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 #include <sys/types.h> 31 #include <sys/param.h> 32 #include <sys/proc.h> 33 #ifdef illumos 34 #include <sys/cmn_err.h> 35 #include <sys/archsystm.h> 36 #include <sys/copyops.h> 37 #include <vm/seg_enum.h> 38 #include <sys/privregs.h> 39 #else 40 #include <sys/cred.h> 41 #include <cddl/dev/dtrace/dtrace_cddl.h> 42 43 typedef u_int model_t; 44 #define DATAMODEL_NATIVE 0 45 int dtrace_dis_get_byte(void *); 46 int dtrace_instr_size(uint8_t *); 47 int dtrace_instr_size_isa(uint8_t *, model_t, int *); 48 #endif 49 50 #include <dis_tables.h> 51 52 /* 53 * This subsystem (with the minor exception of the instr_size() function) is 54 * is called from DTrace probe context. This imposes several requirements on 55 * the implementation: 56 * 57 * 1. External subsystems and functions may not be referenced. The one current 58 * exception is for cmn_err, but only to signal the detection of table 59 * errors. Assuming the tables are correct, no combination of input is to 60 * trigger a cmn_err call. 61 * 62 * 2. These functions can't be allowed to be traced. To prevent this, 63 * all functions in the probe path (everything except instr_size()) must 64 * have names that begin with "dtrace_". 65 */ 66 67 typedef enum dis_isize { 68 DIS_ISIZE_INSTR, 69 DIS_ISIZE_OPERAND 70 } dis_isize_t; 71 72 73 /* 74 * get a byte from instruction stream 75 */ 76 int 77 dtrace_dis_get_byte(void *p) 78 { 79 int ret; 80 uint8_t **instr = p; 81 82 ret = **instr; 83 *instr += 1; 84 85 return (ret); 86 } 87 88 /* 89 * Returns either the size of a given instruction, in bytes, or the size of that 90 * instruction's memory access (if any), depending on the value of `which'. 91 * If a programming error in the tables is detected, the system will panic to 92 * ease diagnosis. Invalid instructions will not be flagged. They will appear 93 * to have an instruction size between 1 and the actual size, and will be 94 * reported as having no memory impact. 95 */ 96 /* ARGSUSED2 */ 97 static int 98 dtrace_dis_isize(uint8_t *instr, dis_isize_t which, model_t model, int *rmindex) 99 { 100 int sz; 101 dis86_t x; 102 uint_t mode = SIZE32; 103 104 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 105 106 x.d86_data = (void **)&instr; 107 x.d86_get_byte = dtrace_dis_get_byte; 108 x.d86_check_func = NULL; 109 110 if (dtrace_disx86(&x, mode) != 0) 111 return (-1); 112 113 if (which == DIS_ISIZE_INSTR) 114 sz = x.d86_len; /* length of the instruction */ 115 else 116 sz = x.d86_memsize; /* length of memory operand */ 117 118 if (rmindex != NULL) 119 *rmindex = x.d86_rmindex; 120 return (sz); 121 } 122 123 int 124 dtrace_instr_size_isa(uint8_t *instr, model_t model, int *rmindex) 125 { 126 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 127 } 128 129 int 130 dtrace_instr_size(uint8_t *instr) 131 { 132 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 133 NULL)); 134 } 135