nptl/sysdeps/x86_64/tls.h

   1 /* Definition for thread-local data handling.  nptl/x86_64 version.
   2    Copyright (C) 2002,2003,2004,2005,2006,2007 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   int gscope_flag;
  51   uintptr_t sysinfo;
  52   uintptr_t stack_guard;
  53   uintptr_t pointer_guard;
  54 } tcbhead_t;
  55
  56 #else /* __ASSEMBLER__ */
  57 # include <tcb-offsets.h>
  58 #endif
  59
  60
  61 /* We require TLS support in the tools.  */
  62 #ifndef HAVE_TLS_SUPPORT
  63 # error "TLS support is required."
  64 #endif
  65
  66 /* Signal that TLS support is available.  */
  67 #define USE_TLS 1
  68
  69 /* Alignment requirement for the stack.  */
  70 #define STACK_ALIGN     16
  71
  72
  73 #ifndef __ASSEMBLER__
  74 /* Get system call information.  */
  75 # include <sysdep.h>
  76
  77
  78 /* Get the thread descriptor definition.  */
  79 # include <nptl/descr.h>
  80
  81 #ifndef LOCK_PREFIX
  82 # ifdef UP
  83 #  define LOCK_PREFIX   /* nothing */
  84 # else
  85 #  define LOCK_PREFIX   "lock;"
  86 # endif
  87 #endif
  88
  89 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
  90    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
  91    struct pthread even when not linked with -lpthread.  */
  92 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
  93
  94 /* Alignment requirements for the initial TCB.  */
  95 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
  96
  97 /* This is the size of the TCB.  */
  98 # define TLS_TCB_SIZE sizeof (struct pthread)
  99
 100 /* Alignment requirements for the TCB.  */
 101 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
 102
 103 /* The TCB can have any size and the memory following the address the
 104    thread pointer points to is unspecified.  Allocate the TCB there.  */
 105 # define TLS_TCB_AT_TP  1
 106
 107
 108 /* Install the dtv pointer.  The pointer passed is to the element with
 109    index -1 which contain the length.  */
 110 # define INSTALL_DTV(descr, dtvp) \
 111   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 112
 113 /* Install new dtv for current thread.  */
 114 # define INSTALL_NEW_DTV(dtvp) \
 115   ({ struct pthread *__pd;                                                    \
 116      THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
 117
 118 /* Return dtv of given thread descriptor.  */
 119 # define GET_DTV(descr) \
 120   (((tcbhead_t *) (descr))->dtv)
 121
 122
 123 /* Macros to load from and store into segment registers.  */
 124 # define TLS_GET_FS() \
 125   ({ int __seg; __asm ("movl %%fs, %0" : "=q" (__seg)); __seg; })
 126 # define TLS_SET_FS(val) \
 127   __asm ("movl %0, %%fs" :: "q" (val))
 128
 129
 130 /* Code to initially initialize the thread pointer.  This might need
 131    special attention since 'errno' is not yet available and if the
 132    operation can cause a failure 'errno' must not be touched.
 133
 134    We have to make the syscall for both uses of the macro since the
 135    address might be (and probably is) different.  */
 136 # define TLS_INIT_TP(thrdescr, secondcall) \
 137   ({ void *_thrdescr = (thrdescr);                                            \
 138      tcbhead_t *_head = _thrdescr;                                            \
 139      int _result;                                                             \
 140                                                                               \
 141      _head->tcb = _thrdescr;                                                  \
 142      /* For now the thread descriptor is at the same address.  */             \
 143      _head->self = _thrdescr;                                                 \
 144                                                                               \
 145      /* It is a simple syscall to set the %fs value for the thread.  */       \
 146      asm volatile ("syscall"                                                  \
 147                    : "=a" (_result)                                           \
 148                    : "0" ((unsigned long int) __NR_arch_prctl),               \
 149                      "D" ((unsigned long int) ARCH_SET_FS),                   \
 150                      "S" (_thrdescr)                                          \
 151                    : "memory", "cc", "r11", "cx");                            \
 152                                                                               \
 153     _result ? "cannot set %fs base address for thread-local storage" : 0;     \
 154   })
 155
 156
 157 /* Return the address of the dtv for the current thread.  */
 158 # define THREAD_DTV() \
 159   ({ struct pthread *__pd;                                                    \
 160      THREAD_GETMEM (__pd, header.dtv); })
 161
 162
 163 /* Return the thread descriptor for the current thread.
 164
 165    The contained asm must *not* be marked volatile since otherwise
 166    assignments like
 167         pthread_descr self = thread_self();
 168    do not get optimized away.  */
 169 # define THREAD_SELF \
 170   ({ struct pthread *__self;                                                  \
 171      asm ("movq %%fs:%c1,%q0" : "=r" (__self)                                 \
 172           : "i" (offsetof (struct pthread, header.self)));                    \
 173      __self;})
 174
 175 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 176 # define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */
 177 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
 178
 179 /* Read member of the thread descriptor directly.  */
 180 # define THREAD_GETMEM(descr, member) \
 181   ({ __typeof (descr->member) __value;                                        \
 182      if (sizeof (__value) == 1)                                               \
 183        asm volatile ("movb %%fs:%P2,%b0"                                      \
 184                      : "=q" (__value)                                         \
 185                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
 186      else if (sizeof (__value) == 4)                                          \
 187        asm volatile ("movl %%fs:%P1,%0"                                       \
 188                      : "=r" (__value)                                         \
 189                      : "i" (offsetof (struct pthread, member)));              \
 190      else                                                                     \
 191        {                                                                      \
 192          if (sizeof (__value) != 8)                                           \
 193            /* There should not be any value with a size other than 1,         \
 194               4 or 8.  */                                                     \
 195            abort ();                                                          \
 196                                                                               \
 197          asm volatile ("movq %%fs:%P1,%q0"                                    \
 198                        : "=r" (__value)                                       \
 199                        : "i" (offsetof (struct pthread, member)));            \
 200        }                                                                      \
 201      __value; })
 202
 203
 204 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 205 # define THREAD_GETMEM_NC(descr, member, idx) \
 206   ({ __typeof (descr->member[0]) __value;                                     \
 207      if (sizeof (__value) == 1)                                               \
 208        asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
 209                      : "=q" (__value)                                         \
 210                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
 211                        "r" (idx));                                            \
 212      else if (sizeof (__value) == 4)                                          \
 213        asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
 214                      : "=r" (__value)                                         \
 215                      : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
 216      else                                                                     \
 217        {                                                                      \
 218          if (sizeof (__value) != 8)                                           \
 219            /* There should not be any value with a size other than 1,         \
 220               4 or 8.  */                                                     \
 221            abort ();                                                          \
 222                                                                               \
 223          asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                            \
 224                        : "=r" (__value)                                       \
 225                        : "i" (offsetof (struct pthread, member[0])),          \
 226                          "r" (idx));                                          \
 227        }                                                                      \
 228      __value; })
 229
 230
 231 /* Loading addresses of objects on x86-64 needs to be treated special
 232    when generating PIC code.  */
 233 #ifdef __pic__
 234 # define IMM_MODE "nr"
 235 #else
 236 # define IMM_MODE "ir"
 237 #endif
 238
 239
 240 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 241 # define THREAD_SETMEM(descr, member, value) \
 242   ({ if (sizeof (descr->member) == 1)                                         \
 243        asm volatile ("movb %b0,%%fs:%P1" :                                    \
 244                      : "iq" (value),                                          \
 245                        "i" (offsetof (struct pthread, member)));              \
 246      else if (sizeof (descr->member) == 4)                                    \
 247        asm volatile ("movl %0,%%fs:%P1" :                                     \
 248                      : IMM_MODE (value),                                      \
 249                        "i" (offsetof (struct pthread, member)));              \
 250      else                                                                     \
 251        {                                                                      \
 252          if (sizeof (descr->member) != 8)                                     \
 253            /* There should not be any value with a size other than 1,         \
 254               4 or 8.  */                                                     \
 255            abort ();                                                          \
 256                                                                               \
 257          asm volatile ("movq %q0,%%fs:%P1" :                                  \
 258                        : IMM_MODE ((unsigned long int) value),                \
 259                          "i" (offsetof (struct pthread, member)));            \
 260        }})
 261
 262
 263 /* Set member of the thread descriptor directly.  */
 264 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 265   ({ if (sizeof (descr->member[0]) == 1)                                      \
 266        asm volatile ("movb %b0,%%fs:%P1(%q2)" :                               \
 267                      : "iq" (value),                                          \
 268                        "i" (offsetof (struct pthread, member[0])),            \
 269                        "r" (idx));                                            \
 270      else if (sizeof (descr->member[0]) == 4)                                 \
 271        asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :                             \
 272                      : IMM_MODE (value),                                      \
 273                        "i" (offsetof (struct pthread, member[0])),            \
 274                        "r" (idx));                                            \
 275      else                                                                     \
 276        {                                                                      \
 277          if (sizeof (descr->member[0]) != 8)                                  \
 278            /* There should not be any value with a size other than 1,         \
 279               4 or 8.  */                                                     \
 280            abort ();                                                          \
 281                                                                               \
 282          asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :                          \
 283                        : IMM_MODE ((unsigned long int) value),                \
 284                          "i" (offsetof (struct pthread, member[0])),          \
 285                          "r" (idx));                                          \
 286        }})
 287
 288
 289 /* Atomic compare and exchange on TLS, returning old value.  */
 290 #define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 291   ({ __typeof (descr->member) __ret;                                          \
 292      __typeof (oldval) __old = (oldval);                                      \
 293      if (sizeof (descr->member) == 4)                                         \
 294        asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"                      \
 295                      : "=a" (__ret)                                           \
 296                      : "0" (__old), "r" (newval),                             \
 297                        "i" (offsetof (struct pthread, member)));              \
 298      else                                                                     \
 299        /* Not necessary for other sizes in the moment.  */                    \
 300        abort ();                                                              \
 301      __ret; })
 302
 303
 304 /* Atomic set bit.  */
 305 #define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 306   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 307               asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"                    \
 308                             :: "i" (offsetof (struct pthread, member)),       \
 309                                "ir" (1 << (bit)));                            \
 310             else                                                              \
 311               /* Not necessary for other sizes in the moment.  */             \
 312               abort (); })
 313
 314
 315 #define CALL_THREAD_FCT(descr) \
 316   ({ void *__res;                                                             \
 317      asm volatile ("movq %%fs:%P2, %%rdi\n\t"                                 \
 318                    "callq *%%fs:%P1"                                          \
 319                    : "=a" (__res)                                             \
 320                    : "i" (offsetof (struct pthread, start_routine)),          \
 321                      "i" (offsetof (struct pthread, arg))                     \
 322                    : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11",        \
 323                      "memory", "cc");                                         \
 324      __res; })
 325
 326
 327 /* Set the stack guard field in TCB head.  */
 328 # define THREAD_SET_STACK_GUARD(value) \
 329     THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
 330 # define THREAD_COPY_STACK_GUARD(descr) \
 331     ((descr)->header.stack_guard                                              \
 332      = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 333
 334
 335 /* Set the pointer guard field in the TCB head.  */
 336 #define THREAD_SET_POINTER_GUARD(value) \
 337   THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
 338 #define THREAD_COPY_POINTER_GUARD(descr) \
 339   ((descr)->header.pointer_guard                                              \
 340    = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
 341
 342
 343 /* Get and set the global scope generation counter in the TCB head.  */
 344 #define THREAD_GSCOPE_FLAG_UNUSED 0
 345 #define THREAD_GSCOPE_FLAG_USED   1
 346 #define THREAD_GSCOPE_FLAG_WAIT   2
 347 #define THREAD_GSCOPE_RESET_FLAG() \
 348   do                                                                          \
 349     { int __res;                                                              \
 350       asm volatile ("xchgl %0, %%fs:%P1"                                      \
 351                     : "=r" (__res)                                            \
 352                     : "i" (offsetof (struct pthread, header.gscope_flag)),    \
 353                       "0" (THREAD_GSCOPE_FLAG_UNUSED));                       \
 354       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 355         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1);                 \
 356     }                                                                         \
 357   while (0)
 358 #define THREAD_GSCOPE_SET_FLAG() \
 359   THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
 360 #define THREAD_GSCOPE_WAIT() \
 361   GL(dl_wait_lookup_done) ()
 362
 363 #endif /* __ASSEMBLER__ */
 364
 365 #endif  /* tls.h */