rfork_thread.S revision 256281
1/*- 2 * Copyright (c) 2000 Peter Wemm <peter@FreeBSD.org> 3 * Copyright (c) 2003 Alan L. Cox <alc@cs.rice.edu> 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__FBSDID("$FreeBSD: stable/10/lib/libc/amd64/gen/rfork_thread.S 240178 2012-09-06 20:59:49Z jilles $"); 30 31/* 32 * With thanks to John Dyson for the original version of this. 33 */ 34 35#include <SYS.h> 36 37/* 38 * %edi %rsi %rdx %rcx 39 * rfork_thread(flags, stack_addr, start_fnc, start_arg); 40 * 41 * flags: Flags to rfork system call. See rfork(2). 42 * stack_addr: Top of stack for thread. 43 * start_fnc: Address of thread function to call in child. 44 * start_arg: Argument to pass to the thread function in child. 45 */ 46 47ENTRY(rfork_thread) 48 pushq %rbx 49 pushq %r12 50 movq %rdx, %rbx 51 movq %rcx, %r12 52 53 /* 54 * Prepare and execute the thread creation syscall 55 */ 56 movq $SYS_rfork, %rax 57 KERNCALL 58 jb 2f 59 60 /* 61 * Check to see if we are in the parent or child 62 */ 63 cmpl $0, %edx 64 jnz 1f 65 popq %r12 66 popq %rbx 67 ret 68 69 /* 70 * If we are in the child (new thread), then 71 * set-up the call to the internal subroutine. If it 72 * returns, then call __exit. 73 */ 741: 75 movq %rsi, %rsp 76 movq %r12, %rdi 77 call *%rbx 78 movl %eax, %edi 79 80 /* 81 * Exit system call 82 */ 83#ifdef SYS_exit 84 movq $SYS_exit, %rax 85#else 86 movq $SYS_sys_exit, %rax 87#endif 88 KERNCALL 89 90 /* 91 * Branch here if the thread creation fails: 92 */ 932: 94 popq %r12 95 popq %rbx 96 jmp HIDENAME(cerror) 97END(rfork_thread) 98 99 .section .note.GNU-stack,"",%progbits 100