1/* $NetBSD: db_access.c,v 1.22 2015/06/06 22:06:05 matt 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 1.22 2015/06/06 22:06:05 matt 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
58db_expr_t
59db_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 db_expr_t value;
63 size_t i;
64
65 db_read_bytes(addr, size, data);
66
67 value = 0;
68#if BYTE_ORDER == LITTLE_ENDIAN
69 for (i = size; i-- > 0;)
70#else /* BYTE_ORDER == BIG_ENDIAN */
71 for (i = 0; i < size; i++)
72#endif /* BYTE_ORDER */
73 value = (value << 8) + (data[i] & 0xFF);
74
75 if (size < sizeof(db_expr_t) && is_signed
76 && (value & ((db_expr_t)1 << (8*size - 1)))) {
77 value |= ~(db_expr_t)0 << (8*size - 1);
78 }
79 return (value);
80}
81
82void
83db_put_value(db_addr_t addr, size_t size, db_expr_t value)
84{
85 char data[sizeof(db_expr_t)] __aligned(sizeof(db_expr_t));
86 size_t i;
87
88#if BYTE_ORDER == LITTLE_ENDIAN
89 for (i = 0; i < size; i++)
90#else /* BYTE_ORDER == BIG_ENDIAN */
91 for (i = size; i-- > 0;)
92#endif /* BYTE_ORDER */
93 {
94 data[i] = value & 0xFF;
95 value >>= 8;
96 }
97
98 db_write_bytes(addr, size, data);
99}
100
101#endif /* _COMPILE_THIS || KGDB && SOFTWARE_SSTEP */
102
103#ifdef _COMPILE_THIS
104
105void *
106db_read_ptr(const char *name)
107{
108 db_expr_t val;
109 void *p;
110
111 if (!db_value_of_name(name, &val)) {
112 db_printf("db_read_ptr: cannot find `%s'\n", name);
113 db_error(NULL);
114 /* NOTREACHED */
115 }
116 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p);
117 return p;
118}
119
120int
121db_read_int(const char *name)
122{
123 db_expr_t val;
124 int p;
125
126 if (!db_value_of_name(name, &val)) {
127 db_printf("db_read_int: cannot find `%s'\n", name);
128 db_error(NULL);
129 /* NOTREACHED */
130 }
131 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p);
132 return p;
133}
134
135#endif /* _COMPILE_THIS */
136