glibc/linuxthreads/sysdeps/i386/tls.h
Ulrich Drepper 535b764df5 Update.
* elf/rtld.c (_dl_start_final): Allocate TLS and initialize
	thread-pointer as soon as possible.
	* sysdeps/generic/ldsodefs.h: Include <tls.h>.  Define first TLS
	elements in rtld_global.
	* sysdeps/generic/tls.h: New file.
	* elf/Makefile (distribute): Add tls.h.
	* sysdeps/i386/dl-machine.h (elf_machine_rel): Add support for TLS
	relocations.  Not complete yet.

	* resolv/resolv.h: Allow user to define __need_res_state and only
	define __res_start structure then.
	* include/resolv.h: Only declare functions if _RESOLV_H_ is defined.
2002-02-05 00:57:29 +00:00

96 lines
3.0 KiB
C

/* Definition for thread-local data handling. linuxthreads/i386 version.
Copyright (C) 2002 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
/* Type for the dtv. */
typedef union dtv
{
size_t counter;
void *pointer;
} dtv_t;
typedef struct
{
void *tcb;
dtv_t *dtv;
} tcbhead_t;
/* Get the thread descriptor definition. */
#include <linuxthreads/descr.h>
/* We can support TLS only if the floating-stack support is available. */
#if FLOATING_STACKS && defined HAVE_TLS_SUPPORT
/* Get system call information. */
# include <sysdep.h>
/* Signal that TLS support is available. */
# define USE_TLS 1
/* 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
/* 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, dtvp) \
do { \
void *_descr = (descr); \
struct modify_ldt_ldt_s ldt_entry = \
{ 0, (unsigned long int) _descr, 1048576, 1, 0, 0, 1, 0, 1, 0 }; \
int result; \
tcbhead_t *head = _descr; \
\
head->tcb = _descr; \
head->dtv = dtvp; \
\
asm ("pushl %%ebx\n\t" \
"movl $1, %%ebx\n\t" \
"int $0x80\n\t" \
"popl %%ebx" \
: "=a" (result) \
: "0" (__NR_modify_ldt), "d" (sizeof (ldt_entry)), "c" (&ldt_entry));\
\
if (__builtin_expect (result, 0) != 0) \
/* Nothing else we can do. */ \
asm ("hlt"); \
} while (0)
#endif
#endif /* tls.h */