sys/ddb/db_command.c

   1 /*-
   2  * SPDX-License-Identifier: MIT-CMU
   3  *
   4  * Mach Operating System
   5  * Copyright (c) 1991,1990 Carnegie Mellon University
   6  * All Rights Reserved.
   7  *
   8  * Permission to use, copy, modify and distribute this software and its
   9  * documentation is hereby granted, provided that both the copyright
  10  * notice and this permission notice appear in all copies of the
  11  * software, derivative works or modified versions, and any portions
  12  * thereof, and that both notices appear in supporting documentation.
  13  *
  14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
  15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  16  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  17  *
  18  * Carnegie Mellon requests users of this software to return to
  19  *
  20  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  21  *  School of Computer Science
  22  *  Carnegie Mellon University
  23  *  Pittsburgh PA 15213-3890
  24  *
  25  * any improvements or extensions that they make and grant Carnegie the
  26  * rights to redistribute these changes.
  27  */
  28 /*
  29  *      Author: David B. Golub, Carnegie Mellon University
  30  *      Date:   7/90
  31  */
  32 /*
  33  * Command dispatcher.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD$");
  38
  39 #include <sys/param.h>
  40 #include <sys/eventhandler.h>
  41 #include <sys/linker_set.h>
  42 #include <sys/lock.h>
  43 #include <sys/kdb.h>
  44 #include <sys/mutex.h>
  45 #include <sys/proc.h>
  46 #include <sys/reboot.h>
  47 #include <sys/signalvar.h>
  48 #include <sys/systm.h>
  49 #include <sys/cons.h>
  50 #include <sys/conf.h>
  51 #include <sys/watchdog.h>
  52 #include <sys/kernel.h>
  53
  54 #include <ddb/ddb.h>
  55 #include <ddb/db_command.h>
  56 #include <ddb/db_lex.h>
  57 #include <ddb/db_output.h>
  58
  59 #include <machine/cpu.h>
  60 #include <machine/setjmp.h>
  61
  62 /*
  63  * Exported global variables
  64  */
  65 int             db_cmd_loop_done;
  66 db_addr_t       db_dot;
  67 db_addr_t       db_last_addr;
  68 db_addr_t       db_prev;
  69 db_addr_t       db_next;
  70
  71 static db_cmdfcn_t      db_dump;
  72 static db_cmdfcn_t      db_fncall;
  73 static db_cmdfcn_t      db_gdb;
  74 static db_cmdfcn_t      db_halt;
  75 static db_cmdfcn_t      db_kill;
  76 static db_cmdfcn_t      db_reset;
  77 static db_cmdfcn_t      db_stack_trace;
  78 static db_cmdfcn_t      db_stack_trace_active;
  79 static db_cmdfcn_t      db_stack_trace_all;
  80 static db_cmdfcn_t      db_watchdog;
  81
  82 /*
  83  * 'show' commands
  84  */
  85
  86 static struct command db_show_active_cmds[] = {
  87         { "trace",      db_stack_trace_active,  0,      NULL },
  88 };
  89 struct command_table db_show_active_table =
  90     LIST_HEAD_INITIALIZER(db_show_active_table);
  91
  92 static struct command db_show_all_cmds[] = {
  93         { "trace",      db_stack_trace_all,     0,      NULL },
  94 };
  95 struct command_table db_show_all_table =
  96     LIST_HEAD_INITIALIZER(db_show_all_table);
  97
  98 static struct command db_show_cmds[] = {
  99         { "active",     0,                      0,      &db_show_active_table },
 100         { "all",        0,                      0,      &db_show_all_table },
 101         { "registers",  db_show_regs,           0,      NULL },
 102         { "breaks",     db_listbreak_cmd,       0,      NULL },
 103         { "threads",    db_show_threads,        0,      NULL },
 104 };
 105 struct command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
 106
 107 static struct command db_cmds[] = {
 108         { "print",      db_print_cmd,           0,      NULL },
 109         { "p",          db_print_cmd,           0,      NULL },
 110         { "examine",    db_examine_cmd,         CS_SET_DOT, NULL },
 111         { "x",          db_examine_cmd,         CS_SET_DOT, NULL },
 112         { "search",     db_search_cmd,          CS_OWN|CS_SET_DOT, NULL },
 113         { "set",        db_set_cmd,             CS_OWN, NULL },
 114         { "write",      db_write_cmd,           CS_MORE|CS_SET_DOT, NULL },
 115         { "w",          db_write_cmd,           CS_MORE|CS_SET_DOT, NULL },
 116         { "delete",     db_delete_cmd,          0,      NULL },
 117         { "d",          db_delete_cmd,          0,      NULL },
 118         { "dump",       db_dump,                0,      NULL },
 119         { "break",      db_breakpoint_cmd,      0,      NULL },
 120         { "b",          db_breakpoint_cmd,      0,      NULL },
 121         { "dwatch",     db_deletewatch_cmd,     0,      NULL },
 122         { "watch",      db_watchpoint_cmd,      CS_MORE,NULL },
 123         { "dhwatch",    db_deletehwatch_cmd,    0,      NULL },
 124         { "hwatch",     db_hwatchpoint_cmd,     0,      NULL },
 125         { "step",       db_single_step_cmd,     0,      NULL },
 126         { "s",          db_single_step_cmd,     0,      NULL },
 127         { "continue",   db_continue_cmd,        0,      NULL },
 128         { "c",          db_continue_cmd,        0,      NULL },
 129         { "until",      db_trace_until_call_cmd,0,      NULL },
 130         { "next",       db_trace_until_matching_cmd,0,  NULL },
 131         { "match",      db_trace_until_matching_cmd,0,  NULL },
 132         { "trace",      db_stack_trace,         CS_OWN, NULL },
 133         { "t",          db_stack_trace,         CS_OWN, NULL },
 134         /* XXX alias for active trace */
 135         { "acttrace",   db_stack_trace_active,  0,      NULL },
 136         /* XXX alias for all trace */
 137         { "alltrace",   db_stack_trace_all,     0,      NULL },
 138         { "where",      db_stack_trace,         CS_OWN, NULL },
 139         { "bt",         db_stack_trace,         CS_OWN, NULL },
 140         { "call",       db_fncall,              CS_OWN, NULL },
 141         { "show",       0,                      0,      &db_show_table },
 142         { "ps",         db_ps,                  0,      NULL },
 143         { "gdb",        db_gdb,                 0,      NULL },
 144         { "halt",       db_halt,                0,      NULL },
 145         { "reboot",     db_reset,               0,      NULL },
 146         { "reset",      db_reset,               0,      NULL },
 147         { "kill",       db_kill,                CS_OWN, NULL },
 148         { "watchdog",   db_watchdog,            CS_OWN, NULL },
 149         { "thread",     db_set_thread,          0,      NULL },
 150         { "run",        db_run_cmd,             CS_OWN, NULL },
 151         { "script",     db_script_cmd,          CS_OWN, NULL },
 152         { "scripts",    db_scripts_cmd,         0,      NULL },
 153         { "unscript",   db_unscript_cmd,        CS_OWN, NULL },
 154         { "capture",    db_capture_cmd,         CS_OWN, NULL },
 155         { "textdump",   db_textdump_cmd,        CS_OWN, NULL },
 156         { "findstack",  db_findstack_cmd,       0,      NULL },
 157 };
 158 struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
 159
 160 static struct command   *db_last_command = NULL;
 161
 162 /*
 163  * if 'ed' style: 'dot' is set at start of last item printed,
 164  * and '+' points to next line.
 165  * Otherwise: 'dot' points to next item, '..' points to last.
 166  */
 167 static bool     db_ed_style = true;
 168
 169 /*
 170  * Utility routine - discard tokens through end-of-line.
 171  */
 172 void
 173 db_skip_to_eol(void)
 174 {
 175         int     t;
 176         do {
 177             t = db_read_token();
 178         } while (t != tEOL);
 179 }
 180
 181 /*
 182  * Results of command search.
 183  */
 184 #define CMD_UNIQUE      0
 185 #define CMD_FOUND       1
 186 #define CMD_NONE        2
 187 #define CMD_AMBIGUOUS   3
 188 #define CMD_HELP        4
 189
 190 static void     db_cmd_match(char *name, struct command *cmd,
 191                     struct command **cmdp, int *resultp);
 192 static void     db_cmd_list(struct command_table *table);
 193 static int      db_cmd_search(char *name, struct command_table *table,
 194                     struct command **cmdp);
 195 static void     db_command(struct command **last_cmdp,
 196                     struct command_table *cmd_table, int dopager);
 197
 198 /*
 199  * Initialize the command lists from the static tables.
 200  */
 201 void
 202 db_command_init(void)
 203 {
 204 #define N(a)    (sizeof(a) / sizeof(a[0]))
 205         int i;
 206
 207         for (i = 0; i < N(db_cmds); i++)
 208                 db_command_register(&db_cmd_table, &db_cmds[i]);
 209         for (i = 0; i < N(db_show_cmds); i++)
 210                 db_command_register(&db_show_table, &db_show_cmds[i]);
 211         for (i = 0; i < N(db_show_active_cmds); i++)
 212                 db_command_register(&db_show_active_table,
 213                     &db_show_active_cmds[i]);
 214         for (i = 0; i < N(db_show_all_cmds); i++)
 215                 db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
 216 #undef N
 217 }
 218
 219 /*
 220  * Register a command.
 221  */
 222 void
 223 db_command_register(struct command_table *list, struct command *cmd)
 224 {
 225         struct command *c, *last;
 226
 227         last = NULL;
 228         LIST_FOREACH(c, list, next) {
 229                 int n = strcmp(cmd->name, c->name);
 230
 231                 /* Check that the command is not already present. */
 232                 if (n == 0) {
 233                         printf("%s: Warning, the command \"%s\" already exists;"
 234                              " ignoring request\n", __func__, cmd->name);
 235                         return;
 236                 }
 237                 if (n < 0) {
 238                         /* NB: keep list sorted lexicographically */
 239                         LIST_INSERT_BEFORE(c, cmd, next);
 240                         return;
 241                 }
 242                 last = c;
 243         }
 244         if (last == NULL)
 245                 LIST_INSERT_HEAD(list, cmd, next);
 246         else
 247                 LIST_INSERT_AFTER(last, cmd, next);
 248 }
 249
 250 /*
 251  * Remove a command previously registered with db_command_register.
 252  */
 253 void
 254 db_command_unregister(struct command_table *list, struct command *cmd)
 255 {
 256         struct command *c;
 257
 258         LIST_FOREACH(c, list, next) {
 259                 if (cmd == c) {
 260                         LIST_REMOVE(cmd, next);
 261                         return;
 262                 }
 263         }
 264         /* NB: intentionally quiet */
 265 }
 266
 267 /*
 268  * Helper function to match a single command.
 269  */
 270 static void
 271 db_cmd_match(char *name, struct command *cmd, struct command **cmdp,
 272     int *resultp)
 273 {
 274         char *lp, *rp;
 275         int c;
 276
 277         lp = name;
 278         rp = cmd->name;
 279         while ((c = *lp) == *rp) {
 280                 if (c == 0) {
 281                         /* complete match */
 282                         *cmdp = cmd;
 283                         *resultp = CMD_UNIQUE;
 284                         return;
 285                 }
 286                 lp++;
 287                 rp++;
 288         }
 289         if (c == 0) {
 290                 /* end of name, not end of command -
 291                    partial match */
 292                 if (*resultp == CMD_FOUND) {
 293                         *resultp = CMD_AMBIGUOUS;
 294                         /* but keep looking for a full match -
 295                            this lets us match single letters */
 296                 } else {
 297                         *cmdp = cmd;
 298                         *resultp = CMD_FOUND;
 299                 }
 300         }
 301 }
 302
 303 /*
 304  * Search for command prefix.
 305  */
 306 static int
 307 db_cmd_search(char *name, struct command_table *table, struct command **cmdp)
 308 {
 309         struct command  *cmd;
 310         int             result = CMD_NONE;
 311
 312         LIST_FOREACH(cmd, table, next) {
 313                 db_cmd_match(name,cmd,cmdp,&result);
 314                 if (result == CMD_UNIQUE)
 315                         break;
 316         }
 317
 318         if (result == CMD_NONE) {
 319                 /* check for 'help' */
 320                 if (name[0] == 'h' && name[1] == 'e'
 321                     && name[2] == 'l' && name[3] == 'p')
 322                         result = CMD_HELP;
 323         }
 324         return (result);
 325 }
 326
 327 static void
 328 db_cmd_list(struct command_table *table)
 329 {
 330         struct command  *cmd;
 331         int have_subcommands;
 332
 333         have_subcommands = 0;
 334         LIST_FOREACH(cmd, table, next) {
 335                 if (cmd->more != NULL)
 336                         have_subcommands++;
 337                 db_printf("%-16s", cmd->name);
 338                 db_end_line(16);
 339         }
 340
 341         if (have_subcommands > 0) {
 342                 db_printf("\nThe following have subcommands; append \"help\" "
 343                     "to list (e.g. \"show help\"):\n");
 344                 LIST_FOREACH(cmd, table, next) {
 345                         if (cmd->more == NULL)
 346                                 continue;
 347                         db_printf("%-16s", cmd->name);
 348                         db_end_line(16);
 349                 }
 350         }
 351 }
 352
 353 static void
 354 db_command(struct command **last_cmdp, struct command_table *cmd_table,
 355     int dopager)
 356 {
 357         struct command  *cmd = NULL;
 358         int             t;
 359         char            modif[TOK_STRING_SIZE];
 360         db_expr_t       addr, count;
 361         bool            have_addr = false;
 362         int             result;
 363
 364         t = db_read_token();
 365         if (t == tEOL) {
 366             /* empty line repeats last command, at 'next' */
 367             cmd = *last_cmdp;
 368             addr = (db_expr_t)db_next;
 369             have_addr = false;
 370             count = 1;
 371             modif[0] = '\0';
 372         }
 373         else if (t == tEXCL) {
 374             db_fncall((db_expr_t)0, (bool)false, (db_expr_t)0, (char *)0);
 375             return;
 376         }
 377         else if (t != tIDENT) {
 378             db_printf("Unrecognized input; use \"help\" "
 379                 "to list available commands\n");
 380             db_flush_lex();
 381             return;
 382         }
 383         else {
 384             /*
 385              * Search for command
 386              */
 387             while (cmd_table) {
 388                 result = db_cmd_search(db_tok_string,
 389                                        cmd_table,
 390                                        &cmd);
 391                 switch (result) {
 392                     case CMD_NONE:
 393                         db_printf("No such command; use \"help\" "
 394                             "to list available commands\n");
 395                         db_flush_lex();
 396                         return;
 397                     case CMD_AMBIGUOUS:
 398                         db_printf("Ambiguous\n");
 399                         db_flush_lex();
 400                         return;
 401                     case CMD_HELP:
 402                         if (cmd_table == &db_cmd_table) {
 403                             db_printf("This is ddb(4), the kernel debugger; "
 404                                 "see https://man.FreeBSD.org/ddb/4 for help.\n");
 405                             db_printf("Use \"bt\" for backtrace, \"dump\" for "
 406                                 "kernel core dump, \"reset\" to reboot.\n");
 407                             db_printf("Available commands:\n");
 408                         }
 409                         db_cmd_list(cmd_table);
 410                         db_flush_lex();
 411                         return;
 412                     default:
 413                         break;
 414                 }
 415                 if ((cmd_table = cmd->more) != NULL) {
 416                     t = db_read_token();
 417                     if (t != tIDENT) {
 418                         db_printf("Subcommand required; "
 419                             "available subcommands:\n");
 420                         db_cmd_list(cmd_table);
 421                         db_flush_lex();
 422                         return;
 423                     }
 424                 }
 425             }
 426
 427             if ((cmd->flag & CS_OWN) == 0) {
 428                 /*
 429                  * Standard syntax:
 430                  * command [/modifier] [addr] [,count]
 431                  */
 432                 t = db_read_token();
 433                 if (t == tSLASH) {
 434                     t = db_read_token();
 435                     if (t != tIDENT) {
 436                         db_printf("Bad modifier\n");
 437                         db_flush_lex();
 438                         return;
 439                     }
 440                     db_strcpy(modif, db_tok_string);
 441                 }
 442                 else {
 443                     db_unread_token(t);
 444                     modif[0] = '\0';
 445                 }
 446
 447                 if (db_expression(&addr)) {
 448                     db_dot = (db_addr_t) addr;
 449                     db_last_addr = db_dot;
 450                     have_addr = true;
 451                 }
 452                 else {
 453                     addr = (db_expr_t) db_dot;
 454                     have_addr = false;
 455                 }
 456                 t = db_read_token();
 457                 if (t == tCOMMA) {
 458                     if (!db_expression(&count)) {
 459                         db_printf("Count missing\n");
 460                         db_flush_lex();
 461                         return;
 462                     }
 463                 }
 464                 else {
 465                     db_unread_token(t);
 466                     count = -1;
 467                 }
 468                 if ((cmd->flag & CS_MORE) == 0) {
 469                     db_skip_to_eol();
 470                 }
 471             }
 472         }
 473         *last_cmdp = cmd;
 474         if (cmd != NULL) {
 475             /*
 476              * Execute the command.
 477              */
 478             if (dopager)
 479                 db_enable_pager();
 480             else
 481                 db_disable_pager();
 482             (*cmd->fcn)(addr, have_addr, count, modif);
 483             if (dopager)
 484                 db_disable_pager();
 485
 486             if (cmd->flag & CS_SET_DOT) {
 487                 /*
 488                  * If command changes dot, set dot to
 489                  * previous address displayed (if 'ed' style).
 490                  */
 491                 if (db_ed_style) {
 492                     db_dot = db_prev;
 493                 }
 494                 else {
 495                     db_dot = db_next;
 496                 }
 497             }
 498             else {
 499                 /*
 500                  * If command does not change dot,
 501                  * set 'next' location to be the same.
 502                  */
 503                 db_next = db_dot;
 504             }
 505         }
 506 }
 507
 508 /*
 509  * At least one non-optional command must be implemented using
 510  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
 511  */
 512 DB_COMMAND(panic, db_panic)
 513 {
 514         db_disable_pager();
 515         panic("from debugger");
 516 }
 517
 518 void
 519 db_command_loop(void)
 520 {
 521         /*
 522          * Initialize 'prev' and 'next' to dot.
 523          */
 524         db_prev = db_dot;
 525         db_next = db_dot;
 526
 527         db_cmd_loop_done = 0;
 528         while (!db_cmd_loop_done) {
 529             if (db_print_position() != 0)
 530                 db_printf("\n");
 531
 532             db_printf("db> ");
 533             (void) db_read_line();
 534
 535             db_command(&db_last_command, &db_cmd_table, /* dopager */ 1);
 536         }
 537 }
 538
 539 /*
 540  * Execute a command on behalf of a script.  The caller is responsible for
 541  * making sure that the command string is < DB_MAXLINE or it will be
 542  * truncated.
 543  *
 544  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
 545  * nicer to use an alternative approach that didn't mess with the previous
 546  * command buffer.
 547  */
 548 void
 549 db_command_script(const char *command)
 550 {
 551         db_prev = db_next = db_dot;
 552         db_inject_line(command);
 553         db_command(&db_last_command, &db_cmd_table, /* dopager */ 0);
 554 }
 555
 556 void
 557 db_error(const char *s)
 558 {
 559         if (s)
 560             db_printf("%s", s);
 561         db_flush_lex();
 562         kdb_reenter_silent();
 563 }
 564
 565 static void
 566 db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
 567 {
 568         int error;
 569
 570         if (textdump_pending) {
 571                 db_printf("textdump_pending set.\n"
 572                     "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
 573                 return;
 574         }
 575         error = doadump(false);
 576         if (error) {
 577                 db_printf("Cannot dump: ");
 578                 switch (error) {
 579                 case EBUSY:
 580                         db_printf("debugger got invoked while dumping.\n");
 581                         break;
 582                 case ENXIO:
 583                         db_printf("no dump device specified.\n");
 584                         break;
 585                 default:
 586                         db_printf("unknown error (error=%d).\n", error);
 587                         break;
 588                 }
 589         }
 590 }
 591
 592 /*
 593  * Call random function:
 594  * !expr(arg,arg,arg)
 595  */
 596
 597 /* The generic implementation supports a maximum of 10 arguments. */
 598 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
 599     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
 600
 601 static __inline int
 602 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
 603 {
 604         __db_f *f = (__db_f *)addr;
 605
 606         if (nargs > 10) {
 607                 db_printf("Too many arguments (max 10)\n");
 608                 return (0);
 609         }
 610         *rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
 611             args[6], args[7], args[8], args[9]);
 612         return (1);
 613 }
 614
 615 static void
 616 db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
 617 {
 618         db_expr_t       fn_addr;
 619         db_expr_t       args[DB_MAXARGS];
 620         int             nargs = 0;
 621         db_expr_t       retval;
 622         int             t;
 623
 624         if (!db_expression(&fn_addr)) {
 625             db_printf("Bad function\n");
 626             db_flush_lex();
 627             return;
 628         }
 629
 630         t = db_read_token();
 631         if (t == tLPAREN) {
 632             if (db_expression(&args[0])) {
 633                 nargs++;
 634                 while ((t = db_read_token()) == tCOMMA) {
 635                     if (nargs == DB_MAXARGS) {
 636                         db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
 637                         db_flush_lex();
 638                         return;
 639                     }
 640                     if (!db_expression(&args[nargs])) {
 641                         db_printf("Argument missing\n");
 642                         db_flush_lex();
 643                         return;
 644                     }
 645                     nargs++;
 646                 }
 647                 db_unread_token(t);
 648             }
 649             if (db_read_token() != tRPAREN) {
 650                 db_printf("Mismatched parens\n");
 651                 db_flush_lex();
 652                 return;
 653             }
 654         }
 655         db_skip_to_eol();
 656         db_disable_pager();
 657
 658         if (DB_CALL(fn_addr, &retval, nargs, args))
 659                 db_printf("= %#lr\n", (long)retval);
 660 }
 661
 662 static void
 663 db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
 664 {
 665
 666         cpu_halt();
 667 }
 668
 669 static void
 670 db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
 671 {
 672         db_expr_t old_radix, pid, sig;
 673         struct proc *p;
 674
 675 #define DB_ERROR(f)     do { db_printf f; db_flush_lex(); goto out; } while (0)
 676
 677         /*
 678          * PIDs and signal numbers are typically represented in base
 679          * 10, so make that the default here.  It can, of course, be
 680          * overridden by specifying a prefix.
 681          */
 682         old_radix = db_radix;
 683         db_radix = 10;
 684         /* Retrieve arguments. */
 685         if (!db_expression(&sig))
 686                 DB_ERROR(("Missing signal number\n"));
 687         if (!db_expression(&pid))
 688                 DB_ERROR(("Missing process ID\n"));
 689         db_skip_to_eol();
 690         if (!_SIG_VALID(sig))
 691                 DB_ERROR(("Signal number out of range\n"));
 692
 693         /*
 694          * Find the process in question.  allproc_lock is not needed
 695          * since we're in DDB.
 696          */
 697         /* sx_slock(&allproc_lock); */
 698         FOREACH_PROC_IN_SYSTEM(p)
 699             if (p->p_pid == pid)
 700                     break;
 701         /* sx_sunlock(&allproc_lock); */
 702         if (p == NULL)
 703                 DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
 704
 705         /* If it's already locked, bail; otherwise, do the deed. */
 706         if (PROC_TRYLOCK(p) == 0)
 707                 DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
 708         else {
 709                 pksignal(p, sig, NULL);
 710                 PROC_UNLOCK(p);
 711         }
 712
 713 out:
 714         db_radix = old_radix;
 715 #undef DB_ERROR
 716 }
 717
 718 /*
 719  * Reboot.  In case there is an additional argument, take it as delay in
 720  * seconds.  Default to 15s if we cannot parse it and make sure we will
 721  * never wait longer than 1 week.  Some code is similar to
 722  * kern_shutdown.c:shutdown_panic().
 723  */
 724 #ifndef DB_RESET_MAXDELAY
 725 #define DB_RESET_MAXDELAY       (3600 * 24 * 7)
 726 #endif
 727
 728 static void
 729 db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
 730     char *modif __unused)
 731 {
 732         int delay, loop;
 733
 734         if (have_addr) {
 735                 delay = (int)db_hex2dec(addr);
 736
 737                 /* If we parse to fail, use 15s. */
 738                 if (delay == -1)
 739                         delay = 15;
 740
 741                 /* Cap at one week. */
 742                 if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
 743                         delay = DB_RESET_MAXDELAY;
 744
 745                 db_printf("Automatic reboot in %d seconds - "
 746                     "press a key on the console to abort\n", delay);
 747                 for (loop = delay * 10; loop > 0; --loop) {
 748                         DELAY(1000 * 100); /* 1/10th second */
 749                         /* Did user type a key? */
 750                         if (cncheckc() != -1)
 751                                 return;
 752                 }
 753         }
 754
 755         cpu_reset();
 756 }
 757
 758 static void
 759 db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
 760 {
 761         db_expr_t old_radix, tout;
 762         int err, i;
 763
 764         old_radix = db_radix;
 765         db_radix = 10;
 766         err = db_expression(&tout);
 767         db_skip_to_eol();
 768         db_radix = old_radix;
 769
 770         /* If no argument is provided the watchdog will just be disabled. */
 771         if (err == 0) {
 772                 db_printf("No argument provided, disabling watchdog\n");
 773                 tout = 0;
 774         } else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
 775                 db_error("Out of range watchdog interval\n");
 776                 return;
 777         }
 778         EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
 779 }
 780
 781 static void
 782 db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
 783 {
 784
 785         if (kdb_dbbe_select("gdb") != 0) {
 786                 db_printf("The remote GDB backend could not be selected.\n");
 787                 return;
 788         }
 789         /*
 790          * Mark that we are done in the debugger.  kdb_trap()
 791          * should re-enter with the new backend.
 792          */
 793         db_cmd_loop_done = 1;
 794         db_printf("(ctrl-c will return control to ddb)\n");
 795 }
 796
 797 static void
 798 db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
 799 {
 800         struct thread *td;
 801         db_expr_t radix;
 802         pid_t pid;
 803         int t;
 804
 805         /*
 806          * We parse our own arguments. We don't like the default radix.
 807          */
 808         radix = db_radix;
 809         db_radix = 10;
 810         hastid = db_expression(&tid);
 811         t = db_read_token();
 812         if (t == tCOMMA) {
 813                 if (!db_expression(&count)) {
 814                         db_printf("Count missing\n");
 815                         db_flush_lex();
 816                         db_radix = radix;
 817                         return;
 818                 }
 819         } else {
 820                 db_unread_token(t);
 821                 count = -1;
 822         }
 823         db_skip_to_eol();
 824         db_radix = radix;
 825
 826         if (hastid) {
 827                 td = kdb_thr_lookup((lwpid_t)tid);
 828                 if (td == NULL)
 829                         td = kdb_thr_from_pid((pid_t)tid);
 830                 if (td == NULL) {
 831                         db_printf("Thread %d not found\n", (int)tid);
 832                         return;
 833                 }
 834         } else
 835                 td = kdb_thread;
 836         if (td->td_proc != NULL)
 837                 pid = td->td_proc->p_pid;
 838         else
 839                 pid = -1;
 840         db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
 841         db_trace_thread(td, count);
 842 }
 843
 844 static void
 845 _db_stack_trace_all(bool active_only)
 846 {
 847         struct proc *p;
 848         struct thread *td;
 849         jmp_buf jb;
 850         void *prev_jb;
 851
 852         FOREACH_PROC_IN_SYSTEM(p) {
 853                 prev_jb = kdb_jmpbuf(jb);
 854                 if (setjmp(jb) == 0) {
 855                         FOREACH_THREAD_IN_PROC(p, td) {
 856                                 if (td->td_state == TDS_RUNNING)
 857                                         db_printf("\nTracing command %s pid %d"
 858                                             " tid %ld td %p (CPU %d)\n",
 859                                             p->p_comm, p->p_pid,
 860                                             (long)td->td_tid, td,
 861                                             td->td_oncpu);
 862                                 else if (active_only)
 863                                         continue;
 864                                 else
 865                                         db_printf("\nTracing command %s pid %d"
 866                                             " tid %ld td %p\n", p->p_comm,
 867                                             p->p_pid, (long)td->td_tid, td);
 868                                 db_trace_thread(td, -1);
 869                                 if (db_pager_quit) {
 870                                         kdb_jmpbuf(prev_jb);
 871                                         return;
 872                                 }
 873                         }
 874                 }
 875                 kdb_jmpbuf(prev_jb);
 876         }
 877 }
 878
 879 static void
 880 db_stack_trace_active(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
 881     char *dummy4)
 882 {
 883
 884         _db_stack_trace_all(true);
 885 }
 886
 887 static void
 888 db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
 889     char *dummy4)
 890 {
 891
 892         _db_stack_trace_all(false);
 893 }
 894
 895 /*
 896  * Take the parsed expression value from the command line that was parsed
 897  * as a hexadecimal value and convert it as if the expression was parsed
 898  * as a decimal value.  Returns -1 if the expression was not a valid
 899  * decimal value.
 900  */
 901 db_expr_t
 902 db_hex2dec(db_expr_t expr)
 903 {
 904         uintptr_t x, y;
 905         db_expr_t val;
 906
 907         y = 1;
 908         val = 0;
 909         x = expr;
 910         while (x != 0) {
 911                 if (x % 16 > 9)
 912                         return (-1);
 913                 val += (x % 16) * (y);
 914                 x >>= 4;
 915                 y *= 10;
 916         }
 917         return (val);
 918 }