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("$FreeBSD$"); 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('0'); 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 } 331