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 # include <sysdep.h>
  30 # include <kernel-features.h>
  31
  32
  33 /* Type for the dtv.  */
  34 typedef union dtv
  35 {
  36   size_t counter;
  37   struct
  38   {
  39     void *val;
  40     bool is_static;
  41   } pointer;
  42 } dtv_t;
  43
  44
  45 typedef struct
  46 {
  47   void *tcb;            /* Pointer to the TCB.  Not necessarily the
  48                            thread descriptor used by libpthread.  */
  49   dtv_t *dtv;
  50   void *self;           /* Pointer to the thread descriptor.  */
  51   int multiple_threads;
  52   int gscope_flag;
  53   uintptr_t sysinfo;
  54   uintptr_t stack_guard;
  55   uintptr_t pointer_guard;
  56   unsigned long int vgetcpu_cache[2];
  57 #ifndef __ASSUME_PRIVATE_FUTEX
  58   int private_futex;
  59 #endif
  60 } tcbhead_t;
  61
  62 #else /* __ASSEMBLER__ */
  63 # include <tcb-offsets.h>
  64 #endif
  65
  66
  67 /* We require TLS support in the tools.  */
  68 #ifndef HAVE_TLS_SUPPORT
  69 # error "TLS support is required."
  70 #endif
  71
  72 /* Alignment requirement for the stack.  */
  73 #define STACK_ALIGN     16
  74
  75
  76 #ifndef __ASSEMBLER__
  77 /* Get system call information.  */
  78 # include <sysdep.h>
  79
  80
  81 /* Get the thread descriptor definition.  */
  82 # include <nptl/descr.h>
  83
  84 #ifndef LOCK_PREFIX
  85 # ifdef UP
  86 #  define LOCK_PREFIX   /* nothing */
  87 # else
  88 #  define LOCK_PREFIX   "lock;"
  89 # endif
  90 #endif
  91
  92 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
  93    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
  94    struct pthread even when not linked with -lpthread.  */
  95 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
  96
  97 /* Alignment requirements for the initial TCB.  */
  98 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
  99
 100 /* This is the size of the TCB.  */
 101 # define TLS_TCB_SIZE sizeof (struct pthread)
 102
 103 /* Alignment requirements for the TCB.  */
 104 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
 105
 106 /* The TCB can have any size and the memory following the address the
 107    thread pointer points to is unspecified.  Allocate the TCB there.  */
 108 # define TLS_TCB_AT_TP  1
 109
 110
 111 /* Install the dtv pointer.  The pointer passed is to the element with
 112    index -1 which contain the length.  */
 113 # define INSTALL_DTV(descr, dtvp) \
 114   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 115
 116 /* Install new dtv for current thread.  */
 117 # define INSTALL_NEW_DTV(dtvp) \
 118   ({ struct pthread *__pd;                                                    \
 119      THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
 120
 121 /* Return dtv of given thread descriptor.  */
 122 # define GET_DTV(descr) \
 123   (((tcbhead_t *) (descr))->dtv)
 124
 125
 126 /* Macros to load from and store into segment registers.  */
 127 # define TLS_GET_FS() \
 128   ({ int __seg; __asm ("movl %%fs, %0" : "=q" (__seg)); __seg; })
 129 # define TLS_SET_FS(val) \
 130   __asm ("movl %0, %%fs" :: "q" (val))
 131
 132
 133 /* Code to initially initialize the thread pointer.  This might need
 134    special attention since 'errno' is not yet available and if the
 135    operation can cause a failure 'errno' must not be touched.
 136
 137    We have to make the syscall for both uses of the macro since the
 138    address might be (and probably is) different.  */
 139 # define TLS_INIT_TP(thrdescr, secondcall) \
 140   ({ void *_thrdescr = (thrdescr);                                            \
 141      tcbhead_t *_head = _thrdescr;                                            \
 142      int _result;                                                             \
 143                                                                               \
 144      _head->tcb = _thrdescr;                                                  \
 145      /* For now the thread descriptor is at the same address.  */             \
 146      _head->self = _thrdescr;                                                 \
 147                                                                               \
 148      /* It is a simple syscall to set the %fs value for the thread.  */       \
 149      asm volatile ("syscall"                                                  \
 150                    : "=a" (_result)                                           \
 151                    : "0" ((unsigned long int) __NR_arch_prctl),               \
 152                      "D" ((unsigned long int) ARCH_SET_FS),                   \
 153                      "S" (_thrdescr)                                          \
 154                    : "memory", "cc", "r11", "cx");                            \
 155                                                                               \
 156     _result ? "cannot set %fs base address for thread-local storage" : 0;     \
 157   })
 158
 159
 160 /* Return the address of the dtv for the current thread.  */
 161 # define THREAD_DTV() \
 162   ({ struct pthread *__pd;                                                    \
 163      THREAD_GETMEM (__pd, header.dtv); })
 164
 165
 166 /* Return the thread descriptor for the current thread.
 167
 168    The contained asm must *not* be marked volatile since otherwise
 169    assignments like
 170         pthread_descr self = thread_self();
 171    do not get optimized away.  */
 172 # define THREAD_SELF \
 173   ({ struct pthread *__self;                                                  \
 174      asm ("movq %%fs:%c1,%q0" : "=r" (__self)                                 \
 175           : "i" (offsetof (struct pthread, header.self)));                    \
 176      __self;})
 177
 178 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 179 # define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */
 180 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
 181
 182 /* Read member of the thread descriptor directly.  */
 183 # define THREAD_GETMEM(descr, member) \
 184   ({ __typeof (descr->member) __value;                                        \
 185      if (sizeof (__value) == 1)                                               \
 186        asm volatile ("movb %%fs:%P2,%b0"                                      \
 187                      : "=q" (__value)                                         \
 188                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
 189      else if (sizeof (__value) == 4)                                          \
 190        asm volatile ("movl %%fs:%P1,%0"                                       \
 191                      : "=r" (__value)                                         \
 192                      : "i" (offsetof (struct pthread, member)));              \
 193      else                                                                     \
 194        {                                                                      \
 195          if (sizeof (__value) != 8)                                           \
 196            /* There should not be any value with a size other than 1,         \
 197               4 or 8.  */                                                     \
 198            abort ();                                                          \
 199                                                                               \
 200          asm volatile ("movq %%fs:%P1,%q0"                                    \
 201                        : "=r" (__value)                                       \
 202                        : "i" (offsetof (struct pthread, member)));            \
 203        }                                                                      \
 204      __value; })
 205
 206
 207 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 208 # define THREAD_GETMEM_NC(descr, member, idx) \
 209   ({ __typeof (descr->member[0]) __value;                                     \
 210      if (sizeof (__value) == 1)                                               \
 211        asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
 212                      : "=q" (__value)                                         \
 213                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
 214                        "r" (idx));                                            \
 215      else if (sizeof (__value) == 4)                                          \
 216        asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
 217                      : "=r" (__value)                                         \
 218                      : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
 219      else                                                                     \
 220        {                                                                      \
 221          if (sizeof (__value) != 8)                                           \
 222            /* There should not be any value with a size other than 1,         \
 223               4 or 8.  */                                                     \
 224            abort ();                                                          \
 225                                                                               \
 226          asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                            \
 227                        : "=r" (__value)                                       \
 228                        : "i" (offsetof (struct pthread, member[0])),          \
 229                          "r" (idx));                                          \
 230        }                                                                      \
 231      __value; })
 232
 233
 234 /* Loading addresses of objects on x86-64 needs to be treated special
 235    when generating PIC code.  */
 236 #ifdef __pic__
 237 # define IMM_MODE "nr"
 238 #else
 239 # define IMM_MODE "ir"
 240 #endif
 241
 242
 243 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 244 # define THREAD_SETMEM(descr, member, value) \
 245   ({ if (sizeof (descr->member) == 1)                                         \
 246        asm volatile ("movb %b0,%%fs:%P1" :                                    \
 247                      : "iq" (value),                                          \
 248                        "i" (offsetof (struct pthread, member)));              \
 249      else if (sizeof (descr->member) == 4)                                    \
 250        asm volatile ("movl %0,%%fs:%P1" :                                     \
 251                      : IMM_MODE (value),                                      \
 252                        "i" (offsetof (struct pthread, member)));              \
 253      else                                                                     \
 254        {                                                                      \
 255          if (sizeof (descr->member) != 8)                                     \
 256            /* There should not be any value with a size other than 1,         \
 257               4 or 8.  */                                                     \
 258            abort ();                                                          \
 259                                                                               \
 260          asm volatile ("movq %q0,%%fs:%P1" :                                  \
 261                        : IMM_MODE ((unsigned long int) value),                \
 262                          "i" (offsetof (struct pthread, member)));            \
 263        }})
 264
 265
 266 /* Set member of the thread descriptor directly.  */
 267 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 268   ({ if (sizeof (descr->member[0]) == 1)                                      \
 269        asm volatile ("movb %b0,%%fs:%P1(%q2)" :                               \
 270                      : "iq" (value),                                          \
 271                        "i" (offsetof (struct pthread, member[0])),            \
 272                        "r" (idx));                                            \
 273      else if (sizeof (descr->member[0]) == 4)                                 \
 274        asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :                             \
 275                      : IMM_MODE (value),                                      \
 276                        "i" (offsetof (struct pthread, member[0])),            \
 277                        "r" (idx));                                            \
 278      else                                                                     \
 279        {                                                                      \
 280          if (sizeof (descr->member[0]) != 8)                                  \
 281            /* There should not be any value with a size other than 1,         \
 282               4 or 8.  */                                                     \
 283            abort ();                                                          \
 284                                                                               \
 285          asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :                          \
 286                        : IMM_MODE ((unsigned long int) value),                \
 287                          "i" (offsetof (struct pthread, member[0])),          \
 288                          "r" (idx));                                          \
 289        }})
 290
 291
 292 /* Atomic compare and exchange on TLS, returning old value.  */
 293 #define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 294   ({ __typeof (descr->member) __ret;                                          \
 295      __typeof (oldval) __old = (oldval);                                      \
 296      if (sizeof (descr->member) == 4)                                         \
 297        asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"                      \
 298                      : "=a" (__ret)                                           \
 299                      : "0" (__old), "r" (newval),                             \
 300                        "i" (offsetof (struct pthread, member)));              \
 301      else                                                                     \
 302        /* Not necessary for other sizes in the moment.  */                    \
 303        abort ();                                                              \
 304      __ret; })
 305
 306
 307 /* Atomic set bit.  */
 308 #define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 309   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 310               asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"                    \
 311                             :: "i" (offsetof (struct pthread, member)),       \
 312                                "ir" (1 << (bit)));                            \
 313             else                                                              \
 314               /* Not necessary for other sizes in the moment.  */             \
 315               abort (); })
 316
 317
 318 #define CALL_THREAD_FCT(descr) \
 319   ({ void *__res;                                                             \
 320      asm volatile ("movq %%fs:%P2, %%rdi\n\t"                                 \
 321                    "callq *%%fs:%P1"                                          \
 322                    : "=a" (__res)                                             \
 323                    : "i" (offsetof (struct pthread, start_routine)),          \
 324                      "i" (offsetof (struct pthread, arg))                     \
 325                    : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11",        \
 326                      "memory", "cc");                                         \
 327      __res; })
 328
 329
 330 /* Set the stack guard field in TCB head.  */
 331 # define THREAD_SET_STACK_GUARD(value) \
 332     THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
 333 # define THREAD_COPY_STACK_GUARD(descr) \
 334     ((descr)->header.stack_guard                                              \
 335      = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 336
 337
 338 /* Set the pointer guard field in the TCB head.  */
 339 #define THREAD_SET_POINTER_GUARD(value) \
 340   THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
 341 #define THREAD_COPY_POINTER_GUARD(descr) \
 342   ((descr)->header.pointer_guard                                              \
 343    = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
 344
 345
 346 /* Get and set the global scope generation counter in the TCB head.  */
 347 #define THREAD_GSCOPE_FLAG_UNUSED 0
 348 #define THREAD_GSCOPE_FLAG_USED   1
 349 #define THREAD_GSCOPE_FLAG_WAIT   2
 350 #define THREAD_GSCOPE_RESET_FLAG() \
 351   do                                                                          \
 352     { int __res;                                                              \
 353       asm volatile ("xchgl %0, %%fs:%P1"                                      \
 354                     : "=r" (__res)                                            \
 355                     : "i" (offsetof (struct pthread, header.gscope_flag)),    \
 356                       "0" (THREAD_GSCOPE_FLAG_UNUSED));                       \
 357       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 358         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
 359     }                                                                         \
 360   while (0)
 361 #define THREAD_GSCOPE_SET_FLAG() \
 362   THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
 363 #define THREAD_GSCOPE_WAIT() \
 364   GL(dl_wait_lookup_done) ()
 365
 366 #endif /* __ASSEMBLER__ */
 367
 368 #endif  /* tls.h */