| /* 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; |
| struct |
| { |
| void *val; |
| bool is_static; |
| } 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. */ |
| int multiple_threads; |
| uintptr_t sysinfo; |
| } tcbhead_t; |
| |
| #else /* __ASSEMBLER__ */ |
| # include <tcb-offsets.h> |
| #endif |
| |
| /* We can support TLS only if the floating-stack support is available. |
| However, we want to compile in the support and test at runtime whether |
| the running kernel can support it or not. To avoid bothering with the |
| TLS support code at all, use configure --without-tls. |
| |
| We need USE_TLS to be consistently defined, for ldsodefs.h conditionals. |
| But some of the code below can cause problems in building libpthread |
| (e.g. useldt.h will defined FLOATING_STACKS when it shouldn't). */ |
| |
| #if defined HAVE_TLS_SUPPORT \ |
| && (defined FLOATING_STACKS || !defined IS_IN_libpthread) |
| |
| /* 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 |
| |
| # if !defined IS_IN_libpthread && !defined DO_MODIFY_LDT |
| # include "useldt.h" /* For the structure. */ |
| # endif |
| # if __ASSUME_LDT_WORKS > 0 |
| # define TLS_DO_MODIFY_LDT_KERNEL_CHECK(doit) (doit) /* Nothing to check. */ |
| # else |
| # define TLS_DO_MODIFY_LDT_KERNEL_CHECK(doit) \ |
| (__builtin_expect (GLRO(dl_osversion) < 131939, 0) \ |
| ? "kernel too old for thread-local storage support\n" \ |
| : (doit)) |
| # endif |
| |
| # define TLS_DO_MODIFY_LDT(descr, nr) \ |
| TLS_DO_MODIFY_LDT_KERNEL_CHECK( \ |
| ({ \ |
| 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 \ |
| ? ({ __asm__ ("movw %w0, %%gs" : : "q" ((nr) * 8 + 7)); NULL; }) \ |
| : "cannot set up LDT for thread-local storage\n"; \ |
| })) |
| |
| # 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)); \ |
| if (__builtin_expect (result, 0) == 0) \ |
| __asm__ ("movw %w0, %%gs" : : "q" (ldt_entry.entry_number * 8 + 3)); \ |
| result; \ |
| }) |
| |
| # ifdef __ASSUME_SET_THREAD_AREA_SYSCALL |
| # define TLS_SETUP_GS_SEGMENT(descr, secondcall) \ |
| (TLS_DO_SET_THREAD_AREA (descr, secondcall) \ |
| ? "set_thread_area failed when setting up thread-local storage\n" : NULL) |
| # elif defined __NR_set_thread_area |
| # define TLS_SETUP_GS_SEGMENT(descr, secondcall) \ |
| (TLS_DO_SET_THREAD_AREA (descr, secondcall) \ |
| ? TLS_DO_MODIFY_LDT (descr, 0) : NULL) |
| # else |
| # define TLS_SETUP_GS_SEGMENT(descr, secondcall) \ |
| TLS_DO_MODIFY_LDT ((descr), 0) |
| # endif |
| |
| #if defined NEED_DL_SYSINFO |
| # define INIT_SYSINFO \ |
| head->sysinfo = GLRO(dl_sysinfo) |
| #else |
| # define INIT_SYSINFO |
| #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. |
| |
| The value of this macro is null if successful, or an error string. */ |
| # define TLS_INIT_TP(descr, secondcall) \ |
| ({ \ |
| void *_descr = (descr); \ |
| tcbhead_t *head = _descr; \ |
| \ |
| head->tcb = _descr; \ |
| /* For now the thread descriptor is at the same address. */ \ |
| head->self = _descr; \ |
| \ |
| INIT_SYSINFO; \ |
| TLS_SETUP_GS_SEGMENT (_descr, secondcall); \ |
| }) |
| |
| /* Indicate that dynamic linker shouldn't try to initialize TLS even |
| when no PT_TLS segments are found in the program and libraries |
| it is linked against. */ |
| # define TLS_INIT_TP_EXPENSIVE 1 |
| |
| /* 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 /* HAVE_TLS_SUPPORT && (FLOATING_STACKS || !IS_IN_libpthread) */ |
| #endif /* __ASSEMBLER__ */ |
| |
| #endif /* tls.h */ |