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
dtrace_dis_get_byte(void * p)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
dtrace_dis_isize(uint8_t * instr,dis_isize_t which,model_t model,int * rmindex)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
dtrace_instr_size_isa(uint8_t * instr,model_t model,int * rmindex)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
dtrace_instr_size(uint8_t * instr)133 dtrace_instr_size(uint8_t *instr)
134 {
135 return (dtrace_dis_isize(instr, DIS_ISIZE_INSTR, DATAMODEL_NATIVE,
136 NULL));
137 }
138