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 int 127 gdb_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 gdb_tx_err(0); 204 break; 205 case 'H': { /* Set thread. */ 206 intmax_t tid; 207 struct thread *thr; 208 gdb_rx_char(); 209 if (gdb_rx_varhex(&tid)) { 210 gdb_tx_err(EINVAL); 211 break; 212 } 213 if (tid > 0) { 214 thr = kdb_thr_lookup(tid); 215 if (thr == NULL) { 216 gdb_tx_err(ENOENT); 217 break; 218 } 219 kdb_thr_select(thr); 220 } 221 gdb_tx_ok(); 222 break; 223 } 224 case 'k': /* Kill request. */ 225 kdb_cpu_clear_singlestep(); 226 gdb_listening = 1; 227 return (1); 228 case 'm': { /* Read memory. */ 229 uintmax_t addr, size; 230 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' || 231 gdb_rx_varhex(&size)) { 232 gdb_tx_err(EINVAL); 233 break; 234 } 235 gdb_tx_begin(0); 236 if (gdb_tx_mem((char *)(uintptr_t)addr, size)) 237 gdb_tx_end(); 238 else 239 gdb_tx_err(EIO); 240 break; 241 } 242 case 'M': { /* Write memory. */ 243 uintmax_t addr, size; 244 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' || 245 gdb_rx_varhex(&size) || gdb_rx_char() != ':') { 246 gdb_tx_err(EINVAL); 247 break; 248 } 249 if (gdb_rx_mem((char *)(uintptr_t)addr, size) == 0) 250 gdb_tx_err(EIO); 251 else 252 gdb_tx_ok(); 253 break; 254 } 255 case 'P': { /* Write register. */ 256 char *val; 257 uintmax_t reg; 258 val = gdb_rxp; 259 if (gdb_rx_varhex(®) || gdb_rx_char() != '=' || 260 !gdb_rx_mem(val, gdb_cpu_regsz(reg))) { 261 gdb_tx_err(EINVAL); 262 break; 263 } 264 gdb_cpu_setreg(reg, val); 265 gdb_tx_ok(); 266 break; 267 } 268 case 'q': /* General query. */ 269 if (gdb_rx_equal("fThreadInfo")) { 270 thr_iter = kdb_thr_first(); 271 gdb_tx_begin('m'); 272 gdb_tx_hex((long)thr_iter->td_tid, 8); 273 gdb_tx_end(); 274 } else if (gdb_rx_equal("sThreadInfo")) { 275 if (thr_iter == NULL) { 276 gdb_tx_err(ENXIO); 277 break; 278 } 279 thr_iter = kdb_thr_next(thr_iter); 280 if (thr_iter != NULL) { 281 gdb_tx_begin('m'); 282 gdb_tx_hex((long)thr_iter->td_tid, 8); 283 gdb_tx_end(); 284 } else { 285 gdb_tx_begin('l'); 286 gdb_tx_end(); 287 } 288 } else if (gdb_rx_equal("Search:memory:")) { 289 gdb_do_mem_search(); 290 } else if (!gdb_cpu_query()) 291 gdb_tx_empty(); 292 break; 293 case 's': { /* Step. */ 294 uintmax_t addr; 295 register_t pc; 296 if (!gdb_rx_varhex(&addr)) { 297 pc = addr; 298 gdb_cpu_setreg(GDB_REG_PC, &pc); 299 } 300 kdb_cpu_set_singlestep(); 301 gdb_listening = 1; 302 return (1); 303 } 304 case 'S': { /* Step with signal. */ 305 uintmax_t addr, sig; 306 register_t pc; 307 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' && 308 !gdb_rx_varhex(&addr)) { 309 pc = addr; 310 gdb_cpu_setreg(GDB_REG_PC, &pc); 311 } 312 kdb_cpu_set_singlestep(); 313 gdb_listening = 1; 314 return (1); 315 } 316 case 'T': { /* Thread alive. */ 317 intmax_t tid; 318 if (gdb_rx_varhex(&tid)) { 319 gdb_tx_err(EINVAL); 320 break; 321 } 322 if (kdb_thr_lookup(tid) != NULL) 323 gdb_tx_ok(); 324 else 325 gdb_tx_err(ENOENT); 326 break; 327 } 328 case -1: 329 /* Empty command. Treat as unknown command. */ 330 /* FALLTHROUGH */ 331 default: 332 /* Unknown command. Send empty response. */ 333 gdb_tx_empty(); 334 break; 335 } 336 } 337 (void)kdb_jmpbuf(prev_jb); 338 return (0); 339 } 340