1 /* $NetBSD: db_disasm.c,v 1.12 2024/02/07 04:20:26 msaitoh Exp $ */
2
3 /*
4 * Copyright (c) 2017 Ryo Shimizu
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: db_disasm.c,v 1.12 2024/02/07 04:20:26 msaitoh Exp $");
31
32 #ifdef _KERNEL_OPT
33 #include "opt_compat_netbsd32.h"
34 #endif
35
36 #include <sys/param.h>
37 #include <machine/db_machdep.h>
38 #include <ddb/db_interface.h>
39 #include <ddb/db_sym.h>
40 #include <ddb/db_output.h>
41 #include <ddb/db_access.h>
42 #include <ddb/db_user.h>
43
44 #include <aarch64/machdep.h>
45 #include <arch/aarch64/aarch64/disasm.h>
46
47 #include <arm/cpufunc.h>
48
49 static uint32_t
db_disasm_readword(uintptr_t address)50 db_disasm_readword(uintptr_t address)
51 {
52 return db_get_value(address, sizeof(uint32_t), false);
53 }
54
55 static void
db_disasm_printaddr(uintptr_t address)56 db_disasm_printaddr(uintptr_t address)
57 {
58 db_printf("%lx <", address);
59 db_printsym((db_addr_t)address, DB_STGY_ANY, db_printf);
60 db_printf(">");
61 }
62
63 static const disasm_interface_t db_disasm_interface = {
64 .di_readword = db_disasm_readword,
65 .di_printaddr = db_disasm_printaddr,
66 .di_printf = db_printf
67 };
68
69 db_addr_t
db_disasm(db_addr_t loc,bool altfmt)70 db_disasm(db_addr_t loc, bool altfmt)
71 {
72 return disasm(&db_disasm_interface, loc);
73 }
74
75
76 static char *strdisasm_ptr;
77 static char strdisasm_buf[256];
78
79 static uint32_t
strdisasm_readword(uintptr_t address)80 strdisasm_readword(uintptr_t address)
81 {
82 #ifdef _KERNEL
83 /*
84 * if it cannot be read due to a EFAULT etc.,
85 * ignores the error and returns 0
86 */
87 uint32_t word = 0;
88
89 switch (aarch64_addressspace((vaddr_t)address)) {
90 case AARCH64_ADDRSPACE_UPPER:
91 kcopy((void*)address, &word, sizeof(word));
92 break;
93 case AARCH64_ADDRSPACE_LOWER:
94 ufetch_32((uint32_t *)address, &word);
95 break;
96 default:
97 break;
98 }
99
100 return word;
101 #else
102 return *(uint32_t *)address;
103 #endif
104 }
105
106 static void __printflike(1, 2)
strdisasm_printf(const char * fmt,...)107 strdisasm_printf(const char *fmt, ...)
108 {
109 va_list ap;
110 int len;
111
112 /* calculation spaces to append a string */
113 len = strdisasm_buf + sizeof(strdisasm_buf) - strdisasm_ptr;
114
115 va_start(ap, fmt);
116 len = vsnprintf(strdisasm_ptr, len, fmt, ap);
117 va_end(ap);
118
119 strdisasm_ptr += len;
120 }
121
122 static void
strdisasm_printaddr(uintptr_t address)123 strdisasm_printaddr(uintptr_t address)
124 {
125 strdisasm_printf("0x%lx", address);
126 }
127
128 static const disasm_interface_t strdisasm_interface = {
129 .di_readword = strdisasm_readword,
130 .di_printaddr = strdisasm_printaddr,
131 .di_printf = strdisasm_printf
132 };
133
134 const char *
strdisasm(vaddr_t pc,uint64_t spsr)135 strdisasm(vaddr_t pc, uint64_t spsr)
136 {
137 #ifdef COMPAT_NETBSD32
138 if (spsr & SPSR_A32) {
139 uint32_t insn = 0;
140 int size;
141 const char *arch = (spsr & SPSR_A32_T) ? "T32" : "A32";
142
143 size = fetch_arm_insn(pc, spsr, &insn);
144 if (size != 2)
145 size = 4;
146 snprintf(strdisasm_buf, sizeof(strdisasm_buf),
147 ".insn 0x%0*x (%s)", size * 2, insn, arch);
148 } else
149 #endif /* COMPAT_NETBSD32 */
150 {
151 char *p;
152
153 /* disasm an aarch64 instruction */
154 strdisasm_ptr = strdisasm_buf;
155 disasm(&strdisasm_interface, (db_addr_t)pc);
156
157 /* replace tab to space, and chomp '\n' */
158 for (p = strdisasm_buf; *p != '\0'; p++) {
159 if (*p == '\t')
160 *p = ' ';
161 }
162 if ((p > strdisasm_buf) && (p[-1] == '\n'))
163 p[-1] = '\0';
164 }
165
166 return strdisasm_buf;
167 }
168