| /* 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, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #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 */ |