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_dis_get_byte(void *); 53 int dtrace_instr_size(uint8_t *); 54 int dtrace_instr_size_isa(uint8_t *, model_t, int *); 55 #endif 56 57 #include <dis_tables.h> 58 59 /* 60 * This subsystem (with the minor exception of the instr_size() function) is 61 * is called from DTrace probe context. This imposes several requirements on 62 * the implementation: 63 * 64 * 1. External subsystems and functions may not be referenced. The one current 65 * exception is for cmn_err, but only to signal the detection of table 66 * errors. Assuming the tables are correct, no combination of input is to 67 * trigger a cmn_err call. 68 * 69 * 2. These functions can't be allowed to be traced. To prevent this, 70 * all functions in the probe path (everything except instr_size()) must 71 * have names that begin with "dtrace_". 72 */ 73 74 typedef enum dis_isize { 75 DIS_ISIZE_INSTR, 76 DIS_ISIZE_OPERAND 77 } dis_isize_t; 78 79 80 /* 81 * get a byte from instruction stream 82 */ 83 int 84 dtrace_dis_get_byte(void *p) 85 { 86 int ret; 87 uint8_t **instr = p; 88 89 ret = **instr; 90 *instr += 1; 91 92 return (ret); 93 } 94 95 /* 96 * Returns either the size of a given instruction, in bytes, or the size of that 97 * instruction's memory access (if any), depending on the value of `which'. 98 * If a programming error in the tables is detected, the system will panic to 99 * ease diagnosis. Invalid instructions will not be flagged. They will appear 100 * to have an instruction size between 1 and the actual size, and will be 101 * reported as having no memory impact. 102 */ 103 /* ARGSUSED2 */ 104 static int 105 dtrace_dis_isize(uint8_t *instr, dis_isize_t which, model_t model, int *rmindex) 106 { 107 int sz; 108 dis86_t x; 109 uint_t mode = SIZE32; 110 111 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 112 113 x.d86_data = (void **)&instr; 114 x.d86_get_byte = dtrace_dis_get_byte; 115 x.d86_check_func = NULL; 116 117 if (dtrace_disx86(&x, mode) != 0) 118 return (-1); 119 120 if (which == DIS_ISIZE_INSTR) 121 sz = x.d86_len; /* length of the instruction */ 122 else 123 sz = x.d86_memsize; /* length of memory operand */ 124 125 if (rmindex != NULL) 126 *rmindex = x.d86_rmindex; 127 return (sz); 128 } 129 130 int 131 dtrace_instr_size_isa(uint8_t *instr, model_t model, int *rmindex) 132 { 133 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 134 } 135 136 int 137 dtrace_instr_size(uint8_t *instr) 138 { 139 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 140 NULL)); 141 } 142