nptl/sysdeps/x86_64/tls.h

   1 /* Definition for thread-local data handling.  nptl/x86_64 version.
   2    Copyright (C) 2002, 2003 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 #include <asm/prctl.h>  /* For ARCH_SET_FS.  */
  24 #ifndef __ASSEMBLER__
  25 # include <stddef.h>
  26 # include <stdint.h>
  27 # include <stdlib.h>
  28
  29
  30 /* Type for the dtv.  */
  31 typedef union dtv
  32 {
  33   size_t counter;
  34   void *pointer;
  35 } dtv_t;
  36
  37
  38 typedef struct
  39 {
  40   void *tcb;            /* Pointer to the TCB.  Not necessary the
  41                            thread descriptor used by libpthread.  */
  42   dtv_t *dtv;
  43   void *self;           /* Pointer to the thread descriptor.  */
  44   int multiple_threads;
  45 } tcbhead_t;
  46
  47 #else /* __ASSEMBLER__ */
  48 # include <tcb-offsets.h>
  49 #endif
  50
  51
  52 /* We require TLS support in the tools.  */
  53 #ifndef HAVE_TLS_SUPPORT
  54 # error "TLS support is required."
  55 #endif
  56
  57 /* Signal that TLS support is available.  */
  58 #define USE_TLS 1
  59
  60 /* Alignment requirement for the stack.  */
  61 #define STACK_ALIGN     16
  62
  63
  64 #ifndef __ASSEMBLER__
  65 /* Get system call information.  */
  66 # include <sysdep.h>
  67
  68
  69 /* Get the thread descriptor definition.  */
  70 # include <nptl/descr.h>
  71
  72 #ifndef LOCK_PREFIX
  73 # ifdef UP
  74 #  define LOCK_PREFIX   /* nothing */
  75 # else
  76 #  define LOCK_PREFIX   "lock;"
  77 # endif
  78 #endif
  79
  80 /* This is the size of the initial TCB.  */
  81 # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
  82
  83 /* Alignment requirements for the initial TCB.  */
  84 # define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
  85
  86 /* This is the size of the TCB.  */
  87 # define TLS_TCB_SIZE sizeof (struct pthread)
  88
  89 /* Alignment requirements for the TCB.  */
  90 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
  91
  92 /* The TCB can have any size and the memory following the address the
  93    thread pointer points to is unspecified.  Allocate the TCB there.  */
  94 # define TLS_TCB_AT_TP  1
  95
  96
  97 /* Install the dtv pointer.  The pointer passed is to the element with
  98    index -1 which contain the length.  */
  99 # define INSTALL_DTV(descr, dtvp) \
 100   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 101
 102 /* Install new dtv for current thread.  */
 103 # define INSTALL_NEW_DTV(dtvp) \
 104   ({ struct pthread *__pd;                                                    \
 105      THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
 106
 107 /* Return dtv of given thread descriptor.  */
 108 # define GET_DTV(descr) \
 109   (((tcbhead_t *) (descr))->dtv)
 110
 111
 112 /* Macros to load from and store into segment registers.  */
 113 # define TLS_GET_FS() \
 114   ({ int __seg; __asm ("movl %%fs, %0" : "=q" (__seg)); __seg; })
 115 # define TLS_SET_FS(val) \
 116   __asm ("movl %0, %%fs" :: "q" (val))
 117
 118
 119 /* Code to initially initialize the thread pointer.  This might need
 120    special attention since 'errno' is not yet available and if the
 121    operation can cause a failure 'errno' must not be touched.
 122
 123    We have to make the syscall for both uses of the macro since the
 124    address might be (and probably is) different.  */
 125 # define TLS_INIT_TP(thrdescr, secondcall) \
 126   ({ void *_thrdescr = (thrdescr);                                            \
 127      tcbhead_t *_head = _thrdescr;                                            \
 128      int _result;                                                             \
 129                                                                               \
 130      _head->tcb = _thrdescr;                                                  \
 131      /* For now the thread descriptor is at the same address.  */             \
 132      _head->self = _thrdescr;                                                 \
 133                                                                               \
 134      /* It is a simple syscall to set the %fs value for the thread.  */       \
 135      asm volatile ("syscall"                                                  \
 136                    : "=a" (_result)                                           \
 137                    : "0" ((unsigned long int) __NR_arch_prctl),               \
 138                      "D" ((unsigned long int) ARCH_SET_FS),                   \
 139                      "S" (_thrdescr)                                          \
 140                    : "memory", "cc", "r11", "cx");                            \
 141                                                                               \
 142     _result ? "cannot set %fs base address for thread-local storage" : 0;     \
 143   })
 144
 145
 146 /* Return the address of the dtv for the current thread.  */
 147 # define THREAD_DTV() \
 148   ({ struct pthread *__pd;                                                    \
 149      THREAD_GETMEM (__pd, header.dtv); })
 150
 151
 152 /* Return the thread descriptor for the current thread.
 153
 154    The contained asm must *not* be marked volatile since otherwise
 155    assignments like
 156         pthread_descr self = thread_self();
 157    do not get optimized away.  */
 158 # define THREAD_SELF \
 159   ({ struct pthread *__self;                                                  \
 160      asm ("movq %%fs:%c1,%q0" : "=r" (__self)                                 \
 161           : "i" (offsetof (struct pthread, header.self)));                    \
 162      __self;})
 163
 164 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 165 # define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */
 166 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
 167
 168 /* Read member of the thread descriptor directly.  */
 169 # define THREAD_GETMEM(descr, member) \
 170   ({ __typeof (descr->member) __value;                                        \
 171      if (sizeof (__value) == 1)                                               \
 172        asm volatile ("movb %%fs:%P2,%b0"                                      \
 173                      : "=q" (__value)                                         \
 174                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
 175      else if (sizeof (__value) == 4)                                          \
 176        asm volatile ("movl %%fs:%P1,%0"                                       \
 177                      : "=r" (__value)                                         \
 178                      : "i" (offsetof (struct pthread, member)));              \
 179      else                                                                     \
 180        {                                                                      \
 181          if (sizeof (__value) != 8)                                           \
 182            /* There should not be any value with a size other than 1,         \
 183               4 or 8.  */                                                     \
 184            abort ();                                                          \
 185                                                                               \
 186          asm volatile ("movq %%fs:%P1,%q0"                                    \
 187                        : "=r" (__value)                                       \
 188                        : "i" (offsetof (struct pthread, member)));            \
 189        }                                                                      \
 190      __value; })
 191
 192
 193 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 194 # define THREAD_GETMEM_NC(descr, member, idx) \
 195   ({ __typeof (descr->member[0]) __value;                                     \
 196      if (sizeof (__value) == 1)                                               \
 197        asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
 198                      : "=q" (__value)                                         \
 199                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
 200                        "r" (idx));                                            \
 201      else if (sizeof (__value) == 4)                                          \
 202        asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
 203                      : "=r" (__value)                                         \
 204                      : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
 205      else                                                                     \
 206        {                                                                      \
 207          if (sizeof (__value) != 8)                                           \
 208            /* There should not be any value with a size other than 1,         \
 209               4 or 8.  */                                                     \
 210            abort ();                                                          \
 211                                                                               \
 212          asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                            \
 213                        : "=r" (__value)                                       \
 214                        : "i" (offsetof (struct pthread, member[0])),          \
 215                          "r" (idx));                                          \
 216        }                                                                      \
 217      __value; })
 218
 219
 220 /* Loading addresses of objects on x86-64 needs to be treated special
 221    when generating PIC code.  */
 222 #ifdef __pic__
 223 # define IMM_MODE "nr"
 224 #else
 225 # define IMM_MODE "ir"
 226 #endif
 227
 228
 229 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 230 # define THREAD_SETMEM(descr, member, value) \
 231   ({ if (sizeof (descr->member) == 1)                                         \
 232        asm volatile ("movb %b0,%%fs:%P1" :                                    \
 233                      : "iq" (value),                                          \
 234                        "i" (offsetof (struct pthread, member)));              \
 235      else if (sizeof (descr->member) == 4)                                    \
 236        asm volatile ("movl %0,%%fs:%P1" :                                     \
 237                      : IMM_MODE (value),                                      \
 238                        "i" (offsetof (struct pthread, member)));              \
 239      else                                                                     \
 240        {                                                                      \
 241          if (sizeof (descr->member) != 8)                                     \
 242            /* There should not be any value with a size other than 1,         \
 243               4 or 8.  */                                                     \
 244            abort ();                                                          \
 245                                                                               \
 246          asm volatile ("movq %q0,%%fs:%P1" :                                  \
 247                        : IMM_MODE ((unsigned long int) value),                \
 248                          "i" (offsetof (struct pthread, member)));            \
 249        }})
 250
 251
 252 /* Set member of the thread descriptor directly.  */
 253 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 254   ({ if (sizeof (descr->member[0]) == 1)                                      \
 255        asm volatile ("movb %b0,%%fs:%P1(%q2)" :                               \
 256                      : "iq" (value),                                          \
 257                        "i" (offsetof (struct pthread, member[0])),            \
 258                        "r" (idx));                                            \
 259      else if (sizeof (descr->member[0]) == 4)                                 \
 260        asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :                             \
 261                      : IMM_MODE (value),                                      \
 262                        "i" (offsetof (struct pthread, member[0])),            \
 263                        "r" (idx));                                            \
 264      else                                                                     \
 265        {                                                                      \
 266          if (sizeof (descr->member[0]) != 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(,%q2,8)" :                          \
 272                        : IMM_MODE ((unsigned long int) value),                \
 273                          "i" (offsetof (struct pthread, member[0])),          \
 274                          "r" (idx));                                          \
 275        }})
 276
 277
 278 /* Atomic compare and exchange on TLS, returning old value.  */
 279 #define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 280   ({ __typeof (descr->member) __ret;                                          \
 281      __typeof (oldval) __old = (oldval);                                      \
 282      if (sizeof (descr->member) == 4)                                         \
 283        asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"                      \
 284                      : "=a" (__ret)                                           \
 285                      : "0" (__old), "r" (newval),                             \
 286                        "i" (offsetof (struct pthread, member)));              \
 287      else                                                                     \
 288        /* Not necessary for other sizes in the moment.  */                    \
 289        abort ();                                                              \
 290      __ret; })
 291
 292
 293 /* Atomic set bit.  */
 294 #define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 295   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 296               asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"                    \
 297                             :: "i" (offsetof (struct pthread, member)),       \
 298                                "ir" (1 << (bit)));                            \
 299             else                                                              \
 300               /* Not necessary for other sizes in the moment.  */             \
 301               abort (); })
 302
 303
 304 #define CALL_THREAD_FCT(descr) \
 305   ({ void *__res;                                                             \
 306      asm volatile ("movq %%fs:%P2, %%rdi\n\t"                                 \
 307                    "callq *%%fs:%P1"                                          \
 308                    : "=a" (__res)                                             \
 309                    : "i" (offsetof (struct pthread, start_routine)),          \
 310                      "i" (offsetof (struct pthread, arg))                     \
 311                    : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11",        \
 312                      "memory", "cc");                                         \
 313      __res; })
 314
 315
 316 #endif /* __ASSEMBLER__ */
 317
 318 #endif  /* tls.h */