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 .file "setjmp.s" 31 32#include <sys/asm_linkage.h> 33 34 ANSI_PRAGMA_WEAK(setjmp,function) 35 ANSI_PRAGMA_WEAK(longjmp,function) 36 37#include <sys/trap.h> 38 39JB_FLAGS = (0*4) ! offsets in jmpbuf (see siglonglmp.c) 40JB_SP = (1*4) ! words 5 through 11 are unused! 41JB_PC = (2*4) 42JB_FP = (3*4) 43JB_I7 = (4*4) 44 45/* 46 * setjmp(buf_ptr) 47 * buf_ptr points to a twelve word array (jmp_buf) 48 */ 49 ENTRY(setjmp) 50 clr [%o0 + JB_FLAGS] ! clear flags (used by sigsetjmp) 51 st %sp, [%o0 + JB_SP] ! save caller's sp 52 add %o7, 8, %o1 ! comupte return pc 53 st %o1, [%o0 + JB_PC] ! save pc 54 st %fp, [%o0 + JB_FP] ! save fp 55 st %i7, [%o0 + JB_I7] ! save %i7 56 retl 57 clr %o0 ! return (0) 58 59 SET_SIZE(setjmp) 60 61/* 62 * longjmp(buf_ptr, val) 63 * buf_ptr points to a jmpbuf which has been initialized by setjmp. 64 * val is the value we wish to return to setjmp's caller 65 * 66 * We flush the register file to the stack by doing a kernel call. 67 * This is necessary to ensure that the registers we want to 68 * pick up are stored on the stack, and that subsequent restores 69 * will function correctly. 70 * 71 * sp, fp, and %i7, the caller's return address, are all restored 72 * to the values they had at the time of the call to setjmp(). All 73 * other locals, ins and outs are set to potentially random values 74 * (as per the man page). This is sufficient to permit the correct 75 * operation of normal code. 76 * 77 * Actually, the above description is not quite correct. If the routine 78 * that called setjmp() has not altered the sp value of their frame we 79 * will restore the remaining locals and ins to the values these 80 * registers had in the this frame at the time of the call to longjmp() 81 * (not setjmp()!). This is intended to help compilers, typically not 82 * C compilers, that have some registers assigned to fixed purposes, 83 * and that only alter the values of these registers on function entry 84 * and exit. 85 * 86 * Since a C routine could call setjmp() followed by alloca() and thus 87 * alter the sp this feature will typically not be helpful for a C 88 * compiler. 89 * 90 * Note also that because the caller of a routine compiled "flat" (without 91 * register windows) assumes that their ins and locals are preserved, 92 * routines that call setjmp() must not be flat. 93 */ 94 ENTRY(longjmp) 95 ta ST_FLUSH_WINDOWS ! flush all reg windows to the stack. 96 ld [%o0 + JB_SP], %o2 ! sp in %o2 until safe to puke there 97 ldd [%o2 + (0*8)], %l0 ! restore locals and ins if we can 98 ldd [%o2 + (1*8)], %l2 99 ldd [%o2 + (2*8)], %l4 100 ldd [%o2 + (3*8)], %l6 101 ldd [%o2 + (4*8)], %i0 102 ldd [%o2 + (5*8)], %i2 103 ldd [%o2 + (6*8)], %i4 104 ld [%o0 + JB_FP], %fp ! restore fp 105 mov %o2, %sp ! restore sp 106 ld [%o0 + JB_I7], %i7 ! restore %i7 107 ld [%o0 + JB_PC], %o3 ! get new return pc 108 tst %o1 ! is return value 0? 109 bnz 1f ! no - leave it alone 110 sub %o3, 8, %o7 ! normalize return (for adb) (dly slot) 111 mov 1, %o1 ! yes - set it to one 1121: 113 retl 114 mov %o1, %o0 ! return (val) 115 116 SET_SIZE(longjmp) 117