1 /*- 2 * Copyright (c) 2002 Daniel Eischen <deischen@freebsd.org>. 3 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD$ 28 */ 29 30 /* 31 * Machine-dependent thread prototypes/definitions. 32 */ 33 #ifndef _PTHREAD_MD_H_ 34 #define _PTHREAD_MD_H_ 35 36 #include <stddef.h> 37 #include <sys/types.h> 38 #include <machine/sysarch.h> 39 40 #define DTV_OFFSET offsetof(struct tcb, tcb_dtv) 41 42 extern int _thr_using_setbase; 43 44 /* 45 * Variant II tcb, first two members are required by rtld, 46 * %gs points to the structure. 47 */ 48 struct tcb { 49 struct tcb *tcb_self; /* required by rtld */ 50 void *tcb_dtv; /* required by rtld */ 51 struct pthread *tcb_thread; 52 int tcb_ldt; 53 }; 54 55 /* 56 * Evaluates to the byte offset of the per-tcb variable name. 57 */ 58 #define __tcb_offset(name) __offsetof(struct tcb, name) 59 60 /* 61 * Evaluates to the type of the per-tcb variable name. 62 */ 63 #define __tcb_type(name) __typeof(((struct tcb *)0)->name) 64 65 /* 66 * Evaluates to the value of the per-tcb variable name. 67 */ 68 #define TCB_GET32(name) ({ \ 69 __tcb_type(name) __result; \ 70 \ 71 u_int __i; \ 72 __asm __volatile("movl %%gs:%1, %0" \ 73 : "=r" (__i) \ 74 : "m" (*(u_int *)(__tcb_offset(name)))); \ 75 __result = (__tcb_type(name))__i; \ 76 \ 77 __result; \ 78 }) 79 80 /* 81 * The constructors. 82 */ 83 struct tcb *_tcb_ctor(struct pthread *, int); 84 void _tcb_dtor(struct tcb *tcb); 85 86 /* Called from the thread to set its private data. */ 87 static __inline void 88 _tcb_set(struct tcb *tcb) 89 { 90 #ifndef COMPAT_32BIT 91 int val; 92 93 if (_thr_using_setbase == 1) { 94 i386_set_gsbase(tcb); 95 } else { 96 val = (tcb->tcb_ldt << 3) | 7; 97 __asm __volatile("movl %0, %%gs" : : "r" (val)); 98 } 99 #else 100 _amd64_set_gsbase(tcb); 101 #endif 102 103 } 104 105 /* Get the current kcb. */ 106 static __inline struct tcb * 107 _tcb_get(void) 108 { 109 return (TCB_GET32(tcb_self)); 110 } 111 112 extern struct pthread *_thr_initial; 113 114 /* Get the current thread. */ 115 static __inline struct pthread * 116 _get_curthread(void) 117 { 118 if (_thr_initial) 119 return (TCB_GET32(tcb_thread)); 120 return (NULL); 121 } 122 #endif 123