gdb_main.c revision 176651
1178476Sjb/*- 2178476Sjb * Copyright (c) 2004 Marcel Moolenaar 3178476Sjb * All rights reserved. 4178476Sjb * 5178476Sjb * Redistribution and use in source and binary forms, with or without 6178476Sjb * modification, are permitted provided that the following conditions 7178476Sjb * are met: 8178476Sjb * 9178476Sjb * 1. Redistributions of source code must retain the above copyright 10178476Sjb * notice, this list of conditions and the following disclaimer. 11178476Sjb * 2. Redistributions in binary form must reproduce the above copyright 12178476Sjb * notice, this list of conditions and the following disclaimer in the 13178476Sjb * documentation and/or other materials provided with the distribution. 14178476Sjb * 15178476Sjb * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 16178476Sjb * 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: head/sys/gdb/gdb_main.c 176651 2008-02-29 01:57:20Z grehan $"); 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 44static dbbe_init_f gdb_init; 45static dbbe_trap_f gdb_trap; 46 47KDB_BACKEND(gdb, gdb_init, NULL, gdb_trap); 48 49static struct gdb_dbgport null_gdb_dbgport; 50DATA_SET(gdb_dbgport_set, null_gdb_dbgport); 51SET_DECLARE(gdb_dbgport_set, struct gdb_dbgport); 52 53struct gdb_dbgport *gdb_cur = NULL; 54int gdb_listening = 0; 55 56static int 57gdb_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 95static int 96gdb_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 'D': { /* Detach */ 149 gdb_tx_ok(); 150 kdb_cpu_clear_singlestep(); 151 return (1); 152 } 153 case 'g': { /* Read registers. */ 154 size_t r; 155 gdb_tx_begin(0); 156 for (r = 0; r < GDB_NREGS; r++) 157 gdb_tx_reg(r); 158 gdb_tx_end(); 159 break; 160 } 161 case 'G': /* Write registers. */ 162 gdb_tx_err(0); 163 break; 164 case 'H': { /* Set thread. */ 165 intmax_t tid; 166 struct thread *thr; 167 gdb_rx_char(); 168 if (gdb_rx_varhex(&tid)) { 169 gdb_tx_err(EINVAL); 170 break; 171 } 172 if (tid > 0) { 173 thr = kdb_thr_lookup(tid); 174 if (thr == NULL) { 175 gdb_tx_err(ENOENT); 176 break; 177 } 178 kdb_thr_select(thr); 179 } 180 gdb_tx_ok(); 181 break; 182 } 183 case 'k': /* Kill request. */ 184 kdb_cpu_clear_singlestep(); 185 gdb_listening = 1; 186 return (1); 187 case 'm': { /* Read memory. */ 188 uintmax_t addr, size; 189 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' || 190 gdb_rx_varhex(&size)) { 191 gdb_tx_err(EINVAL); 192 break; 193 } 194 gdb_tx_begin(0); 195 if (gdb_tx_mem((char *)(uintptr_t)addr, size)) 196 gdb_tx_end(); 197 else 198 gdb_tx_err(EIO); 199 break; 200 } 201 case 'M': { /* Write memory. */ 202 uintmax_t addr, size; 203 if (gdb_rx_varhex(&addr) || gdb_rx_char() != ',' || 204 gdb_rx_varhex(&size) || gdb_rx_char() != ':') { 205 gdb_tx_err(EINVAL); 206 break; 207 } 208 if (gdb_rx_mem((char *)(uintptr_t)addr, size) == 0) 209 gdb_tx_err(EIO); 210 else 211 gdb_tx_ok(); 212 break; 213 } 214 case 'P': { /* Write register. */ 215 char *val; 216 uintmax_t reg; 217 val = gdb_rxp; 218 if (gdb_rx_varhex(®) || gdb_rx_char() != '=' || 219 !gdb_rx_mem(val, gdb_cpu_regsz(reg))) { 220 gdb_tx_err(EINVAL); 221 break; 222 } 223 gdb_cpu_setreg(reg, val); 224 gdb_tx_ok(); 225 break; 226 } 227 case 'q': /* General query. */ 228 if (gdb_rx_equal("fThreadInfo")) { 229 thr_iter = kdb_thr_first(); 230 gdb_tx_begin('m'); 231 gdb_tx_hex((long)thr_iter->td_tid, 8); 232 gdb_tx_end(); 233 } else if (gdb_rx_equal("sThreadInfo")) { 234 if (thr_iter == NULL) { 235 gdb_tx_err(ENXIO); 236 break; 237 } 238 thr_iter = kdb_thr_next(thr_iter); 239 if (thr_iter != NULL) { 240 gdb_tx_begin('m'); 241 gdb_tx_hex((long)thr_iter->td_tid, 8); 242 gdb_tx_end(); 243 } else { 244 gdb_tx_begin('l'); 245 gdb_tx_end(); 246 } 247 } else if (!gdb_cpu_query()) 248 gdb_tx_empty(); 249 break; 250 case 's': { /* Step. */ 251 uintmax_t addr; 252 register_t pc; 253 if (!gdb_rx_varhex(&addr)) { 254 pc = addr; 255 gdb_cpu_setreg(GDB_REG_PC, &pc); 256 } 257 kdb_cpu_set_singlestep(); 258 gdb_listening = 1; 259 return (1); 260 } 261 case 'S': { /* Step with signal. */ 262 uintmax_t addr, sig; 263 register_t pc; 264 if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' && 265 !gdb_rx_varhex(&addr)) { 266 pc = addr; 267 gdb_cpu_setreg(GDB_REG_PC, &pc); 268 } 269 kdb_cpu_set_singlestep(); 270 gdb_listening = 1; 271 return (1); 272 } 273 case 'T': { /* Thread alive. */ 274 intmax_t tid; 275 if (gdb_rx_varhex(&tid)) { 276 gdb_tx_err(EINVAL); 277 break; 278 } 279 if (kdb_thr_lookup(tid) != NULL) 280 gdb_tx_ok(); 281 else 282 gdb_tx_err(ENOENT); 283 break; 284 } 285 case -1: 286 /* Empty command. Treat as unknown command. */ 287 /* FALLTHROUGH */ 288 default: 289 /* Unknown command. Send empty response. */ 290 gdb_tx_empty(); 291 break; 292 } 293 } 294 return (0); 295} 296