sysdeps/s390/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/s390 version.
   2    Copyright (C) 2003-2017 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 #include <dl-sysdep.h>
  23 #ifndef __ASSEMBLER__
  24 # include <stdbool.h>
  25 # include <stddef.h>
  26 # include <stdint.h>
  27 # include <stdlib.h>
  28 # include <list.h>
  29 # include <kernel-features.h>
  30 # include <dl-dtv.h>
  31
  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   uintptr_t sysinfo;
  40   uintptr_t stack_guard;
  41   int gscope_flag;
  42 #ifndef __ASSUME_PRIVATE_FUTEX
  43   int private_futex;
  44 #else
  45   int __glibc_reserved1;
  46 #endif
  47   /* GCC split stack support.  */
  48   void *__private_ss;
  49 } tcbhead_t;
  50
  51 # ifndef __s390x__
  52 #  define TLS_MULTIPLE_THREADS_IN_TCB 1
  53 # endif
  54
  55 #else /* __ASSEMBLER__ */
  56 # include <tcb-offsets.h>
  57 #endif
  58
  59
  60 /* Alignment requirement for the stack.  For IA-32 this is governed by
  61    the SSE memory functions.  */
  62 #define STACK_ALIGN     16
  63
  64 #ifndef __ASSEMBLER__
  65 /* Get system call information.  */
  66 # include <sysdep.h>
  67
  68 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
  69    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
  70    struct pthread even when not linked with -lpthread.  */
  71 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
  72
  73 /* Alignment requirements for the initial TCB.  */
  74 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
  75
  76 /* This is the size of the TCB.  */
  77 # define TLS_TCB_SIZE sizeof (struct pthread)
  78
  79 /* Alignment requirements for the TCB.  */
  80 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
  81
  82 /* The TCB can have any size and the memory following the address the
  83    thread pointer points to is unspecified.  Allocate the TCB there.  */
  84 # define TLS_TCB_AT_TP  1
  85 # define TLS_DTV_AT_TP  0
  86
  87 /* Get the thread descriptor definition.  */
  88 # include <nptl/descr.h>
  89
  90
  91 /* Install the dtv pointer.  The pointer passed is to the element with
  92    index -1 which contain the length.  */
  93 #  define INSTALL_DTV(descr, dtvp) \
  94   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
  95
  96 /* Install new dtv for current thread.  */
  97 #  define INSTALL_NEW_DTV(dtv) \
  98   (((tcbhead_t *) __builtin_thread_pointer ())->dtv = (dtv))
  99
 100 /* Return dtv of given thread descriptor.  */
 101 #  define GET_DTV(descr) \
 102   (((tcbhead_t *) (descr))->dtv)
 103
 104 #if defined NEED_DL_SYSINFO && defined SHARED
 105 # define INIT_SYSINFO \
 106   _head->sysinfo = GLRO(dl_sysinfo)
 107 #else
 108 # define INIT_SYSINFO
 109 #endif
 110
 111 /* Code to initially initialize the thread pointer.  This might need
 112    special attention since 'errno' is not yet available and if the
 113    operation can cause a failure 'errno' must not be touched.  */
 114 # define TLS_INIT_TP(thrdescr) \
 115   ({ void *_thrdescr = (thrdescr);                                            \
 116      tcbhead_t *_head = _thrdescr;                                            \
 117                                                                               \
 118      _head->tcb = _thrdescr;                                                  \
 119      /* For now the thread descriptor is at the same address.  */             \
 120      _head->self = _thrdescr;                                                 \
 121      /* New syscall handling support.  */                                     \
 122      INIT_SYSINFO;                                                            \
 123                                                                               \
 124     __builtin_set_thread_pointer (_thrdescr);                                 \
 125     NULL;                                                                     \
 126   })
 127
 128 /* Value passed to 'clone' for initialization of the thread register.  */
 129 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)
 130
 131 /* Return the address of the dtv for the current thread.  */
 132 #  define THREAD_DTV() \
 133   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
 134
 135 /* Return the thread descriptor for the current thread.  */
 136 # define THREAD_SELF ((struct pthread *) __builtin_thread_pointer ())
 137
 138 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 139 # define DB_THREAD_SELF REGISTER (32, 32, 18 * 4, 0) \
 140                         REGISTER (64, __WORDSIZE, 18 * 8, 0)
 141
 142 /* Access to data in the thread descriptor is easy.  */
 143 #define THREAD_GETMEM(descr, member) \
 144   descr->member
 145 #define THREAD_GETMEM_NC(descr, member, idx) \
 146   descr->member[idx]
 147 #define THREAD_SETMEM(descr, member, value) \
 148   descr->member = (value)
 149 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 150   descr->member[idx] = (value)
 151
 152 /* Set the stack guard field in TCB head.  */
 153 #define THREAD_SET_STACK_GUARD(value) \
 154   do                                                                          \
 155    {                                                                          \
 156      __asm__ __volatile__ ("" : : : "a0", "a1");                              \
 157      THREAD_SETMEM (THREAD_SELF, header.stack_guard, value);                  \
 158    }                                                                          \
 159   while (0)
 160 #define THREAD_COPY_STACK_GUARD(descr) \
 161   ((descr)->header.stack_guard                                                \
 162    = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 163
 164 /* s390 doesn't have HP_TIMING_*, so for the time being
 165    use stack_guard as pointer_guard.  */
 166 #define THREAD_GET_POINTER_GUARD() \
 167   THREAD_GETMEM (THREAD_SELF, header.stack_guard)
 168 #define THREAD_SET_POINTER_GUARD(value) ((void) (value))
 169 #define THREAD_COPY_POINTER_GUARD(descr)
 170
 171 /* Get and set the global scope generation counter in struct pthread.  */
 172 #define THREAD_GSCOPE_FLAG_UNUSED 0
 173 #define THREAD_GSCOPE_FLAG_USED   1
 174 #define THREAD_GSCOPE_FLAG_WAIT   2
 175 #define THREAD_GSCOPE_RESET_FLAG() \
 176   do                                                                         \
 177     { int __res                                                              \
 178         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 179                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 180       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 181         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 182     }                                                                        \
 183   while (0)
 184 #define THREAD_GSCOPE_SET_FLAG() \
 185   do                                                                         \
 186     {                                                                        \
 187       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 188       atomic_write_barrier ();                                               \
 189     }                                                                        \
 190   while (0)
 191 #define THREAD_GSCOPE_WAIT() \
 192   GL(dl_wait_lookup_done) ()
 193
 194 #endif /* __ASSEMBLER__ */
 195
 196 #endif  /* tls.h */