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 46 static dbbe_init_f gdb_init; 47 static dbbe_trap_f gdb_trap; 48 49 KDB_BACKEND(gdb, gdb_init, NULL, NULL, gdb_trap); 50 51 static struct gdb_dbgport null_gdb_dbgport; 52 DATA_SET(gdb_dbgport_set, null_gdb_dbgport); 53 SET_DECLARE(gdb_dbgport_set, struct gdb_dbgport); 54 55 struct gdb_dbgport *gdb_cur = NULL; 56 int gdb_listening = 0; 57 58 static unsigned char gdb_bindata[64]; 59 60 static int 61 gdb_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 99 static void 100 gdb_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 } 125 126 static void 127 gdb_do_threadinfo(struct thread **thr_iter) 128 { 129 static struct thread * const done_sentinel = (void *)(uintptr_t)1; 130 static const size_t tidsz_hex = sizeof(lwpid_t) * 2; 131 size_t tds_sent; 132 133 if (*thr_iter == NULL) { 134 gdb_tx_err(ENXIO); 135 return; 136 } 137 138 if (*thr_iter == done_sentinel) { 139 gdb_tx_begin('l'); 140 *thr_iter = NULL; 141 goto sendit; 142 } 143 144 gdb_tx_begin('m'); 145 146 for (tds_sent = 0; 147 *thr_iter != NULL && gdb_txbuf_has_capacity(tidsz_hex + 1); 148 *thr_iter = kdb_thr_next(*thr_iter), tds_sent++) { 149 if (tds_sent > 0) 150 gdb_tx_char(','); 151 gdb_tx_varhex((*thr_iter)->td_tid); 152 } 153 154 /* 155 * Can't send EOF and "some" in same packet, so set a sentinel to send 156 * EOF when GDB asks us next. 157 */ 158 if (*thr_iter == NULL && tds_sent > 0) 159 *thr_iter = done_sentinel; 160 161 sendit: 162 gdb_tx_end(); 163 } 164 165 static int 166 gdb_trap(int type, int code) 167 { 168 jmp_buf jb; 169 struct thread *thr_iter; 170 void *prev_jb; 171 172 prev_jb = kdb_jmpbuf(jb); 173 if (setjmp(jb) != 0) { 174 printf("%s bailing, hopefully back to ddb!\n", __func__); 175 gdb_listening = 0; 176 (void)kdb_jmpbuf(prev_jb); 177 return (1); 178 } 179 180 gdb_listening = 0; 181 /* 182 * Send a T packet. We currently do not support watchpoints (the 183 * awatch, rwatch or watch elements). 184 */ 185 gdb_tx_begin('T'); 186 gdb_tx_hex(gdb_cpu_signal(type, code), 2); 187 gdb_tx_varhex(GDB_REG_PC); 188 gdb_tx_char(':'); 189 gdb_tx_reg(GDB_REG_PC); 190 gdb_tx_char(';'); 191 gdb_tx_str("thread:"); 192 gdb_tx_varhex((long)kdb_thread->td_tid); 193 gdb_tx_char(';'); 194 gdb_tx_end(); /* XXX check error condition. */ 195 196 thr_iter = NULL; 197 while (gdb_rx_begin() == 0) { 198 /* printf("GDB: got '%s'\n", gdb_rxp); */ 199 switch (gdb_rx_char()) { 200 case '?': /* Last signal. */ 201 gdb_tx_begin('S'); 202 gdb_tx_hex(gdb_cpu_signal(type, code), 2); 203 gdb_tx_end(); 204 break; 205 case 'c': { /* Continue. */ 206 uintmax_t addr; 207 register_t pc; 208 if (!gdb_rx_varhex(&addr)) { 209 pc = addr; 210 gdb_cpu_setreg(GDB_REG_PC, &pc); 211 } 212 kdb_cpu_clear_singlestep(); 213 gdb_listening = 1; 214 return (1); 215 } 216 case 'C': { /* Continue with signal. */ 217 uintmax_t addr, sig; 218 register_t pc; 219 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' && 220 !gdb_rx_varhex(&addr)) { 221 pc = addr; 222 gdb_cpu_setreg(GDB_REG_PC, &pc); 223 } 224 kdb_cpu_clear_singlestep(); 225 gdb_listening = 1; 226 return (1); 227 } 228 case 'D': { /* Detach */ 229 gdb_tx_ok(); 230 kdb_cpu_clear_singlestep(); 231 return (1); 232 } 233 case 'g': { /* Read registers. */ 234 size_t r; 235 gdb_tx_begin(0); 236 for (r = 0; r < GDB_NREGS; r++) 237 gdb_tx_reg(r); 238 gdb_tx_end(); 239 break; 240 } 241 case 'G': /* Write registers. */ 242 gdb_tx_err(0); 243 break; 244 case 'H': { /* Set thread. */ 245 intmax_t tid; 246 struct thread *thr; 247 gdb_rx_char(); 248 if (gdb_rx_varhex(&tid)) { 249 gdb_tx_err(EINVAL); 250 break; 251 } 252 if (tid > 0) { 253 thr = kdb_thr_lookup(tid); 254 if (thr == NULL) { 255 gdb_tx_err(ENOENT); 256 break; 257 } 258 kdb_thr_select(thr); 259 } 260 gdb_tx_ok(); 261 break; 262 } 263 case 'k': /* Kill request. */ 264 kdb_cpu_clear_singlestep(); 265 gdb_listening = 1; 266 return (1); 267 case 'm': { /* Read memory. */ 268 uintmax_t addr, size; 269 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' || 270 gdb_rx_varhex(&size)) { 271 gdb_tx_err(EINVAL); 272 break; 273 } 274 gdb_tx_begin(0); 275 if (gdb_tx_mem((char *)(uintptr_t)addr, size)) 276 gdb_tx_end(); 277 else 278 gdb_tx_err(EIO); 279 break; 280 } 281 case 'M': { /* Write memory. */ 282 uintmax_t addr, size; 283 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' || 284 gdb_rx_varhex(&size) || gdb_rx_char() != ':') { 285 gdb_tx_err(EINVAL); 286 break; 287 } 288 if (gdb_rx_mem((char *)(uintptr_t)addr, size) == 0) 289 gdb_tx_err(EIO); 290 else 291 gdb_tx_ok(); 292 break; 293 } 294 case 'P': { /* Write register. */ 295 char *val; 296 uintmax_t reg; 297 val = gdb_rxp; 298 if (gdb_rx_varhex(®) || gdb_rx_char() != '=' || 299 !gdb_rx_mem(val, gdb_cpu_regsz(reg))) { 300 gdb_tx_err(EINVAL); 301 break; 302 } 303 gdb_cpu_setreg(reg, val); 304 gdb_tx_ok(); 305 break; 306 } 307 case 'q': /* General query. */ 308 if (gdb_rx_equal("C")) { 309 gdb_tx_begin('Q'); 310 gdb_tx_char('C'); 311 gdb_tx_varhex((long)kdb_thread->td_tid); 312 gdb_tx_end(); 313 } else if (gdb_rx_equal("fThreadInfo")) { 314 thr_iter = kdb_thr_first(); 315 gdb_do_threadinfo(&thr_iter); 316 } else if (gdb_rx_equal("sThreadInfo")) { 317 gdb_do_threadinfo(&thr_iter); 318 } else if (gdb_rx_equal("Search:memory:")) { 319 gdb_do_mem_search(); 320 } else if (!gdb_cpu_query()) 321 gdb_tx_empty(); 322 break; 323 case 's': { /* Step. */ 324 uintmax_t addr; 325 register_t pc; 326 if (!gdb_rx_varhex(&addr)) { 327 pc = addr; 328 gdb_cpu_setreg(GDB_REG_PC, &pc); 329 } 330 kdb_cpu_set_singlestep(); 331 gdb_listening = 1; 332 return (1); 333 } 334 case 'S': { /* Step with signal. */ 335 uintmax_t addr, sig; 336 register_t pc; 337 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' && 338 !gdb_rx_varhex(&addr)) { 339 pc = addr; 340 gdb_cpu_setreg(GDB_REG_PC, &pc); 341 } 342 kdb_cpu_set_singlestep(); 343 gdb_listening = 1; 344 return (1); 345 } 346 case 'T': { /* Thread alive. */ 347 intmax_t tid; 348 if (gdb_rx_varhex(&tid)) { 349 gdb_tx_err(EINVAL); 350 break; 351 } 352 if (kdb_thr_lookup(tid) != NULL) 353 gdb_tx_ok(); 354 else 355 gdb_tx_err(ENOENT); 356 break; 357 } 358 case -1: 359 /* Empty command. Treat as unknown command. */ 360 /* FALLTHROUGH */ 361 default: 362 /* Unknown command. Send empty response. */ 363 gdb_tx_empty(); 364 break; 365 } 366 } 367 (void)kdb_jmpbuf(prev_jb); 368 return (0); 369 } 370