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
  31 /* Replacement type for __m128 since this file is included by ld.so,
  32    which is compiled with -mno-sse.  It must not change the alignment
  33    of rtld_savespace_sse.  */
  34 typedef struct
  35 {
  36   int i[4];
  37 } __128bits;
  38
  39
  40 /* Type for the dtv.  */
  41 typedef union dtv
  42 {
  43   size_t counter;
  44   struct
  45   {
  46     void *val;
  47     bool is_static;
  48   } pointer;
  49 } dtv_t;
  50
  51
  52 typedef struct
  53 {
  54   void *tcb;            /* Pointer to the TCB.  Not necessarily the
  55                            thread descriptor used by libpthread.  */
  56   dtv_t *dtv;
  57   void *self;           /* Pointer to the thread descriptor.  */
  58   int multiple_threads;
  59   int gscope_flag;
  60   uintptr_t sysinfo;
  61   uintptr_t stack_guard;
  62   uintptr_t pointer_guard;
  63   unsigned long int vgetcpu_cache[2];
  64 # ifndef __ASSUME_PRIVATE_FUTEX
  65   int private_futex;
  66 # else
  67   int __unused1;
  68 # endif
  69   int rtld_must_xmm_save;
  70   /* Reservation of some values for the TM ABI.  */
  71   void *__private_tm[5];
  72   long int __unused2;
  73   /* Have space for the post-AVX register size.  */
  74   __128bits rtld_savespace_sse[8][4] __attribute__ ((aligned (32)));
  75
  76   void *__padding[8];
  77 } tcbhead_t;
  78
  79 #else /* __ASSEMBLER__ */
  80 # include <tcb-offsets.h>
  81 #endif
  82
  83
  84 /* Alignment requirement for the stack.  */
  85 #define STACK_ALIGN     16
  86
  87
  88 #ifndef __ASSEMBLER__
  89 /* Get system call information.  */
  90 # include <sysdep.h>
  91
  92
  93 /* Get the thread descriptor definition.  */
  94 # include <nptl/descr.h>
  95
  96 #ifndef LOCK_PREFIX
  97 # ifdef UP
  98 #  define LOCK_PREFIX   /* nothing */
  99 # else
 100 #  define LOCK_PREFIX   "lock;"
 101 # endif
 102 #endif
 103
 104 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
 105    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
 106    struct pthread even when not linked with -lpthread.  */
 107 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
 108
 109 /* Alignment requirements for the initial TCB.  */
 110 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
 111
 112 /* This is the size of the TCB.  */
 113 # define TLS_TCB_SIZE sizeof (struct pthread)
 114
 115 /* Alignment requirements for the TCB.  */
 116 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
 117
 118 /* The TCB can have any size and the memory following the address the
 119    thread pointer points to is unspecified.  Allocate the TCB there.  */
 120 # define TLS_TCB_AT_TP  1
 121
 122
 123 /* Install the dtv pointer.  The pointer passed is to the element with
 124    index -1 which contain the length.  */
 125 # define INSTALL_DTV(descr, dtvp) \
 126   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 127
 128 /* Install new dtv for current thread.  */
 129 # define INSTALL_NEW_DTV(dtvp) \
 130   ({ struct pthread *__pd;                                                    \
 131      THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
 132
 133 /* Return dtv of given thread descriptor.  */
 134 # define GET_DTV(descr) \
 135   (((tcbhead_t *) (descr))->dtv)
 136
 137
 138 /* Code to initially initialize the thread pointer.  This might need
 139    special attention since 'errno' is not yet available and if the
 140    operation can cause a failure 'errno' must not be touched.
 141
 142    We have to make the syscall for both uses of the macro since the
 143    address might be (and probably is) different.  */
 144 # define TLS_INIT_TP(thrdescr, secondcall) \
 145   ({ void *_thrdescr = (thrdescr);                                            \
 146      tcbhead_t *_head = _thrdescr;                                            \
 147      int _result;                                                             \
 148                                                                               \
 149      _head->tcb = _thrdescr;                                                  \
 150      /* For now the thread descriptor is at the same address.  */             \
 151      _head->self = _thrdescr;                                                 \
 152                                                                               \
 153      /* It is a simple syscall to set the %fs value for the thread.  */       \
 154      asm volatile ("syscall"                                                  \
 155                    : "=a" (_result)                                           \
 156                    : "0" ((unsigned long int) __NR_arch_prctl),               \
 157                      "D" ((unsigned long int) ARCH_SET_FS),                   \
 158                      "S" (_thrdescr)                                          \
 159                    : "memory", "cc", "r11", "cx");                            \
 160                                                                               \
 161     _result ? "cannot set %fs base address for thread-local storage" : 0;     \
 162   })
 163
 164
 165 /* Return the address of the dtv for the current thread.  */
 166 # define THREAD_DTV() \
 167   ({ struct pthread *__pd;                                                    \
 168      THREAD_GETMEM (__pd, header.dtv); })
 169
 170
 171 /* Return the thread descriptor for the current thread.
 172
 173    The contained asm must *not* be marked volatile since otherwise
 174    assignments like
 175         pthread_descr self = thread_self();
 176    do not get optimized away.  */
 177 # define THREAD_SELF \
 178   ({ struct pthread *__self;                                                  \
 179      asm ("mov %%fs:%c1,%0" : "=r" (__self)                                   \
 180           : "i" (offsetof (struct pthread, header.self)));                    \
 181      __self;})
 182
 183 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 184 # define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */
 185 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
 186
 187 /* Read member of the thread descriptor directly.  */
 188 # define THREAD_GETMEM(descr, member) \
 189   ({ __typeof (descr->member) __value;                                        \
 190      if (sizeof (__value) == 1)                                               \
 191        asm volatile ("movb %%fs:%P2,%b0"                                      \
 192                      : "=q" (__value)                                         \
 193                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
 194      else if (sizeof (__value) == 4)                                          \
 195        asm volatile ("movl %%fs:%P1,%0"                                       \
 196                      : "=r" (__value)                                         \
 197                      : "i" (offsetof (struct pthread, member)));              \
 198      else                                                                     \
 199        {                                                                      \
 200          if (sizeof (__value) != 8)                                           \
 201            /* There should not be any value with a size other than 1,         \
 202               4 or 8.  */                                                     \
 203            abort ();                                                          \
 204                                                                               \
 205          asm volatile ("movq %%fs:%P1,%q0"                                    \
 206                        : "=r" (__value)                                       \
 207                        : "i" (offsetof (struct pthread, member)));            \
 208        }                                                                      \
 209      __value; })
 210
 211
 212 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 213 # define THREAD_GETMEM_NC(descr, member, idx) \
 214   ({ __typeof (descr->member[0]) __value;                                     \
 215      if (sizeof (__value) == 1)                                               \
 216        asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
 217                      : "=q" (__value)                                         \
 218                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
 219                        "r" (idx));                                            \
 220      else if (sizeof (__value) == 4)                                          \
 221        asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
 222                      : "=r" (__value)                                         \
 223                      : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
 224      else                                                                     \
 225        {                                                                      \
 226          if (sizeof (__value) != 8)                                           \
 227            /* There should not be any value with a size other than 1,         \
 228               4 or 8.  */                                                     \
 229            abort ();                                                          \
 230                                                                               \
 231          asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                            \
 232                        : "=r" (__value)                                       \
 233                        : "i" (offsetof (struct pthread, member[0])),          \
 234                          "r" (idx));                                          \
 235        }                                                                      \
 236      __value; })
 237
 238
 239 /* Loading addresses of objects on x86-64 needs to be treated special
 240    when generating PIC code.  */
 241 #ifdef __pic__
 242 # define IMM_MODE "nr"
 243 #else
 244 # define IMM_MODE "ir"
 245 #endif
 246
 247
 248 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 249 # define THREAD_SETMEM(descr, member, value) \
 250   ({ if (sizeof (descr->member) == 1)                                         \
 251        asm volatile ("movb %b0,%%fs:%P1" :                                    \
 252                      : "iq" (value),                                          \
 253                        "i" (offsetof (struct pthread, member)));              \
 254      else if (sizeof (descr->member) == 4)                                    \
 255        asm volatile ("movl %0,%%fs:%P1" :                                     \
 256                      : IMM_MODE (value),                                      \
 257                        "i" (offsetof (struct pthread, member)));              \
 258      else                                                                     \
 259        {                                                                      \
 260          if (sizeof (descr->member) != 8)                                     \
 261            /* There should not be any value with a size other than 1,         \
 262               4 or 8.  */                                                     \
 263            abort ();                                                          \
 264                                                                               \
 265          asm volatile ("movq %q0,%%fs:%P1" :                                  \
 266                        : IMM_MODE ((uint64_t) (value)),                       \
 267                          "i" (offsetof (struct pthread, member)));            \
 268        }})
 269
 270
 271 /* Set member of the thread descriptor directly.  */
 272 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 273   ({ if (sizeof (descr->member[0]) == 1)                                      \
 274        asm volatile ("movb %b0,%%fs:%P1(%q2)" :                               \
 275                      : "iq" (value),                                          \
 276                        "i" (offsetof (struct pthread, member[0])),            \
 277                        "r" (idx));                                            \
 278      else if (sizeof (descr->member[0]) == 4)                                 \
 279        asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :                             \
 280                      : IMM_MODE (value),                                      \
 281                        "i" (offsetof (struct pthread, member[0])),            \
 282                        "r" (idx));                                            \
 283      else                                                                     \
 284        {                                                                      \
 285          if (sizeof (descr->member[0]) != 8)                                  \
 286            /* There should not be any value with a size other than 1,         \
 287               4 or 8.  */                                                     \
 288            abort ();                                                          \
 289                                                                               \
 290          asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :                          \
 291                        : IMM_MODE ((uint64_t) (value)),                       \
 292                          "i" (offsetof (struct pthread, member[0])),          \
 293                          "r" (idx));                                          \
 294        }})
 295
 296
 297 /* Atomic compare and exchange on TLS, returning old value.  */
 298 # define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 299   ({ __typeof (descr->member) __ret;                                          \
 300      __typeof (oldval) __old = (oldval);                                      \
 301      if (sizeof (descr->member) == 4)                                         \
 302        asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"                      \
 303                      : "=a" (__ret)                                           \
 304                      : "0" (__old), "r" (newval),                             \
 305                        "i" (offsetof (struct pthread, member)));              \
 306      else                                                                     \
 307        /* Not necessary for other sizes in the moment.  */                    \
 308        abort ();                                                              \
 309      __ret; })
 310
 311
 312 /* Atomic logical and.  */
 313 # define THREAD_ATOMIC_AND(descr, member, val) \
 314   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 315               asm volatile (LOCK_PREFIX "andl %1, %%fs:%P0"                   \
 316                             :: "i" (offsetof (struct pthread, member)),       \
 317                                "ir" (val));                                   \
 318             else                                                              \
 319               /* Not necessary for other sizes in the moment.  */             \
 320               abort (); })
 321
 322
 323 /* Atomic set bit.  */
 324 # define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 325   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 326               asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"                    \
 327                             :: "i" (offsetof (struct pthread, member)),       \
 328                                "ir" (1 << (bit)));                            \
 329             else                                                              \
 330               /* Not necessary for other sizes in the moment.  */             \
 331               abort (); })
 332
 333
 334 # define CALL_THREAD_FCT(descr) \
 335   ({ void *__res;                                                             \
 336      asm volatile ("movq %%fs:%P2, %%rdi\n\t"                                 \
 337                    "callq *%%fs:%P1"                                          \
 338                    : "=a" (__res)                                             \
 339                    : "i" (offsetof (struct pthread, start_routine)),          \
 340                      "i" (offsetof (struct pthread, arg))                     \
 341                    : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11",        \
 342                      "memory", "cc");                                         \
 343      __res; })
 344
 345
 346 /* Set the stack guard field in TCB head.  */
 347 # define THREAD_SET_STACK_GUARD(value) \
 348     THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
 349 # define THREAD_COPY_STACK_GUARD(descr) \
 350     ((descr)->header.stack_guard                                              \
 351      = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 352
 353
 354 /* Set the pointer guard field in the TCB head.  */
 355 # define THREAD_SET_POINTER_GUARD(value) \
 356   THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
 357 # define THREAD_COPY_POINTER_GUARD(descr) \
 358   ((descr)->header.pointer_guard                                              \
 359    = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
 360
 361
 362 /* Get and set the global scope generation counter in the TCB head.  */
 363 # define THREAD_GSCOPE_FLAG_UNUSED 0
 364 # define THREAD_GSCOPE_FLAG_USED   1
 365 # define THREAD_GSCOPE_FLAG_WAIT   2
 366 # define THREAD_GSCOPE_RESET_FLAG() \
 367   do                                                                          \
 368     { int __res;                                                              \
 369       asm volatile ("xchgl %0, %%fs:%P1"                                      \
 370                     : "=r" (__res)                                            \
 371                     : "i" (offsetof (struct pthread, header.gscope_flag)),    \
 372                       "0" (THREAD_GSCOPE_FLAG_UNUSED));                       \
 373       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 374         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
 375     }                                                                         \
 376   while (0)
 377 # define THREAD_GSCOPE_SET_FLAG() \
 378   THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
 379 # define THREAD_GSCOPE_WAIT() \
 380   GL(dl_wait_lookup_done) ()
 381
 382
 383 # ifdef SHARED
 384 /* Defined in dl-trampoline.S.  */
 385 extern void _dl_x86_64_save_sse (void);
 386 extern void _dl_x86_64_restore_sse (void);
 387
 388 # define RTLD_CHECK_FOREIGN_CALL \
 389   (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) != 0)
 390
 391 /* NB: Don't use the xchg operation because that would imply a lock
 392    prefix which is expensive and unnecessary.  The cache line is also
 393    not contested at all.  */
 394 #  define RTLD_ENABLE_FOREIGN_CALL \
 395   int old_rtld_must_xmm_save = THREAD_GETMEM (THREAD_SELF,                    \
 396                                               header.rtld_must_xmm_save);     \
 397   THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 1)
 398
 399 #  define RTLD_PREPARE_FOREIGN_CALL \
 400   do if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save))              \
 401     {                                                                         \
 402       _dl_x86_64_save_sse ();                                                 \
 403       THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 0);              \
 404     }                                                                         \
 405   while (0)
 406
 407 #  define RTLD_FINALIZE_FOREIGN_CALL \
 408   do {                                                                        \
 409     if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) == 0)          \
 410       _dl_x86_64_restore_sse ();                                              \
 411     THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save,                    \
 412                    old_rtld_must_xmm_save);                                   \
 413   } while (0)
 414 # endif
 415
 416
 417 #endif /* __ASSEMBLER__ */
 418
 419 #endif  /* tls.h */