1 /* $NetBSD: db_access.c,v 1.27 2023/09/01 10:55:23 andvar Exp $ */
2
3 /*
4 * Mach Operating System
5 * Copyright (c) 1991,1990 Carnegie Mellon University
6 * All Rights Reserved.
7 *
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
13 *
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 *
18 * Carnegie Mellon requests users of this software to return to
19 *
20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
24 *
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
27 *
28 * Author: David B. Golub, Carnegie Mellon University
29 * Date: 7/90
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: db_access.c,v 1.27 2023/09/01 10:55:23 andvar Exp $");
34
35 #if defined(_KERNEL_OPT)
36 #include "opt_kgdb.h"
37 #endif
38
39 #include <sys/param.h>
40 #include <sys/proc.h>
41 #include <sys/endian.h>
42
43 #include <ddb/ddb.h>
44
45 /*
46 * Access unaligned data items on aligned (longword)
47 * boundaries.
48 *
49 * This file is shared by ddb, kgdb and crash(8).
50 */
51
52 #if defined(DDB) || !defined(DDB) && !defined(KGDB)
53 #define _COMPILE_THIS
54 #endif
55
56 #if defined(_COMPILE_THIS) || defined(KGDB) && defined(SOFTWARE_SSTEP)
57
58 db_expr_t
db_get_value(db_addr_t addr,size_t size,bool is_signed)59 db_get_value(db_addr_t addr, size_t size, bool is_signed)
60 {
61 char data[sizeof(db_expr_t)] __aligned(sizeof(db_expr_t));
62 uintmax_t uvalue;
63 db_expr_t value;
64 size_t i;
65
66 db_read_bytes(addr, size, data);
67
68 uvalue = 0;
69 #if BYTE_ORDER == LITTLE_ENDIAN
70 for (i = size; i-- > 0;)
71 #else /* BYTE_ORDER == BIG_ENDIAN */
72 for (i = 0; i < size; i++)
73 #endif /* BYTE_ORDER */
74 uvalue = (uvalue << 8) + (data[i] & 0xFF);
75
76 value = (db_expr_t)uvalue;
77
78 if (size < sizeof(db_expr_t) && is_signed
79 && (value & ((db_expr_t)1 << (8*size - 1)))) {
80 value |= (unsigned long)~(db_expr_t)0 << (8*size - 1);
81 }
82 return (value);
83 }
84
85 quad_t
db_get_qvalue(db_addr_t addr,size_t size,bool is_signed)86 db_get_qvalue(db_addr_t addr, size_t size, bool is_signed)
87 {
88 uint64_t data;
89
90 if (size < sizeof(uint64_t)) {
91 if (is_signed)
92 return db_get_value(addr, size, true);
93 return (uint32_t)db_get_value(addr, size, false);
94 }
95
96 if (size != sizeof(data)) {
97 db_error("unsupported size\n");
98 /*NOTREACHED*/
99 }
100
101 db_read_bytes(addr, sizeof(data), (char *)&data);
102 return data;
103 }
104
105 void
db_put_value(db_addr_t addr,size_t size,db_expr_t value)106 db_put_value(db_addr_t addr, size_t size, db_expr_t value)
107 {
108 char data[sizeof(db_expr_t)] __aligned(sizeof(db_expr_t));
109 size_t i;
110
111 #if BYTE_ORDER == LITTLE_ENDIAN
112 for (i = 0; i < size; i++)
113 #else /* BYTE_ORDER == BIG_ENDIAN */
114 for (i = size; i-- > 0;)
115 #endif /* BYTE_ORDER */
116 {
117 data[i] = value & 0xFF;
118 value >>= 8;
119 }
120
121 db_write_bytes(addr, size, data);
122 }
123
124 #endif /* _COMPILE_THIS || KGDB && SOFTWARE_SSTEP */
125
126 #ifdef _COMPILE_THIS
127
128 void *
db_read_ptr(const char * name)129 db_read_ptr(const char *name)
130 {
131 db_expr_t val;
132 void *p;
133
134 if (!db_value_of_name(name, &val)) {
135 db_printf("db_read_ptr: cannot find `%s'\n", name);
136 db_error(NULL);
137 /* NOTREACHED */
138 }
139 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p);
140 return p;
141 }
142
143 int
db_read_int(const char * name)144 db_read_int(const char *name)
145 {
146 db_expr_t val;
147 int p;
148
149 if (!db_value_of_name(name, &val)) {
150 db_printf("db_read_int: cannot find `%s'\n", name);
151 db_error(NULL);
152 /* NOTREACHED */
153 }
154 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p);
155 return p;
156 }
157
158 #endif /* _COMPILE_THIS */
159