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: head/sys/cddl/dev/dtrace/x86/instr_size.c 303050 2016-07-20 00:02:10Z markj $ 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/proc.h> 39 #include <sys/param.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 #endif 47 #ifdef __FreeBSD__ 48 #include <sys/cred.h> 49 #include <cddl/dev/dtrace/dtrace_cddl.h> 50 51 typedef u_int model_t; 52 #define DATAMODEL_NATIVE 0 53 int dtrace_instr_size(uchar_t *); 54 int dtrace_instr_size_isa(uchar_t *, model_t, int *); 55 #endif 56 #ifdef __NetBSD__ 57 #include <dtrace_cddl.h> 58 59 typedef u_int model_t; 60 #define DATAMODEL_NATIVE 0 61 int dtrace_instr_size(uchar_t *); 62 int dtrace_instr_size_isa(uchar_t *, model_t, int *); 63 #endif 64 65 #include <dis_tables.h> 66 67 /* 68 * This subsystem (with the minor exception of the instr_size() function) is 69 * is called from DTrace probe context. This imposes several requirements on 70 * the implementation: 71 * 72 * 1. External subsystems and functions may not be referenced. The one current 73 * exception is for cmn_err, but only to signal the detection of table 74 * errors. Assuming the tables are correct, no combination of input is to 75 * trigger a cmn_err call. 76 * 77 * 2. These functions can't be allowed to be traced. To prevent this, 78 * all functions in the probe path (everything except instr_size()) must 79 * have names that begin with "dtrace_". 80 */ 81 82 typedef enum dis_isize { 83 DIS_ISIZE_INSTR, 84 DIS_ISIZE_OPERAND 85 } dis_isize_t; 86 87 88 /* 89 * get a byte from instruction stream 90 */ 91 static int 92 dtrace_dis_get_byte(void *p) 93 { 94 int ret; 95 uchar_t **instr = p; 96 97 ret = **instr; 98 *instr += 1; 99 100 return (ret); 101 } 102 103 /* 104 * Returns either the size of a given instruction, in bytes, or the size of that 105 * instruction's memory access (if any), depending on the value of `which'. 106 * If a programming error in the tables is detected, the system will panic to 107 * ease diagnosis. Invalid instructions will not be flagged. They will appear 108 * to have an instruction size between 1 and the actual size, and will be 109 * reported as having no memory impact. 110 */ 111 /* ARGSUSED2 */ 112 static int 113 dtrace_dis_isize(uchar_t *instr, dis_isize_t which, model_t model, int *rmindex) 114 { 115 int sz; 116 dis86_t x; 117 uint_t mode = SIZE32; 118 119 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 120 121 x.d86_data = (void **)&instr; 122 x.d86_get_byte = dtrace_dis_get_byte; 123 x.d86_check_func = NULL; 124 125 if (dtrace_disx86(&x, mode) != 0) 126 return (-1); 127 128 if (which == DIS_ISIZE_INSTR) 129 sz = x.d86_len; /* length of the instruction */ 130 else 131 sz = x.d86_memsize; /* length of memory operand */ 132 133 if (rmindex != NULL) 134 *rmindex = x.d86_rmindex; 135 return (sz); 136 } 137 138 int 139 dtrace_instr_size_isa(uchar_t *instr, model_t model, int *rmindex) 140 { 141 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 142 } 143 144 int 145 dtrace_instr_size(uchar_t *instr) 146 { 147 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 148 NULL)); 149 } 150