sysdeps/s390/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/s390 version.
   2    Copyright (C) 2003-2018 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   int __glibc_reserved1;
  43   /* GCC split stack support.  */
  44   void *__private_ss;
  45 } tcbhead_t;
  46
  47 # ifndef __s390x__
  48 #  define TLS_MULTIPLE_THREADS_IN_TCB 1
  49 # endif
  50
  51 #else /* __ASSEMBLER__ */
  52 # include <tcb-offsets.h>
  53 #endif
  54
  55
  56 /* Alignment requirement for the stack.  For IA-32 this is governed by
  57    the SSE memory functions.  */
  58 #define STACK_ALIGN     16
  59
  60 #ifndef __ASSEMBLER__
  61 /* Get system call information.  */
  62 # include <sysdep.h>
  63
  64 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
  65    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
  66    struct pthread even when not linked with -lpthread.  */
  67 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
  68
  69 /* Alignment requirements for the initial TCB.  */
  70 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
  71
  72 /* This is the size of the TCB.  */
  73 # define TLS_TCB_SIZE sizeof (struct pthread)
  74
  75 /* Alignment requirements for the TCB.  */
  76 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
  77
  78 /* The TCB can have any size and the memory following the address the
  79    thread pointer points to is unspecified.  Allocate the TCB there.  */
  80 # define TLS_TCB_AT_TP  1
  81 # define TLS_DTV_AT_TP  0
  82
  83 /* Get the thread descriptor definition.  */
  84 # include <nptl/descr.h>
  85
  86
  87 /* Install the dtv pointer.  The pointer passed is to the element with
  88    index -1 which contain the length.  */
  89 #  define INSTALL_DTV(descr, dtvp) \
  90   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
  91
  92 /* Install new dtv for current thread.  */
  93 #  define INSTALL_NEW_DTV(dtv) \
  94   (((tcbhead_t *) __builtin_thread_pointer ())->dtv = (dtv))
  95
  96 /* Return dtv of given thread descriptor.  */
  97 #  define GET_DTV(descr) \
  98   (((tcbhead_t *) (descr))->dtv)
  99
 100 #if defined NEED_DL_SYSINFO && defined SHARED
 101 # define INIT_SYSINFO \
 102   _head->sysinfo = GLRO(dl_sysinfo)
 103 #else
 104 # define INIT_SYSINFO
 105 #endif
 106
 107 /* Code to initially initialize the thread pointer.  This might need
 108    special attention since 'errno' is not yet available and if the
 109    operation can cause a failure 'errno' must not be touched.  */
 110 # define TLS_INIT_TP(thrdescr) \
 111   ({ void *_thrdescr = (thrdescr);                                            \
 112      tcbhead_t *_head = _thrdescr;                                            \
 113                                                                               \
 114      _head->tcb = _thrdescr;                                                  \
 115      /* For now the thread descriptor is at the same address.  */             \
 116      _head->self = _thrdescr;                                                 \
 117      /* New syscall handling support.  */                                     \
 118      INIT_SYSINFO;                                                            \
 119                                                                               \
 120     __builtin_set_thread_pointer (_thrdescr);                                 \
 121     NULL;                                                                     \
 122   })
 123
 124 /* Value passed to 'clone' for initialization of the thread register.  */
 125 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)
 126
 127 /* Return the address of the dtv for the current thread.  */
 128 #  define THREAD_DTV() \
 129   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
 130
 131 /* Return the thread descriptor for the current thread.  */
 132 # define THREAD_SELF ((struct pthread *) __builtin_thread_pointer ())
 133
 134 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 135 # define DB_THREAD_SELF REGISTER (32, 32, 18 * 4, 0) \
 136                         REGISTER (64, __WORDSIZE, 18 * 8, 0)
 137
 138 /* Access to data in the thread descriptor is easy.  */
 139 #define THREAD_GETMEM(descr, member) \
 140   descr->member
 141 #define THREAD_GETMEM_NC(descr, member, idx) \
 142   descr->member[idx]
 143 #define THREAD_SETMEM(descr, member, value) \
 144   descr->member = (value)
 145 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 146   descr->member[idx] = (value)
 147
 148 /* Set the stack guard field in TCB head.  */
 149 #define THREAD_SET_STACK_GUARD(value) \
 150   do                                                                          \
 151    {                                                                          \
 152      __asm__ __volatile__ ("" : : : "a0", "a1");                              \
 153      THREAD_SETMEM (THREAD_SELF, header.stack_guard, value);                  \
 154    }                                                                          \
 155   while (0)
 156 #define THREAD_COPY_STACK_GUARD(descr) \
 157   ((descr)->header.stack_guard                                                \
 158    = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 159
 160 /* s390 doesn't have HP_TIMING_*, so for the time being
 161    use stack_guard as pointer_guard.  */
 162 #define THREAD_GET_POINTER_GUARD() \
 163   THREAD_GETMEM (THREAD_SELF, header.stack_guard)
 164 #define THREAD_SET_POINTER_GUARD(value) ((void) (value))
 165 #define THREAD_COPY_POINTER_GUARD(descr)
 166
 167 /* Get and set the global scope generation counter in struct pthread.  */
 168 #define THREAD_GSCOPE_IN_TCB      1
 169 #define THREAD_GSCOPE_FLAG_UNUSED 0
 170 #define THREAD_GSCOPE_FLAG_USED   1
 171 #define THREAD_GSCOPE_FLAG_WAIT   2
 172 #define THREAD_GSCOPE_RESET_FLAG() \
 173   do                                                                         \
 174     { int __res                                                              \
 175         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 176                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 177       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 178         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 179     }                                                                        \
 180   while (0)
 181 #define THREAD_GSCOPE_SET_FLAG() \
 182   do                                                                         \
 183     {                                                                        \
 184       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 185       atomic_write_barrier ();                                               \
 186     }                                                                        \
 187   while (0)
 188 #define THREAD_GSCOPE_WAIT() \
 189   GL(dl_wait_lookup_done) ()
 190
 191 #endif /* __ASSEMBLER__ */
 192
 193 #endif  /* tls.h */