nptl/sysdeps/x86_64/tls.h

   1 /* Definition for thread-local data handling.  nptl/x86_64 version.
   2    Copyright (C) 2002-2013 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 <libc-internal.h>
  30 # include <kernel-features.h>
  31
  32 /* Replacement type for __m128 since this file is included by ld.so,
  33    which is compiled with -mno-sse.  It must not change the alignment
  34    of rtld_savespace_sse.  */
  35 typedef struct
  36 {
  37   int i[4];
  38 } __128bits;
  39
  40
  41 /* Type for the dtv.  */
  42 typedef union dtv
  43 {
  44   size_t counter;
  45   struct
  46   {
  47     void *val;
  48     bool is_static;
  49   } pointer;
  50 } dtv_t;
  51
  52
  53 typedef struct
  54 {
  55   void *tcb;            /* Pointer to the TCB.  Not necessarily the
  56                            thread descriptor used by libpthread.  */
  57   dtv_t *dtv;
  58   void *self;           /* Pointer to the thread descriptor.  */
  59   int multiple_threads;
  60   int gscope_flag;
  61   uintptr_t sysinfo;
  62   uintptr_t stack_guard;
  63   uintptr_t pointer_guard;
  64   unsigned long int vgetcpu_cache[2];
  65 # ifndef __ASSUME_PRIVATE_FUTEX
  66   int private_futex;
  67 # else
  68   int __unused1;
  69 # endif
  70   int rtld_must_xmm_save;
  71   /* Reservation of some values for the TM ABI.  */
  72   void *__private_tm[5];
  73   long int __unused2;
  74   /* Have space for the post-AVX register size.  */
  75   __128bits rtld_savespace_sse[8][4] __attribute__ ((aligned (32)));
  76
  77   void *__padding[8];
  78 } tcbhead_t;
  79
  80 #else /* __ASSEMBLER__ */
  81 # include <tcb-offsets.h>
  82 #endif
  83
  84
  85 /* Alignment requirement for the stack.  */
  86 #define STACK_ALIGN     16
  87
  88
  89 #ifndef __ASSEMBLER__
  90 /* Get system call information.  */
  91 # include <sysdep.h>
  92
  93
  94 /* Get the thread descriptor definition.  */
  95 # include <nptl/descr.h>
  96
  97 #ifndef LOCK_PREFIX
  98 # ifdef UP
  99 #  define LOCK_PREFIX   /* nothing */
 100 # else
 101 #  define LOCK_PREFIX   "lock;"
 102 # endif
 103 #endif
 104
 105 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
 106    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
 107    struct pthread even when not linked with -lpthread.  */
 108 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
 109
 110 /* Alignment requirements for the initial TCB.  */
 111 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
 112
 113 /* This is the size of the TCB.  */
 114 # define TLS_TCB_SIZE sizeof (struct pthread)
 115
 116 /* Alignment requirements for the TCB.  */
 117 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
 118
 119 /* The TCB can have any size and the memory following the address the
 120    thread pointer points to is unspecified.  Allocate the TCB there.  */
 121 # define TLS_TCB_AT_TP  1
 122
 123
 124 /* Install the dtv pointer.  The pointer passed is to the element with
 125    index -1 which contain the length.  */
 126 # define INSTALL_DTV(descr, dtvp) \
 127   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 128
 129 /* Install new dtv for current thread.  */
 130 # define INSTALL_NEW_DTV(dtvp) \
 131   ({ struct pthread *__pd;                                                    \
 132      THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
 133
 134 /* Return dtv of given thread descriptor.  */
 135 # define GET_DTV(descr) \
 136   (((tcbhead_t *) (descr))->dtv)
 137
 138
 139 /* Code to initially initialize the thread pointer.  This might need
 140    special attention since 'errno' is not yet available and if the
 141    operation can cause a failure 'errno' must not be touched.
 142
 143    We have to make the syscall for both uses of the macro since the
 144    address might be (and probably is) different.  */
 145 # define TLS_INIT_TP(thrdescr, secondcall) \
 146   ({ void *_thrdescr = (thrdescr);                                            \
 147      tcbhead_t *_head = _thrdescr;                                            \
 148      int _result;                                                             \
 149                                                                               \
 150      _head->tcb = _thrdescr;                                                  \
 151      /* For now the thread descriptor is at the same address.  */             \
 152      _head->self = _thrdescr;                                                 \
 153                                                                               \
 154      /* It is a simple syscall to set the %fs value for the thread.  */       \
 155      asm volatile ("syscall"                                                  \
 156                    : "=a" (_result)                                           \
 157                    : "0" ((unsigned long int) __NR_arch_prctl),               \
 158                      "D" ((unsigned long int) ARCH_SET_FS),                   \
 159                      "S" (_thrdescr)                                          \
 160                    : "memory", "cc", "r11", "cx");                            \
 161                                                                               \
 162     _result ? "cannot set %fs base address for thread-local storage" : 0;     \
 163   })
 164
 165
 166 /* Return the address of the dtv for the current thread.  */
 167 # define THREAD_DTV() \
 168   ({ struct pthread *__pd;                                                    \
 169      THREAD_GETMEM (__pd, header.dtv); })
 170
 171
 172 /* Return the thread descriptor for the current thread.
 173
 174    The contained asm must *not* be marked volatile since otherwise
 175    assignments like
 176         pthread_descr self = thread_self();
 177    do not get optimized away.  */
 178 # define THREAD_SELF \
 179   ({ struct pthread *__self;                                                  \
 180      asm ("mov %%fs:%c1,%0" : "=r" (__self)                                   \
 181           : "i" (offsetof (struct pthread, header.self)));                    \
 182      __self;})
 183
 184 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 185 # define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */
 186 # define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
 187
 188 /* Read member of the thread descriptor directly.  */
 189 # define THREAD_GETMEM(descr, member) \
 190   ({ __typeof (descr->member) __value;                                        \
 191      if (sizeof (__value) == 1)                                               \
 192        asm volatile ("movb %%fs:%P2,%b0"                                      \
 193                      : "=q" (__value)                                         \
 194                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
 195      else if (sizeof (__value) == 4)                                          \
 196        asm volatile ("movl %%fs:%P1,%0"                                       \
 197                      : "=r" (__value)                                         \
 198                      : "i" (offsetof (struct pthread, member)));              \
 199      else                                                                     \
 200        {                                                                      \
 201          if (sizeof (__value) != 8)                                           \
 202            /* There should not be any value with a size other than 1,         \
 203               4 or 8.  */                                                     \
 204            abort ();                                                          \
 205                                                                               \
 206          asm volatile ("movq %%fs:%P1,%q0"                                    \
 207                        : "=r" (__value)                                       \
 208                        : "i" (offsetof (struct pthread, member)));            \
 209        }                                                                      \
 210      __value; })
 211
 212
 213 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 214 # define THREAD_GETMEM_NC(descr, member, idx) \
 215   ({ __typeof (descr->member[0]) __value;                                     \
 216      if (sizeof (__value) == 1)                                               \
 217        asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
 218                      : "=q" (__value)                                         \
 219                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
 220                        "r" (idx));                                            \
 221      else if (sizeof (__value) == 4)                                          \
 222        asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
 223                      : "=r" (__value)                                         \
 224                      : "i" (offsetof (struct pthread, member[0])), "r" (idx));\
 225      else                                                                     \
 226        {                                                                      \
 227          if (sizeof (__value) != 8)                                           \
 228            /* There should not be any value with a size other than 1,         \
 229               4 or 8.  */                                                     \
 230            abort ();                                                          \
 231                                                                               \
 232          asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                            \
 233                        : "=r" (__value)                                       \
 234                        : "i" (offsetof (struct pthread, member[0])),          \
 235                          "r" (idx));                                          \
 236        }                                                                      \
 237      __value; })
 238
 239
 240 /* Loading addresses of objects on x86-64 needs to be treated special
 241    when generating PIC code.  */
 242 #ifdef __pic__
 243 # define IMM_MODE "nr"
 244 #else
 245 # define IMM_MODE "ir"
 246 #endif
 247
 248
 249 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 250 # define THREAD_SETMEM(descr, member, value) \
 251   ({ if (sizeof (descr->member) == 1)                                         \
 252        asm volatile ("movb %b0,%%fs:%P1" :                                    \
 253                      : "iq" (value),                                          \
 254                        "i" (offsetof (struct pthread, member)));              \
 255      else if (sizeof (descr->member) == 4)                                    \
 256        asm volatile ("movl %0,%%fs:%P1" :                                     \
 257                      : IMM_MODE (value),                                      \
 258                        "i" (offsetof (struct pthread, member)));              \
 259      else                                                                     \
 260        {                                                                      \
 261          if (sizeof (descr->member) != 8)                                     \
 262            /* There should not be any value with a size other than 1,         \
 263               4 or 8.  */                                                     \
 264            abort ();                                                          \
 265                                                                               \
 266          asm volatile ("movq %q0,%%fs:%P1" :                                  \
 267                        : IMM_MODE ((uint64_t) cast_to_integer (value)),       \
 268                          "i" (offsetof (struct pthread, member)));            \
 269        }})
 270
 271
 272 /* Set member of the thread descriptor directly.  */
 273 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 274   ({ if (sizeof (descr->member[0]) == 1)                                      \
 275        asm volatile ("movb %b0,%%fs:%P1(%q2)" :                               \
 276                      : "iq" (value),                                          \
 277                        "i" (offsetof (struct pthread, member[0])),            \
 278                        "r" (idx));                                            \
 279      else if (sizeof (descr->member[0]) == 4)                                 \
 280        asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :                             \
 281                      : IMM_MODE (value),                                      \
 282                        "i" (offsetof (struct pthread, member[0])),            \
 283                        "r" (idx));                                            \
 284      else                                                                     \
 285        {                                                                      \
 286          if (sizeof (descr->member[0]) != 8)                                  \
 287            /* There should not be any value with a size other than 1,         \
 288               4 or 8.  */                                                     \
 289            abort ();                                                          \
 290                                                                               \
 291          asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :                          \
 292                        : IMM_MODE ((uint64_t) cast_to_integer (value)),       \
 293                          "i" (offsetof (struct pthread, member[0])),          \
 294                          "r" (idx));                                          \
 295        }})
 296
 297
 298 /* Atomic compare and exchange on TLS, returning old value.  */
 299 # define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 300   ({ __typeof (descr->member) __ret;                                          \
 301      __typeof (oldval) __old = (oldval);                                      \
 302      if (sizeof (descr->member) == 4)                                         \
 303        asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"                      \
 304                      : "=a" (__ret)                                           \
 305                      : "0" (__old), "r" (newval),                             \
 306                        "i" (offsetof (struct pthread, member)));              \
 307      else                                                                     \
 308        /* Not necessary for other sizes in the moment.  */                    \
 309        abort ();                                                              \
 310      __ret; })
 311
 312
 313 /* Atomic logical and.  */
 314 # define THREAD_ATOMIC_AND(descr, member, val) \
 315   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 316               asm volatile (LOCK_PREFIX "andl %1, %%fs:%P0"                   \
 317                             :: "i" (offsetof (struct pthread, member)),       \
 318                                "ir" (val));                                   \
 319             else                                                              \
 320               /* Not necessary for other sizes in the moment.  */             \
 321               abort (); })
 322
 323
 324 /* Atomic set bit.  */
 325 # define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 326   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 327               asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"                    \
 328                             :: "i" (offsetof (struct pthread, member)),       \
 329                                "ir" (1 << (bit)));                            \
 330             else                                                              \
 331               /* Not necessary for other sizes in the moment.  */             \
 332               abort (); })
 333
 334
 335 # define CALL_THREAD_FCT(descr) \
 336   ({ void *__res;                                                             \
 337      asm volatile ("movq %%fs:%P2, %%rdi\n\t"                                 \
 338                    "callq *%%fs:%P1"                                          \
 339                    : "=a" (__res)                                             \
 340                    : "i" (offsetof (struct pthread, start_routine)),          \
 341                      "i" (offsetof (struct pthread, arg))                     \
 342                    : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11",        \
 343                      "memory", "cc");                                         \
 344      __res; })
 345
 346
 347 /* Set the stack guard field in TCB head.  */
 348 # define THREAD_SET_STACK_GUARD(value) \
 349     THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
 350 # define THREAD_COPY_STACK_GUARD(descr) \
 351     ((descr)->header.stack_guard                                              \
 352      = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 353
 354
 355 /* Set the pointer guard field in the TCB head.  */
 356 # define THREAD_SET_POINTER_GUARD(value) \
 357   THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
 358 # define THREAD_COPY_POINTER_GUARD(descr) \
 359   ((descr)->header.pointer_guard                                              \
 360    = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
 361
 362
 363 /* Get and set the global scope generation counter in the TCB head.  */
 364 # define THREAD_GSCOPE_FLAG_UNUSED 0
 365 # define THREAD_GSCOPE_FLAG_USED   1
 366 # define THREAD_GSCOPE_FLAG_WAIT   2
 367 # define THREAD_GSCOPE_RESET_FLAG() \
 368   do                                                                          \
 369     { int __res;                                                              \
 370       asm volatile ("xchgl %0, %%fs:%P1"                                      \
 371                     : "=r" (__res)                                            \
 372                     : "i" (offsetof (struct pthread, header.gscope_flag)),    \
 373                       "0" (THREAD_GSCOPE_FLAG_UNUSED));                       \
 374       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 375         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
 376     }                                                                         \
 377   while (0)
 378 # define THREAD_GSCOPE_SET_FLAG() \
 379   THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
 380 # define THREAD_GSCOPE_WAIT() \
 381   GL(dl_wait_lookup_done) ()
 382
 383
 384 # ifdef SHARED
 385 /* Defined in dl-trampoline.S.  */
 386 extern void _dl_x86_64_save_sse (void);
 387 extern void _dl_x86_64_restore_sse (void);
 388
 389 # define RTLD_CHECK_FOREIGN_CALL \
 390   (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) != 0)
 391
 392 /* NB: Don't use the xchg operation because that would imply a lock
 393    prefix which is expensive and unnecessary.  The cache line is also
 394    not contested at all.  */
 395 #  define RTLD_ENABLE_FOREIGN_CALL \
 396   int old_rtld_must_xmm_save = THREAD_GETMEM (THREAD_SELF,                    \
 397                                               header.rtld_must_xmm_save);     \
 398   THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 1)
 399
 400 #  define RTLD_PREPARE_FOREIGN_CALL \
 401   do if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save))              \
 402     {                                                                         \
 403       _dl_x86_64_save_sse ();                                                 \
 404       THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 0);              \
 405     }                                                                         \
 406   while (0)
 407
 408 #  define RTLD_FINALIZE_FOREIGN_CALL \
 409   do {                                                                        \
 410     if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) == 0)          \
 411       _dl_x86_64_restore_sse ();                                              \
 412     THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save,                    \
 413                    old_rtld_must_xmm_save);                                   \
 414   } while (0)
 415 # endif
 416
 417
 418 #endif /* __ASSEMBLER__ */
 419
 420 #endif  /* tls.h */