sysdeps/i386/nptl/tcb-access.h

   1 /* THREAD_* accessors.  i386 version.
   2    Copyright (C) 2002-2023 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    <https://www.gnu.org/licenses/>.  */
  18
  19 /* Read member of the thread descriptor directly.  */
  20 #define THREAD_GETMEM(descr, member) \
  21   ({ __typeof (descr->member) __value;                                        \
  22      _Static_assert (sizeof (__value) == 1                                    \
  23                      || sizeof (__value) == 4                                 \
  24                      || sizeof (__value) == 8,                                \
  25                      "size of per-thread data");                              \
  26      if (sizeof (__value) == 1)                                               \
  27        asm volatile ("movb %%gs:%P2,%b0"                                      \
  28                      : "=q" (__value)                                         \
  29                      : "0" (0), "i" (offsetof (struct pthread, member)));     \
  30      else if (sizeof (__value) == 4)                                          \
  31        asm volatile ("movl %%gs:%P1,%0"                                       \
  32                      : "=r" (__value)                                         \
  33                      : "i" (offsetof (struct pthread, member)));              \
  34      else /* 8 */                                                                     \
  35        {                                                                      \
  36          asm volatile ("movl %%gs:%P1,%%eax\n\t"                              \
  37                        "movl %%gs:%P2,%%edx"                                  \
  38                        : "=A" (__value)                                       \
  39                        : "i" (offsetof (struct pthread, member)),             \
  40                          "i" (offsetof (struct pthread, member) + 4));        \
  41        }                                                                      \
  42      __value; })
  43
  44 /* THREAD_GETMEM already forces a read.  */
  45 #define THREAD_GETMEM_VOLATILE(descr, member) THREAD_GETMEM (descr, member)
  46
  47 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
  48 #define THREAD_GETMEM_NC(descr, member, idx) \
  49   ({ __typeof (descr->member[0]) __value;                                     \
  50      _Static_assert (sizeof (__value) == 1                                    \
  51                      || sizeof (__value) == 4                                 \
  52                      || sizeof (__value) == 8,                                \
  53                      "size of per-thread data");                              \
  54      if (sizeof (__value) == 1)                                               \
  55        asm volatile ("movb %%gs:%P2(%3),%b0"                                  \
  56                      : "=q" (__value)                                         \
  57                      : "0" (0), "i" (offsetof (struct pthread, member[0])),   \
  58                      "r" (idx));                                              \
  59      else if (sizeof (__value) == 4)                                          \
  60        asm volatile ("movl %%gs:%P1(,%2,4),%0"                                \
  61                      : "=r" (__value)                                         \
  62                      : "i" (offsetof (struct pthread, member[0])),            \
  63                        "r" (idx));                                            \
  64      else /* 8 */                                                             \
  65        {                                                                      \
  66          asm volatile  ("movl %%gs:%P1(,%2,8),%%eax\n\t"                      \
  67                         "movl %%gs:4+%P1(,%2,8),%%edx"                        \
  68                         : "=&A" (__value)                                     \
  69                         : "i" (offsetof (struct pthread, member[0])),         \
  70                           "r" (idx));                                         \
  71        }                                                                      \
  72      __value; })
  73
  74
  75
  76 /* Set member of the thread descriptor directly.  */
  77 #define THREAD_SETMEM(descr, member, value) \
  78   ({                                                                          \
  79      _Static_assert (sizeof (descr->member) == 1                              \
  80                      || sizeof (descr->member) == 4                           \
  81                      || sizeof (descr->member) == 8,                          \
  82                      "size of per-thread data");                              \
  83      if (sizeof (descr->member) == 1)                                         \
  84        asm volatile ("movb %b0,%%gs:%P1" :                                    \
  85                      : "iq" (value),                                          \
  86                        "i" (offsetof (struct pthread, member)));              \
  87      else if (sizeof (descr->member) == 4)                                    \
  88        asm volatile ("movl %0,%%gs:%P1" :                                     \
  89                      : "ir" (value),                                          \
  90                        "i" (offsetof (struct pthread, member)));              \
  91      else /* 8 */                                                             \
  92        {                                                                      \
  93          asm volatile ("movl %%eax,%%gs:%P1\n\t"                              \
  94                        "movl %%edx,%%gs:%P2" :                                \
  95                        : "A" ((uint64_t) cast_to_integer (value)),            \
  96                          "i" (offsetof (struct pthread, member)),             \
  97                          "i" (offsetof (struct pthread, member) + 4));        \
  98        }})
  99
 100
 101 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 102 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 103   ({                                                                          \
 104      _Static_assert (sizeof (descr->member[0]) == 1                           \
 105                      || sizeof (descr->member[0]) == 4                        \
 106                      || sizeof (descr->member[0]) == 8,                       \
 107                      "size of per-thread data");                              \
 108      if (sizeof (descr->member[0]) == 1)                                      \
 109        asm volatile ("movb %b0,%%gs:%P1(%2)" :                                \
 110                      : "iq" (value),                                          \
 111                        "i" (offsetof (struct pthread, member)),               \
 112                        "r" (idx));                                            \
 113      else if (sizeof (descr->member[0]) == 4)                                 \
 114        asm volatile ("movl %0,%%gs:%P1(,%2,4)" :                              \
 115                      : "ir" (value),                                          \
 116                        "i" (offsetof (struct pthread, member)),               \
 117                        "r" (idx));                                            \
 118      else /* 8 */                                                             \
 119        {                                                                      \
 120          asm volatile ("movl %%eax,%%gs:%P1(,%2,8)\n\t"                       \
 121                        "movl %%edx,%%gs:4+%P1(,%2,8)" :                       \
 122                        : "A" ((uint64_t) cast_to_integer (value)),            \
 123                          "i" (offsetof (struct pthread, member)),             \
 124                          "r" (idx));                                          \
 125        }})