1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22/* Copyright (c) 1988 AT&T */ 23/* All Rights Reserved */ 24 25 26/* 27 * Copyright 1987-2003 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 31.ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.4 */ 32 33 .file "setjmp.s" 34 35#include <sys/asm_linkage.h> 36 37 ANSI_PRAGMA_WEAK(setjmp,function) 38 ANSI_PRAGMA_WEAK(longjmp,function) 39 40#include "synonyms.h" 41 42#include <sys/trap.h> 43 44JB_FLAGS = (0*4) ! offsets in jmpbuf (see siglonglmp.c) 45JB_SP = (1*4) ! words 5 through 11 are unused! 46JB_PC = (2*4) 47JB_FP = (3*4) 48JB_I7 = (4*4) 49 50/* 51 * setjmp(buf_ptr) 52 * buf_ptr points to a twelve word array (jmp_buf) 53 */ 54 ENTRY(setjmp) 55 clr [%o0 + JB_FLAGS] ! clear flags (used by sigsetjmp) 56 st %sp, [%o0 + JB_SP] ! save caller's sp 57 add %o7, 8, %o1 ! comupte return pc 58 st %o1, [%o0 + JB_PC] ! save pc 59 st %fp, [%o0 + JB_FP] ! save fp 60 st %i7, [%o0 + JB_I7] ! save %i7 61 retl 62 clr %o0 ! return (0) 63 64 SET_SIZE(setjmp) 65 66/* 67 * longjmp(buf_ptr, val) 68 * buf_ptr points to a jmpbuf which has been initialized by setjmp. 69 * val is the value we wish to return to setjmp's caller 70 * 71 * We flush the register file to the stack by doing a kernel call. 72 * This is necessary to ensure that the registers we want to 73 * pick up are stored on the stack, and that subsequent restores 74 * will function correctly. 75 * 76 * sp, fp, and %i7, the caller's return address, are all restored 77 * to the values they had at the time of the call to setjmp(). All 78 * other locals, ins and outs are set to potentially random values 79 * (as per the man page). This is sufficient to permit the correct 80 * operation of normal code. 81 * 82 * Actually, the above description is not quite correct. If the routine 83 * that called setjmp() has not altered the sp value of their frame we 84 * will restore the remaining locals and ins to the values these 85 * registers had in the this frame at the time of the call to longjmp() 86 * (not setjmp()!). This is intended to help compilers, typically not 87 * C compilers, that have some registers assigned to fixed purposes, 88 * and that only alter the values of these registers on function entry 89 * and exit. 90 * 91 * Since a C routine could call setjmp() followed by alloca() and thus 92 * alter the sp this feature will typically not be helpful for a C 93 * compiler. 94 * 95 * Note also that because the caller of a routine compiled "flat" (without 96 * register windows) assumes that their ins and locals are preserved, 97 * routines that call setjmp() must not be flat. 98 */ 99 ENTRY(longjmp) 100 ta ST_FLUSH_WINDOWS ! flush all reg windows to the stack. 101 ld [%o0 + JB_SP], %o2 ! sp in %o2 until safe to puke there 102 ldd [%o2 + (0*8)], %l0 ! restore locals and ins if we can 103 ldd [%o2 + (1*8)], %l2 104 ldd [%o2 + (2*8)], %l4 105 ldd [%o2 + (3*8)], %l6 106 ldd [%o2 + (4*8)], %i0 107 ldd [%o2 + (5*8)], %i2 108 ldd [%o2 + (6*8)], %i4 109 ld [%o0 + JB_FP], %fp ! restore fp 110 mov %o2, %sp ! restore sp 111 ld [%o0 + JB_I7], %i7 ! restore %i7 112 ld [%o0 + JB_PC], %o3 ! get new return pc 113 tst %o1 ! is return value 0? 114 bnz 1f ! no - leave it alone 115 sub %o3, 8, %o7 ! normalize return (for adb) (dly slot) 116 mov 1, %o1 ! yes - set it to one 1171: 118 retl 119 mov %o1, %o0 ! return (val) 120 121 SET_SIZE(longjmp) 122