1/* $NetBSD: __clone.S,v 1.6 2003/02/08 04:01:53 simonb Exp $ */ 2 3/*- 4 * Copyright (c) 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39#include <sys/errno.h> 40 41#include "SYS.h" 42 43#ifdef WEAK_ALIAS 44WEAK_ALIAS(clone, __clone) 45#endif 46 47/* 48 * int __clone(int (*fn)(void *), void *stack, int flags, void *arg); 49 */ 50LEAF(__clone) 51 PIC_PROLOGUE(__clone, t9) 52 53 /* 54 * Sanity checks: func and stack may not be NULL. 55 */ 56 li v0, EINVAL 57 beq a0, zero, 8f 58 beq a1, zero, 8f 59 60 /* 61 * We need to be able to get at the func and arg arguments 62 * in the child. Luckily, we have a convenient place to 63 * do this: the child's stack. 64 */ 65 subu a1, a1, (2 * SZREG) 66 REG_S a0, 0(a1) 67 REG_S a3, SZREG(a1) 68 69 /* 70 * The system call expects (flags, stack). 71 */ 72 move a0, a2 73 SYSTRAP(__clone) 74 bne a3, zero, 8f 75 76 bne v1, zero, 9f # v1 (rv[1]) == 0, parent, child pid in v0 77 78 j ra # parent return 79 808: PIC_CALL(__cerror, t9) 81 /* NOTREACHED */ 82 839: /* 84 * Child: Fetch the function and argument from the new stack, 85 * and create a frame so that the child can be safely called. 86 * 87 * There are already register slots on the stack from above. 88 * We take 4 register slots more. The lower 4 accommodate o32 89 * argument save area. The next higher is used to save GP (if 90 * ABICALLS). The highest is unused. 91 */ 92 REG_L t9, 0(sp) 93 REG_L a0, SZREG(sp) 94 subu sp, sp, (4 * SZREG) 95 96#ifdef __ABICALLS__ 97 .cprestore (4 * SZREG) 98#endif 99 100 /* Call the clone's entry point. */ 101 jal t9 102 103 /* Pass the return value to _exit(). */ 104 move a0, v0 105 PIC_CALL(_exit, t9) 106 107 /* NOTREACHED */ 108END(__clone) 109