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 * $FreeBSD$ 23 */ 24/* 25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 26 * Use is subject to license terms. 27 */ 28 29/* Copyright (c) 1988 AT&T */ 30/* All Rights Reserved */ 31 32 33#ifdef illumos 34#pragma ident "@(#)instr_size.c 1.14 05/07/08 SMI" 35#endif 36 37#include <sys/types.h> 38#include <sys/param.h> 39#include <sys/proc.h> 40#ifdef illumos 41#include <sys/cmn_err.h> 42#include <sys/archsystm.h> 43#include <sys/copyops.h> 44#include <vm/seg_enum.h> 45#include <sys/privregs.h> 46#else 47typedef u_int model_t; 48#define DATAMODEL_NATIVE 0 49int dtrace_instr_size(uchar_t *); 50int dtrace_instr_size_isa(uchar_t *, model_t, int *); 51#endif 52 53#include <dis_tables.h> 54 55/* 56 * This subsystem (with the minor exception of the instr_size() function) is 57 * is called from DTrace probe context. This imposes several requirements on 58 * the implementation: 59 * 60 * 1. External subsystems and functions may not be referenced. The one current 61 * exception is for cmn_err, but only to signal the detection of table 62 * errors. Assuming the tables are correct, no combination of input is to 63 * trigger a cmn_err call. 64 * 65 * 2. These functions can't be allowed to be traced. To prevent this, 66 * all functions in the probe path (everything except instr_size()) must 67 * have names that begin with "dtrace_". 68 */ 69 70typedef enum dis_isize { 71 DIS_ISIZE_INSTR, 72 DIS_ISIZE_OPERAND 73} dis_isize_t; 74 75 76/* 77 * get a byte from instruction stream 78 */ 79static int 80dtrace_dis_get_byte(void *p) 81{ 82 int ret; 83 uchar_t **instr = p; 84 85 ret = **instr; 86 *instr += 1; 87 88 return (ret); 89} 90 91/* 92 * Returns either the size of a given instruction, in bytes, or the size of that 93 * instruction's memory access (if any), depending on the value of `which'. 94 * If a programming error in the tables is detected, the system will panic to 95 * ease diagnosis. Invalid instructions will not be flagged. They will appear 96 * to have an instruction size between 1 and the actual size, and will be 97 * reported as having no memory impact. 98 */ 99/* ARGSUSED2 */ 100static int 101dtrace_dis_isize(uchar_t *instr, dis_isize_t which, model_t model, int *rmindex) 102{ 103 int sz; 104 dis86_t x; 105 uint_t mode = SIZE32; 106 107#ifdef illumos 108 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 109#endif 110 111 x.d86_data = (void **)&instr; 112 x.d86_get_byte = dtrace_dis_get_byte; 113 x.d86_check_func = NULL; 114 115 if (dtrace_disx86(&x, mode) != 0) 116 return (-1); 117 118 if (which == DIS_ISIZE_INSTR) 119 sz = x.d86_len; /* length of the instruction */ 120 else 121 sz = x.d86_memsize; /* length of memory operand */ 122 123 if (rmindex != NULL) 124 *rmindex = x.d86_rmindex; 125 return (sz); 126} 127 128int 129dtrace_instr_size_isa(uchar_t *instr, model_t model, int *rmindex) 130{ 131 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 132} 133 134int 135dtrace_instr_size(uchar_t *instr) 136{ 137 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 138 NULL)); 139} 140