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