1 /* Definition for thread-local data handling. NPTL/PowerPC 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
24 #ifndef __ASSEMBLER__
25 # include <stdbool.h>
26 # include <stddef.h>
27 # include <stdint.h>
28 # include <dl-dtv.h>
29 # include <thread_pointer.h>
30
31 #else /* __ASSEMBLER__ */
32 # include <tcb-offsets.h>
33 # define __ASSEMBLY__
34 # include <asm/ptrace.h>
35 #endif /* __ASSEMBLER__ */
36
37 #ifndef __powerpc64__
38 /* Register r2 (tp) is reserved by the ABI as "thread pointer". */
39 # define PT_THREAD_POINTER PT_R2
40
41 #else /* __powerpc64__ */
42 /* Register r13 (tp) is reserved by the ABI as "thread pointer". */
43 # define PT_THREAD_POINTER PT_R13
44 #endif /* __powerpc64__ */
45
46 #ifndef __ASSEMBLER__
47
48 /* Get system call information. */
49 # include <sysdep.h>
50
51 /* The TP points to the start of the thread blocks. */
52 # define TLS_DTV_AT_TP 1
53 # define TLS_TCB_AT_TP 0
54
55 /* We use the multiple_threads field in the pthread struct */
56 #define TLS_MULTIPLE_THREADS_IN_TCB 1
57
58 /* Get the thread descriptor definition. */
59 # include <nptl/descr.h>
60
61
62 /* The stack_guard is accessed directly by GCC -fstack-protector code,
63 so it is a part of public ABI. The dtv and pointer_guard fields
64 are private. */
65 typedef struct
66 {
67 /* Reservation for HWCAP data. To be accessed by GCC in
68 __builtin_cpu_supports(), so it is a part of public ABI. */
69 uint64_t hwcap;
70 /* Reservation for AT_PLATFORM data. To be accessed by GCC in
71 __builtin_cpu_is(), so it is a part of public ABI. Since there
72 are different ABIs for 32 and 64 bit, we put this field in a
73 previously empty padding space for powerpc64. */
74 #ifndef __powerpc64__
75 /* Padding to maintain alignment. */
76 uint32_t padding;
77 uint32_t at_platform;
78 #endif
79 uint32_t __unused;
80 /* Reservation for AT_PLATFORM data - powerpc64. */
81 #ifdef __powerpc64__
82 uint32_t at_platform;
83 #endif
84 /* Reservation for Dynamic System Optimizer ABI. */
85 uintptr_t dso_slot2;
86 uintptr_t dso_slot1;
87 /* Reservation for tar register (ISA 2.07). */
88 uintptr_t tar_save;
89 /* GCC split stack support. */
90 void *__private_ss;
91 /* Reservation for the Event-Based Branching ABI. */
92 uintptr_t ebb_handler;
93 uintptr_t ebb_ctx_pointer;
94 uintptr_t ebb_reserved1;
95 uintptr_t ebb_reserved2;
96 uintptr_t pointer_guard;
97 uintptr_t stack_guard;
98 dtv_t *dtv;
99 } tcbhead_t;
100
101 # include <hwcapinfo.h>
102
103 /* This is the size of the initial TCB. */
104 # define TLS_INIT_TCB_SIZE 0
105
106 /* This is the size of the TCB. */
107 # define TLS_TCB_SIZE 0
108
109 /* This is the size we need before TCB. */
110 # define TLS_PRE_TCB_SIZE \
111 (sizeof (struct pthread) \
112 + ((sizeof (tcbhead_t) + __alignof (struct pthread) - 1) \
113 & ~(__alignof (struct pthread) - 1)))
114
115 /* The following assumes that TP (R2 or R13) points to the end of the
116 TCB + 0x7000 (per the ABI). This implies that TCB address is
117 TP - 0x7000. As we define TLS_DTV_AT_TP we can
118 assume that the pthread struct is allocated immediately ahead of the
119 TCB. This implies that the pthread_descr address is
120 TP - (TLS_PRE_TCB_SIZE + 0x7000). */
121 # define TLS_TCB_OFFSET 0x7000
122
123 /* Install the dtv pointer. The pointer passed is to the element with
124 index -1 which contain the length. */
125 # define INSTALL_DTV(tcbp, dtvp) \
126 ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
127
128 /* Install new dtv for current thread. */
129 # define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
130
131 /* Return dtv of given thread descriptor. */
132 # define GET_DTV(tcbp) (((tcbhead_t *) (tcbp))[-1].dtv)
133
134 /* Code to initially initialize the thread pointer. This might need
135 special attention since 'errno' is not yet available and if the
136 operation can cause a failure 'errno' must not be touched. */
137 # define TLS_INIT_TP(tcbp) \
138 ({ \
139 __thread_register = (void *) (tcbp) + TLS_TCB_OFFSET; \
140 THREAD_SET_HWCAP (__tcb.hwcap); \
141 THREAD_SET_AT_PLATFORM (__tcb.at_platform); \
142 true; \
143 })
144
145 /* Value passed to 'clone' for initialization of the thread register. */
146 # define TLS_DEFINE_INIT_TP(tp, pd) \
147 void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE; \
148 (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].hwcap) = \
149 THREAD_GET_HWCAP (); \
150 (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].at_platform) = \
151 THREAD_GET_AT_PLATFORM ();
152
153 /* Return the address of the dtv for the current thread. */
154 # define THREAD_DTV() \
155 (((tcbhead_t *) (__thread_register - TLS_TCB_OFFSET))[-1].dtv)
156
157 /* Return the thread descriptor for the current thread. */
158 # define THREAD_SELF \
159 ((struct pthread *) (__thread_register \
160 - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
161
162 /* Magic for libthread_db to know how to do THREAD_SELF. */
163 # define DB_THREAD_SELF \
164 REGISTER (32, 32, PT_THREAD_POINTER * 4, \
165 - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE) \
166 REGISTER (64, 64, PT_THREAD_POINTER * 8, \
167 - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
168
169 # include <tcb-access.h>
170
171 /* Set the stack guard field in TCB head. */
172 # define THREAD_SET_STACK_GUARD(value) \
173 (((tcbhead_t *) ((char *) __thread_register \
174 - TLS_TCB_OFFSET))[-1].stack_guard = (value))
175 # define THREAD_COPY_STACK_GUARD(descr) \
176 (((tcbhead_t *) ((char *) (descr) \
177 + TLS_PRE_TCB_SIZE))[-1].stack_guard \
178 = ((tcbhead_t *) ((char *) __thread_register \
179 - TLS_TCB_OFFSET))[-1].stack_guard)
180
181 /* Set the stack guard field in TCB head. */
182 # define THREAD_GET_POINTER_GUARD() \
183 (((tcbhead_t *) ((char *) __thread_register \
184 - TLS_TCB_OFFSET))[-1].pointer_guard)
185 # define THREAD_SET_POINTER_GUARD(value) \
186 (THREAD_GET_POINTER_GUARD () = (value))
187 # define THREAD_COPY_POINTER_GUARD(descr) \
188 (((tcbhead_t *) ((char *) (descr) \
189 + TLS_PRE_TCB_SIZE))[-1].pointer_guard \
190 = THREAD_GET_POINTER_GUARD())
191
192 /* hwcap field in TCB head. */
193 # define THREAD_GET_HWCAP() \
194 (((tcbhead_t *) ((char *) __thread_register \
195 - TLS_TCB_OFFSET))[-1].hwcap)
196 # define THREAD_SET_HWCAP(value) \
197 (THREAD_GET_HWCAP () = (value))
198
199 /* at_platform field in TCB head. */
200 # define THREAD_GET_AT_PLATFORM() \
201 (((tcbhead_t *) ((char *) __thread_register \
202 - TLS_TCB_OFFSET))[-1].at_platform)
203 # define THREAD_SET_AT_PLATFORM(value) \
204 (THREAD_GET_AT_PLATFORM () = (value))
205
206 /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
207 different value to mean unset l_tls_offset. */
208 # define NO_TLS_OFFSET -1
209
210 /* Get and set the global scope generation counter in struct pthread. */
211 #define THREAD_GSCOPE_FLAG_UNUSED 0
212 #define THREAD_GSCOPE_FLAG_USED 1
213 #define THREAD_GSCOPE_FLAG_WAIT 2
214 #define THREAD_GSCOPE_RESET_FLAG() \
215 do \
216 { int __res \
217 = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
218 THREAD_GSCOPE_FLAG_UNUSED); \
219 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
220 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
221 } \
222 while (0)
223 #define THREAD_GSCOPE_SET_FLAG() \
224 do \
225 { \
226 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
227 atomic_write_barrier (); \
228 } \
229 while (0)
230
231 #endif /* __ASSEMBLER__ */
232
233 #endif /* tls.h */