l4/pkg/uclibc/lib/libpthread/src/sysdeps/i386/tls.h

   1 /* Definition for thread-local data handling.  nptl/i386 version.
   2    Copyright (C) 2002-2007, 2009 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 <stdbool.h>
  25 # include <stddef.h>
  26 # include <stdint.h>
  27 # include <stdlib.h>
  28 //# include <sysdep.h>
  29 # include <bits/kernel-features.h>
  30
  31
  32 /* Type for the dtv.  */
  33 typedef union dtv
  34 {
  35   size_t counter;
  36   struct
  37   {
  38     void *val;
  39     bool is_static;
  40   } pointer;
  41 } dtv_t;
  42
  43
  44 typedef struct
  45 {
  46   void *tcb;            /* Pointer to the TCB.  Not necessarily the
  47                            thread descriptor used by libpthread.  */
  48   dtv_t *dtv;
  49   void *self;           /* Pointer to the thread descriptor.  */
  50   int multiple_threads;
  51   uintptr_t sysinfo;
  52   uintptr_t stack_guard;
  53   uintptr_t pointer_guard;
  54   int gscope_flag;
  55 #ifndef __ASSUME_PRIVATE_FUTEX
  56   int private_futex;
  57 #else
  58   int __unused1;
  59 #endif
  60   /* Reservation of some values for the TM ABI.  */
  61   void *__private_tm[5];
  62 } tcbhead_t;
  63
  64 # define TLS_MULTIPLE_THREADS_IN_TCB 1
  65
  66 #else /* __ASSEMBLER__ */
  67 # include <tcb-offsets.h>
  68 #endif
  69
  70
  71 /* We require TLS support in the tools.  */
  72 #define HAVE_TLS_SUPPORT
  73 #define HAVE___THREAD 1
  74 #define HAVE_TLS_MODEL_ATTRIBUTE 1
  75
  76 /* Signal that TLS support is available.  */
  77 #define USE_TLS        1
  78
  79
  80 /* Alignment requirement for the stack.  For IA-32 this is governed by
  81    the SSE memory functions.  */
  82 #define STACK_ALIGN     16
  83
  84 #ifndef __ASSEMBLER__
  85 /* Get system call information.  */
  86 //# include <sysdep.h>
  87
  88 /* The old way: using LDT.  */
  89
  90 struct x86_descr {
  91     union {
  92         struct {
  93             unsigned int a;
  94             unsigned int b;
  95         };
  96         struct {
  97             uint16_t limit0;
  98             uint16_t base0;
  99             unsigned base1: 8, type: 4, s: 1, dpl: 2, p: 1;
 100             unsigned limit: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
 101         };
 102     };
 103 } __attribute__((packed));
 104
 105
 106
 107 /* Get the thread descriptor definition.  */
 108 # include <descr.h>
 109 # include <l4/sys/utcb.h>
 110 # include <l4/sys/segment.h>
 111
 112 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
 113    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
 114    struct pthread even when not linked with -lpthread.  */
 115 # define TLS_INIT_TCB_SIZE sizeof (struct _pthread_descr_struct)
 116
 117 /* Alignment requirements for the initial TCB.  */
 118 # define TLS_INIT_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
 119
 120 /* This is the size of the TCB.  */
 121 # define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct)
 122
 123 /* Alignment requirements for the TCB.  */
 124 # define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
 125
 126 /* The TCB can have any size and the memory following the address the
 127    thread pointer points to is unspecified.  Allocate the TCB there.  */
 128 # define TLS_TCB_AT_TP  1
 129
 130
 131 /* Install the dtv pointer.  The pointer passed is to the element with
 132    index -1 which contain the length.  */
 133 # define INSTALL_DTV(descr, dtvp) \
 134   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 135
 136 /* Install new dtv for current thread.  */
 137 # define INSTALL_NEW_DTV(dtvpx) \
 138   ({ struct _pthread_descr_struct *__pd;                                                      \
 139      THREAD_SETMEM (__pd, p_header.data.dtvp, (dtvpx)); })
 140
 141 /* Return dtv of given thread descriptor.  */
 142 # define GET_DTV(descr) \
 143   (((tcbhead_t *) (descr))->dtv)
 144
 145 #define THREAD_SELF_SYSINFO     THREAD_GETMEM (THREAD_SELF, header.sysinfo)
 146 #define THREAD_SYSINFO(pd)      ((pd)->header.sysinfo)
 147
 148 /* Macros to load from and store into segment registers.  */
 149 # ifndef TLS_GET_GS
 150 #  define TLS_GET_GS() \
 151   ({ int __seg; __asm__ ("movw %%gs, %w0" : "=q" (__seg)); __seg & 0xffff; })
 152 # endif
 153 # ifndef TLS_SET_GS
 154 #  define TLS_SET_GS(val) \
 155   __asm__ ("movw %w0, %%gs" :: "q" (val))
 156 # endif
 157
 158
 159 # ifndef __NR_set_thread_area
 160 #  define __NR_set_thread_area 243
 161 # endif
 162 # ifndef TLS_FLAG_WRITABLE
 163 #  define TLS_FLAG_WRITABLE             0x00000001
 164 # endif
 165
 166 // XXX Enable for the real world.
 167 #if 0
 168 # ifndef __ASSUME_SET_THREAD_AREA
 169 #  error "we need set_thread_area"
 170 # endif
 171 #endif
 172
 173 # ifdef __PIC__
 174 #  define TLS_EBX_ARG "r"
 175 #  define TLS_LOAD_EBX "xchgl %3, %%ebx\n\t"
 176 # else
 177 #  define TLS_EBX_ARG "b"
 178 #  define TLS_LOAD_EBX
 179 # endif
 180
 181 #if defined NEED_DL_SYSINFO
 182 # define INIT_SYSINFO \
 183   _head->sysinfo = GLRO(dl_sysinfo)
 184 #else
 185 # define INIT_SYSINFO
 186 #endif
 187
 188 #ifndef LOCK_PREFIX
 189 # ifdef UP
 190 #  define LOCK_PREFIX  /* nothing */
 191 # else
 192 #  define LOCK_PREFIX "lock;"
 193 # endif
 194 #endif
 195
 196 static inline char const *TLS_INIT_TP(void *thrdescr, int secondcall)
 197 {
 198   (void)secondcall;
 199   tcbhead_t *_head = (tcbhead_t *)thrdescr;
 200   struct x86_descr segdesc;
 201   long seg;
 202
 203   _head->tcb = thrdescr;
 204   _head->self = thrdescr;
 205   INIT_SYSINFO;
 206   segdesc.limit0 = 0xffff;
 207   segdesc.base0 = ((unsigned long)thrdescr) & 0x0ffff;
 208   segdesc.base1 = (((unsigned long)thrdescr) & 0x0ff0000) >> 16;
 209   segdesc.type = 2;
 210   segdesc.s = 1;
 211   segdesc.dpl = 3;
 212   segdesc.p = 1;
 213   segdesc.limit = 0xf;
 214   segdesc.avl = 1;
 215   segdesc.d = 1; // 32bit
 216   segdesc.g = 1; // pages
 217   segdesc.base2 = (((unsigned long)thrdescr) & 0xff000000) >> 24;
 218   segdesc.l = 0;
 219   seg = fiasco_gdt_set(L4_INVALID_CAP, &segdesc, 8, 0, l4_utcb());
 220   if (seg < 0)
 221     return "ERROR";
 222
 223   TLS_SET_GS(seg);
 224
 225   return NULL;
 226 }
 227 #if 0
 228 /* Code to initially initialize the thread pointer.  This might need
 229    special attention since 'errno' is not yet available and if the
 230    operation can cause a failure 'errno' must not be touched.  */
 231 # define TLS_INIT_TP(thrdescr, secondcall) \
 232   ({ void *_thrdescr = (thrdescr);                                            \
 233      tcbhead_t *_head = _thrdescr;                                            \
 234      union user_desc_init _segdescr;                                          \
 235      int _result;                                                             \
 236                                                                               \
 237      _head->tcb = _thrdescr;                                                  \
 238      /* For now the thread descriptor is at the same address.  */             \
 239      _head->self = _thrdescr;                                                 \
 240      /* New syscall handling support.  */                                     \
 241      INIT_SYSINFO;                                                            \
 242                                                                               \
 243      /* The 'entry_number' field.  Let the kernel pick a value.  */           \
 244      if (secondcall)                                                          \
 245        _segdescr.vals[0] = TLS_GET_GS () >> 3;                                \
 246      else                                                                     \
 247        _segdescr.vals[0] = -1;                                                \
 248      /* The 'base_addr' field.  Pointer to the TCB.  */                       \
 249      _segdescr.vals[1] = (unsigned long int) _thrdescr;                       \
 250      /* The 'limit' field.  We use 4GB which is 0xfffff pages.  */            \
 251      _segdescr.vals[2] = 0xfffff;                                             \
 252      /* Collapsed value of the bitfield:                                      \
 253           .seg_32bit = 1                                                      \
 254           .contents = 0                                                       \
 255           .read_exec_only = 0                                                 \
 256           .limit_in_pages = 1                                                 \
 257           .seg_not_present = 0                                                \
 258           .useable = 1 */                                                     \
 259      _segdescr.vals[3] = 0x51;                                                \
 260                                                                               \
 261      /* Install the TLS.  */                                                  \
 262      __asm__ __volatile__ (TLS_LOAD_EBX                                           \
 263                    "int $0x80\n\t"                                            \
 264                    TLS_LOAD_EBX                                               \
 265                    : "=a" (_result), "=m" (_segdescr.desc.entry_number)       \
 266                    : "0" (__NR_set_thread_area),                              \
 267                      TLS_EBX_ARG (&_segdescr.desc), "m" (_segdescr.desc));    \
 268                                                                               \
 269      if (_result == 0)                                                        \
 270        /* We know the index in the GDT, now load the segment register.        \
 271           The use of the GDT is described by the value 3 in the lower         \
 272           three bits of the segment descriptor value.                         \
 273                                                                               \
 274           Note that we have to do this even if the numeric value of           \
 275           the descriptor does not change.  Loading the segment register       \
 276           causes the segment information from the GDT to be loaded            \
 277           which is necessary since we have changed it.   */                   \
 278        TLS_SET_GS (_segdescr.desc.entry_number * 8 + 3);                      \
 279                                                                               \
 280      _result == 0 ? NULL                                                      \
 281      : "set_thread_area failed when setting up thread-local storage\n"; })
 282
 283 #endif
 284 /* Return the address of the dtv for the current thread.  */
 285 # define THREAD_DTV() \
 286   ({ struct _pthread_descr_struct *__pd;                                                      \
 287      THREAD_GETMEM (__pd, p_header.data.dtvp); })
 288
 289
 290 /* Return the thread descriptor for the current thread.
 291
 292    The contained asm must *not* be marked __volatile__ since otherwise
 293    assignments like
 294         pthread_descr self = thread_self();
 295    do not get optimized away.  */
 296 # define THREAD_SELF \
 297   ({ struct _pthread_descr_struct *__self;                                                    \
 298      __asm__ ("movl %%gs:%c1,%0" : "=r" (__self)                                    \
 299           : "i" (offsetof (struct _pthread_descr_struct, p_header.data.self)));               \
 300      __self;})
 301
 302 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 303 # define DB_THREAD_SELF \
 304   REGISTER_THREAD_AREA (32, offsetof (struct user_regs_struct, xgs), 3) \
 305   REGISTER_THREAD_AREA (64, 26 * 8, 3) /* x86-64's user_regs_struct->gs */
 306
 307
 308 /* Read member of the thread descriptor directly.  */
 309 # define THREAD_GETMEM(descr, member) \
 310   ({ __typeof (descr->member) __value;                                        \
 311      if (sizeof (__value) == 1)                                               \
 312        __asm__ __volatile__ ("movb %%gs:%P2,%b0"                                    \
 313                      : "=q" (__value)                                         \
 314                      : "0" (0), "i" (offsetof (struct _pthread_descr_struct, member)));     \
 315      else if (sizeof (__value) == 4)                                          \
 316        __asm__ __volatile__ ("movl %%gs:%P1,%0"                                     \
 317                      : "=r" (__value)                                         \
 318                      : "i" (offsetof (struct _pthread_descr_struct, member)));        \
 319      else                                                                     \
 320        {                                                                      \
 321          if (sizeof (__value) != 8)                                           \
 322            /* There should not be any value with a size other than 1,         \
 323               4 or 8.  */                                                     \
 324            abort ();                                                          \
 325                                                                               \
 326          __asm__ __volatile__ ("movl %%gs:%P1,%%eax\n\t"                              \
 327                        "movl %%gs:%P2,%%edx"                                  \
 328                        : "=A" (__value)                                       \
 329                        : "i" (offsetof (struct _pthread_descr_struct, member)),       \
 330                          "i" (offsetof (struct _pthread_descr_struct, member) + 4));          \
 331        }                                                                      \
 332      __value; })
 333
 334
 335 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 336 # define THREAD_GETMEM_NC(descr, member, idx) \
 337   ({ __typeof (descr->member[0]) __value;                                     \
 338      if (sizeof (__value) == 1)                                               \
 339        __asm__ __volatile__ ("movb %%gs:%P2(%3),%b0"                                  \
 340                      : "=q" (__value)                                         \
 341                      : "0" (0), "i" (offsetof (struct _pthread_descr_struct, member[0])),   \
 342                      "r" (idx));                                              \
 343      else if (sizeof (__value) == 4)                                          \
 344        __asm__ __volatile__ ("movl %%gs:%P1(,%2,4),%0"                                \
 345                      : "=r" (__value)                                         \
 346                      : "i" (offsetof (struct _pthread_descr_struct, member[0])),              \
 347                        "r" (idx));                                            \
 348      else                                                                     \
 349        {                                                                      \
 350          if (sizeof (__value) != 8)                                           \
 351            /* There should not be any value with a size other than 1,         \
 352               4 or 8.  */                                                     \
 353            abort ();                                                          \
 354                                                                               \
 355          __asm__ __volatile__  ("movl %%gs:%P1(,%2,8),%%eax\n\t"                      \
 356                         "movl %%gs:4+%P1(,%2,8),%%edx"                        \
 357                         : "=&A" (__value)                                     \
 358                         : "i" (offsetof (struct _pthread_descr_struct, member[0])),           \
 359                           "r" (idx));                                         \
 360        }                                                                      \
 361      __value; })
 362
 363
 364 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 365 # define THREAD_SETMEM(descr, member, value) \
 366   ({ if (sizeof (descr->member) == 1)                                         \
 367        __asm__ __volatile__ ("movb %b0,%%gs:%P1" :                                    \
 368                      : "iq" (value),                                          \
 369                        "i" (offsetof (struct _pthread_descr_struct, member)));        \
 370      else if (sizeof (descr->member) == 4)                                    \
 371        __asm__ __volatile__ ("movl %0,%%gs:%P1" :                                     \
 372                      : "ir" (value),                                          \
 373                        "i" (offsetof (struct _pthread_descr_struct, member)));        \
 374      else                                                                     \
 375        {                                                                      \
 376          if (sizeof (descr->member) != 8)                                     \
 377            /* There should not be any value with a size other than 1,         \
 378               4 or 8.  */                                                     \
 379            abort ();                                                          \
 380                                                                               \
 381          __asm__ __volatile__ ("movl %%eax,%%gs:%P1\n\t"                              \
 382                        "movl %%edx,%%gs:%P2" :                                \
 383                        : "A" (value),                                         \
 384                          "i" (offsetof (struct _pthread_descr_struct, member)),       \
 385                          "i" (offsetof (struct _pthread_descr_struct, member) + 4));          \
 386        }})
 387
 388
 389 /* Set member of the thread descriptor directly.  */
 390 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 391   ({ if (sizeof (descr->member[0]) == 1)                                      \
 392        __asm__ __volatile__ ("movb %b0,%%gs:%P1(%2)" :                                \
 393                      : "iq" (value),                                          \
 394                        "i" (offsetof (struct _pthread_descr_struct, member)),                 \
 395                        "r" (idx));                                            \
 396      else if (sizeof (descr->member[0]) == 4)                                 \
 397        __asm__ __volatile__ ("movl %0,%%gs:%P1(,%2,4)" :                              \
 398                      : "ir" (value),                                          \
 399                        "i" (offsetof (struct _pthread_descr_struct, member)),                 \
 400                        "r" (idx));                                            \
 401      else                                                                     \
 402        {                                                                      \
 403          if (sizeof (descr->member[0]) != 8)                                  \
 404            /* There should not be any value with a size other than 1,         \
 405               4 or 8.  */                                                     \
 406            abort ();                                                          \
 407                                                                               \
 408          __asm__ __volatile__ ("movl %%eax,%%gs:%P1(,%2,8)\n\t"                       \
 409                        "movl %%edx,%%gs:4+%P1(,%2,8)" :                       \
 410                        : "A" (value),                                         \
 411                          "i" (offsetof (struct _pthread_descr_struct, member)),       \
 412                          "r" (idx));                                          \
 413        }})
 414
 415
 416 /* Atomic compare and exchange on TLS, returning old value.  */
 417 #define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
 418   ({ __typeof (descr->member) __ret;                                          \
 419      __typeof (oldval) __old = (oldval);                                      \
 420      if (sizeof (descr->member) == 4)                                         \
 421        __asm__ __volatile__ (LOCK_PREFIX "cmpxchgl %2, %%gs:%P3"                      \
 422                      : "=a" (__ret)                                           \
 423                      : "0" (__old), "r" (newval),                             \
 424                        "i" (offsetof (struct _pthread_descr_struct, member)));        \
 425      else                                                                     \
 426        /* Not necessary for other sizes in the moment.  */                    \
 427        abort ();                                                              \
 428      __ret; })
 429
 430
 431 /* Atomic logical and.  */
 432 #define THREAD_ATOMIC_AND(descr, member, val) \
 433   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 434               __asm__ __volatile__ (LOCK_PREFIX "andl %1, %%gs:%P0"                   \
 435                             :: "i" (offsetof (struct _pthread_descr_struct, member)),         \
 436                                "ir" (val));                                   \
 437             else                                                              \
 438               /* Not necessary for other sizes in the moment.  */             \
 439               abort (); })
 440
 441
 442 /* Atomic set bit.  */
 443 #define THREAD_ATOMIC_BIT_SET(descr, member, bit) \
 444   (void) ({ if (sizeof ((descr)->member) == 4)                                \
 445               __asm__ __volatile__ (LOCK_PREFIX "orl %1, %%gs:%P0"                    \
 446                             :: "i" (offsetof (struct _pthread_descr_struct, member)),         \
 447                                "ir" (1 << (bit)));                            \
 448             else                                                              \
 449               /* Not necessary for other sizes in the moment.  */             \
 450               abort (); })
 451
 452
 453 /* Call the user-provided thread function.  */
 454 #define CALL_THREAD_FCT(descr) \
 455   ({ void *__res;                                                             \
 456      int __ignore1, __ignore2;                                                \
 457      __asm__ __volatile__ ("pushl %%eax\n\t"                                          \
 458                    "pushl %%eax\n\t"                                          \
 459                    "pushl %%eax\n\t"                                          \
 460                    "pushl %%gs:%P4\n\t"                                       \
 461                    "call *%%gs:%P3\n\t"                                       \
 462                    "addl $16, %%esp"                                          \
 463                    : "=a" (__res), "=c" (__ignore1), "=d" (__ignore2)         \
 464                    : "i" (offsetof (struct _pthread_descr_struct, start_routine)),            \
 465                      "i" (offsetof (struct _pthread_descr_struct, arg)));                     \
 466      __res; })
 467
 468
 469 /* Set the stack guard field in TCB head.  */
 470 #define THREAD_SET_STACK_GUARD(value) \
 471   THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
 472 #define THREAD_COPY_STACK_GUARD(descr) \
 473   ((descr)->header.stack_guard                                                \
 474    = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 475
 476
 477 /* Set the pointer guard field in the TCB head.  */
 478 #define THREAD_SET_POINTER_GUARD(value) \
 479   THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
 480 #define THREAD_COPY_POINTER_GUARD(descr) \
 481   ((descr)->header.pointer_guard                                              \
 482    = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
 483
 484
 485 /* Get and set the global scope generation counter in the TCB head.  */
 486 #define THREAD_GSCOPE_FLAG_UNUSED 0
 487 #define THREAD_GSCOPE_FLAG_USED   1
 488 #define THREAD_GSCOPE_FLAG_WAIT   2
 489 #define THREAD_GSCOPE_RESET_FLAG() \
 490   do                                                                          \
 491     { int __res;                                                              \
 492       __asm__ __volatile__ ("xchgl %0, %%gs:%P1"                                      \
 493                     : "=r" (__res)                                            \
 494                     : "i" (offsetof (struct _pthread_descr_struct, header.gscope_flag)),    \
 495                       "0" (THREAD_GSCOPE_FLAG_UNUSED));                       \
 496       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 497         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
 498     }                                                                         \
 499   while (0)
 500 #define THREAD_GSCOPE_SET_FLAG() \
 501   THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
 502 #define THREAD_GSCOPE_WAIT() \
 503   GL(dl_wait_lookup_done) ()
 504
 505 #endif /* __ASSEMBLER__ */
 506
 507 #endif  /* tls.h */