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1 /* Definition for thread-local data handling. nptl/x86_64 version.
2 Copyright (C) 2002, 2003, 2004, 2005, 2006 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, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
19
20 #ifndef _TLS_H
21 #define _TLS_H 1
22
23 #ifndef __ASSEMBLER__
24 # include <asm/prctl.h> /* For ARCH_SET_FS. */
25 # include <stdbool.h>
26 # include <stddef.h>
27 # include <stdint.h>
28 # include <stdlib.h>
29
30
31 /* Type for the dtv. */
32 typedef union dtv
33 {
34 size_t counter;
35 struct
36 {
37 void *val;
38 bool is_static;
39 } pointer;
40 } dtv_t;
41
42
43 typedef struct
44 {
45 void *tcb; /* Pointer to the TCB. Not necessary the
46 thread descriptor used by libpthread. */
47 dtv_t *dtv;
48 void *self; /* Pointer to the thread descriptor. */
49 int multiple_threads;
50 uintptr_t sysinfo;
51 uintptr_t stack_guard;
52 uintptr_t pointer_guard;
53 } tcbhead_t;
54
55 #else /* __ASSEMBLER__ */
56 # include <tcb-offsets.h>
57 #endif
58
59
60 /* We require TLS support in the tools. */
61 #ifndef HAVE_TLS_SUPPORT
62 # error "TLS support is required."
63 #endif
64
65 /* Signal that TLS support is available. */
66 #define USE_TLS 1
67
68 /* Alignment requirement for the stack. */
69 #define STACK_ALIGN 16
70
71
72 #ifndef __ASSEMBLER__
73 /* Get system call information. */
74 # include <sysdep.h>
75
76
77 /* Get the thread descriptor definition. */
78 # include <nptl/descr.h>
79
80 #ifndef LOCK_PREFIX
81 # ifdef UP
82 # define LOCK_PREFIX /* nothing */
83 # else
84 # define LOCK_PREFIX "lock;"
85 # endif
86 #endif
87
88 /* This is the size of the initial TCB. Can't be just sizeof (tcbhead_t),
89 because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
90 struct pthread even when not linked with -lpthread. */
91 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
92
93 /* Alignment requirements for the initial TCB. */
94 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
95
96 /* This is the size of the TCB. */
97 # define TLS_TCB_SIZE sizeof (struct pthread)
98
99 /* Alignment requirements for the TCB. */
100 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
101
102 /* The TCB can have any size and the memory following the address the
103 thread pointer points to is unspecified. Allocate the TCB there. */
104 # define TLS_TCB_AT_TP 1
105
106
107 /* Install the dtv pointer. The pointer passed is to the element with
108 index -1 which contain the length. */
109 # define INSTALL_DTV(descr, dtvp) \
110 ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
111
112 /* Install new dtv for current thread. */
113 # define INSTALL_NEW_DTV(dtvp) \
114 ({ struct pthread *__pd; \
115 THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
116
117 /* Return dtv of given thread descriptor. */
118 # define GET_DTV(descr) \
119 (((tcbhead_t *) (descr))->dtv)
120
121
122 /* Macros to load from and store into segment registers. */
123 # define TLS_GET_FS() \
124 ({ int __seg; __asm ("movl %%fs, %0" : "=q" (__seg)); __seg; })
125 # define TLS_SET_FS(val) \
126 __asm ("movl %0, %%fs" :: "q" (val))
127
128
129 /* Code to initially initialize the thread pointer. This might need
130 special attention since 'errno' is not yet available and if the
131 operation can cause a failure 'errno' must not be touched.
132
133 We have to make the syscall for both uses of the macro since the
134 address might be (and probably is) different. */
135 # define TLS_INIT_TP(thrdescr, secondcall) \
136 ({ void *_thrdescr = (thrdescr); \
137 tcbhead_t *_head = _thrdescr; \
138 int _result; \
139 \
140 _head->tcb = _thrdescr; \
141 /* For now the thread descriptor is at the same address. */ \
142 _head->self = _thrdescr; \
143 \
144 /* It is a simple syscall to set the %fs value for the thread. */ \
145 asm volatile ("syscall" \
146 : "=a" (_result) \
147 : "0" ((unsigned long int) __NR_arch_prctl), \
148 "D" ((unsigned long int) ARCH_SET_FS), \
149 "S" (_thrdescr) \
150 : "memory", "cc", "r11", "cx"); \
151 \
152 _result ? "cannot set %fs base address for thread-local storage" : 0; \
153 })
154
155
156 /* Return the address of the dtv for the current thread. */
157 # define THREAD_DTV() \
158 ({ struct pthread *__pd; \
159 THREAD_GETMEM (__pd, header.dtv); })
160
161
162 /* Return the thread descriptor for the current thread.
163
164 The contained asm must *not* be marked volatile since otherwise
165 assignments like
166 pthread_descr self = thread_self();
167 do not get optimized away. */
168 # define THREAD_SELF \
169 ({ struct pthread *__self; \
170 asm ("movq %%fs:%c1,%q0" : "=r" (__self) \
171 : "i" (offsetof (struct pthread, header.self))); \
172 __self;})
173
174 /* Magic for libthread_db to know how to do THREAD_SELF. */
175 # define DB_THREAD_SELF_INCLUDE <sys/reg.h> /* For the FS constant. */
176 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
177
178 /* Read member of the thread descriptor directly. */
179 # define THREAD_GETMEM(descr, member) \
180 ({ __typeof (descr->member) __value; \
181 if (sizeof (__value) == 1) \
182 asm volatile ("movb %%fs:%P2,%b0" \
183 : "=q" (__value) \
184 : "0" (0), "i" (offsetof (struct pthread, member))); \
185 else if (sizeof (__value) == 4) \
186 asm volatile ("movl %%fs:%P1,%0" \
187 : "=r" (__value) \
188 : "i" (offsetof (struct pthread, member))); \
189 else \
190 { \
191 if (sizeof (__value) != 8) \
192 /* There should not be any value with a size other than 1, \
193 4 or 8. */ \
194 abort (); \
195 \
196 asm volatile ("movq %%fs:%P1,%q0" \
197 : "=r" (__value) \
198 : "i" (offsetof (struct pthread, member))); \
199 } \
200 __value; })
201
202
203 /* Same as THREAD_GETMEM, but the member offset can be non-constant. */
204 # define THREAD_GETMEM_NC(descr, member, idx) \
205 ({ __typeof (descr->member[0]) __value; \
206 if (sizeof (__value) == 1) \
207 asm volatile ("movb %%fs:%P2(%q3),%b0" \
208 : "=q" (__value) \
209 : "0" (0), "i" (offsetof (struct pthread, member[0])), \
210 "r" (idx)); \
211 else if (sizeof (__value) == 4) \
212 asm volatile ("movl %%fs:%P1(,%q2,4),%0" \
213 : "=r" (__value) \
214 : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
215 else \
216 { \
217 if (sizeof (__value) != 8) \
218 /* There should not be any value with a size other than 1, \
219 4 or 8. */ \
220 abort (); \
221 \
222 asm volatile ("movq %%fs:%P1(,%q2,8),%q0" \
223 : "=r" (__value) \
224 : "i" (offsetof (struct pthread, member[0])), \
225 "r" (idx)); \
226 } \
227 __value; })
228
229
230 /* Loading addresses of objects on x86-64 needs to be treated special
231 when generating PIC code. */
232 #ifdef __pic__
233 # define IMM_MODE "nr"
234 #else
235 # define IMM_MODE "ir"
236 #endif
237
238
239 /* Same as THREAD_SETMEM, but the member offset can be non-constant. */
240 # define THREAD_SETMEM(descr, member, value) \
241 ({ if (sizeof (descr->member) == 1) \
242 asm volatile ("movb %b0,%%fs:%P1" : \
243 : "iq" (value), \
244 "i" (offsetof (struct pthread, member))); \
245 else if (sizeof (descr->member) == 4) \
246 asm volatile ("movl %0,%%fs:%P1" : \
247 : IMM_MODE (value), \
248 "i" (offsetof (struct pthread, member))); \
249 else \
250 { \
251 if (sizeof (descr->member) != 8) \
252 /* There should not be any value with a size other than 1, \
253 4 or 8. */ \
254 abort (); \
255 \
256 asm volatile ("movq %q0,%%fs:%P1" : \
257 : IMM_MODE ((unsigned long int) value), \
258 "i" (offsetof (struct pthread, member))); \
259 }})
260
261
262 /* Set member of the thread descriptor directly. */
263 # define THREAD_SETMEM_NC(descr, member, idx, value) \
264 ({ if (sizeof (descr->member[0]) == 1) \
265 asm volatile ("movb %b0,%%fs:%P1(%q2)" : \
266 : "iq" (value), \
267 "i" (offsetof (struct pthread, member[0])), \
268 "r" (idx)); \
269 else if (sizeof (descr->member[0]) == 4) \
270 asm volatile ("movl %0,%%fs:%P1(,%q2,4)" : \
271 : IMM_MODE (value), \
272 "i" (offsetof (struct pthread, member[0])), \
273 "r" (idx)); \
274 else \
275 { \
276 if (sizeof (descr->member[0]) != 8) \
277 /* There should not be any value with a size other than 1, \
278 4 or 8. */ \
279 abort (); \
280 \
281 asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" : \
282 : IMM_MODE ((unsigned long int) value), \
283 "i" (offsetof (struct pthread, member[0])), \
284 "r" (idx)); \
285 }})
286
287
288 /* Atomic compare and exchange on TLS, returning old value. */
289 #define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
290 ({ __typeof (descr->member) __ret; \
291 __typeof (oldval) __old = (oldval); \
292 if (sizeof (descr->member) == 4) \
293 asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3" \
294 : "=a" (__ret) \
295 : "0" (__old), "r" (newval), \
296 "i" (offsetof (struct pthread, member))); \
297 else \
298 /* Not necessary for other sizes in the moment. */ \
299 abort (); \
300 __ret; })
301
302
303 /* Atomic set bit. */
304 #define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
305 (void) ({ if (sizeof ((descr)->member) == 4) \
306 asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0" \
307 :: "i" (offsetof (struct pthread, member)), \
308 "ir" (1 << (bit))); \
309 else \
310 /* Not necessary for other sizes in the moment. */ \
311 abort (); })
312
313
314 #define CALL_THREAD_FCT(descr) \
315 ({ void *__res; \
316 asm volatile ("movq %%fs:%P2, %%rdi\n\t" \
317 "callq *%%fs:%P1" \
318 : "=a" (__res) \
319 : "i" (offsetof (struct pthread, start_routine)), \
320 "i" (offsetof (struct pthread, arg)) \
321 : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11", \
322 "memory", "cc"); \
323 __res; })
324
325
326 /* Set the stack guard field in TCB head. */
327 # define THREAD_SET_STACK_GUARD(value) \
328 THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
329 # define THREAD_COPY_STACK_GUARD(descr) \
330 ((descr)->header.stack_guard \
331 = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
332
333
334 /* Set the pointer guard field in the TCB head. */
335 #define THREAD_SET_POINTER_GUARD(value) \
336 THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
337 #define THREAD_COPY_POINTER_GUARD(descr) \
338 ((descr)->header.pointer_guard \
339 = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
340
341
342 #endif /* __ASSEMBLER__ */
343
344 #endif /* tls.h */