1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2004 Marcel Moolenaar 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 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include <sys/cdefs.h> 30__FBSDID("$FreeBSD$"); 31 32#include <sys/param.h> 33#include <sys/systm.h> 34#include <sys/kdb.h> 35#include <sys/kernel.h> 36#include <sys/pcpu.h> 37#include <sys/proc.h> 38#include <sys/reboot.h> 39 40#include <machine/gdb_machdep.h> 41#include <machine/kdb.h> 42 43#include <gdb/gdb.h> 44#include <gdb/gdb_int.h> 45 46static dbbe_init_f gdb_init; 47static dbbe_trap_f gdb_trap; 48 49KDB_BACKEND(gdb, gdb_init, NULL, NULL, gdb_trap); 50 51static struct gdb_dbgport null_gdb_dbgport; 52DATA_SET(gdb_dbgport_set, null_gdb_dbgport); 53SET_DECLARE(gdb_dbgport_set, struct gdb_dbgport); 54 55struct gdb_dbgport *gdb_cur = NULL; 56int gdb_listening = 0; 57 58static unsigned char gdb_bindata[64]; 59 60static int 61gdb_init(void) 62{ 63 struct gdb_dbgport *dp, **iter; 64 int cur_pri, pri; 65 66 gdb_cur = NULL; 67 cur_pri = -1; 68 SET_FOREACH(iter, gdb_dbgport_set) { 69 dp = *iter; 70 pri = (dp->gdb_probe != NULL) ? dp->gdb_probe() : -1; 71 dp->gdb_active = (pri >= 0) ? 0 : -1; 72 if (pri > cur_pri) { 73 cur_pri = pri; 74 gdb_cur = dp; 75 } 76 } 77 if (gdb_cur != NULL) { 78 printf("GDB: debug ports:"); 79 SET_FOREACH(iter, gdb_dbgport_set) { 80 dp = *iter; 81 if (dp->gdb_active == 0) 82 printf(" %s", dp->gdb_name); 83 } 84 printf("\n"); 85 } else 86 printf("GDB: no debug ports present\n"); 87 if (gdb_cur != NULL) { 88 gdb_cur->gdb_init(); 89 printf("GDB: current port: %s\n", gdb_cur->gdb_name); 90 } 91 if (gdb_cur != NULL) { 92 cur_pri = (boothowto & RB_GDB) ? 2 : 0; 93 gdb_consinit(); 94 } else 95 cur_pri = -1; 96 return (cur_pri); 97} 98 99static void 100gdb_do_mem_search(void) 101{ 102 size_t patlen; 103 intmax_t addr, size; 104 const unsigned char *found; 105 106 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ';' || 107 gdb_rx_varhex(&size) || gdb_rx_char() != ';' || 108 gdb_rx_bindata(gdb_bindata, sizeof(gdb_bindata), &patlen)) { 109 gdb_tx_err(EINVAL); 110 return; 111 } 112 if (gdb_search_mem((char *)(uintptr_t)addr, size, gdb_bindata, 113 patlen, &found)) { 114 if (found == 0ULL) 115 gdb_tx_begin('0'); 116 else { 117 gdb_tx_begin('1'); 118 gdb_tx_char(','); 119 gdb_tx_hex((intmax_t)(uintptr_t)found, 8); 120 } 121 gdb_tx_end(); 122 } else 123 gdb_tx_err(EIO); 124} 125 126static int 127gdb_trap(int type, int code) 128{ 129 jmp_buf jb; 130 struct thread *thr_iter; 131 void *prev_jb; 132 133 prev_jb = kdb_jmpbuf(jb); 134 if (setjmp(jb) != 0) { 135 printf("%s bailing, hopefully back to ddb!\n", __func__); 136 gdb_listening = 0; 137 (void)kdb_jmpbuf(prev_jb); 138 return (1); 139 } 140 141 gdb_listening = 0; 142 /* 143 * Send a T packet. We currently do not support watchpoints (the 144 * awatch, rwatch or watch elements). 145 */ 146 gdb_tx_begin('T'); 147 gdb_tx_hex(gdb_cpu_signal(type, code), 2); 148 gdb_tx_varhex(GDB_REG_PC); 149 gdb_tx_char(':'); 150 gdb_tx_reg(GDB_REG_PC); 151 gdb_tx_char(';'); 152 gdb_tx_str("thread:"); 153 gdb_tx_varhex((long)kdb_thread->td_tid); 154 gdb_tx_char(';'); 155 gdb_tx_end(); /* XXX check error condition. */ 156 157 thr_iter = NULL; 158 while (gdb_rx_begin() == 0) { 159 /* printf("GDB: got '%s'\n", gdb_rxp); */ 160 switch (gdb_rx_char()) { 161 case '?': /* Last signal. */ 162 gdb_tx_begin('S'); 163 gdb_tx_hex(gdb_cpu_signal(type, code), 2); 164 gdb_tx_end(); 165 break; 166 case 'c': { /* Continue. */ 167 uintmax_t addr; 168 register_t pc; 169 if (!gdb_rx_varhex(&addr)) { 170 pc = addr; 171 gdb_cpu_setreg(GDB_REG_PC, &pc); 172 } 173 kdb_cpu_clear_singlestep(); 174 gdb_listening = 1; 175 return (1); 176 } 177 case 'C': { /* Continue with signal. */ 178 uintmax_t addr, sig; 179 register_t pc; 180 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' && 181 !gdb_rx_varhex(&addr)) { 182 pc = addr; 183 gdb_cpu_setreg(GDB_REG_PC, &pc); 184 } 185 kdb_cpu_clear_singlestep(); 186 gdb_listening = 1; 187 return (1); 188 } 189 case 'D': { /* Detach */ 190 gdb_tx_ok(); 191 kdb_cpu_clear_singlestep(); 192 return (1); 193 } 194 case 'g': { /* Read registers. */ 195 size_t r; 196 gdb_tx_begin(0); 197 for (r = 0; r < GDB_NREGS; r++) 198 gdb_tx_reg(r); 199 gdb_tx_end(); 200 break; 201 } 202 case 'G': { /* Write registers. */ 203 char *val; 204 bool success; 205 size_t r; 206 for (success = true, r = 0; r < GDB_NREGS; r++) { 207 val = gdb_rxp; 208 if (!gdb_rx_mem(val, gdb_cpu_regsz(r))) { 209 gdb_tx_err(EINVAL); 210 success = false; 211 break; 212 } 213 gdb_cpu_setreg(r, val); 214 } 215 if (success) 216 gdb_tx_ok(); 217 break; 218 } 219 case 'H': { /* Set thread. */ 220 intmax_t tid; 221 struct thread *thr; 222 gdb_rx_char(); 223 if (gdb_rx_varhex(&tid)) { 224 gdb_tx_err(EINVAL); 225 break; 226 } 227 if (tid > 0) { 228 thr = kdb_thr_lookup(tid); 229 if (thr == NULL) { 230 gdb_tx_err(ENOENT); 231 break; 232 } 233 kdb_thr_select(thr); 234 } 235 gdb_tx_ok(); 236 break; 237 } 238 case 'k': /* Kill request. */ 239 kdb_cpu_clear_singlestep(); 240 gdb_listening = 1; 241 return (1); 242 case 'm': { /* Read memory. */ 243 uintmax_t addr, size; 244 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' || 245 gdb_rx_varhex(&size)) { 246 gdb_tx_err(EINVAL); 247 break; 248 } 249 gdb_tx_begin(0); 250 if (gdb_tx_mem((char *)(uintptr_t)addr, size)) 251 gdb_tx_end(); 252 else 253 gdb_tx_err(EIO); 254 break; 255 } 256 case 'M': { /* Write memory. */ 257 uintmax_t addr, size; 258 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' || 259 gdb_rx_varhex(&size) || gdb_rx_char() != ':') { 260 gdb_tx_err(EINVAL); 261 break; 262 } 263 if (gdb_rx_mem((char *)(uintptr_t)addr, size) == 0) 264 gdb_tx_err(EIO); 265 else 266 gdb_tx_ok(); 267 break; 268 } 269 case 'p': { /* Read register. */ 270 uintmax_t reg; 271 if (gdb_rx_varhex(®)) { 272 gdb_tx_err(EINVAL); 273 break; 274 } 275 gdb_tx_begin(0); 276 gdb_tx_reg(reg); 277 gdb_tx_end(); 278 break; 279 } 280 case 'P': { /* Write register. */ 281 char *val; 282 uintmax_t reg; 283 val = gdb_rxp; 284 if (gdb_rx_varhex(®) || gdb_rx_char() != '=' || 285 !gdb_rx_mem(val, gdb_cpu_regsz(reg))) { 286 gdb_tx_err(EINVAL); 287 break; 288 } 289 gdb_cpu_setreg(reg, val); 290 gdb_tx_ok(); 291 break; 292 } 293 case 'q': /* General query. */ 294 if (gdb_rx_equal("fThreadInfo")) { 295 thr_iter = kdb_thr_first(); 296 gdb_tx_begin('m'); 297 gdb_tx_hex((long)thr_iter->td_tid, 8); 298 gdb_tx_end(); 299 } else if (gdb_rx_equal("sThreadInfo")) { 300 if (thr_iter == NULL) { 301 gdb_tx_err(ENXIO); 302 break; 303 } 304 thr_iter = kdb_thr_next(thr_iter); 305 if (thr_iter != NULL) { 306 gdb_tx_begin('m'); 307 gdb_tx_hex((long)thr_iter->td_tid, 8); 308 gdb_tx_end(); 309 } else { 310 gdb_tx_begin('l'); 311 gdb_tx_end(); 312 } 313 } else if (gdb_rx_equal("Search:memory:")) { 314 gdb_do_mem_search(); 315 } else if (!gdb_cpu_query()) 316 gdb_tx_empty(); 317 break; 318 case 's': { /* Step. */ 319 uintmax_t addr; 320 register_t pc; 321 if (!gdb_rx_varhex(&addr)) { 322 pc = addr; 323 gdb_cpu_setreg(GDB_REG_PC, &pc); 324 } 325 kdb_cpu_set_singlestep(); 326 gdb_listening = 1; 327 return (1); 328 } 329 case 'S': { /* Step with signal. */ 330 uintmax_t addr, sig; 331 register_t pc; 332 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' && 333 !gdb_rx_varhex(&addr)) { 334 pc = addr; 335 gdb_cpu_setreg(GDB_REG_PC, &pc); 336 } 337 kdb_cpu_set_singlestep(); 338 gdb_listening = 1; 339 return (1); 340 } 341 case 'T': { /* Thread alive. */ 342 intmax_t tid; 343 if (gdb_rx_varhex(&tid)) { 344 gdb_tx_err(EINVAL); 345 break; 346 } 347 if (kdb_thr_lookup(tid) != NULL) 348 gdb_tx_ok(); 349 else 350 gdb_tx_err(ENOENT); 351 break; 352 } 353 case -1: 354 /* Empty command. Treat as unknown command. */ 355 /* FALLTHROUGH */ 356 default: 357 /* Unknown command. Send empty response. */ 358 gdb_tx_empty(); 359 break; 360 } 361 } 362 (void)kdb_jmpbuf(prev_jb); 363 return (0); 364} 365