nptl/sysdeps/x86_64/tls.h

   1 /* Definition for thread-local data handling.  nptl/x86_64 version.
   2    Copyright (C) 2002-2007, 2008, 2009 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 # include <sysdep.h>
  30 # include <kernel-features.h>
  31 # include <bits/wordsize.h>
  32 # include <xmmintrin.h>
  33
  34
  35 /* Type for the dtv.  */
  36 typedef union dtv
  37 {
  38   size_t counter;
  39   struct
  40   {
  41     void *val;
  42     bool is_static;
  43   } pointer;
  44 } dtv_t;
  45
  46
  47 typedef struct
  48 {
  49   void *tcb;            /* Pointer to the TCB.  Not necessarily the
  50                            thread descriptor used by libpthread.  */
  51   dtv_t *dtv;
  52   void *self;           /* Pointer to the thread descriptor.  */
  53   int multiple_threads;
  54   int gscope_flag;
  55   uintptr_t sysinfo;
  56   uintptr_t stack_guard;
  57   uintptr_t pointer_guard;
  58   unsigned long int vgetcpu_cache[2];
  59 # ifndef __ASSUME_PRIVATE_FUTEX
  60   int private_futex;
  61 # else
  62   int __unused1;
  63 # endif
  64 # if __WORDSIZE == 64
  65   int rtld_must_xmm_save;
  66 # endif
  67   /* Reservation of some values for the TM ABI.  */
  68   void *__private_tm[5];
  69 # if __WORDSIZE == 64
  70   long int __unused2;
  71   /* Have space for the post-AVX register size.  */
  72   __m128 rtld_savespace_sse[8][4];
  73
  74   void *__padding[8];
  75 # endif
  76 } tcbhead_t;
  77
  78 #else /* __ASSEMBLER__ */
  79 # include <tcb-offsets.h>
  80 #endif
  81
  82
  83 /* We require TLS support in the tools.  */
  84 #ifndef HAVE_TLS_SUPPORT
  85 # error "TLS support is required."
  86 #endif
  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
  97 /* Get the thread descriptor definition.  */
  98 # include <nptl/descr.h>
  99
 100 #ifndef LOCK_PREFIX
 101 # ifdef UP
 102 #  define LOCK_PREFIX   /* nothing */
 103 # else
 104 #  define LOCK_PREFIX   "lock;"
 105 # endif
 106 #endif
 107
 108 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
 109    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
 110    struct pthread even when not linked with -lpthread.  */
 111 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
 112
 113 /* Alignment requirements for the initial TCB.  */
 114 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
 115
 116 /* This is the size of the TCB.  */
 117 # define TLS_TCB_SIZE sizeof (struct pthread)
 118
 119 /* Alignment requirements for the TCB.  */
 120 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
 121
 122 /* The TCB can have any size and the memory following the address the
 123    thread pointer points to is unspecified.  Allocate the TCB there.  */
 124 # define TLS_TCB_AT_TP  1
 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 /* Macros to load from and store into segment registers.  */
 143 # define TLS_GET_FS() \
 144   ({ int __seg; __asm ("movl %%fs, %0" : "=q" (__seg)); __seg; })
 145 # define TLS_SET_FS(val) \
 146   __asm ("movl %0, %%fs" :: "q" (val))
 147
 148
 149 /* Code to initially initialize the thread pointer.  This might need
 150    special attention since 'errno' is not yet available and if the
 151    operation can cause a failure 'errno' must not be touched.
 152
 153    We have to make the syscall for both uses of the macro since the
 154    address might be (and probably is) different.  */
 155 # define TLS_INIT_TP(thrdescr, secondcall) \
 156   ({ void *_thrdescr = (thrdescr);                                            \
 157      tcbhead_t *_head = _thrdescr;                                            \
 158      int _result;                                                             \
 159                                                                               \
 160      _head->tcb = _thrdescr;                                                  \
 161      /* For now the thread descriptor is at the same address.  */             \
 162      _head->self = _thrdescr;                                                 \
 163                                                                               \
 164      /* It is a simple syscall to set the %fs value for the thread.  */       \
 165      asm volatile ("syscall"                                                  \
 166                    : "=a" (_result)                                           \
 167                    : "0" ((unsigned long int) __NR_arch_prctl),               \
 168                      "D" ((unsigned long int) ARCH_SET_FS),                   \
 169                      "S" (_thrdescr)                                          \
 170                    : "memory", "cc", "r11", "cx");                            \
 171                                                                               \
 172     _result ? "cannot set %fs base address for thread-local storage" : 0;     \
 173   })
 174
 175
 176 /* Return the address of the dtv for the current thread.  */
 177 # define THREAD_DTV() \
 178   ({ struct pthread *__pd;                                                    \
 179      THREAD_GETMEM (__pd, header.dtv); })
 180
 181
 182 /* Return the thread descriptor for the current thread.
 183
 184    The contained asm must *not* be marked volatile since otherwise
 185    assignments like
 186         pthread_descr self = thread_self();
 187    do not get optimized away.  */
 188 # define THREAD_SELF \
 189   ({ struct pthread *__self;                                                  \
 190      asm ("movq %%fs:%c1,%q0" : "=r" (__self)                                 \
 191           : "i" (offsetof (struct pthread, header.self)));                    \
 192      __self;})
 193
 194 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 195 # define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */
 196 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
 197
 198 /* Read member of the thread descriptor directly.  */
 199 # define THREAD_GETMEM(descr, member) \
 200   ({ __typeof (descr->member) __value;                                        \
 201      if (sizeof (__value) == 1)                                               \
 202        asm volatile ("movb %%fs:%P2,%b0"                                      \
 203                      : "=q" (__value)                                         \
 204                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
 205      else if (sizeof (__value) == 4)                                          \
 206        asm volatile ("movl %%fs:%P1,%0"                                       \
 207                      : "=r" (__value)                                         \
 208                      : "i" (offsetof (struct pthread, member)));              \
 209      else                                                                     \
 210        {                                                                      \
 211          if (sizeof (__value) != 8)                                           \
 212            /* There should not be any value with a size other than 1,         \
 213               4 or 8.  */                                                     \
 214            abort ();                                                          \
 215                                                                               \
 216          asm volatile ("movq %%fs:%P1,%q0"                                    \
 217                        : "=r" (__value)                                       \
 218                        : "i" (offsetof (struct pthread, member)));            \
 219        }                                                                      \
 220      __value; })
 221
 222
 223 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 224 # define THREAD_GETMEM_NC(descr, member, idx) \
 225   ({ __typeof (descr->member[0]) __value;                                     \
 226      if (sizeof (__value) == 1)                                               \
 227        asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
 228                      : "=q" (__value)                                         \
 229                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
 230                        "r" (idx));                                            \
 231      else if (sizeof (__value) == 4)                                          \
 232        asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
 233                      : "=r" (__value)                                         \
 234                      : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
 235      else                                                                     \
 236        {                                                                      \
 237          if (sizeof (__value) != 8)                                           \
 238            /* There should not be any value with a size other than 1,         \
 239               4 or 8.  */                                                     \
 240            abort ();                                                          \
 241                                                                               \
 242          asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                            \
 243                        : "=r" (__value)                                       \
 244                        : "i" (offsetof (struct pthread, member[0])),          \
 245                          "r" (idx));                                          \
 246        }                                                                      \
 247      __value; })
 248
 249
 250 /* Loading addresses of objects on x86-64 needs to be treated special
 251    when generating PIC code.  */
 252 #ifdef __pic__
 253 # define IMM_MODE "nr"
 254 #else
 255 # define IMM_MODE "ir"
 256 #endif
 257
 258
 259 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 260 # define THREAD_SETMEM(descr, member, value) \
 261   ({ if (sizeof (descr->member) == 1)                                         \
 262        asm volatile ("movb %b0,%%fs:%P1" :                                    \
 263                      : "iq" (value),                                          \
 264                        "i" (offsetof (struct pthread, member)));              \
 265      else if (sizeof (descr->member) == 4)                                    \
 266        asm volatile ("movl %0,%%fs:%P1" :                                     \
 267                      : IMM_MODE (value),                                      \
 268                        "i" (offsetof (struct pthread, member)));              \
 269      else                                                                     \
 270        {                                                                      \
 271          if (sizeof (descr->member) != 8)                                     \
 272            /* There should not be any value with a size other than 1,         \
 273               4 or 8.  */                                                     \
 274            abort ();                                                          \
 275                                                                               \
 276          asm volatile ("movq %q0,%%fs:%P1" :                                  \
 277                        : IMM_MODE ((unsigned long int) value),                \
 278                          "i" (offsetof (struct pthread, member)));            \
 279        }})
 280
 281
 282 /* Set member of the thread descriptor directly.  */
 283 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 284   ({ if (sizeof (descr->member[0]) == 1)                                      \
 285        asm volatile ("movb %b0,%%fs:%P1(%q2)" :                               \
 286                      : "iq" (value),                                          \
 287                        "i" (offsetof (struct pthread, member[0])),            \
 288                        "r" (idx));                                            \
 289      else if (sizeof (descr->member[0]) == 4)                                 \
 290        asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :                             \
 291                      : IMM_MODE (value),                                      \
 292                        "i" (offsetof (struct pthread, member[0])),            \
 293                        "r" (idx));                                            \
 294      else                                                                     \
 295        {                                                                      \
 296          if (sizeof (descr->member[0]) != 8)                                  \
 297            /* There should not be any value with a size other than 1,         \
 298               4 or 8.  */                                                     \
 299            abort ();                                                          \
 300                                                                               \
 301          asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :                          \
 302                        : IMM_MODE ((unsigned long int) value),                \
 303                          "i" (offsetof (struct pthread, member[0])),          \
 304                          "r" (idx));                                          \
 305        }})
 306
 307
 308 /* Atomic compare and exchange on TLS, returning old value.  */
 309 # define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 310   ({ __typeof (descr->member) __ret;                                          \
 311      __typeof (oldval) __old = (oldval);                                      \
 312      if (sizeof (descr->member) == 4)                                         \
 313        asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"                      \
 314                      : "=a" (__ret)                                           \
 315                      : "0" (__old), "r" (newval),                             \
 316                        "i" (offsetof (struct pthread, member)));              \
 317      else                                                                     \
 318        /* Not necessary for other sizes in the moment.  */                    \
 319        abort ();                                                              \
 320      __ret; })
 321
 322
 323 /* Atomic logical and.  */
 324 # define THREAD_ATOMIC_AND(descr, member, val) \
 325   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 326               asm volatile (LOCK_PREFIX "andl %1, %%fs:%P0"                   \
 327                             :: "i" (offsetof (struct pthread, member)),       \
 328                                "ir" (val));                                   \
 329             else                                                              \
 330               /* Not necessary for other sizes in the moment.  */             \
 331               abort (); })
 332
 333
 334 /* Atomic set bit.  */
 335 # define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 336   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 337               asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"                    \
 338                             :: "i" (offsetof (struct pthread, member)),       \
 339                                "ir" (1 << (bit)));                            \
 340             else                                                              \
 341               /* Not necessary for other sizes in the moment.  */             \
 342               abort (); })
 343
 344
 345 # define CALL_THREAD_FCT(descr) \
 346   ({ void *__res;                                                             \
 347      asm volatile ("movq %%fs:%P2, %%rdi\n\t"                                 \
 348                    "callq *%%fs:%P1"                                          \
 349                    : "=a" (__res)                                             \
 350                    : "i" (offsetof (struct pthread, start_routine)),          \
 351                      "i" (offsetof (struct pthread, arg))                     \
 352                    : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11",        \
 353                      "memory", "cc");                                         \
 354      __res; })
 355
 356
 357 /* Set the stack guard field in TCB head.  */
 358 # define THREAD_SET_STACK_GUARD(value) \
 359     THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
 360 # define THREAD_COPY_STACK_GUARD(descr) \
 361     ((descr)->header.stack_guard                                              \
 362      = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 363
 364
 365 /* Set the pointer guard field in the TCB head.  */
 366 # define THREAD_SET_POINTER_GUARD(value) \
 367   THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
 368 # define THREAD_COPY_POINTER_GUARD(descr) \
 369   ((descr)->header.pointer_guard                                              \
 370    = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
 371
 372
 373 /* Get and set the global scope generation counter in the TCB head.  */
 374 # define THREAD_GSCOPE_FLAG_UNUSED 0
 375 # define THREAD_GSCOPE_FLAG_USED   1
 376 # define THREAD_GSCOPE_FLAG_WAIT   2
 377 # define THREAD_GSCOPE_RESET_FLAG() \
 378   do                                                                          \
 379     { int __res;                                                              \
 380       asm volatile ("xchgl %0, %%fs:%P1"                                      \
 381                     : "=r" (__res)                                            \
 382                     : "i" (offsetof (struct pthread, header.gscope_flag)),    \
 383                       "0" (THREAD_GSCOPE_FLAG_UNUSED));                       \
 384       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 385         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
 386     }                                                                         \
 387   while (0)
 388 # define THREAD_GSCOPE_SET_FLAG() \
 389   THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
 390 # define THREAD_GSCOPE_WAIT() \
 391   GL(dl_wait_lookup_done) ()
 392
 393
 394 # ifdef SHARED
 395 /* Defined in dl-trampoline.S.  */
 396 extern void _dl_x86_64_save_sse (void);
 397 extern void _dl_x86_64_restore_sse (void);
 398
 399 # define RTLD_CHECK_FOREIGN_CALL \
 400   (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) != 0)
 401
 402 /* NB: Don't use the xchg operation because that would imply a lock
 403    prefix which is expensive and unnecessary.  The cache line is also
 404    not contested at all.  */
 405 #  define RTLD_ENABLE_FOREIGN_CALL \
 406   int old_rtld_must_xmm_save = THREAD_GETMEM (THREAD_SELF,                    \
 407                                               header.rtld_must_xmm_save);     \
 408   THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 1)
 409
 410 #  define RTLD_PREPARE_FOREIGN_CALL \
 411   do if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save))              \
 412     {                                                                         \
 413       _dl_x86_64_save_sse ();                                                 \
 414       THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 0);              \
 415     }                                                                         \
 416   while (0)
 417
 418 #  define RTLD_FINALIZE_FOREIGN_CALL \
 419   do {                                                                        \
 420     if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) == 0)          \
 421       _dl_x86_64_restore_sse ();                                              \
 422     THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save,                    \
 423                    old_rtld_must_xmm_save);                                   \
 424   } while (0)
 425 # endif
 426
 427
 428 #endif /* __ASSEMBLER__ */
 429
 430 #endif  /* tls.h */