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 2005 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 31 #ifdef illumos 32 #pragma ident "@(#)instr_size.c 1.14 05/07/08 SMI" 33 #endif 34 35 #include <sys/types.h> 36 #include <sys/param.h> 37 #include <sys/proc.h> 38 #ifdef illumos 39 #include <sys/cmn_err.h> 40 #include <sys/archsystm.h> 41 #include <sys/copyops.h> 42 #include <vm/seg_enum.h> 43 #include <sys/privregs.h> 44 #else 45 #include <sys/cred.h> 46 #include <cddl/dev/dtrace/dtrace_cddl.h> 47 48 typedef u_int model_t; 49 #define DATAMODEL_NATIVE 0 50 int dtrace_dis_get_byte(void *); 51 int dtrace_instr_size(uint8_t *); 52 int dtrace_instr_size_isa(uint8_t *, model_t, int *); 53 #endif 54 55 #include <dis_tables.h> 56 57 /* 58 * This subsystem (with the minor exception of the instr_size() function) is 59 * is called from DTrace probe context. This imposes several requirements on 60 * the implementation: 61 * 62 * 1. External subsystems and functions may not be referenced. The one current 63 * exception is for cmn_err, but only to signal the detection of table 64 * errors. Assuming the tables are correct, no combination of input is to 65 * trigger a cmn_err call. 66 * 67 * 2. These functions can't be allowed to be traced. To prevent this, 68 * all functions in the probe path (everything except instr_size()) must 69 * have names that begin with "dtrace_". 70 */ 71 72 typedef enum dis_isize { 73 DIS_ISIZE_INSTR, 74 DIS_ISIZE_OPERAND 75 } dis_isize_t; 76 77 78 /* 79 * get a byte from instruction stream 80 */ 81 int 82 dtrace_dis_get_byte(void *p) 83 { 84 int ret; 85 uint8_t **instr = p; 86 87 ret = **instr; 88 *instr += 1; 89 90 return (ret); 91 } 92 93 /* 94 * Returns either the size of a given instruction, in bytes, or the size of that 95 * instruction's memory access (if any), depending on the value of `which'. 96 * If a programming error in the tables is detected, the system will panic to 97 * ease diagnosis. Invalid instructions will not be flagged. They will appear 98 * to have an instruction size between 1 and the actual size, and will be 99 * reported as having no memory impact. 100 */ 101 /* ARGSUSED2 */ 102 static int 103 dtrace_dis_isize(uint8_t *instr, dis_isize_t which, model_t model, int *rmindex) 104 { 105 int sz; 106 dis86_t x; 107 uint_t mode = SIZE32; 108 109 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 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 } 127 128 int 129 dtrace_instr_size_isa(uint8_t *instr, model_t model, int *rmindex) 130 { 131 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 132 } 133 134 int 135 dtrace_instr_size(uint8_t *instr) 136 { 137 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 138 NULL)); 139 } 140