sys/ddb/db_command.c

   1 /*-
   2  * Mach Operating System
   3  * Copyright (c) 1991,1990 Carnegie Mellon University
   4  * All Rights Reserved.
   5  *
   6  * Permission to use, copy, modify and distribute this software and its
   7  * documentation is hereby granted, provided that both the copyright
   8  * notice and this permission notice appear in all copies of the
   9  * software, derivative works or modified versions, and any portions
  10  * thereof, and that both notices appear in supporting documentation.
  11  *
  12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
  13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  15  *
  16  * Carnegie Mellon requests users of this software to return to
  17  *
  18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  19  *  School of Computer Science
  20  *  Carnegie Mellon University
  21  *  Pittsburgh PA 15213-3890
  22  *
  23  * any improvements or extensions that they make and grant Carnegie the
  24  * rights to redistribute these changes.
  25  */
  26 /*
  27  *      Author: David B. Golub, Carnegie Mellon University
  28  *      Date:   7/90
  29  */
  30 /*
  31  * Command dispatcher.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/linker_set.h>
  39 #include <sys/lock.h>
  40 #include <sys/kdb.h>
  41 #include <sys/mutex.h>
  42 #include <sys/proc.h>
  43 #include <sys/reboot.h>
  44 #include <sys/signalvar.h>
  45 #include <sys/systm.h>
  46 #include <sys/cons.h>
  47 #include <sys/conf.h>
  48 #include <sys/watchdog.h>
  49 #include <sys/kernel.h>
  50
  51 #include <ddb/ddb.h>
  52 #include <ddb/db_command.h>
  53 #include <ddb/db_lex.h>
  54 #include <ddb/db_output.h>
  55
  56 #include <machine/cpu.h>
  57 #include <machine/setjmp.h>
  58
  59 /*
  60  * Exported global variables
  61  */
  62 bool            db_cmd_loop_done;
  63 db_addr_t       db_dot;
  64 db_addr_t       db_last_addr;
  65 db_addr_t       db_prev;
  66 db_addr_t       db_next;
  67
  68 static db_cmdfcn_t      db_dump;
  69 static db_cmdfcn_t      db_fncall;
  70 static db_cmdfcn_t      db_gdb;
  71 static db_cmdfcn_t      db_halt;
  72 static db_cmdfcn_t      db_kill;
  73 static db_cmdfcn_t      db_reset;
  74 static db_cmdfcn_t      db_stack_trace;
  75 static db_cmdfcn_t      db_stack_trace_all;
  76 static db_cmdfcn_t      db_watchdog;
  77
  78 /*
  79  * 'show' commands
  80  */
  81
  82 static struct command db_show_all_cmds[] = {
  83         { "trace",      db_stack_trace_all,     0,      NULL },
  84 };
  85 struct command_table db_show_all_table =
  86     LIST_HEAD_INITIALIZER(db_show_all_table);
  87
  88 static struct command db_show_cmds[] = {
  89         { "all",        0,                      0,      &db_show_all_table },
  90         { "registers",  db_show_regs,           0,      NULL },
  91         { "breaks",     db_listbreak_cmd,       0,      NULL },
  92         { "threads",    db_show_threads,        0,      NULL },
  93 };
  94 struct command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
  95
  96 static struct command db_cmds[] = {
  97         { "print",      db_print_cmd,           0,      NULL },
  98         { "p",          db_print_cmd,           0,      NULL },
  99         { "examine",    db_examine_cmd,         CS_SET_DOT, NULL },
 100         { "x",          db_examine_cmd,         CS_SET_DOT, NULL },
 101         { "search",     db_search_cmd,          CS_OWN|CS_SET_DOT, NULL },
 102         { "set",        db_set_cmd,             CS_OWN, NULL },
 103         { "write",      db_write_cmd,           CS_MORE|CS_SET_DOT, NULL },
 104         { "w",          db_write_cmd,           CS_MORE|CS_SET_DOT, NULL },
 105         { "delete",     db_delete_cmd,          0,      NULL },
 106         { "d",          db_delete_cmd,          0,      NULL },
 107         { "dump",       db_dump,                0,      NULL },
 108         { "break",      db_breakpoint_cmd,      0,      NULL },
 109         { "b",          db_breakpoint_cmd,      0,      NULL },
 110         { "dwatch",     db_deletewatch_cmd,     0,      NULL },
 111         { "watch",      db_watchpoint_cmd,      CS_MORE,NULL },
 112         { "dhwatch",    db_deletehwatch_cmd,    0,      NULL },
 113         { "hwatch",     db_hwatchpoint_cmd,     0,      NULL },
 114         { "step",       db_single_step_cmd,     0,      NULL },
 115         { "s",          db_single_step_cmd,     0,      NULL },
 116         { "continue",   db_continue_cmd,        0,      NULL },
 117         { "c",          db_continue_cmd,        0,      NULL },
 118         { "until",      db_trace_until_call_cmd,0,      NULL },
 119         { "next",       db_trace_until_matching_cmd,0,  NULL },
 120         { "match",      db_trace_until_matching_cmd,0,  NULL },
 121         { "trace",      db_stack_trace,         CS_OWN, NULL },
 122         { "t",          db_stack_trace,         CS_OWN, NULL },
 123         /* XXX alias for all trace */
 124         { "alltrace",   db_stack_trace_all,     0,      NULL },
 125         { "where",      db_stack_trace,         CS_OWN, NULL },
 126         { "bt",         db_stack_trace,         CS_OWN, NULL },
 127         { "call",       db_fncall,              CS_OWN, NULL },
 128         { "show",       0,                      0,      &db_show_table },
 129         { "ps",         db_ps,                  0,      NULL },
 130         { "gdb",        db_gdb,                 0,      NULL },
 131         { "halt",       db_halt,                0,      NULL },
 132         { "reboot",     db_reset,               0,      NULL },
 133         { "reset",      db_reset,               0,      NULL },
 134         { "kill",       db_kill,                CS_OWN, NULL },
 135         { "watchdog",   db_watchdog,            CS_OWN, NULL },
 136         { "thread",     db_set_thread,          CS_OWN, NULL },
 137         { "run",        db_run_cmd,             CS_OWN, NULL },
 138         { "script",     db_script_cmd,          CS_OWN, NULL },
 139         { "scripts",    db_scripts_cmd,         0,      NULL },
 140         { "unscript",   db_unscript_cmd,        CS_OWN, NULL },
 141         { "capture",    db_capture_cmd,         CS_OWN, NULL },
 142         { "textdump",   db_textdump_cmd,        CS_OWN, NULL },
 143         { "findstack",  db_findstack_cmd,       0,      NULL },
 144 };
 145 struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
 146
 147 static struct command   *db_last_command = NULL;
 148
 149 /*
 150  * if 'ed' style: 'dot' is set at start of last item printed,
 151  * and '+' points to next line.
 152  * Otherwise: 'dot' points to next item, '..' points to last.
 153  */
 154 static bool     db_ed_style = true;
 155
 156 /*
 157  * Utility routine - discard tokens through end-of-line.
 158  */
 159 void
 160 db_skip_to_eol(void)
 161 {
 162         int     t;
 163         do {
 164             t = db_read_token();
 165         } while (t != tEOL);
 166 }
 167
 168 /*
 169  * Results of command search.
 170  */
 171 #define CMD_UNIQUE      0
 172 #define CMD_FOUND       1
 173 #define CMD_NONE        2
 174 #define CMD_AMBIGUOUS   3
 175 #define CMD_HELP        4
 176
 177 static void     db_cmd_match(char *name, struct command *cmd,
 178                     struct command **cmdp, int *resultp);
 179 static void     db_cmd_list(struct command_table *table);
 180 static int      db_cmd_search(char *name, struct command_table *table,
 181                     struct command **cmdp);
 182 static void     db_command(struct command **last_cmdp,
 183                     struct command_table *cmd_table, int dopager);
 184
 185 /*
 186  * Initialize the command lists from the static tables.
 187  */
 188 void
 189 db_command_init(void)
 190 {
 191 #define N(a)    (sizeof(a) / sizeof(a[0]))
 192         int i;
 193
 194         for (i = 0; i < N(db_cmds); i++)
 195                 db_command_register(&db_cmd_table, &db_cmds[i]);
 196         for (i = 0; i < N(db_show_cmds); i++)
 197                 db_command_register(&db_show_table, &db_show_cmds[i]);
 198         for (i = 0; i < N(db_show_all_cmds); i++)
 199                 db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
 200 #undef N
 201 }
 202
 203 /*
 204  * Register a command.
 205  */
 206 void
 207 db_command_register(struct command_table *list, struct command *cmd)
 208 {
 209         struct command *c, *last;
 210
 211         last = NULL;
 212         LIST_FOREACH(c, list, next) {
 213                 int n = strcmp(cmd->name, c->name);
 214
 215                 /* Check that the command is not already present. */
 216                 if (n == 0) {
 217                         printf("%s: Warning, the command \"%s\" already exists;"
 218                              " ignoring request\n", __func__, cmd->name);
 219                         return;
 220                 }
 221                 if (n < 0) {
 222                         /* NB: keep list sorted lexicographically */
 223                         LIST_INSERT_BEFORE(c, cmd, next);
 224                         return;
 225                 }
 226                 last = c;
 227         }
 228         if (last == NULL)
 229                 LIST_INSERT_HEAD(list, cmd, next);
 230         else
 231                 LIST_INSERT_AFTER(last, cmd, next);
 232 }
 233
 234 /*
 235  * Remove a command previously registered with db_command_register.
 236  */
 237 void
 238 db_command_unregister(struct command_table *list, struct command *cmd)
 239 {
 240         struct command *c;
 241
 242         LIST_FOREACH(c, list, next) {
 243                 if (cmd == c) {
 244                         LIST_REMOVE(cmd, next);
 245                         return;
 246                 }
 247         }
 248         /* NB: intentionally quiet */
 249 }
 250
 251 /*
 252  * Helper function to match a single command.
 253  */
 254 static void
 255 db_cmd_match(char *name, struct command *cmd, struct command **cmdp,
 256     int *resultp)
 257 {
 258         char *lp, *rp;
 259         int c;
 260
 261         lp = name;
 262         rp = cmd->name;
 263         while ((c = *lp) == *rp) {
 264                 if (c == 0) {
 265                         /* complete match */
 266                         *cmdp = cmd;
 267                         *resultp = CMD_UNIQUE;
 268                         return;
 269                 }
 270                 lp++;
 271                 rp++;
 272         }
 273         if (c == 0) {
 274                 /* end of name, not end of command -
 275                    partial match */
 276                 if (*resultp == CMD_FOUND) {
 277                         *resultp = CMD_AMBIGUOUS;
 278                         /* but keep looking for a full match -
 279                            this lets us match single letters */
 280                 } else {
 281                         *cmdp = cmd;
 282                         *resultp = CMD_FOUND;
 283                 }
 284         }
 285 }
 286
 287 /*
 288  * Search for command prefix.
 289  */
 290 static int
 291 db_cmd_search(char *name, struct command_table *table, struct command **cmdp)
 292 {
 293         struct command  *cmd;
 294         int             result = CMD_NONE;
 295
 296         LIST_FOREACH(cmd, table, next) {
 297                 db_cmd_match(name,cmd,cmdp,&result);
 298                 if (result == CMD_UNIQUE)
 299                         break;
 300         }
 301
 302         if (result == CMD_NONE) {
 303                 /* check for 'help' */
 304                 if (name[0] == 'h' && name[1] == 'e'
 305                     && name[2] == 'l' && name[3] == 'p')
 306                         result = CMD_HELP;
 307         }
 308         return (result);
 309 }
 310
 311 static void
 312 db_cmd_list(struct command_table *table)
 313 {
 314         struct command  *cmd;
 315         int have_subcommands;
 316
 317         have_subcommands = 0;
 318         LIST_FOREACH(cmd, table, next) {
 319                 if (cmd->more != NULL)
 320                         have_subcommands++;
 321                 db_printf("%-16s", cmd->name);
 322                 db_end_line(16);
 323         }
 324
 325         if (have_subcommands > 0) {
 326                 db_printf("\nThe following have subcommands; append \"help\" "
 327                     "to list (e.g. \"show help\"):\n");
 328                 LIST_FOREACH(cmd, table, next) {
 329                         if (cmd->more == NULL)
 330                                 continue;
 331                         db_printf("%-16s", cmd->name);
 332                         db_end_line(16);
 333                 }
 334         }
 335 }
 336
 337 static void
 338 db_command(struct command **last_cmdp, struct command_table *cmd_table,
 339     int dopager)
 340 {
 341         struct command  *cmd = NULL;
 342         int             t;
 343         char            modif[TOK_STRING_SIZE];
 344         db_expr_t       addr, count;
 345         bool            have_addr = false;
 346         int             result;
 347
 348         t = db_read_token();
 349         if (t == tEOL) {
 350             /* empty line repeats last command, at 'next' */
 351             cmd = *last_cmdp;
 352             addr = (db_expr_t)db_next;
 353             have_addr = false;
 354             count = 1;
 355             modif[0] = '\0';
 356         }
 357         else if (t == tEXCL) {
 358             db_fncall((db_expr_t)0, (bool)false, (db_expr_t)0, (char *)0);
 359             return;
 360         }
 361         else if (t != tIDENT) {
 362             db_printf("Unrecognized input; use \"help\" "
 363                 "to list available commands\n");
 364             db_flush_lex();
 365             return;
 366         }
 367         else {
 368             /*
 369              * Search for command
 370              */
 371             while (cmd_table) {
 372                 result = db_cmd_search(db_tok_string,
 373                                        cmd_table,
 374                                        &cmd);
 375                 switch (result) {
 376                     case CMD_NONE:
 377                         db_printf("No such command; use \"help\" "
 378                             "to list available commands\n");
 379                         db_flush_lex();
 380                         return;
 381                     case CMD_AMBIGUOUS:
 382                         db_printf("Ambiguous\n");
 383                         db_flush_lex();
 384                         return;
 385                     case CMD_HELP:
 386                         if (cmd_table == &db_cmd_table) {
 387                             db_printf("This is ddb(4), the kernel debugger; "
 388                                 "see http://man.freebsd.org/ddb/4 for help.\n");
 389                             db_printf("Use \"bt\" for backtrace, \"dump\" for "
 390                                 "kernel core dump, \"reset\" to reboot.\n");
 391                             db_printf("Available commands:\n");
 392                         }
 393                         db_cmd_list(cmd_table);
 394                         db_flush_lex();
 395                         return;
 396                     default:
 397                         break;
 398                 }
 399                 if ((cmd_table = cmd->more) != NULL) {
 400                     t = db_read_token();
 401                     if (t != tIDENT) {
 402                         db_printf("Subcommand required; "
 403                             "available subcommands:\n");
 404                         db_cmd_list(cmd_table);
 405                         db_flush_lex();
 406                         return;
 407                     }
 408                 }
 409             }
 410
 411             if ((cmd->flag & CS_OWN) == 0) {
 412                 /*
 413                  * Standard syntax:
 414                  * command [/modifier] [addr] [,count]
 415                  */
 416                 t = db_read_token();
 417                 if (t == tSLASH) {
 418                     t = db_read_token();
 419                     if (t != tIDENT) {
 420                         db_printf("Bad modifier\n");
 421                         db_flush_lex();
 422                         return;
 423                     }
 424                     db_strcpy(modif, db_tok_string);
 425                 }
 426                 else {
 427                     db_unread_token(t);
 428                     modif[0] = '\0';
 429                 }
 430
 431                 if (db_expression(&addr)) {
 432                     db_dot = (db_addr_t) addr;
 433                     db_last_addr = db_dot;
 434                     have_addr = true;
 435                 }
 436                 else {
 437                     addr = (db_expr_t) db_dot;
 438                     have_addr = false;
 439                 }
 440                 t = db_read_token();
 441                 if (t == tCOMMA) {
 442                     if (!db_expression(&count)) {
 443                         db_printf("Count missing\n");
 444                         db_flush_lex();
 445                         return;
 446                     }
 447                 }
 448                 else {
 449                     db_unread_token(t);
 450                     count = -1;
 451                 }
 452                 if ((cmd->flag & CS_MORE) == 0) {
 453                     db_skip_to_eol();
 454                 }
 455             }
 456         }
 457         *last_cmdp = cmd;
 458         if (cmd != NULL) {
 459             /*
 460              * Execute the command.
 461              */
 462             if (dopager)
 463                 db_enable_pager();
 464             else
 465                 db_disable_pager();
 466             (*cmd->fcn)(addr, have_addr, count, modif);
 467             if (dopager)
 468                 db_disable_pager();
 469
 470             if (cmd->flag & CS_SET_DOT) {
 471                 /*
 472                  * If command changes dot, set dot to
 473                  * previous address displayed (if 'ed' style).
 474                  */
 475                 if (db_ed_style) {
 476                     db_dot = db_prev;
 477                 }
 478                 else {
 479                     db_dot = db_next;
 480                 }
 481             }
 482             else {
 483                 /*
 484                  * If command does not change dot,
 485                  * set 'next' location to be the same.
 486                  */
 487                 db_next = db_dot;
 488             }
 489         }
 490 }
 491
 492 /*
 493  * At least one non-optional command must be implemented using
 494  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
 495  */
 496 DB_COMMAND(panic, db_panic)
 497 {
 498         db_disable_pager();
 499         panic("from debugger");
 500 }
 501
 502 void
 503 db_command_loop(void)
 504 {
 505         /*
 506          * Initialize 'prev' and 'next' to dot.
 507          */
 508         db_prev = db_dot;
 509         db_next = db_dot;
 510
 511         db_cmd_loop_done = 0;
 512         while (!db_cmd_loop_done) {
 513             if (db_print_position() != 0)
 514                 db_printf("\n");
 515
 516             db_printf("db> ");
 517             (void) db_read_line();
 518
 519             db_command(&db_last_command, &db_cmd_table, /* dopager */ 1);
 520         }
 521 }
 522
 523 /*
 524  * Execute a command on behalf of a script.  The caller is responsible for
 525  * making sure that the command string is < DB_MAXLINE or it will be
 526  * truncated.
 527  *
 528  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
 529  * nicer to use an alternative approach that didn't mess with the previous
 530  * command buffer.
 531  */
 532 void
 533 db_command_script(const char *command)
 534 {
 535         db_prev = db_next = db_dot;
 536         db_inject_line(command);
 537         db_command(&db_last_command, &db_cmd_table, /* dopager */ 0);
 538 }
 539
 540 void
 541 db_error(const char *s)
 542 {
 543         if (s)
 544             db_printf("%s", s);
 545         db_flush_lex();
 546         kdb_reenter();
 547 }
 548
 549 static void
 550 db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
 551 {
 552         int error;
 553
 554         if (textdump_pending) {
 555                 db_printf("textdump_pending set.\n"
 556                     "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
 557                 return;
 558         }
 559         error = doadump(false);
 560         if (error) {
 561                 db_printf("Cannot dump: ");
 562                 switch (error) {
 563                 case EBUSY:
 564                         db_printf("debugger got invoked while dumping.\n");
 565                         break;
 566                 case ENXIO:
 567                         db_printf("no dump device specified.\n");
 568                         break;
 569                 default:
 570                         db_printf("unknown error (error=%d).\n", error);
 571                         break;
 572                 }
 573         }
 574 }
 575
 576 /*
 577  * Call random function:
 578  * !expr(arg,arg,arg)
 579  */
 580
 581 /* The generic implementation supports a maximum of 10 arguments. */
 582 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
 583     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
 584
 585 static __inline int
 586 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
 587 {
 588         __db_f *f = (__db_f *)addr;
 589
 590         if (nargs > 10) {
 591                 db_printf("Too many arguments (max 10)\n");
 592                 return (0);
 593         }
 594         *rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
 595             args[6], args[7], args[8], args[9]);
 596         return (1);
 597 }
 598
 599 static void
 600 db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
 601 {
 602         db_expr_t       fn_addr;
 603         db_expr_t       args[DB_MAXARGS];
 604         int             nargs = 0;
 605         db_expr_t       retval;
 606         int             t;
 607
 608         if (!db_expression(&fn_addr)) {
 609             db_printf("Bad function\n");
 610             db_flush_lex();
 611             return;
 612         }
 613
 614         t = db_read_token();
 615         if (t == tLPAREN) {
 616             if (db_expression(&args[0])) {
 617                 nargs++;
 618                 while ((t = db_read_token()) == tCOMMA) {
 619                     if (nargs == DB_MAXARGS) {
 620                         db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
 621                         db_flush_lex();
 622                         return;
 623                     }
 624                     if (!db_expression(&args[nargs])) {
 625                         db_printf("Argument missing\n");
 626                         db_flush_lex();
 627                         return;
 628                     }
 629                     nargs++;
 630                 }
 631                 db_unread_token(t);
 632             }
 633             if (db_read_token() != tRPAREN) {
 634                 db_printf("Mismatched parens\n");
 635                 db_flush_lex();
 636                 return;
 637             }
 638         }
 639         db_skip_to_eol();
 640         db_disable_pager();
 641
 642         if (DB_CALL(fn_addr, &retval, nargs, args))
 643                 db_printf("= %#lr\n", (long)retval);
 644 }
 645
 646 static void
 647 db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
 648 {
 649
 650         cpu_halt();
 651 }
 652
 653 static void
 654 db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
 655 {
 656         db_expr_t old_radix, pid, sig;
 657         struct proc *p;
 658
 659 #define DB_ERROR(f)     do { db_printf f; db_flush_lex(); goto out; } while (0)
 660
 661         /*
 662          * PIDs and signal numbers are typically represented in base
 663          * 10, so make that the default here.  It can, of course, be
 664          * overridden by specifying a prefix.
 665          */
 666         old_radix = db_radix;
 667         db_radix = 10;
 668         /* Retrieve arguments. */
 669         if (!db_expression(&sig))
 670                 DB_ERROR(("Missing signal number\n"));
 671         if (!db_expression(&pid))
 672                 DB_ERROR(("Missing process ID\n"));
 673         db_skip_to_eol();
 674         if (!_SIG_VALID(sig))
 675                 DB_ERROR(("Signal number out of range\n"));
 676
 677         /*
 678          * Find the process in question.  allproc_lock is not needed
 679          * since we're in DDB.
 680          */
 681         /* sx_slock(&allproc_lock); */
 682         FOREACH_PROC_IN_SYSTEM(p)
 683             if (p->p_pid == pid)
 684                     break;
 685         /* sx_sunlock(&allproc_lock); */
 686         if (p == NULL)
 687                 DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
 688
 689         /* If it's already locked, bail; otherwise, do the deed. */
 690         if (PROC_TRYLOCK(p) == 0)
 691                 DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
 692         else {
 693                 pksignal(p, sig, NULL);
 694                 PROC_UNLOCK(p);
 695         }
 696
 697 out:
 698         db_radix = old_radix;
 699 #undef DB_ERROR
 700 }
 701
 702 /*
 703  * Reboot.  In case there is an additional argument, take it as delay in
 704  * seconds.  Default to 15s if we cannot parse it and make sure we will
 705  * never wait longer than 1 week.  Some code is similar to
 706  * kern_shutdown.c:shutdown_panic().
 707  */
 708 #ifndef DB_RESET_MAXDELAY
 709 #define DB_RESET_MAXDELAY       (3600 * 24 * 7)
 710 #endif
 711
 712 static void
 713 db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
 714     char *modif __unused)
 715 {
 716         int delay, loop;
 717
 718         if (have_addr) {
 719                 delay = (int)db_hex2dec(addr);
 720
 721                 /* If we parse to fail, use 15s. */
 722                 if (delay == -1)
 723                         delay = 15;
 724
 725                 /* Cap at one week. */
 726                 if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
 727                         delay = DB_RESET_MAXDELAY;
 728
 729                 db_printf("Automatic reboot in %d seconds - "
 730                     "press a key on the console to abort\n", delay);
 731                 for (loop = delay * 10; loop > 0; --loop) {
 732                         DELAY(1000 * 100); /* 1/10th second */
 733                         /* Did user type a key? */
 734                         if (cncheckc() != -1)
 735                                 return;
 736                 }
 737         }
 738
 739         cpu_reset();
 740 }
 741
 742 static void
 743 db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
 744 {
 745         db_expr_t old_radix, tout;
 746         int err, i;
 747
 748         old_radix = db_radix;
 749         db_radix = 10;
 750         err = db_expression(&tout);
 751         db_skip_to_eol();
 752         db_radix = old_radix;
 753
 754         /* If no argument is provided the watchdog will just be disabled. */
 755         if (err == 0) {
 756                 db_printf("No argument provided, disabling watchdog\n");
 757                 tout = 0;
 758         } else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
 759                 db_error("Out of range watchdog interval\n");
 760                 return;
 761         }
 762         EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
 763 }
 764
 765 static void
 766 db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
 767 {
 768
 769         if (kdb_dbbe_select("gdb") != 0) {
 770                 db_printf("The remote GDB backend could not be selected.\n");
 771                 return;
 772         }
 773         /*
 774          * Mark that we are done in the debugger.  kdb_trap()
 775          * should re-enter with the new backend.
 776          */
 777         db_cmd_loop_done = 1;
 778         db_printf("(ctrl-c will return control to ddb)\n");
 779 }
 780
 781 static void
 782 db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
 783 {
 784         struct thread *td;
 785         db_expr_t radix;
 786         pid_t pid;
 787         int t;
 788
 789         /*
 790          * We parse our own arguments. We don't like the default radix.
 791          */
 792         radix = db_radix;
 793         db_radix = 10;
 794         hastid = db_expression(&tid);
 795         t = db_read_token();
 796         if (t == tCOMMA) {
 797                 if (!db_expression(&count)) {
 798                         db_printf("Count missing\n");
 799                         db_flush_lex();
 800                         return;
 801                 }
 802         } else {
 803                 db_unread_token(t);
 804                 count = -1;
 805         }
 806         db_skip_to_eol();
 807         db_radix = radix;
 808
 809         if (hastid) {
 810                 td = kdb_thr_lookup((lwpid_t)tid);
 811                 if (td == NULL)
 812                         td = kdb_thr_from_pid((pid_t)tid);
 813                 if (td == NULL) {
 814                         db_printf("Thread %d not found\n", (int)tid);
 815                         return;
 816                 }
 817         } else
 818                 td = kdb_thread;
 819         if (td->td_proc != NULL)
 820                 pid = td->td_proc->p_pid;
 821         else
 822                 pid = -1;
 823         db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
 824         db_trace_thread(td, count);
 825 }
 826
 827 static void
 828 db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
 829     char *dummy4)
 830 {
 831         struct proc *p;
 832         struct thread *td;
 833         jmp_buf jb;
 834         void *prev_jb;
 835
 836         FOREACH_PROC_IN_SYSTEM(p) {
 837                 prev_jb = kdb_jmpbuf(jb);
 838                 if (setjmp(jb) == 0) {
 839                         FOREACH_THREAD_IN_PROC(p, td) {
 840                                 db_printf("\nTracing command %s pid %d tid %ld td %p\n",
 841                                           p->p_comm, p->p_pid, (long)td->td_tid, td);
 842                                 db_trace_thread(td, -1);
 843                                 if (db_pager_quit) {
 844                                         kdb_jmpbuf(prev_jb);
 845                                         return;
 846                                 }
 847                         }
 848                 }
 849                 kdb_jmpbuf(prev_jb);
 850         }
 851 }
 852
 853 /*
 854  * Take the parsed expression value from the command line that was parsed
 855  * as a hexadecimal value and convert it as if the expression was parsed
 856  * as a decimal value.  Returns -1 if the expression was not a valid
 857  * decimal value.
 858  */
 859 db_expr_t
 860 db_hex2dec(db_expr_t expr)
 861 {
 862         uintptr_t x, y;
 863         db_expr_t val;
 864
 865         y = 1;
 866         val = 0;
 867         x = expr;
 868         while (x != 0) {
 869                 if (x % 16 > 9)
 870                         return (-1);
 871                 val += (x % 16) * (y);
 872                 x >>= 4;
 873                 y *= 10;
 874         }
 875         return (val);
 876 }