1 /* Copyright (C) 2005-2021 Free Software Foundation, Inc. 2 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 License as 7 published by the Free Software Foundation; either version 2.1 of the 8 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 #ifndef _TLS_H 20 #define _TLS_H 1 21 22 #include <dl-sysdep.h> 23 24 #ifndef __ASSEMBLER__ 25 # include <stdbool.h> 26 # include <stddef.h> 27 # include <stdint.h> 28 # include <dl-dtv.h> 29 #endif /* __ASSEMBLER__ */ 30 31 #ifndef __ASSEMBLER__ 32 33 /* Get system call information. */ 34 # include <sysdep.h> 35 36 /* The TP points to the start of the thread blocks. */ 37 # define TLS_DTV_AT_TP 1 38 # define TLS_TCB_AT_TP 0 39 40 /* Get the thread descriptor definition. */ 41 # include <nptl/descr.h> 42 43 typedef struct 44 { 45 dtv_t *dtv; 46 void *private; 47 } tcbhead_t; 48 49 /* This is the size of the initial TCB. */ 50 # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t) 51 52 /* This is the size of the TCB. */ 53 # define TLS_TCB_SIZE sizeof (tcbhead_t) 54 55 /* This is the size we need before TCB. */ 56 # define TLS_PRE_TCB_SIZE sizeof (struct pthread) 57 58 /* Install the dtv pointer. The pointer passed is to the element with 59 index -1 which contain the length. */ 60 # define INSTALL_DTV(tcbp, dtvp) \ 61 (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1) 62 63 /* Install new dtv for current thread. */ 64 # define INSTALL_NEW_DTV(dtv) \ 65 (THREAD_DTV() = (dtv)) 66 67 /* Return dtv of given thread descriptor. */ 68 # define GET_DTV(tcbp) \ 69 (((tcbhead_t *) (tcbp))->dtv) 70 71 /* Code to initially initialize the thread pointer. This might need 72 special attention since 'errno' is not yet available and if the 73 operation can cause a failure 'errno' must not be touched. */ 74 # define TLS_INIT_TP(tcbp) \ 75 ({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); NULL; }) 76 77 /* Value passed to 'clone' for initialization of the thread register. */ 78 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1 79 80 /* Return the address of the dtv for the current thread. */ 81 # define THREAD_DTV() \ 82 (((tcbhead_t *) __builtin_thread_pointer ())->dtv) 83 84 /* Return the thread descriptor for the current thread. */ 85 # define THREAD_SELF \ 86 ((struct pthread *)__builtin_thread_pointer () - 1) 87 88 /* Magic for libthread_db to know how to do THREAD_SELF. */ 89 # define DB_THREAD_SELF \ 90 CONST_THREAD_AREA (64, sizeof (struct pthread)) 91 92 # include <tcb-access.h> 93 94 /* Get and set the global scope generation counter in struct pthread. */ 95 # define THREAD_GSCOPE_FLAG_UNUSED 0 96 # define THREAD_GSCOPE_FLAG_USED 1 97 # define THREAD_GSCOPE_FLAG_WAIT 2 98 # define THREAD_GSCOPE_RESET_FLAG() \ 99 do \ 100 { int __res \ 101 = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag, \ 102 THREAD_GSCOPE_FLAG_UNUSED); \ 103 if (__res == THREAD_GSCOPE_FLAG_WAIT) \ 104 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \ 105 } \ 106 while (0) 107 # define THREAD_GSCOPE_SET_FLAG() \ 108 do \ 109 { \ 110 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \ 111 atomic_write_barrier (); \ 112 } \ 113 while (0) 114 115 # endif /* __ASSEMBLER__ */ 116 117 #endif /* tls.h */ 118