1 /* Definitions for thread-local data handling. NPTL/sparc 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 #ifndef __ASSEMBLER__
24 # include <stdbool.h>
25 # include <stddef.h>
26 # include <stdint.h>
27 # include <stdlib.h>
28 # include <list.h>
29 # include <kernel-features.h>
30 # include <dl-dtv.h>
31
32 typedef struct
33 {
34 void *tcb; /* Pointer to the TCB. Not necessary the
35 thread descriptor used by libpthread. */
36 dtv_t *dtv;
37 void *self;
38 int multiple_threads;
39 #if __WORDSIZE == 64
40 int gscope_flag;
41 #endif
42 uintptr_t sysinfo;
43 uintptr_t stack_guard;
44 uintptr_t pointer_guard;
45 #if __WORDSIZE != 64
46 int gscope_flag;
47 #endif
48 } tcbhead_t;
49
50 #else /* __ASSEMBLER__ */
51 # include <tcb-offsets.h>
52 #endif /* __ASSEMBLER__ */
53
54
55 #ifndef __ASSEMBLER__
56 /* Get system call information. */
57 # include <sysdep.h>
58
59 register struct pthread *__thread_self __asm__("%g7");
60
61 /* This is the size of the initial TCB. Can't be just sizeof (tcbhead_t),
62 because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
63 struct pthread even when not linked with -lpthread. */
64 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
65
66 /* This is the size of the TCB. */
67 # define TLS_TCB_SIZE sizeof (struct pthread)
68
69 /* The TCB can have any size and the memory following the address the
70 thread pointer points to is unspecified. Allocate the TCB there. */
71 # define TLS_TCB_AT_TP 1
72 # define TLS_DTV_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 /* Code to initially initialize the thread pointer. */
91 # define TLS_INIT_TP(descr) \
92 (__thread_self = (__typeof (__thread_self)) (descr), true)
93
94 /* Value passed to 'clone' for initialization of the thread register. */
95 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)
96
97 /* Return the address of the dtv for the current thread. */
98 # define THREAD_DTV() \
99 (((tcbhead_t *) __thread_self)->dtv)
100
101 /* Return the thread descriptor for the current thread. */
102 #define THREAD_SELF __thread_self
103
104 /* Magic for libthread_db to know how to do THREAD_SELF. */
105 # define DB_THREAD_SELF \
106 REGISTER (32, 32, 10 * 4, 0) \
107 REGISTER (64, __WORDSIZE, (6 * 8) + (__WORDSIZE==64?0:4), 0)
108
109 # include <tcb-access.h>
110
111 /* Set the stack guard field in TCB head. */
112 #define THREAD_SET_STACK_GUARD(value) \
113 THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
114 # define THREAD_COPY_STACK_GUARD(descr) \
115 ((descr)->header.stack_guard \
116 = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
117
118 /* Get/set the stack guard field in TCB head. */
119 #define THREAD_GET_POINTER_GUARD() \
120 THREAD_GETMEM (THREAD_SELF, header.pointer_guard)
121 #define THREAD_SET_POINTER_GUARD(value) \
122 THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
123 # define THREAD_COPY_POINTER_GUARD(descr) \
124 ((descr)->header.pointer_guard = THREAD_GET_POINTER_GUARD ())
125
126 /* Get and set the global scope generation counter in struct pthread. */
127 #define THREAD_GSCOPE_FLAG_UNUSED 0
128 #define THREAD_GSCOPE_FLAG_USED 1
129 #define THREAD_GSCOPE_FLAG_WAIT 2
130 #define THREAD_GSCOPE_RESET_FLAG() \
131 do \
132 { int __res \
133 = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
134 THREAD_GSCOPE_FLAG_UNUSED); \
135 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
136 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
137 } \
138 while (0)
139 #define THREAD_GSCOPE_SET_FLAG() \
140 do \
141 { \
142 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
143 atomic_write_barrier (); \
144 } \
145 while (0)
146
147 #endif /* !ASSEMBLER */
148
149 #endif /* tls.h */