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 #pragma ident "%Z%%M% %I% %E% SMI" 32 33 #include <sys/proc.h> 34 #include <sys/param.h> 35 #include <sys/cmn_err.h> 36 #include <sys/archsystm.h> 37 #include <sys/copyops.h> 38 #include <vm/seg_enum.h> 39 #include <sys/privregs.h> 40 41 #include <dis_tables.h> 42 43 /* 44 * This subsystem (with the minor exception of the instr_size() function) is 45 * is called from DTrace probe context. This imposes several requirements on 46 * the implementation: 47 * 48 * 1. External subsystems and functions may not be referenced. The one current 49 * exception is for cmn_err, but only to signal the detection of table 50 * errors. Assuming the tables are correct, no combination of input is to 51 * trigger a cmn_err call. 52 * 53 * 2. These functions can't be allowed to be traced. To prevent this, 54 * all functions in the probe path (everything except instr_size()) must 55 * have names that begin with "dtrace_". 56 */ 57 58 typedef enum dis_isize { 59 DIS_ISIZE_INSTR, 60 DIS_ISIZE_OPERAND 61 } dis_isize_t; 62 63 64 /* 65 * get a byte from instruction stream 66 */ 67 static int 68 dtrace_dis_get_byte(void *p) 69 { 70 int ret; 71 uchar_t **instr = p; 72 73 ret = **instr; 74 *instr += 1; 75 76 return (ret); 77 } 78 79 /* 80 * Returns either the size of a given instruction, in bytes, or the size of that 81 * instruction's memory access (if any), depending on the value of `which'. 82 * If a programming error in the tables is detected, the system will panic to 83 * ease diagnosis. Invalid instructions will not be flagged. They will appear 84 * to have an instruction size between 1 and the actual size, and will be 85 * reported as having no memory impact. 86 */ 87 /* ARGSUSED2 */ 88 static int 89 dtrace_dis_isize(uchar_t *instr, dis_isize_t which, model_t model, int *rmindex) 90 { 91 int sz; 92 dis86_t x; 93 uint_t mode = SIZE32; 94 95 mode = (model == DATAMODEL_LP64) ? SIZE64 : SIZE32; 96 97 x.d86_data = (void **)&instr; 98 x.d86_get_byte = dtrace_dis_get_byte; 99 x.d86_check_func = NULL; 100 101 if (dtrace_disx86(&x, mode) != 0) 102 return (-1); 103 104 if (which == DIS_ISIZE_INSTR) 105 sz = x.d86_len; /* length of the instruction */ 106 else 107 sz = x.d86_memsize; /* length of memory operand */ 108 109 if (rmindex != NULL) 110 *rmindex = x.d86_rmindex; 111 return (sz); 112 } 113 114 int 115 dtrace_instr_size_isa(uchar_t *instr, model_t model, int *rmindex) 116 { 117 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, model, rmindex)); 118 } 119 120 int 121 dtrace_instr_size(uchar_t *instr) 122 { 123 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE, 124 NULL)); 125 } 126 127 /*ARGSUSED*/ 128 int 129 instr_size(struct regs *rp, caddr_t *addrp, enum seg_rw rw) 130 { 131 uchar_t instr[16]; /* maximum size instruction */ 132 caddr_t pc = (caddr_t)rp->r_pc; 133 134 (void) copyin_nowatch(pc, (caddr_t)instr, sizeof (instr)); 135 136 return (dtrace_dis_isize(instr, 137 rw == S_EXEC ? DIS_ISIZE_INSTR : DIS_ISIZE_OPERAND, 138 curproc->p_model, NULL)); 139 } 140