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 47 #include <sys/cred.h> 48 #include <cddl/dev/dtrace/dtrace_cddl.h> 49 50 typedef u_int model_t; 51 #define DATAMODEL_NATIVE 0 52 int dtrace_instr_size(uint8_t *); 53 int dtrace_instr_size_isa(uint8_t *, model_t, int *); 54 #endif 55 56 #include <dis_tables.h> 57 58 /* 59 * This subsystem (with the minor exception of the instr_size() function) is 60 * is called from DTrace probe context. This imposes several requirements on 61 * the implementation: 62 * 63 * 1. External subsystems and functions may not be referenced. The one current 64 * exception is for cmn_err, but only to signal the detection of table 65 * errors. Assuming the tables are correct, no combination of input is to 66 * trigger a cmn_err call. 67 * 68 * 2. These functions can't be allowed to be traced. To prevent this, 69 * all functions in the probe path (everything except instr_size()) must 70 * have names that begin with "dtrace_". 71 */ 72 73 typedef enum dis_isize { 74 DIS_ISIZE_INSTR, 75 DIS_ISIZE_OPERAND 76 } dis_isize_t; 77 78 79 /* 80 * get a byte from instruction stream 81 */ 82 static int 83 dtrace_dis_get_byte(void *p) 84 { 85 int ret; 86 uint8_t **instr = p; 87 88 ret = **instr; 89 *instr += 1; 90 91 return (ret); 92 } 93 94 /* 95 * Returns either the size of a given instruction, in bytes, or the size of that 96 * instruction's memory access (if any), depending on the value of `which'. 97 * If a programming error in the tables is detected, the system will panic to 98 * ease diagnosis. Invalid instructions will not be flagged. They will appear 99 * to have an instruction size between 1 and the actual size, and will be 100 * reported as having no memory impact. 101 */ 102 /* ARGSUSED2 */ 103 static int 104 dtrace_dis_isize(uint8_t *instr, dis_isize_t which, model_t model, int *rmindex) 105 { 106 int sz; 107 dis86_t x; 108 uint_t mode = SIZE32; 109 110 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 111 112 x.d86_data = (void **)&instr; 113 x.d86_get_byte = dtrace_dis_get_byte; 114 x.d86_check_func = NULL; 115 116 if (dtrace_disx86(&x, mode) != 0) 117 return (-1); 118 119 if (which == DIS_ISIZE_INSTR) 120 sz = x.d86_len; /* length of the instruction */ 121 else 122 sz = x.d86_memsize; /* length of memory operand */ 123 124 if (rmindex != NULL) 125 *rmindex = x.d86_rmindex; 126 return (sz); 127 } 128 129 int 130 dtrace_instr_size_isa(uint8_t *instr, model_t model, int *rmindex) 131 { 132 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 133 } 134 135 int 136 dtrace_instr_size(uint8_t *instr) 137 { 138 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 139 NULL)); 140 } 141