nptl/sysdeps/x86_64/tls.h

   1 /* Definition for thread-local data handling.  nptl/x86_64 version.
   2    Copyright (C) 2002-2009, 2011-2012 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 <kernel-features.h>
  30 # include <bits/wordsize.h>
  31 # include <xmmintrin.h>
  32
  33
  34 /* Type for the dtv.  */
  35 typedef union dtv
  36 {
  37   size_t counter;
  38   struct
  39   {
  40     void *val;
  41     bool is_static;
  42   } pointer;
  43 } dtv_t;
  44
  45
  46 typedef struct
  47 {
  48   void *tcb;            /* Pointer to the TCB.  Not necessarily the
  49                            thread descriptor used by libpthread.  */
  50   dtv_t *dtv;
  51   void *self;           /* Pointer to the thread descriptor.  */
  52   int multiple_threads;
  53   int gscope_flag;
  54   uintptr_t sysinfo;
  55   uintptr_t stack_guard;
  56   uintptr_t pointer_guard;
  57   unsigned long int vgetcpu_cache[2];
  58 # ifndef __ASSUME_PRIVATE_FUTEX
  59   int private_futex;
  60 # else
  61   int __unused1;
  62 # endif
  63 # if __WORDSIZE == 64
  64   int rtld_must_xmm_save;
  65 # endif
  66   /* Reservation of some values for the TM ABI.  */
  67   void *__private_tm[5];
  68 # if __WORDSIZE == 64
  69   long int __unused2;
  70   /* Have space for the post-AVX register size.  */
  71   __m128 rtld_savespace_sse[8][4];
  72
  73   void *__padding[8];
  74 # endif
  75 } tcbhead_t;
  76
  77 #else /* __ASSEMBLER__ */
  78 # include <tcb-offsets.h>
  79 #endif
  80
  81
  82 /* Alignment requirement for the stack.  */
  83 #define STACK_ALIGN     16
  84
  85
  86 #ifndef __ASSEMBLER__
  87 /* Get system call information.  */
  88 # include <sysdep.h>
  89
  90
  91 /* Get the thread descriptor definition.  */
  92 # include <nptl/descr.h>
  93
  94 #ifndef LOCK_PREFIX
  95 # ifdef UP
  96 #  define LOCK_PREFIX   /* nothing */
  97 # else
  98 #  define LOCK_PREFIX   "lock;"
  99 # endif
 100 #endif
 101
 102 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
 103    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
 104    struct pthread even when not linked with -lpthread.  */
 105 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
 106
 107 /* Alignment requirements for the initial TCB.  */
 108 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
 109
 110 /* This is the size of the TCB.  */
 111 # define TLS_TCB_SIZE sizeof (struct pthread)
 112
 113 /* Alignment requirements for the TCB.  */
 114 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
 115
 116 /* The TCB can have any size and the memory following the address the
 117    thread pointer points to is unspecified.  Allocate the TCB there.  */
 118 # define TLS_TCB_AT_TP  1
 119
 120
 121 /* Install the dtv pointer.  The pointer passed is to the element with
 122    index -1 which contain the length.  */
 123 # define INSTALL_DTV(descr, dtvp) \
 124   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 125
 126 /* Install new dtv for current thread.  */
 127 # define INSTALL_NEW_DTV(dtvp) \
 128   ({ struct pthread *__pd;                                                    \
 129      THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
 130
 131 /* Return dtv of given thread descriptor.  */
 132 # define GET_DTV(descr) \
 133   (((tcbhead_t *) (descr))->dtv)
 134
 135
 136 /* Code to initially initialize the thread pointer.  This might need
 137    special attention since 'errno' is not yet available and if the
 138    operation can cause a failure 'errno' must not be touched.
 139
 140    We have to make the syscall for both uses of the macro since the
 141    address might be (and probably is) different.  */
 142 # define TLS_INIT_TP(thrdescr, secondcall) \
 143   ({ void *_thrdescr = (thrdescr);                                            \
 144      tcbhead_t *_head = _thrdescr;                                            \
 145      int _result;                                                             \
 146                                                                               \
 147      _head->tcb = _thrdescr;                                                  \
 148      /* For now the thread descriptor is at the same address.  */             \
 149      _head->self = _thrdescr;                                                 \
 150                                                                               \
 151      /* It is a simple syscall to set the %fs value for the thread.  */       \
 152      asm volatile ("syscall"                                                  \
 153                    : "=a" (_result)                                           \
 154                    : "0" ((unsigned long int) __NR_arch_prctl),               \
 155                      "D" ((unsigned long int) ARCH_SET_FS),                   \
 156                      "S" (_thrdescr)                                          \
 157                    : "memory", "cc", "r11", "cx");                            \
 158                                                                               \
 159     _result ? "cannot set %fs base address for thread-local storage" : 0;     \
 160   })
 161
 162
 163 /* Return the address of the dtv for the current thread.  */
 164 # define THREAD_DTV() \
 165   ({ struct pthread *__pd;                                                    \
 166      THREAD_GETMEM (__pd, header.dtv); })
 167
 168
 169 /* Return the thread descriptor for the current thread.
 170
 171    The contained asm must *not* be marked volatile since otherwise
 172    assignments like
 173         pthread_descr self = thread_self();
 174    do not get optimized away.  */
 175 # define THREAD_SELF \
 176   ({ struct pthread *__self;                                                  \
 177      asm ("movq %%fs:%c1,%q0" : "=r" (__self)                                 \
 178           : "i" (offsetof (struct pthread, header.self)));                    \
 179      __self;})
 180
 181 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 182 # define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */
 183 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
 184
 185 /* Read member of the thread descriptor directly.  */
 186 # define THREAD_GETMEM(descr, member) \
 187   ({ __typeof (descr->member) __value;                                        \
 188      if (sizeof (__value) == 1)                                               \
 189        asm volatile ("movb %%fs:%P2,%b0"                                      \
 190                      : "=q" (__value)                                         \
 191                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
 192      else if (sizeof (__value) == 4)                                          \
 193        asm volatile ("movl %%fs:%P1,%0"                                       \
 194                      : "=r" (__value)                                         \
 195                      : "i" (offsetof (struct pthread, member)));              \
 196      else                                                                     \
 197        {                                                                      \
 198          if (sizeof (__value) != 8)                                           \
 199            /* There should not be any value with a size other than 1,         \
 200               4 or 8.  */                                                     \
 201            abort ();                                                          \
 202                                                                               \
 203          asm volatile ("movq %%fs:%P1,%q0"                                    \
 204                        : "=r" (__value)                                       \
 205                        : "i" (offsetof (struct pthread, member)));            \
 206        }                                                                      \
 207      __value; })
 208
 209
 210 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 211 # define THREAD_GETMEM_NC(descr, member, idx) \
 212   ({ __typeof (descr->member[0]) __value;                                     \
 213      if (sizeof (__value) == 1)                                               \
 214        asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
 215                      : "=q" (__value)                                         \
 216                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
 217                        "r" (idx));                                            \
 218      else if (sizeof (__value) == 4)                                          \
 219        asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
 220                      : "=r" (__value)                                         \
 221                      : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
 222      else                                                                     \
 223        {                                                                      \
 224          if (sizeof (__value) != 8)                                           \
 225            /* There should not be any value with a size other than 1,         \
 226               4 or 8.  */                                                     \
 227            abort ();                                                          \
 228                                                                               \
 229          asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                            \
 230                        : "=r" (__value)                                       \
 231                        : "i" (offsetof (struct pthread, member[0])),          \
 232                          "r" (idx));                                          \
 233        }                                                                      \
 234      __value; })
 235
 236
 237 /* Loading addresses of objects on x86-64 needs to be treated special
 238    when generating PIC code.  */
 239 #ifdef __pic__
 240 # define IMM_MODE "nr"
 241 #else
 242 # define IMM_MODE "ir"
 243 #endif
 244
 245
 246 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 247 # define THREAD_SETMEM(descr, member, value) \
 248   ({ if (sizeof (descr->member) == 1)                                         \
 249        asm volatile ("movb %b0,%%fs:%P1" :                                    \
 250                      : "iq" (value),                                          \
 251                        "i" (offsetof (struct pthread, member)));              \
 252      else if (sizeof (descr->member) == 4)                                    \
 253        asm volatile ("movl %0,%%fs:%P1" :                                     \
 254                      : IMM_MODE (value),                                      \
 255                        "i" (offsetof (struct pthread, member)));              \
 256      else                                                                     \
 257        {                                                                      \
 258          if (sizeof (descr->member) != 8)                                     \
 259            /* There should not be any value with a size other than 1,         \
 260               4 or 8.  */                                                     \
 261            abort ();                                                          \
 262                                                                               \
 263          asm volatile ("movq %q0,%%fs:%P1" :                                  \
 264                        : IMM_MODE ((unsigned long int) value),                \
 265                          "i" (offsetof (struct pthread, member)));            \
 266        }})
 267
 268
 269 /* Set member of the thread descriptor directly.  */
 270 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 271   ({ if (sizeof (descr->member[0]) == 1)                                      \
 272        asm volatile ("movb %b0,%%fs:%P1(%q2)" :                               \
 273                      : "iq" (value),                                          \
 274                        "i" (offsetof (struct pthread, member[0])),            \
 275                        "r" (idx));                                            \
 276      else if (sizeof (descr->member[0]) == 4)                                 \
 277        asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :                             \
 278                      : IMM_MODE (value),                                      \
 279                        "i" (offsetof (struct pthread, member[0])),            \
 280                        "r" (idx));                                            \
 281      else                                                                     \
 282        {                                                                      \
 283          if (sizeof (descr->member[0]) != 8)                                  \
 284            /* There should not be any value with a size other than 1,         \
 285               4 or 8.  */                                                     \
 286            abort ();                                                          \
 287                                                                               \
 288          asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :                          \
 289                        : IMM_MODE ((unsigned long int) value),                \
 290                          "i" (offsetof (struct pthread, member[0])),          \
 291                          "r" (idx));                                          \
 292        }})
 293
 294
 295 /* Atomic compare and exchange on TLS, returning old value.  */
 296 # define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 297   ({ __typeof (descr->member) __ret;                                          \
 298      __typeof (oldval) __old = (oldval);                                      \
 299      if (sizeof (descr->member) == 4)                                         \
 300        asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"                      \
 301                      : "=a" (__ret)                                           \
 302                      : "0" (__old), "r" (newval),                             \
 303                        "i" (offsetof (struct pthread, member)));              \
 304      else                                                                     \
 305        /* Not necessary for other sizes in the moment.  */                    \
 306        abort ();                                                              \
 307      __ret; })
 308
 309
 310 /* Atomic logical and.  */
 311 # define THREAD_ATOMIC_AND(descr, member, val) \
 312   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 313               asm volatile (LOCK_PREFIX "andl %1, %%fs:%P0"                   \
 314                             :: "i" (offsetof (struct pthread, member)),       \
 315                                "ir" (val));                                   \
 316             else                                                              \
 317               /* Not necessary for other sizes in the moment.  */             \
 318               abort (); })
 319
 320
 321 /* Atomic set bit.  */
 322 # define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 323   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 324               asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"                    \
 325                             :: "i" (offsetof (struct pthread, member)),       \
 326                                "ir" (1 << (bit)));                            \
 327             else                                                              \
 328               /* Not necessary for other sizes in the moment.  */             \
 329               abort (); })
 330
 331
 332 # define CALL_THREAD_FCT(descr) \
 333   ({ void *__res;                                                             \
 334      asm volatile ("movq %%fs:%P2, %%rdi\n\t"                                 \
 335                    "callq *%%fs:%P1"                                          \
 336                    : "=a" (__res)                                             \
 337                    : "i" (offsetof (struct pthread, start_routine)),          \
 338                      "i" (offsetof (struct pthread, arg))                     \
 339                    : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11",        \
 340                      "memory", "cc");                                         \
 341      __res; })
 342
 343
 344 /* Set the stack guard field in TCB head.  */
 345 # define THREAD_SET_STACK_GUARD(value) \
 346     THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
 347 # define THREAD_COPY_STACK_GUARD(descr) \
 348     ((descr)->header.stack_guard                                              \
 349      = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 350
 351
 352 /* Set the pointer guard field in the TCB head.  */
 353 # define THREAD_SET_POINTER_GUARD(value) \
 354   THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
 355 # define THREAD_COPY_POINTER_GUARD(descr) \
 356   ((descr)->header.pointer_guard                                              \
 357    = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
 358
 359
 360 /* Get and set the global scope generation counter in the TCB head.  */
 361 # define THREAD_GSCOPE_FLAG_UNUSED 0
 362 # define THREAD_GSCOPE_FLAG_USED   1
 363 # define THREAD_GSCOPE_FLAG_WAIT   2
 364 # define THREAD_GSCOPE_RESET_FLAG() \
 365   do                                                                          \
 366     { int __res;                                                              \
 367       asm volatile ("xchgl %0, %%fs:%P1"                                      \
 368                     : "=r" (__res)                                            \
 369                     : "i" (offsetof (struct pthread, header.gscope_flag)),    \
 370                       "0" (THREAD_GSCOPE_FLAG_UNUSED));                       \
 371       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 372         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
 373     }                                                                         \
 374   while (0)
 375 # define THREAD_GSCOPE_SET_FLAG() \
 376   THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
 377 # define THREAD_GSCOPE_WAIT() \
 378   GL(dl_wait_lookup_done) ()
 379
 380
 381 # ifdef SHARED
 382 /* Defined in dl-trampoline.S.  */
 383 extern void _dl_x86_64_save_sse (void);
 384 extern void _dl_x86_64_restore_sse (void);
 385
 386 # define RTLD_CHECK_FOREIGN_CALL \
 387   (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) != 0)
 388
 389 /* NB: Don't use the xchg operation because that would imply a lock
 390    prefix which is expensive and unnecessary.  The cache line is also
 391    not contested at all.  */
 392 #  define RTLD_ENABLE_FOREIGN_CALL \
 393   int old_rtld_must_xmm_save = THREAD_GETMEM (THREAD_SELF,                    \
 394                                               header.rtld_must_xmm_save);     \
 395   THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 1)
 396
 397 #  define RTLD_PREPARE_FOREIGN_CALL \
 398   do if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save))              \
 399     {                                                                         \
 400       _dl_x86_64_save_sse ();                                                 \
 401       THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 0);              \
 402     }                                                                         \
 403   while (0)
 404
 405 #  define RTLD_FINALIZE_FOREIGN_CALL \
 406   do {                                                                        \
 407     if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) == 0)          \
 408       _dl_x86_64_restore_sse ();                                              \
 409     THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save,                    \
 410                    old_rtld_must_xmm_save);                                   \
 411   } while (0)
 412 # endif
 413
 414
 415 #endif /* __ASSEMBLER__ */
 416
 417 #endif  /* tls.h */