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 #include <sys/proc.h> 32 #include <sys/param.h> 33 #include <sys/cmn_err.h> 34 #include <sys/archsystm.h> 35 #include <sys/copyops.h> 36 #include <vm/seg_enum.h> 37 #include <sys/privregs.h> 38 39 #include <dis_tables.h> 40 41 /* 42 * This subsystem (with the minor exception of the instr_size() function) is 43 * is called from DTrace probe context. This imposes several requirements on 44 * the implementation: 45 * 46 * 1. External subsystems and functions may not be referenced. The one current 47 * exception is for cmn_err, but only to signal the detection of table 48 * errors. Assuming the tables are correct, no combination of input is to 49 * trigger a cmn_err call. 50 * 51 * 2. These functions can't be allowed to be traced. To prevent this, 52 * all functions in the probe path (everything except instr_size()) must 53 * have names that begin with "dtrace_". 54 */ 55 56 typedef enum dis_isize { 57 DIS_ISIZE_INSTR, 58 DIS_ISIZE_OPERAND 59 } dis_isize_t; 60 61 62 /* 63 * get a byte from instruction stream 64 */ 65 static int 66 dtrace_dis_get_byte(void *p) 67 { 68 int ret; 69 uchar_t **instr = p; 70 71 ret = **instr; 72 *instr += 1; 73 74 return (ret); 75 } 76 77 /* 78 * Returns either the size of a given instruction, in bytes, or the size of that 79 * instruction's memory access (if any), depending on the value of `which'. 80 * If a programming error in the tables is detected, the system will panic to 81 * ease diagnosis. Invalid instructions will not be flagged. They will appear 82 * to have an instruction size between 1 and the actual size, and will be 83 * reported as having no memory impact. 84 */ 85 /* ARGSUSED2 */ 86 static int 87 dtrace_dis_isize(uchar_t *instr, dis_isize_t which, model_t model, int *rmindex) 88 { 89 int sz; 90 dis86_t x; 91 uint_t mode = SIZE32; 92 93 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 94 95 x.d86_data = (void **)&instr; 96 x.d86_get_byte = dtrace_dis_get_byte; 97 x.d86_check_func = NULL; 98 99 if (dtrace_disx86(&x, mode) != 0) 100 return (-1); 101 102 if (which == DIS_ISIZE_INSTR) 103 sz = x.d86_len; /* length of the instruction */ 104 else 105 sz = x.d86_memsize; /* length of memory operand */ 106 107 if (rmindex != NULL) 108 *rmindex = x.d86_rmindex; 109 return (sz); 110 } 111 112 int 113 dtrace_instr_size_isa(uchar_t *instr, model_t model, int *rmindex) 114 { 115 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 116 } 117 118 int 119 dtrace_instr_size(uchar_t *instr) 120 { 121 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 122 NULL)); 123 } 124 125 /*ARGSUSED*/ 126 int 127 instr_size(struct regs *rp, caddr_t *addrp, enum seg_rw rw) 128 { 129 uchar_t instr[16]; /* maximum size instruction */ 130 caddr_t pc = (caddr_t)rp->r_pc; 131 132 (void) copyin_nowatch(pc, (caddr_t)instr, sizeof (instr)); 133 134 return (dtrace_dis_isize(instr, 135 rw == S_EXEC ? DIS_ISIZE_INSTR : DIS_ISIZE_OPERAND, 136 curproc->p_model, NULL)); 137 } 138