diff options
Diffstat (limited to 'libpthread/linuxthreads/sysdeps/i386/tls.h')
| -rw-r--r-- | libpthread/linuxthreads/sysdeps/i386/tls.h | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/sysdeps/i386/tls.h b/libpthread/linuxthreads/sysdeps/i386/tls.h new file mode 100644 index 000000000..c5cb07ba3 --- /dev/null +++ b/libpthread/linuxthreads/sysdeps/i386/tls.h @@ -0,0 +1,229 @@ +/* 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; +#ifdef NEED_DL_SYSINFO + uintptr_t sysinfo; +#endif +} 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_linuxthreads && !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 */ |