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
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
|
/* Definition for thread-local data handling. nptl/i386 version.
Copyright (C) 2002 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _TLS_H
#define _TLS_H 1
#include <dl-sysdep.h>
#ifndef __ASSEMBLER__
# include <stddef.h>
# include <stdint.h>
# include <stdlib.h>
# include <list.h>
/* Type for the dtv. */
typedef union dtv
{
size_t counter;
void *pointer;
} dtv_t;
typedef struct
{
void *tcb; /* Pointer to the TCB. Not necessary the
thread descriptor used by libpthread. */
dtv_t *dtv;
void *self; /* Pointer to the thread descriptor. */
int multiple_threads;
uintptr_t sysinfo;
list_t list;
} tcbhead_t;
#endif
/* We require TLS support in the tools. */
#ifndef HAVE_TLS_SUPPORT
# error "TLS support is required."
#endif
/* Signal that TLS support is available. */
#define USE_TLS 1
/* Alignment requirement for the stack. For IA-32 this is governed by
the SSE memory functions. */
#define STACK_ALIGN 16
/* Offset of the MULTIPLE_THREADS element in tcbhead_t. */
#define MULTIPLE_THREADS_OFFSET 12
#ifdef NEED_DL_SYSINFO
/* Offset of the SYSINFO element in tcbhead_t. */
# define SYSINFO_OFFSET 16
#endif
#ifndef __ASSEMBLER__
/* Get system call information. */
# include <sysdep.h>
/* The old way: using LDT. */
/* Structure passed to `modify_ldt', 'set_thread_area', and 'clone' calls. */
struct user_desc
{
unsigned int entry_number;
unsigned long int base_addr;
unsigned int limit;
unsigned int seg_32bit:1;
unsigned int contents:2;
unsigned int read_exec_only:1;
unsigned int limit_in_pages:1;
unsigned int seg_not_present:1;
unsigned int useable:1;
unsigned int empty:25;
};
/* Initializing bit fields is slow. We speed it up by using a union. */
union user_desc_init
{
struct user_desc desc;
unsigned int vals[4];
};
/* Get the thread descriptor definition. */
# include <nptl/descr.h>
/* This is the size of the initial TCB. */
# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
/* Alignment requirements for the initial TCB. */
# define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
/* This is the size of the TCB. */
# define TLS_TCB_SIZE sizeof (struct pthread)
/* Alignment requirements for the TCB. */
# define TLS_TCB_ALIGN __alignof__ (struct pthread)
/* The TCB can have any size and the memory following the address the
thread pointer points to is unspecified. Allocate the TCB there. */
# define TLS_TCB_AT_TP 1
/* Install the dtv pointer. The pointer passed is to the element with
index -1 which contain the length. */
# define INSTALL_DTV(descr, dtvp) \
((tcbhead_t *) (descr))->dtv = dtvp + 1
/* Install new dtv for current thread. */
# define INSTALL_NEW_DTV(dtv) \
({ struct pthread *__pd; \
THREAD_SETMEM (__pd, header.data.dtvp, dtv); })
/* Return dtv of given thread descriptor. */
# define GET_DTV(descr) \
(((tcbhead_t *) (descr))->dtv)
/* Macros to load from and store into segment registers. */
# ifndef TLS_GET_GS
# define TLS_GET_GS() \
({ int __seg; __asm ("movw %%gs, %w0" : "=q" (__seg)); __seg & 0xffff; })
# endif
# ifndef TLS_SET_GS
# define TLS_SET_GS(val) \
__asm ("movw %w0, %%gs" :: "q" (val))
# endif
# ifndef __NR_set_thread_area
# define __NR_set_thread_area 243
# endif
# ifndef TLS_FLAG_WRITABLE
# define TLS_FLAG_WRITABLE 0x00000001
# endif
// XXX Enable for the real world.
#if 0
# ifndef __ASSUME_SET_THREAD_AREA
# error "we need set_thread_area"
# endif
#endif
# ifdef __PIC__
# define TLS_EBX_ARG "r"
# define TLS_LOAD_EBX "xchgl %3, %%ebx\n\t"
# else
# define TLS_EBX_ARG "b"
# define TLS_LOAD_EBX
# endif
#if defined NEED_DL_SYSINFO && defined SHARED
# define INIT_SYSINFO \
_head->sysinfo = GL(dl_sysinfo)
#else
# define INIT_SYSINFO
#endif
/* Code to initially initialize the thread pointer. This might need
special attention since 'errno' is not yet available and if the
operation can cause a failure 'errno' must not be touched. */
# define TLS_INIT_TP(thrdescr, secondcall) \
({ void *_thrdescr = (thrdescr); \
tcbhead_t *_head = _thrdescr; \
union user_desc_init _segdescr; \
int _result; \
\
_head->tcb = _thrdescr; \
/* For now the thread descriptor is at the same address. */ \
_head->self = _thrdescr; \
/* New syscall handling support. */ \
INIT_SYSINFO; \
\
/* The 'entry_number' field. Let the kernel pick a value. */ \
if (secondcall) \
_segdescr.vals[0] = TLS_GET_GS () >> 3; \
else \
_segdescr.vals[0] = -1; \
/* The 'base_addr' field. Pointer to the TCB. */ \
_segdescr.vals[1] = (unsigned long int) _thrdescr; \
/* The 'limit' field. We use 4GB which is 0xfffff pages. */ \
_segdescr.vals[2] = 0xfffff; \
/* Collapsed value of the bitfield: \
.seg_32bit = 1 \
.contents = 0 \
.read_exec_only = 0 \
.limit_in_pages = 1 \
.seg_not_present = 0 \
.useable = 1 */ \
_segdescr.vals[3] = 0x51; \
\
/* Install the TLS. */ \
asm volatile (TLS_LOAD_EBX \
"int $0x80\n\t" \
TLS_LOAD_EBX \
: "=a" (_result), "=m" (_segdescr.desc.entry_number) \
: "0" (__NR_set_thread_area), \
TLS_EBX_ARG (&_segdescr.desc), "m" (_segdescr.desc)); \
\
if (_result == 0) \
/* We know the index in the GDT, now load the segment register. \
The use of the GDT is described by the value 3 in the lower \
three bits of the segment descriptor value. \
\
Note that we have to do this even if the numeric value of \
the descriptor does not change. Loading the segment register \
causes the segment information from the GDT to be loaded \
which is necessary since we have changed it. */ \
TLS_SET_GS (_segdescr.desc.entry_number * 8 + 3); \
\
_result == 0 ? NULL \
: "set_thread_area failed when setting up thread-local storage"; })
/* Return the address of the dtv for the current thread. */
# define THREAD_DTV() \
({ struct pthread *__pd; \
THREAD_GETMEM (__pd, header.data.dtvp); })
/* Return the thread descriptor for the current thread.
The contained asm must *not* be marked volatile since otherwise
assignments like
pthread_descr self = thread_self();
do not get optimized away. */
# define THREAD_SELF \
({ struct pthread *__self; \
asm ("movl %%gs:%c1,%0" : "=r" (__self) \
: "i" (offsetof (struct pthread, header.data.self))); \
__self;})
/* Read member of the thread descriptor directly. */
# define THREAD_GETMEM(descr, member) \
({ __typeof (descr->member) __value; \
if (sizeof (__value) == 1) \
asm ("movb %%gs:%P2,%b0" \
: "=q" (__value) \
: "0" (0), "i" (offsetof (struct pthread, member))); \
else if (sizeof (__value) == 4) \
asm ("movl %%gs:%P1,%0" \
: "=r" (__value) \
: "i" (offsetof (struct pthread, member))); \
else \
{ \
if (sizeof (__value) != 8) \
/* There should not be any value with a size other than 1, \
4 or 8. */ \
abort (); \
\
asm ("movl %%gs:%P1,%%eax\n\t" \
"movl %%gs:%P2,%%edx" \
: "=A" (__value) \
: "i" (offsetof (struct pthread, member)), \
"i" (offsetof (struct pthread, member) + 4)); \
} \
__value; })
/* Same as THREAD_GETMEM, but the member offset can be non-constant. */
# define THREAD_GETMEM_NC(descr, member, idx) \
({ __typeof (descr->member[0]) __value; \
if (sizeof (__value) == 1) \
asm ("movb %%gs:%P2(%3),%b0" \
: "=q" (__value) \
: "0" (0), "i" (offsetof (struct pthread, member[0])), \
"r" (idx)); \
else if (sizeof (__value) == 4) \
asm ("movl %%gs:%P1(,%2,4),%0" \
: "=r" (__value) \
: "i" (offsetof (struct pthread, member[0])), "r" (idx)); \
else \
{ \
if (sizeof (__value) != 8) \
/* There should not be any value with a size other than 1, \
4 or 8. */ \
abort (); \
\
asm ("movl %%gs:%P1(,%2,8),%%eax\n\t" \
"movl %%gs:4+%P1(,%2,8),%%edx" \
: "=&A" (__value) \
: "i" (offsetof (struct pthread, member[0])), "r" (idx)); \
} \
__value; })
/* Same as THREAD_SETMEM, but the member offset can be non-constant. */
# define THREAD_SETMEM(descr, member, value) \
({ if (sizeof (descr->member) == 1) \
asm volatile ("movb %0,%%gs:%P1" : \
: "iq" (value), \
"i" (offsetof (struct pthread, member))); \
else if (sizeof (descr->member) == 4) \
asm volatile ("movl %0,%%gs:%P1" : \
: "ir" (value), \
"i" (offsetof (struct pthread, member))); \
else \
{ \
if (sizeof (descr->member) != 8) \
/* There should not be any value with a size other than 1, \
4 or 8. */ \
abort (); \
\
asm volatile ("movl %%eax,%%gs:%P1\n\t" \
"movl %%edx,%%gs:%P2" : \
: "A" (value), \
"i" (offsetof (struct pthread, member)), \
"i" (offsetof (struct pthread, member) + 4)); \
}})
/* Set member of the thread descriptor directly. */
# define THREAD_SETMEM_NC(descr, member, idx, value) \
({ if (sizeof (descr->member[0]) == 1) \
asm volatile ("movb %0,%%gs:%P1(%2)" : \
: "iq" (value), \
"i" (offsetof (struct pthread, member)), \
"r" (idx)); \
else if (sizeof (descr->member[0]) == 4) \
asm volatile ("movl %0,%%gs:%P1(,%2,4)" : \
: "ir" (value), \
"i" (offsetof (struct pthread, member)), \
"r" (idx)); \
else \
{ \
if (sizeof (descr->member[0]) != 8) \
/* There should not be any value with a size other than 1, \
4 or 8. */ \
abort (); \
\
asm volatile ("movl %%eax,%%gs:%P1(,%2,8)\n\t" \
"movl %%edx,%%gs:4+%P1(,%2,8)" : \
: "A" (value), \
"i" (offsetof (struct pthread, member)), \
"r" (idx)); \
}})
#endif /* __ASSEMBLER__ */
#endif /* tls.h */
|
