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