FreeBSD/Linux Kernel Cross Reference
sys/gdb/gdb_main.c
1 /*-
2 * Copyright (c) 2004 Marcel Moolenaar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kdb.h>
33 #include <sys/kernel.h>
34 #include <sys/pcpu.h>
35 #include <sys/proc.h>
36 #include <sys/reboot.h>
37
38 #include <machine/gdb_machdep.h>
39 #include <machine/kdb.h>
40
41 #include <gdb/gdb.h>
42 #include <gdb/gdb_int.h>
43
44 static dbbe_init_f gdb_init;
45 static dbbe_trap_f gdb_trap;
46
47 KDB_BACKEND(gdb, gdb_init, NULL, gdb_trap);
48
49 static struct gdb_dbgport null_gdb_dbgport;
50 DATA_SET(gdb_dbgport_set, null_gdb_dbgport);
51 SET_DECLARE(gdb_dbgport_set, struct gdb_dbgport);
52
53 struct gdb_dbgport *gdb_cur = NULL;
54 int gdb_listening = 0;
55
56 static int
57 gdb_init(void)
58 {
59 struct gdb_dbgport *dp, **iter;
60 int cur_pri, pri;
61
62 gdb_cur = NULL;
63 cur_pri = -1;
64 SET_FOREACH(iter, gdb_dbgport_set) {
65 dp = *iter;
66 pri = (dp->gdb_probe != NULL) ? dp->gdb_probe() : -1;
67 dp->gdb_active = (pri >= 0) ? 0 : -1;
68 if (pri > cur_pri) {
69 cur_pri = pri;
70 gdb_cur = dp;
71 }
72 }
73 if (gdb_cur != NULL) {
74 printf("GDB: debug ports:");
75 SET_FOREACH(iter, gdb_dbgport_set) {
76 dp = *iter;
77 if (dp->gdb_active == 0)
78 printf(" %s", dp->gdb_name);
79 }
80 printf("\n");
81 } else
82 printf("GDB: no debug ports present\n");
83 if (gdb_cur != NULL) {
84 gdb_cur->gdb_init();
85 printf("GDB: current port: %s\n", gdb_cur->gdb_name);
86 }
87 if (gdb_cur != NULL) {
88 cur_pri = (boothowto & RB_GDB) ? 2 : 0;
89 gdb_consinit();
90 } else
91 cur_pri = -1;
92 return (cur_pri);
93 }
94
95 static int
96 gdb_trap(int type, int code)
97 {
98 struct thread *thr_iter;
99
100 gdb_listening = 0;
101 /*
102 * Send a T packet. We currently do not support watchpoints (the
103 * awatch, rwatch or watch elements).
104 */
105 gdb_tx_begin('T');
106 gdb_tx_hex(gdb_cpu_signal(type, code), 2);
107 gdb_tx_varhex(GDB_REG_PC);
108 gdb_tx_char(':');
109 gdb_tx_reg(GDB_REG_PC);
110 gdb_tx_char(';');
111 gdb_tx_str("thread:");
112 gdb_tx_varhex((long)kdb_thread->td_tid);
113 gdb_tx_char(';');
114 gdb_tx_end(); /* XXX check error condition. */
115
116 thr_iter = NULL;
117 while (gdb_rx_begin() == 0) {
118 /* printf("GDB: got '%s'\n", gdb_rxp); */
119 switch (gdb_rx_char()) {
120 case '?': /* Last signal. */
121 gdb_tx_begin('S');
122 gdb_tx_hex(gdb_cpu_signal(type, code), 2);
123 gdb_tx_end();
124 break;
125 case 'c': { /* Continue. */
126 uintmax_t addr;
127 register_t pc;
128 if (!gdb_rx_varhex(&addr)) {
129 pc = addr;
130 gdb_cpu_setreg(GDB_REG_PC, &pc);
131 }
132 kdb_cpu_clear_singlestep();
133 gdb_listening = 1;
134 return (1);
135 }
136 case 'C': { /* Continue with signal. */
137 uintmax_t addr, sig;
138 register_t pc;
139 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' &&
140 !gdb_rx_varhex(&addr)) {
141 pc = addr;
142 gdb_cpu_setreg(GDB_REG_PC, &pc);
143 }
144 kdb_cpu_clear_singlestep();
145 gdb_listening = 1;
146 return (1);
147 }
148 case 'g': { /* Read registers. */
149 size_t r;
150 gdb_tx_begin(0);
151 for (r = 0; r < GDB_NREGS; r++)
152 gdb_tx_reg(r);
153 gdb_tx_end();
154 break;
155 }
156 case 'G': /* Write registers. */
157 gdb_tx_err(0);
158 break;
159 case 'H': { /* Set thread. */
160 intmax_t tid;
161 struct thread *thr;
162 gdb_rx_char();
163 if (gdb_rx_varhex(&tid)) {
164 gdb_tx_err(EINVAL);
165 break;
166 }
167 if (tid > 0) {
168 thr = kdb_thr_lookup(tid);
169 if (thr == NULL) {
170 gdb_tx_err(ENOENT);
171 break;
172 }
173 kdb_thr_select(thr);
174 }
175 gdb_tx_ok();
176 break;
177 }
178 case 'k': /* Kill request. */
179 kdb_cpu_clear_singlestep();
180 gdb_listening = 1;
181 return (1);
182 case 'm': { /* Read memory. */
183 uintmax_t addr, size;
184 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' ||
185 gdb_rx_varhex(&size)) {
186 gdb_tx_err(EINVAL);
187 break;
188 }
189 gdb_tx_begin(0);
190 if (gdb_tx_mem((char *)(uintptr_t)addr, size))
191 gdb_tx_end();
192 else
193 gdb_tx_err(EIO);
194 break;
195 }
196 case 'M': { /* Write memory. */
197 uintmax_t addr, size;
198 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' ||
199 gdb_rx_varhex(&size) || gdb_rx_char() != ':') {
200 gdb_tx_err(EINVAL);
201 break;
202 }
203 if (gdb_rx_mem((char *)(uintptr_t)addr, size) == 0)
204 gdb_tx_err(EIO);
205 else
206 gdb_tx_ok();
207 break;
208 }
209 case 'P': { /* Write register. */
210 char *val;
211 uintmax_t reg;
212 val = gdb_rxp;
213 if (gdb_rx_varhex(®) || gdb_rx_char() != '=' ||
214 !gdb_rx_mem(val, gdb_cpu_regsz(reg))) {
215 gdb_tx_err(EINVAL);
216 break;
217 }
218 gdb_cpu_setreg(reg, val);
219 gdb_tx_ok();
220 break;
221 }
222 case 'q': /* General query. */
223 if (gdb_rx_equal("fThreadInfo")) {
224 thr_iter = kdb_thr_first();
225 gdb_tx_begin('m');
226 gdb_tx_hex((long)thr_iter->td_tid, 8);
227 gdb_tx_end();
228 } else if (gdb_rx_equal("sThreadInfo")) {
229 if (thr_iter == NULL) {
230 gdb_tx_err(ENXIO);
231 break;
232 }
233 thr_iter = kdb_thr_next(thr_iter);
234 if (thr_iter != NULL) {
235 gdb_tx_begin('m');
236 gdb_tx_hex((long)thr_iter->td_tid, 8);
237 gdb_tx_end();
238 } else {
239 gdb_tx_begin('l');
240 gdb_tx_end();
241 }
242 } else if (!gdb_cpu_query())
243 gdb_tx_empty();
244 break;
245 case 's': { /* Step. */
246 uintmax_t addr;
247 register_t pc;
248 if (!gdb_rx_varhex(&addr)) {
249 pc = addr;
250 gdb_cpu_setreg(GDB_REG_PC, &pc);
251 }
252 kdb_cpu_set_singlestep();
253 gdb_listening = 1;
254 return (1);
255 }
256 case 'S': { /* Step with signal. */
257 uintmax_t addr, sig;
258 register_t pc;
259 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' &&
260 !gdb_rx_varhex(&addr)) {
261 pc = addr;
262 gdb_cpu_setreg(GDB_REG_PC, &pc);
263 }
264 kdb_cpu_set_singlestep();
265 gdb_listening = 1;
266 return (1);
267 }
268 case 'T': { /* Thread alive. */
269 intmax_t tid;
270 if (gdb_rx_varhex(&tid)) {
271 gdb_tx_err(EINVAL);
272 break;
273 }
274 if (kdb_thr_lookup(tid) != NULL)
275 gdb_tx_ok();
276 else
277 gdb_tx_err(ENOENT);
278 break;
279 }
280 case -1:
281 /* Empty command. Treat as unknown command. */
282 /* FALLTHROUGH */
283 default:
284 /* Unknown command. Send empty response. */
285 gdb_tx_empty();
286 break;
287 }
288 }
289 return (0);
290 }
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