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/* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27#pragma ident "%Z%%M% %I% %E% SMI" 28 29#if defined(__lint) 30#include <setjmp.h> 31#endif 32 33#include <sys/asm_linkage.h> 34 35/* 36 * This is a copy of the setjmp (and longjmp) code used in libc. Note that 37 * we use sigsetjmp as an alias for setjmp, with a corresponding alias between 38 * siglongjmp and longjmp. We can do this because there aren't any signals 39 * in kmdb (with the possible exception of the smoke signals the machine will 40 * emit when we break something). We can also use a sigjmp_buf as a jmp_buf, 41 * since the latter is smaller than the former. 42 */ 43 44#if !defined(__lint) 45JB_FLAGS = (0*8) ! offsets in jmpbuf (see sigsetjmp.c) 46JB_SP = (1*8) ! words 5 through 11 are unused! 47JB_PC = (2*8) 48JB_FP = (3*8) 49JB_I7 = (4*8) 50#endif 51 52/* 53 * setjmp(buf_ptr) 54 * buf_ptr points to a twelve word array (jmp_buf) 55 */ 56 57#if defined(__lint) 58/* ARGSUSED */ 59int 60setjmp(jmp_buf env) 61{ 62 return (0); 63} 64 65/* ARGSUSED */ 66int 67sigsetjmp(sigjmp_buf env, int savemask) 68{ 69 return (0); 70} 71#else /* __lint */ 72 73 ENTRY(setjmp) 74 ALTENTRY(sigsetjmp) 75 clr [%o0 + JB_FLAGS] ! clear flags (used by sigsetjmp) 76 stx %sp, [%o0 + JB_SP] ! save caller's sp 77 add %o7, 8, %o1 ! compute return pc 78 stx %o1, [%o0 + JB_PC] ! save pc 79 stx %fp, [%o0 + JB_FP] ! save fp 80 stx %i7, [%o0 + JB_I7] ! save %i7 81 flushw 82 retl 83 clr %o0 ! return (0) 84 85 SET_SIZE(setjmp) 86#endif /* __lint */ 87 88/* 89 * longjmp(buf_ptr, val) 90 * buf_ptr points to a jmpbuf which has been initialized by setjmp. 91 * val is the value we wish to return to setjmp's caller 92 * 93 * We flush the register file to the stack by doing a kernel call. 94 * This is necessary to ensure that the registers we want to 95 * pick up are stored on the stack, and that subsequent restores 96 * will function correctly. 97 * 98 * sp, fp, and %i7, the caller's return address, are all restored 99 * to the values they had at the time of the call to setjmp(). All 100 * other locals, ins and outs are set to potentially random values 101 * (as per the man page). This is sufficient to permit the correct 102 * operation of normal code. 103 * 104 * Actually, the above description is not quite correct. If the routine 105 * that called setjmp() has not altered the sp value of their frame we 106 * will restore the remaining locals and ins to the values these 107 * registers had in the this frame at the time of the call to longjmp() 108 * (not setjmp()!). This is intended to help compilers, typically not 109 * C compilers, that have some registers assigned to fixed purposes, 110 * and that only alter the values of these registers on function entry 111 * and exit. 112 * 113 * Since a C routine could call setjmp() followed by alloca() and thus 114 * alter the sp this feature will typically not be helpful for a C 115 * compiler. 116 * 117 * Note also that because the caller of a routine compiled "flat" (without 118 * register windows) assumes that their ins and locals are preserved, 119 * routines that call setjmp() must not be flat. 120 */ 121 122#if defined(__lint) 123/* ARGSUSED */ 124void 125longjmp(jmp_buf env, int val) 126{ 127} 128 129/* ARGSUSED */ 130void 131siglongjmp(sigjmp_buf env, int val) 132{ 133} 134#else /* __lint */ 135 136 ENTRY(longjmp) 137 ALTENTRY(siglongjmp) 138 139 /* flush all reg windows to the stack. */ 140 save 141 flushw 142 restore 143 nop 144 145 ldx [%o0 + JB_SP], %o2 ! sp in %o2 until safe to puke there 146 ldx [%o2 + STACK_BIAS], %l0 ! restore locals and ins if we can 147 ldx [%o2 + (1*8) + STACK_BIAS], %l1 148 ldx [%o2 + (2*8) + STACK_BIAS], %l2 149 ldx [%o2 + (3*8) + STACK_BIAS], %l3 150 ldx [%o2 + (4*8) + STACK_BIAS], %l4 151 ldx [%o2 + (5*8) + STACK_BIAS], %l5 152 ldx [%o2 + (6*8) + STACK_BIAS], %l6 153 ldx [%o2 + (7*8) + STACK_BIAS], %l7 154 ldx [%o2 + (8*8) + STACK_BIAS], %i0 155 ldx [%o2 + (9*8) + STACK_BIAS], %i1 156 ldx [%o2 + (10*8) + STACK_BIAS], %i2 157 ldx [%o2 + (11*8) + STACK_BIAS], %i3 158 ldx [%o2 + (12*8) + STACK_BIAS], %i4 159 ldx [%o2 + (13*8) + STACK_BIAS], %i5 160 ldx [%o0 + JB_FP], %fp ! restore fp 161 mov %o2, %sp ! restore sp 162 ldx [%o0 + JB_I7], %i7 ! restore %i7 163 ldx [%o0 + JB_PC], %o3 ! get new return pc 164 tst %o1 ! is return value 0? 165 bnz 1f ! no - leave it alone 166 sub %o3, 8, %o7 ! normalize return (for adb) (dly slot) 167 mov 1, %o1 ! yes - set it to one 1681: 169 retl 170 mov %o1, %o0 ! return (val) 171 172 SET_SIZE(longjmp) 173#endif /* __lint */ 174