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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 | /* Definition for thread-local data handling. linuxthreads/i386 version. Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ #ifndef _TLS_H #define _TLS_H # include <pt-machine.h> #ifndef __ASSEMBLER__ # include <stdbool.h> # include <stddef.h> # include <stdint.h> /* Type for the dtv. */ typedef union dtv { size_t counter; void *pointer; } dtv_t; typedef struct { void *tcb; /* Pointer to the TCB. Not necessary the thread descriptor used by libpthread. */ dtv_t *dtv; void *self; /* Pointer to the thread descriptor. */ } tcbhead_t; #endif /* We can support TLS only if the floating-stack support is available. */ #if defined FLOATING_STACKS && defined HAVE_TLS_SUPPORT /* Signal that TLS support is available. */ //# define USE_TLS 1 # ifndef __ASSEMBLER__ /* Get system call information. */ # include <sysdep.h> /* Get the thread descriptor definition. */ # include <linuxthreads/descr.h> /* This is the size of the initial TCB. */ # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t) /* Alignment requirements for the initial TCB. */ # define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t) /* This is the size of the TCB. */ # define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct) /* Alignment requirements for the TCB. */ # define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct) /* The TCB can have any size and the memory following the address the thread pointer points to is unspecified. Allocate the TCB there. */ # define TLS_TCB_AT_TP 1 /* Install the dtv pointer. The pointer passed is to the element with index -1 which contain the length. */ # define INSTALL_DTV(descr, dtvp) \ ((tcbhead_t *) (descr))->dtv = (dtvp) + 1 /* Install new dtv for current thread. */ # define INSTALL_NEW_DTV(dtv) \ ({ struct _pthread_descr_struct *__descr; \ THREAD_SETMEM (__descr, p_header.data.dtvp, (dtv)); }) /* Return dtv of given thread descriptor. */ # define GET_DTV(descr) \ (((tcbhead_t *) (descr))->dtv) # ifdef __PIC__ # define TLS_EBX_ARG "r" # define TLS_LOAD_EBX "xchgl %3, %%ebx\n\t" # else # define TLS_EBX_ARG "b" # define TLS_LOAD_EBX # endif # define TLS_DO_MODIFY_LDT(descr, nr) \ ({ \ struct modify_ldt_ldt_s ldt_entry = \ { nr, (unsigned long int) (descr), 0xfffff /* 4GB in pages */, \ 1, 0, 0, 1, 0, 1, 0 }; \ int result; \ __asm__ __volatile__ (TLS_LOAD_EBX \ "int $0x80\n\t" \ TLS_LOAD_EBX \ : "=a" (result) \ : "0" (__NR_modify_ldt), \ /* The extra argument with the "m" constraint is necessary \ to let the compiler know that we are accessing LDT_ENTRY \ here. */ \ "m" (ldt_entry), TLS_EBX_ARG (1), "c" (&ldt_entry), \ "d" (sizeof (ldt_entry))); \ __builtin_expect (result, 0) != 0 ? -1 : nr * 8 + 7; \ }) # define TLS_DO_SET_THREAD_AREA(descr, secondcall) \ ({ \ struct modify_ldt_ldt_s ldt_entry = \ { -1, (unsigned long int) (descr), 0xfffff /* 4GB in pages */, \ 1, 0, 0, 1, 0, 1, 0 }; \ int result; \ if (secondcall) \ ldt_entry.entry_number = ({ int _gs; \ __asm__ ("movw %%gs, %w0" : "=q" (_gs)); \ (_gs & 0xffff) >> 3; }); \ __asm__ __volatile__ (TLS_LOAD_EBX \ "int $0x80\n\t" \ TLS_LOAD_EBX \ : "=a" (result), "=m" (ldt_entry.entry_number) \ : "0" (__NR_set_thread_area), \ /* The extra argument with the "m" constraint is necessary \ to let the compiler know that we are accessing LDT_ENTRY \ here. */ \ TLS_EBX_ARG (&ldt_entry), "m" (ldt_entry)); \ __builtin_expect (result, 0) == 0 ? ldt_entry.entry_number * 8 + 3 : -1; \ }) # ifdef __ASSUME_SET_THREAD_AREA_SYSCALL # define TLS_SETUP_GS_SEGMENT(descr, secondcall) \ TLS_DO_SET_THREAD_AREA (descr, firstcall) # elif defined __NR_set_thread_area # define TLS_SETUP_GS_SEGMENT(descr, secondcall) \ ({ int __seg = TLS_DO_SET_THREAD_AREA (descr, secondcall); \ __seg == -1 ? TLS_DO_MODIFY_LDT (descr, 0) : __seg; }) # else # define TLS_SETUP_GS_SEGMENT(descr, secondcall) \ TLS_DO_MODIFY_LDT ((descr), 0) # endif /* Code to initially initialize the thread pointer. This might need special attention since 'errno' is not yet available and if the operation can cause a failure 'errno' must not be touched. */ # define TLS_INIT_TP(descr, secondcall) \ ({ \ void *_descr = (descr); \ tcbhead_t *head = _descr; \ int __gs; \ \ head->tcb = _descr; \ /* For now the thread descriptor is at the same address. */ \ head->self = _descr; \ \ __gs = TLS_SETUP_GS_SEGMENT (_descr, secondcall); \ if (__builtin_expect (__gs, 7) != -1) \ { \ __asm__ ("movw %w0, %%gs" : : "q" (__gs)); \ __gs = 0; \ } \ __gs; \ }) /* Return the address of the dtv for the current thread. */ # define THREAD_DTV() \ ({ struct _pthread_descr_struct *__descr; \ THREAD_GETMEM (__descr, p_header.data.dtvp); }) # endif /* FLOATING_STACKS && HAVE_TLS_SUPPORT */ #endif /* __ASSEMBLER__ */ #endif /* tls.h */ |