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/11.2/sys/gdb/gdb_main.c 271173 2014-09-05 16:40:47Z benno $");
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, 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 unsigned char gdb_bindata[64];
57
58 static int
59 gdb_init(void)
60 {
61 struct gdb_dbgport *dp, **iter;
62 int cur_pri, pri;
63
64 gdb_cur = NULL;
65 cur_pri = -1;
66 SET_FOREACH(iter, gdb_dbgport_set) {
67 dp = *iter;
68 pri = (dp->gdb_probe != NULL) ? dp->gdb_probe() : -1;
69 dp->gdb_active = (pri >= 0) ? 0 : -1;
70 if (pri > cur_pri) {
71 cur_pri = pri;
72 gdb_cur = dp;
73 }
74 }
75 if (gdb_cur != NULL) {
76 printf("GDB: debug ports:");
77 SET_FOREACH(iter, gdb_dbgport_set) {
78 dp = *iter;
79 if (dp->gdb_active == 0)
80 printf(" %s", dp->gdb_name);
81 }
82 printf("\n");
83 } else
84 printf("GDB: no debug ports present\n");
85 if (gdb_cur != NULL) {
86 gdb_cur->gdb_init();
87 printf("GDB: current port: %s\n", gdb_cur->gdb_name);
88 }
89 if (gdb_cur != NULL) {
90 cur_pri = (boothowto & RB_GDB) ? 2 : 0;
91 gdb_consinit();
92 } else
93 cur_pri = -1;
94 return (cur_pri);
95 }
96
97 static int
98 gdb_trap(int type, int code)
99 {
100 jmp_buf jb;
101 struct thread *thr_iter;
102 void *prev_jb;
103
104 prev_jb = kdb_jmpbuf(jb);
105 if (setjmp(jb) != 0) {
106 printf("%s bailing, hopefully back to ddb!\n", __func__);
107 gdb_listening = 0;
108 (void)kdb_jmpbuf(prev_jb);
109 return (1);
110 }
111
112 gdb_listening = 0;
113 /*
114 * Send a T packet. We currently do not support watchpoints (the
115 * awatch, rwatch or watch elements).
116 */
117 gdb_tx_begin('T');
118 gdb_tx_hex(gdb_cpu_signal(type, code), 2);
119 gdb_tx_varhex(GDB_REG_PC);
120 gdb_tx_char(':');
121 gdb_tx_reg(GDB_REG_PC);
122 gdb_tx_char(';');
123 gdb_tx_str("thread:");
124 gdb_tx_varhex((long)kdb_thread->td_tid);
125 gdb_tx_char(';');
126 gdb_tx_end(); /* XXX check error condition. */
127
128 thr_iter = NULL;
129 while (gdb_rx_begin() == 0) {
130 /* printf("GDB: got '%s'\n", gdb_rxp); */
131 switch (gdb_rx_char()) {
132 case '?': /* Last signal. */
133 gdb_tx_begin('S');
134 gdb_tx_hex(gdb_cpu_signal(type, code), 2);
135 gdb_tx_end();
136 break;
137 case 'c': { /* Continue. */
138 uintmax_t addr;
139 register_t pc;
140 if (!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 'C': { /* Continue with signal. */
149 uintmax_t addr, sig;
150 register_t pc;
151 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' &&
152 !gdb_rx_varhex(&addr)) {
153 pc = addr;
154 gdb_cpu_setreg(GDB_REG_PC, &pc);
155 }
156 kdb_cpu_clear_singlestep();
157 gdb_listening = 1;
158 return (1);
159 }
160 case 'D': { /* Detach */
161 gdb_tx_ok();
162 kdb_cpu_clear_singlestep();
163 return (1);
164 }
165 case 'g': { /* Read registers. */
166 size_t r;
167 gdb_tx_begin(0);
168 for (r = 0; r < GDB_NREGS; r++)
169 gdb_tx_reg(r);
170 gdb_tx_end();
171 break;
172 }
173 case 'G': /* Write registers. */
174 gdb_tx_err(0);
175 break;
176 case 'H': { /* Set thread. */
177 intmax_t tid;
178 struct thread *thr;
179 gdb_rx_char();
180 if (gdb_rx_varhex(&tid)) {
181 gdb_tx_err(EINVAL);
182 break;
183 }
184 if (tid > 0) {
185 thr = kdb_thr_lookup(tid);
186 if (thr == NULL) {
187 gdb_tx_err(ENOENT);
188 break;
189 }
190 kdb_thr_select(thr);
191 }
192 gdb_tx_ok();
193 break;
194 }
195 case 'k': /* Kill request. */
196 kdb_cpu_clear_singlestep();
197 gdb_listening = 1;
198 return (1);
199 case 'm': { /* Read memory. */
200 uintmax_t addr, size;
201 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' ||
202 gdb_rx_varhex(&size)) {
203 gdb_tx_err(EINVAL);
204 break;
205 }
206 gdb_tx_begin(0);
207 if (gdb_tx_mem((char *)(uintptr_t)addr, size))
208 gdb_tx_end();
209 else
210 gdb_tx_err(EIO);
211 break;
212 }
213 case 'M': { /* Write memory. */
214 uintmax_t addr, size;
215 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' ||
216 gdb_rx_varhex(&size) || gdb_rx_char() != ':') {
217 gdb_tx_err(EINVAL);
218 break;
219 }
220 if (gdb_rx_mem((char *)(uintptr_t)addr, size) == 0)
221 gdb_tx_err(EIO);
222 else
223 gdb_tx_ok();
224 break;
225 }
226 case 'P': { /* Write register. */
227 char *val;
228 uintmax_t reg;
229 val = gdb_rxp;
230 if (gdb_rx_varhex(®) || gdb_rx_char() != '=' ||
231 !gdb_rx_mem(val, gdb_cpu_regsz(reg))) {
232 gdb_tx_err(EINVAL);
233 break;
234 }
235 gdb_cpu_setreg(reg, val);
236 gdb_tx_ok();
237 break;
238 }
239 case 'q': /* General query. */
240 if (gdb_rx_equal("fThreadInfo")) {
241 thr_iter = kdb_thr_first();
242 gdb_tx_begin('m');
243 gdb_tx_hex((long)thr_iter->td_tid, 8);
244 gdb_tx_end();
245 } else if (gdb_rx_equal("sThreadInfo")) {
246 if (thr_iter == NULL) {
247 gdb_tx_err(ENXIO);
248 break;
249 }
250 thr_iter = kdb_thr_next(thr_iter);
251 if (thr_iter != NULL) {
252 gdb_tx_begin('m');
253 gdb_tx_hex((long)thr_iter->td_tid, 8);
254 gdb_tx_end();
255 } else {
256 gdb_tx_begin('l');
257 gdb_tx_end();
258 }
259 } else if (gdb_rx_equal("Search:memory:")) {
260 size_t patlen;
261 intmax_t addr, size;
262 const unsigned char *found;
263 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ';' ||
264 gdb_rx_varhex(&size) || gdb_rx_char() != ';' ||
265 gdb_rx_bindata(gdb_bindata, sizeof(gdb_bindata), &patlen)) {
266 gdb_tx_err(EINVAL);
267 break;
268 }
269 if (gdb_search_mem((char *)(uintptr_t)addr, size, gdb_bindata, patlen, &found)) {
270 if (found == 0ULL)
271 gdb_tx_begin('');
272 else {
273 gdb_tx_begin('1');
274 gdb_tx_char(',');
275 gdb_tx_hex((intmax_t)(uintptr_t)found, 8);
276 }
277 gdb_tx_end();
278 } else
279 gdb_tx_err(EIO);
280 break;
281 } else if (!gdb_cpu_query())
282 gdb_tx_empty();
283 break;
284 case 's': { /* Step. */
285 uintmax_t addr;
286 register_t pc;
287 if (!gdb_rx_varhex(&addr)) {
288 pc = addr;
289 gdb_cpu_setreg(GDB_REG_PC, &pc);
290 }
291 kdb_cpu_set_singlestep();
292 gdb_listening = 1;
293 return (1);
294 }
295 case 'S': { /* Step with signal. */
296 uintmax_t addr, sig;
297 register_t pc;
298 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' &&
299 !gdb_rx_varhex(&addr)) {
300 pc = addr;
301 gdb_cpu_setreg(GDB_REG_PC, &pc);
302 }
303 kdb_cpu_set_singlestep();
304 gdb_listening = 1;
305 return (1);
306 }
307 case 'T': { /* Thread alive. */
308 intmax_t tid;
309 if (gdb_rx_varhex(&tid)) {
310 gdb_tx_err(EINVAL);
311 break;
312 }
313 if (kdb_thr_lookup(tid) != NULL)
314 gdb_tx_ok();
315 else
316 gdb_tx_err(ENOENT);
317 break;
318 }
319 case -1:
320 /* Empty command. Treat as unknown command. */
321 /* FALLTHROUGH */
322 default:
323 /* Unknown command. Send empty response. */
324 gdb_tx_empty();
325 break;
326 }
327 }
328 (void)kdb_jmpbuf(prev_jb);
329 return (0);
330 }
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