for libthread_db to know how to do THREAD_SELF. */
107 # define DB_THREAD_SELF \
108 REGISTER (32, 32, REG_GBR * 4, -sizeof (struct pthread))
109
110 # include <tcb-access.h>
111
112 #define THREAD_GET_POINTER_GUARD() \
113 ({ tcbhead_t *__tcbp; \
114 __asm __volatile ("stc gbr,%0" : "=r" (__tcbp)); \
115 __tcbp->pointer_guard;})
116 #define THREAD_SET_POINTER_GUARD(value) \
117 ({ tcbhead_t *__tcbp; \
118 __asm __volatile ("stc gbr,%0" : "=r" (__tcbp)); \
119 __tcbp->pointer_guard = (value);})
120 #define THREAD_COPY_POINTER_GUARD(descr) \
121 ({ tcbhead_t *__tcbp; \
122 __asm __volatile ("stc gbr,%0" : "=r" (__tcbp)); \
123 ((tcbhead_t *) (descr + 1))->pointer_guard = __tcbp->pointer_guard;})
124
125 /* Get and set the global scope generation counter in struct pthread. */
126 #define THREAD_GSCOPE_FLAG_UNUSED 0
127 #define THREAD_GSCOPE_FLAG_USED 1
128 #define THREAD_GSCOPE_FLAG_WAIT 2
129 #define THREAD_GSCOPE_RESET_FLAG() \
130 do \
131 { int __res \
132 = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
133 THREAD_GSCOPE_FLAG_UNUSED); \
134 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
135 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
136 } \
137 while (0)
138 #define THREAD_GSCOPE_SET_FLAG() \
139 do \
140 { \
141 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
142 atomic_write_barrier (); \
143 } \
144 while (0)
145
146 #endif /* __ASSEMBLER__ */
147
148 #endif /* tls.h */