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 AUTHOR ``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 AUTHOR 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 * $FreeBSD: src/gnu/usr.bin/gdb/kgdb/main.c,v 1.16 2008/04/29 20:32:45 jhb Exp $ 27 */ 28 29 #include <sys/cdefs.h> 30 31 #include <sys/param.h> 32 #include <sys/stat.h> 33 #include <sys/types.h> 34 #include <sys/ioctl.h> 35 #include <sys/resource.h> 36 #include <sys/select.h> 37 #include <sys/time.h> 38 #include <sys/wait.h> 39 #include <errno.h> 40 #include <err.h> 41 #include <inttypes.h> 42 #include <kvm.h> 43 #include <limits.h> 44 #include <paths.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <unistd.h> 49 50 /* libgdb stuff. */ 51 #include <defs.h> 52 #include <frame.h> 53 #include <frame-unwind.h> 54 #include <inferior.h> 55 #include <interps.h> 56 #include <cli-out.h> 57 #include <main.h> 58 #include <gdbcmd.h> 59 #include <objfiles.h> 60 #include <target.h> 61 #include <top.h> 62 #include <ui-file.h> 63 #include <bfd.h> 64 #include <gdbcore.h> 65 #include <wrapper.h> 66 #include <observer.h> 67 #include <arch-utils.h> 68 69 #include "kgdb.h" 70 71 static int dumpnr; 72 static int quiet; 73 static int verbose; 74 75 static char crashdir[PATH_MAX]; 76 static char *kernel; 77 static char *remote; 78 static char *vmcore; 79 static struct ui_file *parse_gdberr; 80 81 static void 82 usage(void) 83 { 84 85 fprintf(stderr, 86 "usage: %s [-afqv] [-d crashdir] [-c core | -n dumpnr | -r device]\n" 87 "\t[kernel [core]]\n", getprogname()); 88 exit(1); 89 } 90 91 static void 92 kernel_from_dumpnr(int nr) 93 { 94 char path[PATH_MAX]; 95 FILE *info; 96 char *s; 97 struct stat st; 98 int l; 99 100 /* 101 * If there's a kernel image right here in the crash directory, then 102 * use it. The kernel image is either called kern.<nr> or is in a 103 * subdirectory kern.<nr> and called kernel. The latter allows us 104 * to collect the modules in the same place. 105 */ 106 snprintf(path, sizeof(path), "%s/kern.%d", crashdir, nr); 107 if (stat(path, &st) == 0) { 108 if (S_ISREG(st.st_mode)) { 109 kernel = strdup(path); 110 return; 111 } 112 if (S_ISDIR(st.st_mode)) { 113 snprintf(path, sizeof(path), "%s/kern.%d/kernel", 114 crashdir, nr); 115 if (stat(path, &st) == 0 && S_ISREG(st.st_mode)) { 116 kernel = strdup(path); 117 return; 118 } 119 } 120 } 121 122 /* 123 * No kernel image here. Parse the dump header. The kernel object 124 * directory can be found there and we probably have the kernel 125 * image still in it. The object directory may also have a kernel 126 * with debugging info (called kernel.debug). If we have a debug 127 * kernel, use it. 128 */ 129 snprintf(path, sizeof(path), "%s/info.%d", crashdir, nr); 130 info = fopen(path, "r"); 131 if (info == NULL) { 132 warn("%s", path); 133 return; 134 } 135 while (fgets(path, sizeof(path), info) != NULL) { 136 l = strlen(path); 137 if (l > 0 && path[l - 1] == '\n') 138 path[--l] = '\0'; 139 if (strncmp(path, " ", 4) == 0) { 140 s = strchr(path, ':'); 141 s = (s == NULL) ? path + 4 : s + 1; 142 l = snprintf(path, sizeof(path), "%s/kernel.debug", s); 143 if (stat(path, &st) == -1 || !S_ISREG(st.st_mode)) { 144 path[l - 6] = '\0'; 145 if (stat(path, &st) == -1 || 146 !S_ISREG(st.st_mode)) 147 break; 148 } 149 kernel = strdup(path); 150 break; 151 } 152 } 153 fclose(info); 154 } 155 156 static void 157 kgdb_new_objfile(struct objfile *objfile) 158 { 159 static int once = 1; 160 161 if (once && objfile != NULL && objfile == symfile_objfile) { 162 char *buf; 163 164 /* 165 * The initial kernel has just been loaded. Start the 166 * remote target if we have one or attach to the core. 167 */ 168 once = 0; 169 170 if (remote != NULL) 171 asprintf(&buf, "target remote %s", remote); 172 else if (vmcore != NULL) 173 asprintf(&buf, "target kernel %s", vmcore); 174 175 if (buf != NULL) { 176 execute_command(buf, 0); 177 free(buf); 178 } 179 } 180 } 181 182 /* 183 * Parse an expression and return its value. If 'quiet' is true, then 184 * any error messages from the parser are masked. 185 */ 186 CORE_ADDR 187 kgdb_parse_1(const char *exp, int quiet) 188 { 189 struct ui_file *old_stderr; 190 struct cleanup *old_chain; 191 struct expression *expr; 192 struct value *val; 193 char *s; 194 CORE_ADDR n; 195 196 old_stderr = gdb_stderr; 197 if (quiet) 198 gdb_stderr = parse_gdberr; 199 n = 0; 200 s = xstrdup(exp); 201 old_chain = make_cleanup(xfree, s); 202 if (gdb_parse_exp_1(&s, NULL, 0, &expr) && *s == '\0') { 203 make_cleanup(free_current_contents, &expr); 204 if (gdb_evaluate_expression(expr, &val)) 205 n = value_as_address(val); 206 } 207 do_cleanups(old_chain); 208 gdb_stderr = old_stderr; 209 return (n); 210 } 211 212 #define MSGBUF_SEQ_TO_POS(size, seq) ((seq) % (size)) 213 214 void 215 kgdb_dmesg(void) 216 { 217 CORE_ADDR bufp; 218 int size, rseq, wseq; 219 char c; 220 221 /* 222 * Display the unread portion of the message buffer. This gives the 223 * user a some initial data to work from. 224 */ 225 if (quiet) 226 return; 227 bufp = kgdb_parse("msgbufp->msg_ptr"); 228 size = (int)kgdb_parse("msgbufp->msg_size"); 229 if (bufp == 0 || size == 0) 230 return; 231 rseq = (int)kgdb_parse("msgbufp->msg_bufr"); 232 wseq = (int)kgdb_parse("msgbufp->msg_bufx"); 233 rseq = MSGBUF_SEQ_TO_POS(size, rseq); 234 wseq = MSGBUF_SEQ_TO_POS(size, wseq); 235 if (rseq == wseq) 236 return; 237 238 printf("\nUnread portion of the kernel message buffer:\n"); 239 while (rseq < wseq) { 240 read_memory(bufp + rseq, &c, 1); 241 putchar(c); 242 rseq++; 243 if (rseq == size) 244 rseq = 0; 245 } 246 if (c != '\n') 247 putchar('\n'); 248 putchar('\n'); 249 } 250 251 static void 252 kgdb_init(char *argv0 __unused) 253 { 254 255 parse_gdberr = mem_fileopen(); 256 set_prompt("(kgdb) "); 257 initialize_kgdb_target(); 258 initialize_kld_target(); 259 observer_attach_new_objfile(kgdb_new_objfile); 260 } 261 262 /* 263 * Remote targets can support any number of syntaxes and we want to 264 * support them all with one addition: we support specifying a device 265 * node for a serial device without the "/dev/" prefix. 266 * 267 * What we do is to stat(2) the existing remote target first. If that 268 * fails, we try it with "/dev/" prepended. If that succeeds we use 269 * the resulting path, otherwise we use the original target. If 270 * either stat(2) succeeds make sure the file is either a character 271 * device or a FIFO. 272 */ 273 static void 274 verify_remote(void) 275 { 276 char path[PATH_MAX]; 277 struct stat st; 278 279 if (stat(remote, &st) != 0) { 280 snprintf(path, sizeof(path), "/dev/%s", remote); 281 if (stat(path, &st) != 0) 282 return; 283 free(remote); 284 remote = strdup(path); 285 } 286 if (!S_ISCHR(st.st_mode) && !S_ISFIFO(st.st_mode)) 287 errx(1, "%s: not a special file, FIFO or socket", remote); 288 } 289 290 static void 291 add_arg(struct captured_main_args *args, char *arg) 292 { 293 294 args->argc++; 295 args->argv = reallocf(args->argv, (args->argc + 1) * sizeof(char *)); 296 if (args->argv == NULL) 297 err(1, "Out of memory building argument list"); 298 args->argv[args->argc] = arg; 299 } 300 301 int 302 main(int argc, char *argv[]) 303 { 304 char path[PATH_MAX]; 305 struct stat st; 306 struct captured_main_args args; 307 char *s; 308 int a, ch; 309 310 dumpnr = -1; 311 312 strlcpy(crashdir, "/var/crash", sizeof(crashdir)); 313 s = getenv("KGDB_CRASH_DIR"); 314 if (s != NULL) 315 strlcpy(crashdir, s, sizeof(crashdir)); 316 317 /* Convert long options into short options. */ 318 for (a = 1; a < argc; a++) { 319 s = argv[a]; 320 if (s[0] == '-') { 321 s++; 322 /* Long options take either 1 or 2 dashes. */ 323 if (s[0] == '-') 324 s++; 325 if (strcmp(s, "quiet") == 0) 326 argv[a] = "-q"; 327 else if (strcmp(s, "fullname") == 0) 328 argv[a] = "-f"; 329 } 330 } 331 332 quiet = 0; 333 memset (&args, 0, sizeof args); 334 args.use_windows = 0; 335 args.interpreter_p = INTERP_CONSOLE; 336 args.argv = malloc(sizeof(char *)); 337 args.argv[0] = argv[0]; 338 add_arg(&args, "--kernel"); 339 340 while ((ch = getopt(argc, argv, "ac:d:fn:qr:vw")) != -1) { 341 switch (ch) { 342 case 'a': 343 annotation_level++; 344 break; 345 case 'c': /* use given core file. */ 346 if (vmcore != NULL) { 347 warnx("option %c: can only be specified once", 348 optopt); 349 usage(); 350 /* NOTREACHED */ 351 } 352 vmcore = strdup(optarg); 353 break; 354 case 'd': /* lookup dumps in given directory. */ 355 strlcpy(crashdir, optarg, sizeof(crashdir)); 356 break; 357 case 'f': 358 annotation_level = 1; 359 break; 360 case 'n': /* use dump with given number. */ 361 dumpnr = strtol(optarg, &s, 0); 362 if (dumpnr < 0 || *s != '\0') { 363 warnx("option %c: invalid kernel dump number", 364 optopt); 365 usage(); 366 /* NOTREACHED */ 367 } 368 break; 369 case 'q': 370 quiet = 1; 371 add_arg(&args, "-q"); 372 break; 373 case 'r': /* use given device for remote session. */ 374 if (remote != NULL) { 375 warnx("option %c: can only be specified once", 376 optopt); 377 usage(); 378 /* NOTREACHED */ 379 } 380 remote = strdup(optarg); 381 break; 382 case 'v': /* increase verbosity. */ 383 verbose++; 384 break; 385 case 'w': /* core file is writeable. */ 386 add_arg(&args, "--write"); 387 break; 388 case '?': 389 default: 390 usage(); 391 } 392 } 393 394 if (((vmcore != NULL) ? 1 : 0) + ((dumpnr >= 0) ? 1 : 0) + 395 ((remote != NULL) ? 1 : 0) > 1) { 396 warnx("options -c, -n and -r are mutually exclusive"); 397 usage(); 398 /* NOTREACHED */ 399 } 400 401 if (verbose > 1) 402 warnx("using %s as the crash directory", crashdir); 403 404 if (argc > optind) 405 kernel = strdup(argv[optind++]); 406 407 if (argc > optind && (dumpnr >= 0 || remote != NULL)) { 408 warnx("options -n and -r do not take a core file. Ignored"); 409 optind = argc; 410 } 411 412 if (dumpnr >= 0) { 413 snprintf(path, sizeof(path), "%s/vmcore.%d", crashdir, dumpnr); 414 if (stat(path, &st) == -1) 415 err(1, "%s", path); 416 if (!S_ISREG(st.st_mode)) 417 errx(1, "%s: not a regular file", path); 418 vmcore = strdup(path); 419 } else if (remote != NULL) { 420 verify_remote(); 421 } else if (argc > optind) { 422 if (vmcore == NULL) 423 vmcore = strdup(argv[optind++]); 424 if (argc > optind) 425 warnx("multiple core files specified. Ignored"); 426 } else if (vmcore == NULL && kernel == NULL) { 427 vmcore = strdup(_PATH_MEM); 428 kernel = strdup(getbootfile()); 429 } 430 431 if (verbose) { 432 if (vmcore != NULL) 433 warnx("core file: %s", vmcore); 434 if (remote != NULL) 435 warnx("device file: %s", remote); 436 if (kernel != NULL) 437 warnx("kernel image: %s", kernel); 438 } 439 440 /* A remote target requires an explicit kernel argument. */ 441 if (remote != NULL && kernel == NULL) { 442 warnx("remote debugging requires a kernel"); 443 usage(); 444 /* NOTREACHED */ 445 } 446 447 /* If we don't have a kernel image yet, try to find one. */ 448 if (kernel == NULL) { 449 if (dumpnr >= 0) 450 kernel_from_dumpnr(dumpnr); 451 452 if (kernel == NULL) 453 errx(1, "couldn't find a suitable kernel image"); 454 if (verbose) 455 warnx("kernel image: %s", kernel); 456 } 457 add_arg(&args, kernel); 458 459 /* 460 if (vmcore != NULL) 461 add_arg(&args, vmcore); 462 */ 463 464 /* The libgdb code uses optind too. Reset it... */ 465 optind = 0; 466 467 /* Terminate argv list. */ 468 add_arg(&args, NULL); 469 470 deprecated_init_ui_hook = kgdb_init; 471 472 return (gdb_main(&args)); 473 } 474