nptl/sysdeps/x86_64/tls.h

   1 /* Definition for thread-local data handling.  nptl/x86_64 version.
   2    Copyright (C) 2002-2009, 2011-2012 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _TLS_H
  20 #define _TLS_H  1
  21
  22 #ifndef __ASSEMBLER__
  23 # include <asm/prctl.h> /* For ARCH_SET_FS.  */
  24 # include <stdbool.h>
  25 # include <stddef.h>
  26 # include <stdint.h>
  27 # include <stdlib.h>
  28 # include <sysdep.h>
  29 # include <kernel-features.h>
  30 # include <xmmintrin.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 # else
  60   int __unused1;
  61 # endif
  62   int rtld_must_xmm_save;
  63   /* Reservation of some values for the TM ABI.  */
  64   void *__private_tm[5];
  65   long int __unused2;
  66   /* Have space for the post-AVX register size.  */
  67   __m128 rtld_savespace_sse[8][4] __attribute__ ((aligned (32)));
  68
  69   void *__padding[8];
  70 } tcbhead_t;
  71
  72 #else /* __ASSEMBLER__ */
  73 # include <tcb-offsets.h>
  74 #endif
  75
  76
  77 /* Alignment requirement for the stack.  */
  78 #define STACK_ALIGN     16
  79
  80
  81 #ifndef __ASSEMBLER__
  82 /* Get system call information.  */
  83 # include <sysdep.h>
  84
  85
  86 /* Get the thread descriptor definition.  */
  87 # include <nptl/descr.h>
  88
  89 #ifndef LOCK_PREFIX
  90 # ifdef UP
  91 #  define LOCK_PREFIX   /* nothing */
  92 # else
  93 #  define LOCK_PREFIX   "lock;"
  94 # endif
  95 #endif
  96
  97 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
  98    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
  99    struct pthread even when not linked with -lpthread.  */
 100 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
 101
 102 /* Alignment requirements for the initial TCB.  */
 103 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
 104
 105 /* This is the size of the TCB.  */
 106 # define TLS_TCB_SIZE sizeof (struct pthread)
 107
 108 /* Alignment requirements for the TCB.  */
 109 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
 110
 111 /* The TCB can have any size and the memory following the address the
 112    thread pointer points to is unspecified.  Allocate the TCB there.  */
 113 # define TLS_TCB_AT_TP  1
 114
 115
 116 /* Install the dtv pointer.  The pointer passed is to the element with
 117    index -1 which contain the length.  */
 118 # define INSTALL_DTV(descr, dtvp) \
 119   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 120
 121 /* Install new dtv for current thread.  */
 122 # define INSTALL_NEW_DTV(dtvp) \
 123   ({ struct pthread *__pd;                                                    \
 124      THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
 125
 126 /* Return dtv of given thread descriptor.  */
 127 # define GET_DTV(descr) \
 128   (((tcbhead_t *) (descr))->dtv)
 129
 130
 131 /* Code to initially initialize the thread pointer.  This might need
 132    special attention since 'errno' is not yet available and if the
 133    operation can cause a failure 'errno' must not be touched.
 134
 135    We have to make the syscall for both uses of the macro since the
 136    address might be (and probably is) different.  */
 137 # define TLS_INIT_TP(thrdescr, secondcall) \
 138   ({ void *_thrdescr = (thrdescr);                                            \
 139      tcbhead_t *_head = _thrdescr;                                            \
 140      int _result;                                                             \
 141                                                                               \
 142      _head->tcb = _thrdescr;                                                  \
 143      /* For now the thread descriptor is at the same address.  */             \
 144      _head->self = _thrdescr;                                                 \
 145                                                                               \
 146      /* It is a simple syscall to set the %fs value for the thread.  */       \
 147      asm volatile ("syscall"                                                  \
 148                    : "=a" (_result)                                           \
 149                    : "0" ((unsigned long int) __NR_arch_prctl),               \
 150                      "D" ((unsigned long int) ARCH_SET_FS),                   \
 151                      "S" (_thrdescr)                                          \
 152                    : "memory", "cc", "r11", "cx");                            \
 153                                                                               \
 154     _result ? "cannot set %fs base address for thread-local storage" : 0;     \
 155   })
 156
 157
 158 /* Return the address of the dtv for the current thread.  */
 159 # define THREAD_DTV() \
 160   ({ struct pthread *__pd;                                                    \
 161      THREAD_GETMEM (__pd, header.dtv); })
 162
 163
 164 /* Return the thread descriptor for the current thread.
 165
 166    The contained asm must *not* be marked volatile since otherwise
 167    assignments like
 168         pthread_descr self = thread_self();
 169    do not get optimized away.  */
 170 # define THREAD_SELF \
 171   ({ struct pthread *__self;                                                  \
 172      asm ("mov %%fs:%c1,%0" : "=r" (__self)                                   \
 173           : "i" (offsetof (struct pthread, header.self)));                    \
 174      __self;})
 175
 176 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 177 # define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */
 178 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
 179
 180 /* Read member of the thread descriptor directly.  */
 181 # define THREAD_GETMEM(descr, member) \
 182   ({ __typeof (descr->member) __value;                                        \
 183      if (sizeof (__value) == 1)                                               \
 184        asm volatile ("movb %%fs:%P2,%b0"                                      \
 185                      : "=q" (__value)                                         \
 186                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
 187      else if (sizeof (__value) == 4)                                          \
 188        asm volatile ("movl %%fs:%P1,%0"                                       \
 189                      : "=r" (__value)                                         \
 190                      : "i" (offsetof (struct pthread, member)));              \
 191      else                                                                     \
 192        {                                                                      \
 193          if (sizeof (__value) != 8)                                           \
 194            /* There should not be any value with a size other than 1,         \
 195               4 or 8.  */                                                     \
 196            abort ();                                                          \
 197                                                                               \
 198          asm volatile ("movq %%fs:%P1,%q0"                                    \
 199                        : "=r" (__value)                                       \
 200                        : "i" (offsetof (struct pthread, member)));            \
 201        }                                                                      \
 202      __value; })
 203
 204
 205 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 206 # define THREAD_GETMEM_NC(descr, member, idx) \
 207   ({ __typeof (descr->member[0]) __value;                                     \
 208      if (sizeof (__value) == 1)                                               \
 209        asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
 210                      : "=q" (__value)                                         \
 211                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
 212                        "r" (idx));                                            \
 213      else if (sizeof (__value) == 4)                                          \
 214        asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
 215                      : "=r" (__value)                                         \
 216                      : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
 217      else                                                                     \
 218        {                                                                      \
 219          if (sizeof (__value) != 8)                                           \
 220            /* There should not be any value with a size other than 1,         \
 221               4 or 8.  */                                                     \
 222            abort ();                                                          \
 223                                                                               \
 224          asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                            \
 225                        : "=r" (__value)                                       \
 226                        : "i" (offsetof (struct pthread, member[0])),          \
 227                          "r" (idx));                                          \
 228        }                                                                      \
 229      __value; })
 230
 231
 232 /* Loading addresses of objects on x86-64 needs to be treated special
 233    when generating PIC code.  */
 234 #ifdef __pic__
 235 # define IMM_MODE "nr"
 236 #else
 237 # define IMM_MODE "ir"
 238 #endif
 239
 240
 241 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 242 # define THREAD_SETMEM(descr, member, value) \
 243   ({ if (sizeof (descr->member) == 1)                                         \
 244        asm volatile ("movb %b0,%%fs:%P1" :                                    \
 245                      : "iq" (value),                                          \
 246                        "i" (offsetof (struct pthread, member)));              \
 247      else if (sizeof (descr->member) == 4)                                    \
 248        asm volatile ("movl %0,%%fs:%P1" :                                     \
 249                      : IMM_MODE (value),                                      \
 250                        "i" (offsetof (struct pthread, member)));              \
 251      else                                                                     \
 252        {                                                                      \
 253          if (sizeof (descr->member) != 8)                                     \
 254            /* There should not be any value with a size other than 1,         \
 255               4 or 8.  */                                                     \
 256            abort ();                                                          \
 257                                                                               \
 258          asm volatile ("movq %q0,%%fs:%P1" :                                  \
 259                        : IMM_MODE ((uint64_t) (value)),                       \
 260                          "i" (offsetof (struct pthread, member)));            \
 261        }})
 262
 263
 264 /* Set member of the thread descriptor directly.  */
 265 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 266   ({ if (sizeof (descr->member[0]) == 1)                                      \
 267        asm volatile ("movb %b0,%%fs:%P1(%q2)" :                               \
 268                      : "iq" (value),                                          \
 269                        "i" (offsetof (struct pthread, member[0])),            \
 270                        "r" (idx));                                            \
 271      else if (sizeof (descr->member[0]) == 4)                                 \
 272        asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :                             \
 273                      : IMM_MODE (value),                                      \
 274                        "i" (offsetof (struct pthread, member[0])),            \
 275                        "r" (idx));                                            \
 276      else                                                                     \
 277        {                                                                      \
 278          if (sizeof (descr->member[0]) != 8)                                  \
 279            /* There should not be any value with a size other than 1,         \
 280               4 or 8.  */                                                     \
 281            abort ();                                                          \
 282                                                                               \
 283          asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :                          \
 284                        : IMM_MODE ((uint64_t) (value)),                       \
 285                          "i" (offsetof (struct pthread, member[0])),          \
 286                          "r" (idx));                                          \
 287        }})
 288
 289
 290 /* Atomic compare and exchange on TLS, returning old value.  */
 291 # define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 292   ({ __typeof (descr->member) __ret;                                          \
 293      __typeof (oldval) __old = (oldval);                                      \
 294      if (sizeof (descr->member) == 4)                                         \
 295        asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"                      \
 296                      : "=a" (__ret)                                           \
 297                      : "0" (__old), "r" (newval),                             \
 298                        "i" (offsetof (struct pthread, member)));              \
 299      else                                                                     \
 300        /* Not necessary for other sizes in the moment.  */                    \
 301        abort ();                                                              \
 302      __ret; })
 303
 304
 305 /* Atomic logical and.  */
 306 # define THREAD_ATOMIC_AND(descr, member, val) \
 307   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 308               asm volatile (LOCK_PREFIX "andl %1, %%fs:%P0"                   \
 309                             :: "i" (offsetof (struct pthread, member)),       \
 310                                "ir" (val));                                   \
 311             else                                                              \
 312               /* Not necessary for other sizes in the moment.  */             \
 313               abort (); })
 314
 315
 316 /* Atomic set bit.  */
 317 # define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 318   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 319               asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"                    \
 320                             :: "i" (offsetof (struct pthread, member)),       \
 321                                "ir" (1 << (bit)));                            \
 322             else                                                              \
 323               /* Not necessary for other sizes in the moment.  */             \
 324               abort (); })
 325
 326
 327 # define CALL_THREAD_FCT(descr) \
 328   ({ void *__res;                                                             \
 329      asm volatile ("movq %%fs:%P2, %%rdi\n\t"                                 \
 330                    "callq *%%fs:%P1"                                          \
 331                    : "=a" (__res)                                             \
 332                    : "i" (offsetof (struct pthread, start_routine)),          \
 333                      "i" (offsetof (struct pthread, arg))                     \
 334                    : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11",        \
 335                      "memory", "cc");                                         \
 336      __res; })
 337
 338
 339 /* Set the stack guard field in TCB head.  */
 340 # define THREAD_SET_STACK_GUARD(value) \
 341     THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
 342 # define THREAD_COPY_STACK_GUARD(descr) \
 343     ((descr)->header.stack_guard                                              \
 344      = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 345
 346
 347 /* Set the pointer guard field in the TCB head.  */
 348 # define THREAD_SET_POINTER_GUARD(value) \
 349   THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
 350 # define THREAD_COPY_POINTER_GUARD(descr) \
 351   ((descr)->header.pointer_guard                                              \
 352    = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
 353
 354
 355 /* Get and set the global scope generation counter in the TCB head.  */
 356 # define THREAD_GSCOPE_FLAG_UNUSED 0
 357 # define THREAD_GSCOPE_FLAG_USED   1
 358 # define THREAD_GSCOPE_FLAG_WAIT   2
 359 # define THREAD_GSCOPE_RESET_FLAG() \
 360   do                                                                          \
 361     { int __res;                                                              \
 362       asm volatile ("xchgl %0, %%fs:%P1"                                      \
 363                     : "=r" (__res)                                            \
 364                     : "i" (offsetof (struct pthread, header.gscope_flag)),    \
 365                       "0" (THREAD_GSCOPE_FLAG_UNUSED));                       \
 366       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 367         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
 368     }                                                                         \
 369   while (0)
 370 # define THREAD_GSCOPE_SET_FLAG() \
 371   THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
 372 # define THREAD_GSCOPE_WAIT() \
 373   GL(dl_wait_lookup_done) ()
 374
 375
 376 # ifdef SHARED
 377 /* Defined in dl-trampoline.S.  */
 378 extern void _dl_x86_64_save_sse (void);
 379 extern void _dl_x86_64_restore_sse (void);
 380
 381 # define RTLD_CHECK_FOREIGN_CALL \
 382   (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) != 0)
 383
 384 /* NB: Don't use the xchg operation because that would imply a lock
 385    prefix which is expensive and unnecessary.  The cache line is also
 386    not contested at all.  */
 387 #  define RTLD_ENABLE_FOREIGN_CALL \
 388   int old_rtld_must_xmm_save = THREAD_GETMEM (THREAD_SELF,                    \
 389                                               header.rtld_must_xmm_save);     \
 390   THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 1)
 391
 392 #  define RTLD_PREPARE_FOREIGN_CALL \
 393   do if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save))              \
 394     {                                                                         \
 395       _dl_x86_64_save_sse ();                                                 \
 396       THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 0);              \
 397     }                                                                         \
 398   while (0)
 399
 400 #  define RTLD_FINALIZE_FOREIGN_CALL \
 401   do {                                                                        \
 402     if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) == 0)          \
 403       _dl_x86_64_restore_sse ();                                              \
 404     THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save,                    \
 405                    old_rtld_must_xmm_save);                                   \
 406   } while (0)
 407 # endif
 408
 409
 410 #endif /* __ASSEMBLER__ */
 411
 412 #endif  /* tls.h */