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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27/* Copyright (c) 1988 AT&T */ 28/* All Rights Reserved */ 29 30#pragma ident "%Z%%M% %I% %E% SMI" 31 32 .file "%M%" 33 34#include <sys/asm_linkage.h> 35 36 ANSI_PRAGMA_WEAK(setjmp,function) 37 ANSI_PRAGMA_WEAK(longjmp,function) 38 39#include <sys/trap.h> 40 41JB_FLAGS = (0*4) ! offsets in jmpbuf (see siglonglmp.c) 42JB_SP = (1*4) ! words 5 through 11 are unused! 43JB_PC = (2*4) 44JB_FP = (3*4) 45JB_I7 = (4*4) 46 47/* 48 * setjmp(buf_ptr) 49 * buf_ptr points to a twelve word array (jmp_buf) 50 */ 51 ENTRY(setjmp) 52 clr [%o0 + JB_FLAGS] ! clear flags (used by sigsetjmp) 53 st %sp, [%o0 + JB_SP] ! save caller's sp 54 add %o7, 8, %o1 ! comupte return pc 55 st %o1, [%o0 + JB_PC] ! save pc 56 st %fp, [%o0 + JB_FP] ! save fp 57 st %i7, [%o0 + JB_I7] ! save %i7 58 retl 59 clr %o0 ! return (0) 60 61 SET_SIZE(setjmp) 62 63/* 64 * longjmp(buf_ptr, val) 65 * buf_ptr points to a jmpbuf which has been initialized by setjmp. 66 * val is the value we wish to return to setjmp's caller 67 * 68 * We flush the register file to the stack by doing a kernel call. 69 * This is necessary to ensure that the registers we want to 70 * pick up are stored on the stack, and that subsequent restores 71 * will function correctly. 72 * 73 * sp, fp, and %i7, the caller's return address, are all restored 74 * to the values they had at the time of the call to setjmp(). All 75 * other locals, ins and outs are set to potentially random values 76 * (as per the man page). This is sufficient to permit the correct 77 * operation of normal code. 78 * 79 * Actually, the above description is not quite correct. If the routine 80 * that called setjmp() has not altered the sp value of their frame we 81 * will restore the remaining locals and ins to the values these 82 * registers had in the this frame at the time of the call to longjmp() 83 * (not setjmp()!). This is intended to help compilers, typically not 84 * C compilers, that have some registers assigned to fixed purposes, 85 * and that only alter the values of these registers on function entry 86 * and exit. 87 * 88 * Since a C routine could call setjmp() followed by alloca() and thus 89 * alter the sp this feature will typically not be helpful for a C 90 * compiler. 91 * 92 * Note also that because the caller of a routine compiled "flat" (without 93 * register windows) assumes that their ins and locals are preserved, 94 * routines that call setjmp() must not be flat. 95 */ 96 ENTRY(longjmp) 97 ta ST_FLUSH_WINDOWS ! flush all reg windows to the stack. 98 ld [%o0 + JB_SP], %o2 ! sp in %o2 until safe to puke there 99 ldd [%o2 + (0*8)], %l0 ! restore locals and ins if we can 100 ldd [%o2 + (1*8)], %l2 101 ldd [%o2 + (2*8)], %l4 102 ldd [%o2 + (3*8)], %l6 103 ldd [%o2 + (4*8)], %i0 104 ldd [%o2 + (5*8)], %i2 105 ldd [%o2 + (6*8)], %i4 106 ld [%o0 + JB_FP], %fp ! restore fp 107 mov %o2, %sp ! restore sp 108 ld [%o0 + JB_I7], %i7 ! restore %i7 109 ld [%o0 + JB_PC], %o3 ! get new return pc 110 tst %o1 ! is return value 0? 111 bnz 1f ! no - leave it alone 112 sub %o3, 8, %o7 ! normalize return (for adb) (dly slot) 113 mov 1, %o1 ! yes - set it to one 1141: 115 retl 116 mov %o1, %o0 ! return (val) 117 118 SET_SIZE(longjmp) 119