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