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 2010 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 <../assym.h> 38#include <sys/trap.h> 39 40JB_FLAGS = (0*4) ! offsets in jmpbuf (see siglonglmp.c) 41JB_SP = (1*4) ! words 5 through 11 are unused! 42JB_PC = (2*4) 43JB_FP = (3*4) 44JB_I7 = (4*4) 45 46/* 47 * Flag telling longjmp to set curthread->ul_siglink to NULL. 48 */ 49JB_CLEARLINK = 0x10 50 51/* 52 * setjmp(buf_ptr) 53 * buf_ptr points to a twelve word array (jmp_buf) 54 */ 55 ENTRY(setjmp) 56 clr %o2 57 ld [%g7 + UL_SIGLINK], %o1 ! are we in a signal context? 58 tst %o1 59 be,a,pt %icc, 1f 60 mov JB_CLEARLINK, %o2 ! no, tell longjmp to clear ul_siglink 611: st %o2, [%o0 + JB_FLAGS] 62 st %sp, [%o0 + JB_SP] ! save caller's sp 63 add %o7, 8, %o1 ! compute return pc 64 st %o1, [%o0 + JB_PC] ! save pc 65 st %fp, [%o0 + JB_FP] ! save fp 66 st %i7, [%o0 + JB_I7] ! save %i7 67 retl 68 clr %o0 ! return (0) 69 70 SET_SIZE(setjmp) 71 72/* 73 * longjmp(buf_ptr, val) 74 * buf_ptr points to a jmpbuf which has been initialized by setjmp. 75 * val is the value we wish to return to setjmp's caller 76 * 77 * We flush the register file to the stack by doing a kernel call. 78 * This is necessary to ensure that the registers we want to 79 * pick up are stored on the stack, and that subsequent restores 80 * will function correctly. 81 * 82 * sp, fp, and %i7, the caller's return address, are all restored 83 * to the values they had at the time of the call to setjmp(). All 84 * other locals, ins and outs are set to potentially random values 85 * (as per the man page). This is sufficient to permit the correct 86 * operation of normal code. 87 * 88 * Actually, the above description is not quite correct. If the routine 89 * that called setjmp() has not altered the sp value of their frame we 90 * will restore the remaining locals and ins to the values these 91 * registers had in the this frame at the time of the call to longjmp() 92 * (not setjmp()!). This is intended to help compilers, typically not 93 * C compilers, that have some registers assigned to fixed purposes, 94 * and that only alter the values of these registers on function entry 95 * and exit. 96 * 97 * Since a C routine could call setjmp() followed by alloca() and thus 98 * alter the sp this feature will typically not be helpful for a C 99 * compiler. 100 * 101 * Note also that because the caller of a routine compiled "flat" (without 102 * register windows) assumes that their ins and locals are preserved, 103 * routines that call setjmp() must not be flat. 104 */ 105 ENTRY(longjmp) 106 ta ST_FLUSH_WINDOWS ! flush all reg windows to the stack. 107 ld [%o0 + JB_SP], %o2 ! sp in %o2 until safe to puke there 108 ldd [%o2 + (0*8)], %l0 ! restore locals and ins if we can 109 ldd [%o2 + (1*8)], %l2 110 ldd [%o2 + (2*8)], %l4 111 ldd [%o2 + (3*8)], %l6 112 ldd [%o2 + (4*8)], %i0 113 ldd [%o2 + (5*8)], %i2 114 ldd [%o2 + (6*8)], %i4 115 ld [%o0 + JB_FP], %fp ! restore fp 116 mov %o2, %sp ! restore sp 117 ld [%o0 + JB_FLAGS], %o2 118 btst JB_CLEARLINK, %o2 ! test JB_CLEARLINK flag 119 bne,a,pt %icc, 1f 120 clr [%g7 + UL_SIGLINK] ! if set, clear ul_siglink 1211: 122 ld [%o0 + JB_I7], %i7 ! restore %i7 123 ld [%o0 + JB_PC], %o3 ! get new return pc 124 tst %o1 ! is return value 0? 125 bnz 1f ! no - leave it alone 126 sub %o3, 8, %o7 ! normalize return (for adb) (dly slot) 127 mov 1, %o1 ! yes - set it to one 1281: 129 retl 130 mov %o1, %o0 ! return (val) 131 132 SET_SIZE(longjmp) 133