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
dtrace_dis_get_byte(void * p)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
dtrace_dis_isize(uint8_t * instr,dis_isize_t which,model_t model,int * rmindex)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
dtrace_instr_size_isa(uint8_t * instr,model_t model,int * rmindex)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
dtrace_instr_size(uint8_t * instr)130 dtrace_instr_size(uint8_t *instr)
131 {
132 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE,
133 NULL));
134 }
135