1 /* $NetBSD: kgdb_machdep.c,v 1.10 2020/06/20 15:45:22 skrll Exp $ */
2
3 /*
4 * Copyright (c) 1996 Matthias Pfaller.
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 WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: kgdb_machdep.c,v 1.10 2020/06/20 15:45:22 skrll Exp $");
30
31 #include "opt_ddb.h"
32 #include "opt_kgdb.h"
33
34 #include <sys/param.h>
35
36 #include <sys/kgdb.h>
37 #include <sys/systm.h>
38
39 #include <uvm/uvm_extern.h>
40
41 #include <machine/frame.h>
42 #include <machine/reg.h>
43 #include <machine/trap.h>
44
45 /*
46 * Determine if the memory at va..(va+len) is valid.
47 */
48 int
kgdb_acc(vaddr_t va,size_t len)49 kgdb_acc(vaddr_t va, size_t len)
50 {
51 vaddr_t last_va;
52
53 last_va = va + len;
54 va &= ~PGOFSET;
55 last_va &= ~PGOFSET;
56
57 do {
58 if (db_validate_address(va))
59 return 0;
60 va += PAGE_SIZE;
61 } while (va < last_va);
62
63 return 1;
64 }
65
66 /*
67 * Translate a trap number into a unix compatible signal value.
68 * (gdb only understands unix signal numbers).
69 */
70 int
kgdb_signal(int type)71 kgdb_signal(int type)
72 {
73
74 switch (type) {
75 case T_BREAKPOINT:
76 return(SIGTRAP);
77 case -1:
78 return(SIGSEGV);
79 default:
80 return(SIGINT);
81 }
82 }
83
84 /*
85 * Definitions exported from gdb.
86 */
87
88 /*
89 * Translate the values stored in the kernel regs struct to the format
90 * understood by gdb.
91 */
92 void
kgdb_getregs(db_regs_t * regs,kgdb_reg_t * gdb_regs)93 kgdb_getregs(db_regs_t *regs, kgdb_reg_t *gdb_regs)
94 {
95
96 gdb_regs[KGDB_REGNUM_R0 + 0] = regs->tf_r0;
97 gdb_regs[KGDB_REGNUM_R0 + 1] = regs->tf_r1;
98 gdb_regs[KGDB_REGNUM_R0 + 2] = regs->tf_r2;
99 gdb_regs[KGDB_REGNUM_R0 + 3] = regs->tf_r3;
100 gdb_regs[KGDB_REGNUM_R0 + 4] = regs->tf_r4;
101 gdb_regs[KGDB_REGNUM_R0 + 5] = regs->tf_r5;
102 gdb_regs[KGDB_REGNUM_R0 + 6] = regs->tf_r6;
103 gdb_regs[KGDB_REGNUM_R0 + 7] = regs->tf_r7;
104 gdb_regs[KGDB_REGNUM_R0 + 8] = regs->tf_r8;
105 gdb_regs[KGDB_REGNUM_R0 + 9] = regs->tf_r9;
106 gdb_regs[KGDB_REGNUM_R0 + 10] = regs->tf_r10;
107 gdb_regs[KGDB_REGNUM_R0 + 11] = regs->tf_r11;
108 gdb_regs[KGDB_REGNUM_R0 + 12] = regs->tf_r12;
109 gdb_regs[KGDB_REGNUM_R0 + 13] = regs->tf_svc_sp;
110 gdb_regs[KGDB_REGNUM_R0 + 14] = regs->tf_svc_lr;
111 gdb_regs[KGDB_REGNUM_R0 + 15] = regs->tf_pc;
112
113 gdb_regs[KGDB_REGNUM_SPSR] = regs->tf_spsr;
114 }
115
116 /*
117 * Reverse the above.
118 */
119 void
kgdb_setregs(db_regs_t * regs,kgdb_reg_t * gdb_regs)120 kgdb_setregs(db_regs_t *regs, kgdb_reg_t *gdb_regs)
121 {
122 regs->tf_r0 = gdb_regs[KGDB_REGNUM_R0 + 0];
123 regs->tf_r1 = gdb_regs[KGDB_REGNUM_R0 + 1];
124 regs->tf_r2 = gdb_regs[KGDB_REGNUM_R0 + 2];
125 regs->tf_r3 = gdb_regs[KGDB_REGNUM_R0 + 3];
126 regs->tf_r4 = gdb_regs[KGDB_REGNUM_R0 + 4];
127 regs->tf_r5 = gdb_regs[KGDB_REGNUM_R0 + 5];
128 regs->tf_r6 = gdb_regs[KGDB_REGNUM_R0 + 6];
129 regs->tf_r7 = gdb_regs[KGDB_REGNUM_R0 + 7];
130 regs->tf_r8 = gdb_regs[KGDB_REGNUM_R0 + 8];
131 regs->tf_r9 = gdb_regs[KGDB_REGNUM_R0 + 9];
132 regs->tf_r10 = gdb_regs[KGDB_REGNUM_R0 + 10];
133 regs->tf_r11 = gdb_regs[KGDB_REGNUM_R0 + 11];
134 regs->tf_r12 = gdb_regs[KGDB_REGNUM_R0 + 12];
135 regs->tf_svc_sp = gdb_regs[KGDB_REGNUM_R0 + 13];
136 regs->tf_svc_lr = gdb_regs[KGDB_REGNUM_R0 + 14];
137 regs->tf_pc = gdb_regs[KGDB_REGNUM_R0 + 15];
138
139 regs->tf_spsr = gdb_regs[KGDB_REGNUM_SPSR];
140 }
141
142 /*
143 * Trap into kgdb to wait for debugger to connect,
144 * noting on the console why nothing else is going on.
145 */
146 void
kgdb_connect(int verbose)147 kgdb_connect(int verbose)
148 {
149
150 if (kgdb_dev == NODEV)
151 return;
152
153 if (verbose)
154 printf("kgdb waiting...");
155
156 __asm volatile(KBPT_ASM);
157
158 if (verbose)
159 printf("connected.\n");
160
161 kgdb_debug_panic = 1;
162 }
163
164 /*
165 * Decide what to do on panic.
166 * (This is called by panic, like Debugger())
167 */
168 void
kgdb_panic(void)169 kgdb_panic(void)
170 {
171
172 if (kgdb_dev != NODEV && kgdb_debug_panic) {
173 printf("entering kgdb\n");
174 kgdb_connect(kgdb_active == 0);
175 }
176 }
177