tls.h 4.1 KB

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  1. /* Definitions for thread-local data handling. linuxthreads/x86-64 version.
  2. Copyright (C) 2002, 2005 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, write to the Free
  14. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  15. 02111-1307 USA. */
  16. #ifndef _TLS_H
  17. #define _TLS_H
  18. #ifndef __ASSEMBLER__
  19. # include <pt-machine.h>
  20. # include <stdbool.h>
  21. # include <stddef.h>
  22. /* Type for the dtv. */
  23. typedef union dtv
  24. {
  25. size_t counter;
  26. struct
  27. {
  28. void *val;
  29. bool is_static;
  30. } pointer;
  31. } dtv_t;
  32. typedef struct
  33. {
  34. void *tcb; /* Pointer to the TCB. Not necessary the
  35. thread descriptor used by libpthread. */
  36. dtv_t *dtv;
  37. void *self; /* Pointer to the thread descriptor. */
  38. int multiple_threads;
  39. } tcbhead_t;
  40. #else /* __ASSEMBLER__ */
  41. # include <tcb-offsets.h>
  42. #endif
  43. #ifdef HAVE_TLS_SUPPORT
  44. /* Signal that TLS support is available. */
  45. # define USE_TLS 1
  46. # ifndef __ASSEMBLER__
  47. /* Get system call information. */
  48. # include <sysdep.h>
  49. /* Get the thread descriptor definition. */
  50. # include <linuxthreads/descr.h>
  51. /* This is the size of the initial TCB. */
  52. # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
  53. /* Alignment requirements for the initial TCB. */
  54. # define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
  55. /* This is the size of the TCB. */
  56. # define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct)
  57. /* Alignment requirements for the TCB. */
  58. # define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
  59. /* The TCB can have any size and the memory following the address the
  60. thread pointer points to is unspecified. Allocate the TCB there. */
  61. # define TLS_TCB_AT_TP 1
  62. /* Install the dtv pointer. The pointer passed is to the element with
  63. index -1 which contain the length. */
  64. # define INSTALL_DTV(descr, dtvp) \
  65. ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
  66. /* Install new dtv for current thread. */
  67. # define INSTALL_NEW_DTV(dtv) \
  68. ({ struct _pthread_descr_struct *__descr; \
  69. THREAD_SETMEM (__descr, p_header.data.dtvp, (dtv)); })
  70. /* Return dtv of given thread descriptor. */
  71. # define GET_DTV(descr) \
  72. (((tcbhead_t *) (descr))->dtv)
  73. /* Code to initially initialize the thread pointer. This might need
  74. special attention since 'errno' is not yet available and if the
  75. operation can cause a failure 'errno' must not be touched. */
  76. # define TLS_INIT_TP(descr, secondcall) \
  77. ({ \
  78. void *_descr = (descr); \
  79. tcbhead_t *head = _descr; \
  80. long int _result; \
  81. \
  82. head->tcb = _descr; \
  83. /* For now the thread descriptor is at the same address. */ \
  84. head->self = _descr; \
  85. \
  86. __asm__ __volatile__ ("syscall" \
  87. : "=a" (_result) \
  88. : "0" ((unsigned long int) __NR_arch_prctl), \
  89. "D" ((unsigned long int) ARCH_SET_FS), \
  90. "S" (_descr) \
  91. : "memory", "cc", "r11", "cx"); \
  92. \
  93. _result ? "cannot set %fs base address for thread-local storage" : 0; \
  94. })
  95. /* Indicate that dynamic linker shouldn't try to initialize TLS even
  96. when no PT_TLS segments are found in the program and libraries
  97. it is linked against. */
  98. # define TLS_INIT_TP_EXPENSIVE 1
  99. /* Return the address of the dtv for the current thread. */
  100. # define THREAD_DTV() \
  101. ({ struct _pthread_descr_struct *__descr; \
  102. THREAD_GETMEM (__descr, p_header.data.dtvp); })
  103. # endif /* HAVE_TLS_SUPPORT */
  104. #endif /* __ASSEMBLER__ */
  105. #endif /* tls.h */