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: releng/8.0/sys/gdb/gdb_main.c 176651 2008-02-29 01:57:20Z grehan $");
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 'D': { /* Detach */
149 gdb_tx_ok();
150 kdb_cpu_clear_singlestep();
151 return (1);
152 }
153 case 'g': { /* Read registers. */
154 size_t r;
155 gdb_tx_begin(0);
156 for (r = 0; r < GDB_NREGS; r++)
157 gdb_tx_reg(r);
158 gdb_tx_end();
159 break;
160 }
161 case 'G': /* Write registers. */
162 gdb_tx_err(0);
163 break;
164 case 'H': { /* Set thread. */
165 intmax_t tid;
166 struct thread *thr;
167 gdb_rx_char();
168 if (gdb_rx_varhex(&tid)) {
169 gdb_tx_err(EINVAL);
170 break;
171 }
172 if (tid > 0) {
173 thr = kdb_thr_lookup(tid);
174 if (thr == NULL) {
175 gdb_tx_err(ENOENT);
176 break;
177 }
178 kdb_thr_select(thr);
179 }
180 gdb_tx_ok();
181 break;
182 }
183 case 'k': /* Kill request. */
184 kdb_cpu_clear_singlestep();
185 gdb_listening = 1;
186 return (1);
187 case 'm': { /* Read memory. */
188 uintmax_t addr, size;
189 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' ||
190 gdb_rx_varhex(&size)) {
191 gdb_tx_err(EINVAL);
192 break;
193 }
194 gdb_tx_begin(0);
195 if (gdb_tx_mem((char *)(uintptr_t)addr, size))
196 gdb_tx_end();
197 else
198 gdb_tx_err(EIO);
199 break;
200 }
201 case 'M': { /* Write memory. */
202 uintmax_t addr, size;
203 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' ||
204 gdb_rx_varhex(&size) || gdb_rx_char() != ':') {
205 gdb_tx_err(EINVAL);
206 break;
207 }
208 if (gdb_rx_mem((char *)(uintptr_t)addr, size) == 0)
209 gdb_tx_err(EIO);
210 else
211 gdb_tx_ok();
212 break;
213 }
214 case 'P': { /* Write register. */
215 char *val;
216 uintmax_t reg;
217 val = gdb_rxp;
218 if (gdb_rx_varhex(®) || gdb_rx_char() != '=' ||
219 !gdb_rx_mem(val, gdb_cpu_regsz(reg))) {
220 gdb_tx_err(EINVAL);
221 break;
222 }
223 gdb_cpu_setreg(reg, val);
224 gdb_tx_ok();
225 break;
226 }
227 case 'q': /* General query. */
228 if (gdb_rx_equal("fThreadInfo")) {
229 thr_iter = kdb_thr_first();
230 gdb_tx_begin('m');
231 gdb_tx_hex((long)thr_iter->td_tid, 8);
232 gdb_tx_end();
233 } else if (gdb_rx_equal("sThreadInfo")) {
234 if (thr_iter == NULL) {
235 gdb_tx_err(ENXIO);
236 break;
237 }
238 thr_iter = kdb_thr_next(thr_iter);
239 if (thr_iter != NULL) {
240 gdb_tx_begin('m');
241 gdb_tx_hex((long)thr_iter->td_tid, 8);
242 gdb_tx_end();
243 } else {
244 gdb_tx_begin('l');
245 gdb_tx_end();
246 }
247 } else if (!gdb_cpu_query())
248 gdb_tx_empty();
249 break;
250 case 's': { /* Step. */
251 uintmax_t addr;
252 register_t pc;
253 if (!gdb_rx_varhex(&addr)) {
254 pc = addr;
255 gdb_cpu_setreg(GDB_REG_PC, &pc);
256 }
257 kdb_cpu_set_singlestep();
258 gdb_listening = 1;
259 return (1);
260 }
261 case 'S': { /* Step with signal. */
262 uintmax_t addr, sig;
263 register_t pc;
264 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' &&
265 !gdb_rx_varhex(&addr)) {
266 pc = addr;
267 gdb_cpu_setreg(GDB_REG_PC, &pc);
268 }
269 kdb_cpu_set_singlestep();
270 gdb_listening = 1;
271 return (1);
272 }
273 case 'T': { /* Thread alive. */
274 intmax_t tid;
275 if (gdb_rx_varhex(&tid)) {
276 gdb_tx_err(EINVAL);
277 break;
278 }
279 if (kdb_thr_lookup(tid) != NULL)
280 gdb_tx_ok();
281 else
282 gdb_tx_err(ENOENT);
283 break;
284 }
285 case -1:
286 /* Empty command. Treat as unknown command. */
287 /* FALLTHROUGH */
288 default:
289 /* Unknown command. Send empty response. */
290 gdb_tx_empty();
291 break;
292 }
293 }
294 return (0);
295 }
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