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b7eb7b0f6d
2002-08-08 Ulrich Drepper <drepper@redhat.com> * gmon/gmon.c (write_gmon): Use O_NOFOLLOW in open calls if available.
152 lines
5.0 KiB
C
152 lines
5.0 KiB
C
/* Definition for thread-local data handling. linuxthreads/i386 version.
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Copyright (C) 2002 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef _TLS_H
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#define _TLS_H
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# include <pt-machine.h>
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#ifndef __ASSEMBLER__
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# include <stddef.h>
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/* Type for the dtv. */
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typedef union dtv
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{
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size_t counter;
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void *pointer;
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} dtv_t;
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typedef struct
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{
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void *tcb; /* Pointer to the TCB. Not necessary the
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thread descriptor used by libpthread. */
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dtv_t *dtv;
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void *self; /* Pointer to the thread descriptor. */
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} tcbhead_t;
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#endif
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/* We can support TLS only if the floating-stack support is available. */
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#if defined FLOATING_STACKS && defined HAVE_TLS_SUPPORT
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/* Signal that TLS support is available. */
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# define USE_TLS 1
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# ifndef __ASSEMBLER__
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/* Get system call information. */
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# include <sysdep.h>
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/* Get the thread descriptor definition. */
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# include <linuxthreads/descr.h>
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/* This is the size of the initial TCB. */
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# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
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/* Alignment requirements for the initial TCB. */
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# define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
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/* This is the size of the TCB. */
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# define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct)
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/* Alignment requirements for the TCB. */
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# define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
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/* The TCB can have any size and the memory following the address the
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thread pointer points to is unspecified. Allocate the TCB there. */
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# define TLS_TCB_AT_TP 1
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/* Install the dtv pointer. The pointer passed is to the element with
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index -1 which contain the length. */
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# define INSTALL_DTV(descr, dtvp) \
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((tcbhead_t *) (descr))->dtv = (dtvp) + 1
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/* Install new dtv for current thread. */
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# define INSTALL_NEW_DTV(dtv) \
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({ struct _pthread_descr_struct *__descr; \
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THREAD_SETMEM (__descr, p_header.data.dtvp, (dtv)); })
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/* Return dtv of given thread descriptor. */
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# define GET_DTV(descr) \
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(((tcbhead_t *) (descr))->dtv)
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# define TLS_DO_MODIFY_LDT(descr, nr) \
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({ \
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struct modify_ldt_ldt_s ldt_entry = \
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{ nr, (unsigned long int) (descr), sizeof (struct _pthread_descr_struct), \
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1, 0, 0, 0, 0, 1, 0 }; \
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int result; \
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asm volatile ( \
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"pushl %%ebx\n\t" \
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"movl $1, %%ebx\n\t" \
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"int $0x80\n\t" \
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"popl %%ebx" \
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: "=a" (result) \
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: "0" (__NR_modify_ldt), \
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/* The extra argument with the "m" constraint is necessary \
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to let the compiler know that we are accessing LDT_ENTRY here. */\
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"m" (ldt_entry), "c" (&ldt_entry), "d" (sizeof (ldt_entry))); \
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__builtin_expect (result, 0) != 0 ? -1 : nr * 8 + 7; \
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})
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# ifdef __ASSUME_SET_THREAD_AREA_SYSCALL
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# define TLS_SETUP_GS_SEGMENT(descr) \
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INLINE_SYSCALL (set_thread_area, 2, descr, 1)
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# elif defined __NR_set_thread_area
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# define TLS_SETUP_GS_SEGMENT(descr) \
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({ int __seg = INLINE_SYSCALL (set_thread_area, 2, descr, 1); \
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__seg == -1 ? TLS_DO_MODIFY_LDT (descr, 0) : __seg; })
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# else
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# define TLS_SETUP_GS_SEGMENT(descr) \
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TLS_DO_MODIFY_LDT (descr, 0)
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# endif
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/* Code to initially initialize the thread pointer. This might need
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special attention since 'errno' is not yet available and if the
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operation can cause a failure 'errno' must not be touched. */
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# define TLS_INIT_TP(descr) \
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do { \
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void *_descr = (descr); \
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tcbhead_t *head = _descr; \
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int __gs; \
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\
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head->tcb = _descr; \
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/* For now the thread descriptor is at the same address. */ \
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head->self = _descr; \
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\
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__gs = TLS_SETUP_GS_SEGMENT (_descr); \
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if (__builtin_expect (__gs, 7) == -1) \
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/* Nothing else we can do. */ \
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asm ("hlt"); \
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asm ("movw %w0, %%gs" : : "q" (__gs)); \
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} while (0)
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/* Return the address of the dtv for the current thread. */
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# define THREAD_DTV() \
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({ struct _pthread_descr_struct *__descr; \
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THREAD_GETMEM (__descr, p_header.data.dtvp); })
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# endif /* FLOATING_STACKS && HAVE_TLS_SUPPORT */
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#endif /* __ASSEMBLER__ */
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#endif /* tls.h */
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