1/* Definition for thread-local data handling. nptl/x86_64 version.
2 Copyright (C) 2002-2016 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 <http://www.gnu.org/licenses/>. */
18
19#ifndef _TLS_H
20#define _TLS_H 1
21
22#ifndef __ASSEMBLER__
23# include <asm/prctl.h> /* For ARCH_SET_FS. */
24# include <stdbool.h>
25# include <stddef.h>
26# include <stdint.h>
27# include <stdlib.h>
28# include <sysdep.h>
29# include <libc-internal.h>
30# include <kernel-features.h>
31
32/* Replacement type for __m128 since this file is included by ld.so,
33 which is compiled with -mno-sse. It must not change the alignment
34 of rtld_savespace_sse. */
35typedef struct
36{
37 int i[4];
38} __128bits;
39
40
41/* Type for the dtv. */
42typedef union dtv
43{
44 size_t counter;
45 struct
46 {
47 void *val;
48 bool is_static;
49 } pointer;
50} dtv_t;
51
52
53typedef struct
54{
55 void *tcb; /* Pointer to the TCB. Not necessarily the
56 thread descriptor used by libpthread. */
57 dtv_t *dtv;
58 void *self; /* Pointer to the thread descriptor. */
59 int multiple_threads;
60 int gscope_flag;
61 uintptr_t sysinfo;
62 uintptr_t stack_guard;
63 uintptr_t pointer_guard;
64 unsigned long int vgetcpu_cache[2];
65# ifndef __ASSUME_PRIVATE_FUTEX
66 int private_futex;
67# else
68 int __glibc_reserved1;
69# endif
70 int __glibc_unused1;
71 /* Reservation of some values for the TM ABI. */
72 void *__private_tm[4];
73 /* GCC split stack support. */
74 void *__private_ss;
75 long int __glibc_reserved2;
76 /* Must be kept even if it is no longer used by glibc since programs,
77 like AddressSanitizer, depend on the size of tcbhead_t. */
78 __128bits __glibc_unused2[8][4] __attribute__ ((aligned (32)));
79
80 void *__padding[8];
81} tcbhead_t;
82
83#else /* __ASSEMBLER__ */
84# include <tcb-offsets.h>
85#endif
86
87
88/* Alignment requirement for the stack. */
89#define STACK_ALIGN 16
90
91
92#ifndef __ASSEMBLER__
93/* Get system call information. */
94# include <sysdep.h>
95
96#ifndef LOCK_PREFIX
97# ifdef UP
98# define LOCK_PREFIX /* nothing */
99# else
100# define LOCK_PREFIX "lock;"
101# endif
102#endif
103
104/* This is the size of the initial TCB. Can't be just sizeof (tcbhead_t),
105 because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
106 struct pthread even when not linked with -lpthread. */
107# define TLS_INIT_TCB_SIZE sizeof (struct pthread)
108
109/* Alignment requirements for the initial TCB. */
110# define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
111
112/* This is the size of the TCB. */
113# define TLS_TCB_SIZE sizeof (struct pthread)
114
115/* Alignment requirements for the TCB. */
116# define TLS_TCB_ALIGN __alignof__ (struct pthread)
117
118/* The TCB can have any size and the memory following the address the
119 thread pointer points to is unspecified. Allocate the TCB there. */
120# define TLS_TCB_AT_TP 1
121# define TLS_DTV_AT_TP 0
122
123/* Get the thread descriptor definition. */
124# include <nptl/descr.h>
125
126
127/* Install the dtv pointer. The pointer passed is to the element with
128 index -1 which contain the length. */
129# define INSTALL_DTV(descr, dtvp) \
130 ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
131
132/* Install new dtv for current thread. */
133# define INSTALL_NEW_DTV(dtvp) \
134 ({ struct pthread *__pd; \
135 THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
136
137/* Return dtv of given thread descriptor. */
138# define GET_DTV(descr) \
139 (((tcbhead_t *) (descr))->dtv)
140
141
142/* Code to initially initialize the thread pointer. This might need
143 special attention since 'errno' is not yet available and if the
144 operation can cause a failure 'errno' must not be touched.
145
146 We have to make the syscall for both uses of the macro since the
147 address might be (and probably is) different. */
148# define TLS_INIT_TP(thrdescr) \
149 ({ void *_thrdescr = (thrdescr); \
150 tcbhead_t *_head = _thrdescr; \
151 int _result; \
152 \
153 _head->tcb = _thrdescr; \
154 /* For now the thread descriptor is at the same address. */ \
155 _head->self = _thrdescr; \
156 \
157 /* It is a simple syscall to set the %fs value for the thread. */ \
158 asm volatile ("syscall" \
159 : "=a" (_result) \
160 : "0" ((unsigned long int) __NR_arch_prctl), \
161 "D" ((unsigned long int) ARCH_SET_FS), \
162 "S" (_thrdescr) \
163 : "memory", "cc", "r11", "cx"); \
164 \
165 _result ? "cannot set %fs base address for thread-local storage" : 0; \
166 })
167
168# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)
169
170
171/* Return the address of the dtv for the current thread. */
172# define THREAD_DTV() \
173 ({ struct pthread *__pd; \
174 THREAD_GETMEM (__pd, header.dtv); })
175
176
177/* Return the thread descriptor for the current thread.
178
179 The contained asm must *not* be marked volatile since otherwise
180 assignments like
181 pthread_descr self = thread_self();
182 do not get optimized away. */
183# define THREAD_SELF \
184 ({ struct pthread *__self; \
185 asm ("mov %%fs:%c1,%0" : "=r" (__self) \
186 : "i" (offsetof (struct pthread, header.self))); \
187 __self;})
188
189/* Magic for libthread_db to know how to do THREAD_SELF. */
190# define DB_THREAD_SELF_INCLUDE <sys/reg.h> /* For the FS constant. */
191# define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
192
193/* Read member of the thread descriptor directly. */
194# define THREAD_GETMEM(descr, member) \
195 ({ __typeof (descr->member) __value; \
196 if (sizeof (__value) == 1) \
197 asm volatile ("movb %%fs:%P2,%b0" \
198 : "=q" (__value) \
199 : "0" (0), "i" (offsetof (struct pthread, member))); \
200 else if (sizeof (__value) == 4) \
201 asm volatile ("movl %%fs:%P1,%0" \
202 : "=r" (__value) \
203 : "i" (offsetof (struct pthread, member))); \
204 else \
205 { \
206 if (sizeof (__value) != 8) \
207 /* There should not be any value with a size other than 1, \
208 4 or 8. */ \
209 abort (); \
210 \
211 asm volatile ("movq %%fs:%P1,%q0" \
212 : "=r" (__value) \
213 : "i" (offsetof (struct pthread, member))); \
214 } \
215 __value; })
216
217
218/* Same as THREAD_GETMEM, but the member offset can be non-constant. */
219# define THREAD_GETMEM_NC(descr, member, idx) \
220 ({ __typeof (descr->member[0]) __value; \
221 if (sizeof (__value) == 1) \
222 asm volatile ("movb %%fs:%P2(%q3),%b0" \
223 : "=q" (__value) \
224 : "0" (0), "i" (offsetof (struct pthread, member[0])), \
225 "r" (idx)); \
226 else if (sizeof (__value) == 4) \
227 asm volatile ("movl %%fs:%P1(,%q2,4),%0" \
228 : "=r" (__value) \
229 : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
230 else \
231 { \
232 if (sizeof (__value) != 8) \
233 /* There should not be any value with a size other than 1, \
234 4 or 8. */ \
235 abort (); \
236 \
237 asm volatile ("movq %%fs:%P1(,%q2,8),%q0" \
238 : "=r" (__value) \
239 : "i" (offsetof (struct pthread, member[0])), \
240 "r" (idx)); \
241 } \
242 __value; })
243
244
245/* Loading addresses of objects on x86-64 needs to be treated special
246 when generating PIC code. */
247#ifdef __pic__
248# define IMM_MODE "nr"
249#else
250# define IMM_MODE "ir"
251#endif
252
253
254/* Set member of the thread descriptor directly. */
255# define THREAD_SETMEM(descr, member, value) \
256 ({ if (sizeof (descr->member) == 1) \
257 asm volatile ("movb %b0,%%fs:%P1" : \
258 : "iq" (value), \
259 "i" (offsetof (struct pthread, member))); \
260 else if (sizeof (descr->member) == 4) \
261 asm volatile ("movl %0,%%fs:%P1" : \
262 : IMM_MODE (value), \
263 "i" (offsetof (struct pthread, member))); \
264 else \
265 { \
266 if (sizeof (descr->member) != 8) \
267 /* There should not be any value with a size other than 1, \
268 4 or 8. */ \
269 abort (); \
270 \
271 asm volatile ("movq %q0,%%fs:%P1" : \
272 : IMM_MODE ((uint64_t) cast_to_integer (value)), \
273 "i" (offsetof (struct pthread, member))); \
274 }})
275
276
277/* Same as THREAD_SETMEM, but the member offset can be non-constant. */
278# define THREAD_SETMEM_NC(descr, member, idx, value) \
279 ({ if (sizeof (descr->member[0]) == 1) \
280 asm volatile ("movb %b0,%%fs:%P1(%q2)" : \
281 : "iq" (value), \
282 "i" (offsetof (struct pthread, member[0])), \
283 "r" (idx)); \
284 else if (sizeof (descr->member[0]) == 4) \
285 asm volatile ("movl %0,%%fs:%P1(,%q2,4)" : \
286 : IMM_MODE (value), \
287 "i" (offsetof (struct pthread, member[0])), \
288 "r" (idx)); \
289 else \
290 { \
291 if (sizeof (descr->member[0]) != 8) \
292 /* There should not be any value with a size other than 1, \
293 4 or 8. */ \
294 abort (); \
295 \
296 asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" : \
297 : IMM_MODE ((uint64_t) cast_to_integer (value)), \
298 "i" (offsetof (struct pthread, member[0])), \
299 "r" (idx)); \
300 }})
301
302
303/* Atomic compare and exchange on TLS, returning old value. */
304# define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
305 ({ __typeof (descr->member) __ret; \
306 __typeof (oldval) __old = (oldval); \
307 if (sizeof (descr->member) == 4) \
308 asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3" \
309 : "=a" (__ret) \
310 : "0" (__old), "r" (newval), \
311 "i" (offsetof (struct pthread, member))); \
312 else \
313 /* Not necessary for other sizes in the moment. */ \
314 abort (); \
315 __ret; })
316
317
318/* Atomic logical and. */
319# define THREAD_ATOMIC_AND(descr, member, val) \
320 (void) ({ if (sizeof ((descr)->member) == 4) \
321 asm volatile (LOCK_PREFIX "andl %1, %%fs:%P0" \
322 :: "i" (offsetof (struct pthread, member)), \
323 "ir" (val)); \
324 else \
325 /* Not necessary for other sizes in the moment. */ \
326 abort (); })
327
328
329/* Atomic set bit. */
330# define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
331 (void) ({ if (sizeof ((descr)->member) == 4) \
332 asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0" \
333 :: "i" (offsetof (struct pthread, member)), \
334 "ir" (1 << (bit))); \
335 else \
336 /* Not necessary for other sizes in the moment. */ \
337 abort (); })
338
339
340# define CALL_THREAD_FCT(descr) \
341 ({ void *__res; \
342 asm volatile ("movq %%fs:%P2, %%rdi\n\t" \
343 "callq *%%fs:%P1" \
344 : "=a" (__res) \
345 : "i" (offsetof (struct pthread, start_routine)), \
346 "i" (offsetof (struct pthread, arg)) \
347 : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11", \
348 "memory", "cc"); \
349 __res; })
350
351
352/* Set the stack guard field in TCB head. */
353# define THREAD_SET_STACK_GUARD(value) \
354 THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
355# define THREAD_COPY_STACK_GUARD(descr) \
356 ((descr)->header.stack_guard \
357 = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
358
359
360/* Set the pointer guard field in the TCB head. */
361# define THREAD_SET_POINTER_GUARD(value) \
362 THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
363# define THREAD_COPY_POINTER_GUARD(descr) \
364 ((descr)->header.pointer_guard \
365 = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
366
367
368/* Get and set the global scope generation counter in the TCB head. */
369# define THREAD_GSCOPE_FLAG_UNUSED 0
370# define THREAD_GSCOPE_FLAG_USED 1
371# define THREAD_GSCOPE_FLAG_WAIT 2
372# define THREAD_GSCOPE_RESET_FLAG() \
373 do \
374 { int __res; \
375 asm volatile ("xchgl %0, %%fs:%P1" \
376 : "=r" (__res) \
377 : "i" (offsetof (struct pthread, header.gscope_flag)), \
378 "0" (THREAD_GSCOPE_FLAG_UNUSED)); \
379 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
380 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
381 } \
382 while (0)
383# define THREAD_GSCOPE_SET_FLAG() \
384 THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
385# define THREAD_GSCOPE_WAIT() \
386 GL(dl_wait_lookup_done) ()
387
388#endif /* __ASSEMBLER__ */
389
390#endif /* tls.h */
391