1 /* $NetBSD: kgdb_machdep.c,v 1.18 2016/07/11 16:15:36 matt Exp $ */
2
3 /*-
4 * Copyright (c) 1997 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 /*
34 * Copyright (c) 1996 Matthias Pfaller.
35 * All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 *
46 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
47 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
48 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
49 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
50 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
51 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
52 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
53 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
54 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
55 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56 */
57
58 #include <sys/cdefs.h>
59 __KERNEL_RCSID(0, "$NetBSD: kgdb_machdep.c,v 1.18 2016/07/11 16:15:36 matt Exp $");
60
61 #include "opt_ddb.h"
62
63 #if defined(DDB)
64 #error "Can't build DDB and KGDB together."
65 #endif
66
67 /*
68 * Machine-dependent functions for remote KGDB. Originally written
69 * for NetBSD/pc532 by Matthias Pfaller. Modified for NetBSD/i386
70 * by Jason R. Thorpe. Modified for NetBSD/mips by Ethan Solomita
71 */
72
73 #include "opt_cputype.h" /* which mips CPUs do we support? */
74
75 #include <sys/types.h>
76 #include <sys/systm.h>
77 #include <sys/param.h>
78 #include <sys/proc.h>
79 #include <sys/reboot.h>
80 #include <sys/kgdb.h>
81
82 #include <uvm/uvm_extern.h>
83
84 #include <mips/pte.h>
85 #include <mips/cpu.h>
86 #include <mips/locore.h>
87 #include <mips/mips_opcode.h>
88 #include <mips/reg.h>
89 #include <mips/trap.h>
90 #include <dev/cons.h>
91
92 #include <machine/db_machdep.h>
93 #include <ddb/db_access.h>
94
95 /*
96 * Is kva a valid address to access? This is used by KGDB.
97 */
98 static int
kvacc(vaddr_t kva)99 kvacc(vaddr_t kva)
100 {
101 if (pmap_md_direct_mapped_vaddr_p(kva))
102 return 1;
103
104 if (kva < VM_MIN_KERNEL_ADDRESS || kva >= VM_MAX_KERNEL_ADDRESS)
105 return 0;
106
107 const pt_entry_t * const ptep = pmap_pte_lookup(pmap_kernel(), kva);
108 return ptep != NULL && pte_valid_p(*pte);
109 }
110
111 /*
112 * Determine if the memory at va..(va+len) is valid.
113 */
114 int
kgdb_acc(vaddr_t va,size_t len)115 kgdb_acc(vaddr_t va, size_t len)
116 {
117 vaddr_t last_va;
118
119 last_va = va + len + PAGE_SIZE - 1;
120 va &= ~PGOFSET;
121 last_va &= ~PGOFSET;
122
123 for (; va < last_va; va += PAGE_SIZE) {
124 if (kvacc(va) == 0)
125 return 0;
126 }
127
128 return (1);
129 }
130
131 /*
132 * Translate a trap number into a unix compatible signal value.
133 * (gdb only understands unix signal numbers).
134 */
135 int
kgdb_signal(int type)136 kgdb_signal(int type)
137 {
138 switch (type) {
139 case T_TLB_MOD:
140 case T_TLB_MOD+T_USER:
141 case T_TLB_LD_MISS:
142 case T_TLB_ST_MISS:
143 case T_TLB_LD_MISS+T_USER:
144 case T_TLB_ST_MISS+T_USER:
145 case T_ADDR_ERR_LD: /* misaligned access */
146 case T_ADDR_ERR_ST: /* misaligned access */
147 case T_BUS_ERR_LD_ST: /* BERR asserted to CPU */
148 case T_ADDR_ERR_LD+T_USER: /* misaligned or kseg access */
149 case T_ADDR_ERR_ST+T_USER: /* misaligned or kseg access */
150 case T_BUS_ERR_IFETCH+T_USER: /* BERR asserted to CPU */
151 case T_BUS_ERR_LD_ST+T_USER: /* BERR asserted to CPU */
152 return (SIGSEGV);
153
154 case T_BREAK:
155 case T_BREAK+T_USER:
156 return (SIGTRAP);
157
158 case T_RES_INST+T_USER:
159 case T_COP_UNUSABLE+T_USER:
160 return (SIGILL);
161
162 case T_FPE+T_USER:
163 case T_OVFLOW+T_USER:
164 return (SIGFPE);
165
166 default:
167 return (SIGEMT);
168 }
169 }
170
171 mips_reg_t kgdb_cause, kgdb_vaddr; /* set by trap() */
172
173 /*
174 * Translate the values stored in the db_regs_t struct to the format
175 * understood by gdb.
176 */
177 void
kgdb_getregs(db_regs_t * regs,kgdb_reg_t * gdb_regs)178 kgdb_getregs(db_regs_t *regs, kgdb_reg_t *gdb_regs)
179 {
180 memset(gdb_regs, 0, KGDB_NUMREGS * sizeof(kgdb_reg_t));
181 gdb_regs[ 1] = regs->r_regs[_R_AST]; /* AT */
182 gdb_regs[ 2] = regs->r_regs[_R_V0]; /* V0 */
183 gdb_regs[ 3] = regs->r_regs[_R_V1]; /* V1 */
184 gdb_regs[ 4] = regs->r_regs[_R_A0]; /* A0 */
185 gdb_regs[ 5] = regs->r_regs[_R_A1]; /* A1 */
186 gdb_regs[ 6] = regs->r_regs[_R_A2]; /* A2 */
187 gdb_regs[ 7] = regs->r_regs[_R_A3]; /* A3 */
188 gdb_regs[ 8] = regs->r_regs[_R_T0]; /* T0 */
189 gdb_regs[ 9] = regs->r_regs[_R_T1]; /* T1 */
190 gdb_regs[10] = regs->r_regs[_R_T2]; /* T2 */
191 gdb_regs[11] = regs->r_regs[_R_T3]; /* T3 */
192 gdb_regs[12] = regs->r_regs[_R_T4]; /* T4 */
193 gdb_regs[13] = regs->r_regs[_R_T5]; /* T5 */
194 gdb_regs[14] = regs->r_regs[_R_T6]; /* T6 */
195 gdb_regs[15] = regs->r_regs[_R_T7]; /* T7 */
196 gdb_regs[16] = regs->r_regs[_R_S0]; /* S0 */
197 gdb_regs[17] = regs->r_regs[_R_S1]; /* S1 */
198 gdb_regs[18] = regs->r_regs[_R_S2]; /* S2 */
199 gdb_regs[19] = regs->r_regs[_R_S3]; /* S3 */
200 gdb_regs[20] = regs->r_regs[_R_S4]; /* S4 */
201 gdb_regs[21] = regs->r_regs[_R_S5]; /* S5 */
202 gdb_regs[22] = regs->r_regs[_R_S6]; /* S6 */
203 gdb_regs[23] = regs->r_regs[_R_S7]; /* S7 */
204 gdb_regs[24] = regs->r_regs[_R_T8]; /* T8 */
205 gdb_regs[25] = regs->r_regs[_R_T9]; /* T9 */
206 gdb_regs[28] = regs->r_regs[_R_GP]; /* GP */
207 gdb_regs[29] = regs->r_regs[_R_SP]; /* SP */
208 gdb_regs[30] = regs->r_regs[_R_S8]; /* S8 */
209 gdb_regs[31] = regs->r_regs[_R_RA]; /* RA */
210 gdb_regs[32] = regs->r_regs[_R_SR]; /* SR */
211 gdb_regs[33] = regs->r_regs[_R_MULLO]; /* MULLO */
212 gdb_regs[34] = regs->r_regs[_R_MULHI]; /* MULHI */
213 gdb_regs[35] = kgdb_vaddr; /* BAD VADDR */
214 gdb_regs[36] = kgdb_cause; /* CAUSE */
215 gdb_regs[37] = regs->r_regs[_R_PC]; /* PC */
216 }
217
218 /*
219 * Reverse the above.
220 */
221 void
kgdb_setregs(db_regs_t * regs,kgdb_reg_t * gdb_regs)222 kgdb_setregs(db_regs_t *regs, kgdb_reg_t *gdb_regs)
223 {
224 regs->r_regs[_R_PC] = gdb_regs[37]; /* PC */
225 }
226
227 /*
228 * Trap into kgdb to wait for debugger to connect,
229 * noting on the console why nothing else is going on.
230 */
231 void
kgdb_connect(int verbose)232 kgdb_connect(int verbose)
233 {
234 if (kgdb_dev < 0)
235 return;
236
237 if (verbose)
238 printf("kgdb waiting...");
239
240 __asm("break");
241
242 if (verbose)
243 printf("connected.\n");
244
245 kgdb_debug_panic = 1;
246 }
247
248 /*
249 * Decide what to do on panic.
250 * (This is called by panic, like Debugger())
251 */
252 void
kgdb_panic(void)253 kgdb_panic(void)
254 {
255 if (kgdb_dev != NODEV && kgdb_debug_panic) {
256 printf("entering kgdb\n");
257 kgdb_connect(kgdb_active == 0);
258 }
259 }
260