__clone.S revision 1.7.8.2
1 1.7.8.2 martin /* $NetBSD: __clone.S,v 1.7.8.2 2008/04/28 20:22:57 martin Exp $ */ 2 1.7.8.2 martin 3 1.7.8.2 martin /*- 4 1.7.8.2 martin * Copyright (c) 2001 The NetBSD Foundation, Inc. 5 1.7.8.2 martin * All rights reserved. 6 1.7.8.2 martin * 7 1.7.8.2 martin * This code is derived from software contributed to The NetBSD Foundation 8 1.7.8.2 martin * by Jason R. Thorpe. 9 1.7.8.2 martin * 10 1.7.8.2 martin * Redistribution and use in source and binary forms, with or without 11 1.7.8.2 martin * modification, are permitted provided that the following conditions 12 1.7.8.2 martin * are met: 13 1.7.8.2 martin * 1. Redistributions of source code must retain the above copyright 14 1.7.8.2 martin * notice, this list of conditions and the following disclaimer. 15 1.7.8.2 martin * 2. Redistributions in binary form must reproduce the above copyright 16 1.7.8.2 martin * notice, this list of conditions and the following disclaimer in the 17 1.7.8.2 martin * documentation and/or other materials provided with the distribution. 18 1.7.8.2 martin * 19 1.7.8.2 martin * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.7.8.2 martin * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.7.8.2 martin * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.7.8.2 martin * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.7.8.2 martin * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.7.8.2 martin * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.7.8.2 martin * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.7.8.2 martin * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.7.8.2 martin * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.7.8.2 martin * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.7.8.2 martin * POSSIBILITY OF SUCH DAMAGE. 30 1.7.8.2 martin */ 31 1.7.8.2 martin 32 1.7.8.2 martin #include <sys/errno.h> 33 1.7.8.2 martin 34 1.7.8.2 martin #include "SYS.h" 35 1.7.8.2 martin 36 1.7.8.2 martin #ifdef WEAK_ALIAS 37 1.7.8.2 martin WEAK_ALIAS(clone, __clone) 38 1.7.8.2 martin #endif 39 1.7.8.2 martin 40 1.7.8.2 martin /* 41 1.7.8.2 martin * int __clone(int (*fn)(void *), void *stack, int flags, void *arg); 42 1.7.8.2 martin */ 43 1.7.8.2 martin LEAF(__clone) 44 1.7.8.2 martin PIC_PROLOGUE(__clone, t9) 45 1.7.8.2 martin 46 1.7.8.2 martin /* 47 1.7.8.2 martin * Sanity checks: func and stack may not be NULL. 48 1.7.8.2 martin */ 49 1.7.8.2 martin li v0, EINVAL 50 1.7.8.2 martin beq a0, zero, 8f 51 1.7.8.2 martin beq a1, zero, 8f 52 1.7.8.2 martin 53 1.7.8.2 martin /* 54 1.7.8.2 martin * We need to be able to get at the func and arg arguments 55 1.7.8.2 martin * in the child. Luckily, we have a convenient place to 56 1.7.8.2 martin * do this: the child's stack. 57 1.7.8.2 martin */ 58 1.7.8.2 martin subu a1, a1, (2 * SZREG) 59 1.7.8.2 martin REG_S a0, 0(a1) 60 1.7.8.2 martin REG_S a3, SZREG(a1) 61 1.7.8.2 martin 62 1.7.8.2 martin /* 63 1.7.8.2 martin * The system call expects (flags, stack). 64 1.7.8.2 martin */ 65 1.7.8.2 martin move a0, a2 66 1.7.8.2 martin SYSTRAP(__clone) 67 1.7.8.2 martin bne a3, zero, 8f 68 1.7.8.2 martin 69 1.7.8.2 martin bne v1, zero, 9f # v1 (rv[1]) == 0, parent, child pid in v0 70 1.7.8.2 martin 71 1.7.8.2 martin j ra # parent return 72 1.7.8.2 martin 73 1.7.8.2 martin 8: PIC_CALL(__cerror, t9) 74 1.7.8.2 martin /* NOTREACHED */ 75 1.7.8.2 martin 76 1.7.8.2 martin 9: /* 77 1.7.8.2 martin * Child: Fetch the function and argument from the new stack, 78 1.7.8.2 martin * and create a frame so that the child can be safely called. 79 1.7.8.2 martin * 80 1.7.8.2 martin * There are already register slots on the stack from above. 81 1.7.8.2 martin * We take 4 register slots more. The lower 4 accommodate o32 82 1.7.8.2 martin * argument save area. The next higher is used to save GP (if 83 1.7.8.2 martin * ABICALLS). The highest is unused. 84 1.7.8.2 martin */ 85 1.7.8.2 martin REG_L t9, 0(sp) 86 1.7.8.2 martin REG_L a0, SZREG(sp) 87 1.7.8.2 martin subu sp, sp, (4 * SZREG) 88 1.7.8.2 martin 89 1.7.8.2 martin #ifdef __ABICALLS__ 90 1.7.8.2 martin .cprestore (4 * SZREG) 91 1.7.8.2 martin #endif 92 1.7.8.2 martin 93 1.7.8.2 martin /* Call the clone's entry point. */ 94 1.7.8.2 martin jal t9 95 1.7.8.2 martin 96 1.7.8.2 martin /* Pass the return value to _exit(). */ 97 1.7.8.2 martin move a0, v0 98 1.7.8.2 martin PIC_CALL(_exit, t9) 99 1.7.8.2 martin 100 1.7.8.2 martin /* NOTREACHED */ 101 1.7.8.2 martin END(__clone) 102
Indexes created Thu Oct 02 01:09:59 GMT 2025