1/* $OpenBSD: tfork_thread.S,v 1.2 2012/04/11 18:36:57 kettenis Exp $ */ 2/*- 3 * Copyright (c) 2000 Peter Wemm <peter@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 28#include <machine/asm.h> 29#if 0 30__FBSDID("$FreeBSD: /repoman/r/ncvs/src/lib/libc/i386/gen/rfork_thread.S,v 1.5 2003/05/07 17:23:25 jhb Exp $"); 31#endif 32 33/* 34 * With thanks to John Dyson for the original version of this. 35 */ 36 37#include "SYS.h" 38 39/* 40 * 8 12 16 20 41 * __tfork_thread(param, stack_addr, start_fnc, start_arg); 42 * 43 * param: Arguments to actual system call. 44 * stack_addr: Top of stack for thread. 45 * start_fnc: Address of thread function to call in child. 46 * start_arg: Argument to pass to the thread function in child. 47 */ 48 49ENTRY(__tfork_thread) 50 pushl %ebp 51 movl %esp, %ebp 52 pushl %esi 53 54 /* 55 * Push thread info onto the new thread's stack 56 */ 57 movl 12(%ebp), %esi # get stack addr 58 59 subl $4, %esi 60 movl 20(%ebp), %eax # get start argument 61 movl %eax, (%esi) 62 63 subl $4, %esi 64 movl 16(%ebp), %eax # get start thread address 65 movl %eax, (%esi) 66 67 /* 68 * Prepare and execute the thread creation syscall 69 */ 70 pushl 8(%ebp) 71 pushl $0 72 movl $SYS___tfork, %eax 73 int $0x80 74 jb 2f 75 76 /* 77 * Check to see if we are in the parent or child 78 */ 79 cmpl $0, %edx 80 jnz 1f 81 addl $8, %esp 82 popl %esi 83 movl %ebp, %esp 84 popl %ebp 85 ret 86 .p2align 2 87 88 /* 89 * If we are in the child (new thread), then 90 * set-up the call to the internal subroutine. If it 91 * returns, then call __exit. 92 */ 931: 94 xorl %ebp, %ebp # mark outermost frame 95 movl %esi, %esp 96 popl %eax 97 call *%eax 98 addl $4, %esp 99 100 /* 101 * Exit system call 102 */ 103 pushl %eax 104 pushl $0 105 movl $SYS___threxit, %eax 106 int $0x80 107 108 /* 109 * Branch here if the thread creation fails: 110 */ 1112: 112 addl $8, %esp 113 popl %esi 114 movl %ebp, %esp 115 popl %ebp 116#ifdef PIC 117 PIC_PROLOGUE 118 movl PIC_GOT(CERROR), %ecx 119 PIC_EPILOGUE 120 jmp *%ecx 121#else 122 jmp CERROR 123#endif 124