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