1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
/* Definition for thread-local data handling. NPTL/OpenRISC version.
Copyright (C) 2022-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<https://www.gnu.org/licenses/>. */
#ifndef _TLS_H
#define _TLS_H 1
#include <dl-sysdep.h>
#ifndef __ASSEMBLER__
# include <stdbool.h>
# include <stddef.h>
# include <stdint.h>
# include <dl-dtv.h>
typedef struct
{
dtv_t *dtv;
void *__padding[3];
} tcbhead_t;
register tcbhead_t *__thread_self __asm__("r10");
# define TLS_MULTIPLE_THREADS_IN_TCB 1
/* Get system call information. */
# include <sysdep.h>
/* The TP points to the start of the TLS block.
As I understand it, this isn't strictly that "TP points to DTV" - it's
more where to place the TCB in the TLS block. This will place it in
the beginning.
Layout:
+-----+-----+----------------------+
| PRE | TCB | TLS MEMORY .. |
+-----+-----+----------------------+
^ r10 / TP
PRE is the struct pthread described below
TCB is tcbhead_t
TLS memory is where the TLS program sections are loaded
See _dl_allocate_tls_storage and __libc_setup_tls for more information. */
# define TLS_DTV_AT_TP 1
# define TLS_TCB_AT_TP 0
/* Get the thread descriptor definition. */
# include <nptl/descr.h>
/* Requirements for the TCB. */
# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
# define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
# define TLS_TCB_SIZE sizeof (tcbhead_t)
# define TLS_TCB_ALIGN __alignof__ (struct pthread)
/* This is the size of the TCB. */
/* This is the size we need before TCB.
To support THREAD_GETMEM with friends we want to have a
struct pthread available.
Yank it in infront of everything, I'm sure nobody will mind.
This memory is really allocated PRE the TLS block, so it's possible
to do ((char*)tlsblock) - TLS_PRE_TCB_SIZE to access it.
This is done for THREAD_SELF. */
# define TLS_PRE_TCB_SIZE sizeof (struct pthread)
/* Install the dtv pointer.
When called, dtvp is a pointer not the DTV per say (which should start
with the generation counter) but to the length of the DTV.
We can always index with -1, so we store dtvp[1]. */
# define INSTALL_DTV(tcbp, dtvp) \
(((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
/* Install new dtv for current thread
In a logicial world dtv here would also point to the length of the DTV.
However it does not, this time it points to the generation counter,
so just store it.
Note: -1 is still valid and contains the length. */
# define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
/* Return dtv of given thread descriptor. */
# define GET_DTV(tcbp) (((tcbhead_t *) (tcbp))->dtv)
/* Code to initially initialize the thread pointer.
Set TP to the address _after_ tcbhead_t. This will allow us
to change the size of tcbhead_t without having to re-link everything.
This has to return NULL on success (or a string with the failure text).
It's hard to fail this, so return NULL always. */
# define TLS_INIT_TP(tcbp) \
({__thread_self = ((tcbhead_t *)tcbp + 1); true;})
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) \
void *tp = ((char *) pd + TLS_PRE_TCB_SIZE + TLS_INIT_TCB_SIZE)
/* Return the address of the dtv for the current thread.
Dereference TP, offset to dtv - really straightforward.
Remember that we made TP point to after tcb, so we need to reverse that. */
# define THREAD_DTV() \
((((tcbhead_t *)__thread_self)-1)->dtv)
/* Return the thread descriptor for the current thread.
Return a pointer to the TLS_PRE area where we allocated space for
a struct pthread. Again, TP points to after tcbhead_t, compensate with
TLS_INIT_TCB_SIZE.
I regard this is a seperate system from the "normal" TLS. */
# define THREAD_SELF \
((struct pthread *) ((char *) __thread_self - TLS_INIT_TCB_SIZE \
- TLS_PRE_TCB_SIZE))
/* Magic for libthread_db to know how to do THREAD_SELF. */
# define DB_THREAD_SELF \
REGISTER (32, 32, 10 * 4, - TLS_INIT_TCB_SIZE - TLS_PRE_TCB_SIZE)
# include <tcb-access.h>
/* Access to data in the thread descriptor is easy. */
#define THREAD_GETMEM(descr, member) \
descr->member
#define THREAD_GETMEM_NC(descr, member, idx) \
descr->member[idx]
#define THREAD_SETMEM(descr, member, value) \
descr->member = (value)
#define THREAD_SETMEM_NC(descr, member, idx, value) \
descr->member[idx] = (value)
/* Get and set the global scope generation counter in struct pthread. */
#define THREAD_GSCOPE_FLAG_UNUSED 0
#define THREAD_GSCOPE_FLAG_USED 1
#define THREAD_GSCOPE_FLAG_WAIT 2
#define THREAD_GSCOPE_RESET_FLAG() \
do \
{ \
int __res = atomic_exchange_release (&THREAD_SELF->header.gscope_flag,\
THREAD_GSCOPE_FLAG_UNUSED); \
if (__res == THREAD_GSCOPE_FLAG_WAIT) \
lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, \
LLL_PRIVATE); \
} \
while (0)
#define THREAD_GSCOPE_SET_FLAG() \
do \
{ \
THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
atomic_write_barrier (); \
} \
while (0)
#endif /* __ASSEMBLER__ */
#endif /* tls.h */
|
