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 #ifdef __FreeBSD__ 33 #include <sys/_mutex.h> 34 #endif 35 #include <sys/proc.h> 36 #ifdef illumos 37 #include <sys/cmn_err.h> 38 #include <sys/archsystm.h> 39 #include <sys/copyops.h> 40 #include <vm/seg_enum.h> 41 #include <sys/privregs.h> 42 #else 43 #include <sys/cred.h> 44 #include <cddl/dev/dtrace/dtrace_cddl.h> 45 46 typedef u_int model_t; 47 #define DATAMODEL_NATIVE 0 48 int dtrace_dis_get_byte(void *); 49 int dtrace_instr_size(uint8_t *); 50 int dtrace_instr_size_isa(uint8_t *, model_t, int *); 51 #endif 52 53 #include <dis_tables.h> 54 55 /* 56 * This subsystem (with the minor exception of the instr_size() function) is 57 * is called from DTrace probe context. This imposes several requirements on 58 * the implementation: 59 * 60 * 1. External subsystems and functions may not be referenced. The one current 61 * exception is for cmn_err, but only to signal the detection of table 62 * errors. Assuming the tables are correct, no combination of input is to 63 * trigger a cmn_err call. 64 * 65 * 2. These functions can't be allowed to be traced. To prevent this, 66 * all functions in the probe path (everything except instr_size()) must 67 * have names that begin with "dtrace_". 68 */ 69 70 typedef enum dis_isize { 71 DIS_ISIZE_INSTR, 72 DIS_ISIZE_OPERAND 73 } dis_isize_t; 74 75 76 /* 77 * get a byte from instruction stream 78 */ 79 int 80 dtrace_dis_get_byte(void *p) 81 { 82 int ret; 83 uint8_t **instr = p; 84 85 ret = **instr; 86 *instr += 1; 87 88 return (ret); 89 } 90 91 /* 92 * Returns either the size of a given instruction, in bytes, or the size of that 93 * instruction's memory access (if any), depending on the value of `which'. 94 * If a programming error in the tables is detected, the system will panic to 95 * ease diagnosis. Invalid instructions will not be flagged. They will appear 96 * to have an instruction size between 1 and the actual size, and will be 97 * reported as having no memory impact. 98 */ 99 /* ARGSUSED2 */ 100 static int 101 dtrace_dis_isize(uint8_t *instr, dis_isize_t which, model_t model, int *rmindex) 102 { 103 int sz; 104 dis86_t x; 105 uint_t mode = SIZE32; 106 107 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 108 109 x.d86_data = (void **)&instr; 110 x.d86_get_byte = dtrace_dis_get_byte; 111 x.d86_check_func = NULL; 112 113 if (dtrace_disx86(&x, mode) != 0) 114 return (-1); 115 116 if (which == DIS_ISIZE_INSTR) 117 sz = x.d86_len; /* length of the instruction */ 118 else 119 sz = x.d86_memsize; /* length of memory operand */ 120 121 if (rmindex != NULL) 122 *rmindex = x.d86_rmindex; 123 return (sz); 124 } 125 126 int 127 dtrace_instr_size_isa(uint8_t *instr, model_t model, int *rmindex) 128 { 129 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 130 } 131 132 int 133 dtrace_instr_size(uint8_t *instr) 134 { 135 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 136 NULL)); 137 } 138