1/* $NetBSD: _resumecontext.S,v 1.13 2020/10/15 05:27:53 skrll 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 Wayne Knowles. 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include <machine/asm.h> 33 34#include "SYS.h" 35#include "assym.h" 36 37#if defined(SYSLIBC_SCCS) && !defined(lint) 38 RCSID("$NetBSD: _resumecontext.S,v 1.13 2020/10/15 05:27:53 skrll Exp $") 39#endif /* SYSLIBC_SCCS && !lint */ 40 41 .set reorder 42 .hidden _C_LABEL(__resumecontext) 43 44LEAF_NOPROFILE(__resumecontext) 45 /* 46 * We get here not by a call through $t9 but thru $ra after the 47 * function passed to makecontext returns. Therefore, we need 48 * to recover gp from ra 49 */ 50#if defined(__mips_o32) || defined(__mips_o64) 51 .set push 52 .set noreorder 53 .cpload ra 54 .set pop 55#endif 56#if defined(__mips_n32) || defined(__mips_n64) 57 .cpsetup ra, t3, __resumecontext 58#endif 59 60 PTR_SUBU sp, sp, UCONTEXT_SIZE # get space for ucontext 61 move a0, sp # arg0 for getcontext 62 PTR_S zero, _UC_LINK(a0) # make sure uc_link is 0 63 SYSTRAP(getcontext) # get context 64 65#if defined(__mips_n32) || defined(__mips_n64) 66 REG_PROLOGUE 67 /* We saved gp in t2 above */ 68 REG_S t3, _UC_GREGS_GP(a0) 69 REG_EPILOGUE 70#endif 71 72 PTR_L a0, _UC_LINK(a0) # linked context? 73 NOP_L 74 beq a0, zero, 1f # nope, exit process 75 nop 76 PIC_TAILCALL(setcontext) # yes, become it. 77 /* NOTREACHED (in theory) */ 78 li a0, -1 # failure, 791: 80 SYSTRAP(exit) # all hope is lost. 81 /* NOTREACHED */ 82END(__resumecontext) 83