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/watchdog.h>
  48
  49 #include <ddb/ddb.h>
  50 #include <ddb/db_command.h>
  51 #include <ddb/db_lex.h>
  52 #include <ddb/db_output.h>
  53
  54 #include <machine/cpu.h>
  55 #include <machine/setjmp.h>
  56
  57 /*
  58  * Exported global variables
  59  */
  60 boolean_t       db_cmd_loop_done;
  61 db_addr_t       db_dot;
  62 db_addr_t       db_last_addr;
  63 db_addr_t       db_prev;
  64 db_addr_t       db_next;
  65
  66 SET_DECLARE(db_cmd_set, struct command);
  67 SET_DECLARE(db_show_cmd_set, struct command);
  68
  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         { "procs",      db_ps,                  0,      0 },
  84         { (char *)0 }
  85 };
  86
  87 static struct command_table db_show_all_table = {
  88         db_show_all_cmds
  89 };
  90
  91 static struct command db_show_cmds[] = {
  92         { "all",        0,                      0,      &db_show_all_table },
  93         { "registers",  db_show_regs,           0,      0 },
  94         { "breaks",     db_listbreak_cmd,       0,      0 },
  95         { "threads",    db_show_threads,        0,      0 },
  96         { (char *)0, }
  97 };
  98
  99 static struct command_table db_show_table = {
 100         db_show_cmds,
 101         SET_BEGIN(db_show_cmd_set),
 102         SET_LIMIT(db_show_cmd_set)
 103 };
 104
 105 static struct command db_commands[] = {
 106         { "print",      db_print_cmd,           0,      0 },
 107         { "p",          db_print_cmd,           0,      0 },
 108         { "examine",    db_examine_cmd,         CS_SET_DOT, 0 },
 109         { "x",          db_examine_cmd,         CS_SET_DOT, 0 },
 110         { "search",     db_search_cmd,          CS_OWN|CS_SET_DOT, 0 },
 111         { "set",        db_set_cmd,             CS_OWN, 0 },
 112         { "write",      db_write_cmd,           CS_MORE|CS_SET_DOT, 0 },
 113         { "w",          db_write_cmd,           CS_MORE|CS_SET_DOT, 0 },
 114         { "delete",     db_delete_cmd,          0,      0 },
 115         { "d",          db_delete_cmd,          0,      0 },
 116         { "break",      db_breakpoint_cmd,      0,      0 },
 117         { "b",          db_breakpoint_cmd,      0,      0 },
 118         { "dwatch",     db_deletewatch_cmd,     0,      0 },
 119         { "watch",      db_watchpoint_cmd,      CS_MORE,0 },
 120         { "dhwatch",    db_deletehwatch_cmd,    0,      0 },
 121         { "hwatch",     db_hwatchpoint_cmd,     0,      0 },
 122         { "step",       db_single_step_cmd,     0,      0 },
 123         { "s",          db_single_step_cmd,     0,      0 },
 124         { "continue",   db_continue_cmd,        0,      0 },
 125         { "c",          db_continue_cmd,        0,      0 },
 126         { "until",      db_trace_until_call_cmd,0,      0 },
 127         { "next",       db_trace_until_matching_cmd,0,  0 },
 128         { "match",      db_trace_until_matching_cmd,0,  0 },
 129         { "trace",      db_stack_trace,         CS_OWN, 0 },
 130         { "t",          db_stack_trace,         CS_OWN, 0 },
 131         { "alltrace",   db_stack_trace_all,     0,      0 },
 132         { "where",      db_stack_trace,         CS_OWN, 0 },
 133         { "bt",         db_stack_trace,         CS_OWN, 0 },
 134         { "call",       db_fncall,              CS_OWN, 0 },
 135         { "show",       0,                      0,      &db_show_table },
 136         { "ps",         db_ps,                  0,      0 },
 137         { "gdb",        db_gdb,                 0,      0 },
 138         { "halt",       db_halt,                0,      0 },
 139         { "reboot",     db_reset,               0,      0 },
 140         { "reset",      db_reset,               0,      0 },
 141         { "kill",       db_kill,                CS_OWN, 0 },
 142         { "watchdog",   db_watchdog,            0,      0 },
 143         { "thread",     db_set_thread,          CS_OWN, 0 },
 144         { "run",        db_run_cmd,             CS_OWN, 0 },
 145         { "script",     db_script_cmd,          CS_OWN, 0 },
 146         { "scripts",    db_scripts_cmd,         0,      0 },
 147         { "unscript",   db_unscript_cmd,        CS_OWN, 0 },
 148         { "capture",    db_capture_cmd,         CS_OWN, 0 },
 149         { "textdump",   db_textdump_cmd,        CS_OWN, 0 },
 150         { (char *)0, }
 151 };
 152
 153 static struct command_table db_command_table = {
 154         db_commands,
 155         SET_BEGIN(db_cmd_set),
 156         SET_LIMIT(db_cmd_set)
 157 };
 158
 159 static struct command   *db_last_command = 0;
 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 boolean_t        db_ed_style = TRUE;
 167
 168 /*
 169  * Utility routine - discard tokens through end-of-line.
 170  */
 171 void
 172 db_skip_to_eol()
 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  * Helper function to match a single command.
 199  */
 200 static void
 201 db_cmd_match(name, cmd, cmdp, resultp)
 202         char *          name;
 203         struct command  *cmd;
 204         struct command  **cmdp; /* out */
 205         int *           resultp;
 206 {
 207         char *lp, *rp;
 208         int c;
 209
 210         lp = name;
 211         rp = cmd->name;
 212         while ((c = *lp) == *rp) {
 213                 if (c == 0) {
 214                         /* complete match */
 215                         *cmdp = cmd;
 216                         *resultp = CMD_UNIQUE;
 217                         return;
 218                 }
 219                 lp++;
 220                 rp++;
 221         }
 222         if (c == 0) {
 223                 /* end of name, not end of command -
 224                    partial match */
 225                 if (*resultp == CMD_FOUND) {
 226                         *resultp = CMD_AMBIGUOUS;
 227                         /* but keep looking for a full match -
 228                            this lets us match single letters */
 229                 } else {
 230                         *cmdp = cmd;
 231                         *resultp = CMD_FOUND;
 232                 }
 233         }
 234 }
 235
 236 /*
 237  * Search for command prefix.
 238  */
 239 static int
 240 db_cmd_search(name, table, cmdp)
 241         char *          name;
 242         struct command_table *table;
 243         struct command  **cmdp; /* out */
 244 {
 245         struct command  *cmd;
 246         struct command  **aux_cmdp;
 247         int             result = CMD_NONE;
 248
 249         for (cmd = table->table; cmd->name != 0; cmd++) {
 250                 db_cmd_match(name, cmd, cmdp, &result);
 251                 if (result == CMD_UNIQUE)
 252                         return (CMD_UNIQUE);
 253         }
 254         if (table->aux_tablep != NULL)
 255                 for (aux_cmdp = table->aux_tablep;
 256                      aux_cmdp < table->aux_tablep_end;
 257                      aux_cmdp++) {
 258                         db_cmd_match(name, *aux_cmdp, cmdp, &result);
 259                         if (result == CMD_UNIQUE)
 260                                 return (CMD_UNIQUE);
 261                 }
 262         if (result == CMD_NONE) {
 263                 /* check for 'help' */
 264                 if (name[0] == 'h' && name[1] == 'e'
 265                     && name[2] == 'l' && name[3] == 'p')
 266                         result = CMD_HELP;
 267         }
 268         return (result);
 269 }
 270
 271 static void
 272 db_cmd_list(table)
 273         struct command_table *table;
 274 {
 275         register struct command *cmd;
 276         register struct command **aux_cmdp;
 277
 278         for (cmd = table->table; cmd->name != 0; cmd++) {
 279             db_printf("%-12s", cmd->name);
 280             db_end_line(12);
 281         }
 282         if (table->aux_tablep == NULL)
 283             return;
 284         for (aux_cmdp = table->aux_tablep; aux_cmdp < table->aux_tablep_end;
 285              aux_cmdp++) {
 286             db_printf("%-12s", (*aux_cmdp)->name);
 287             db_end_line(12);
 288         }
 289 }
 290
 291 static void
 292 db_command(last_cmdp, cmd_table, dopager)
 293         struct command  **last_cmdp;    /* IN_OUT */
 294         struct command_table *cmd_table;
 295         int dopager;
 296 {
 297         struct command  *cmd;
 298         int             t;
 299         char            modif[TOK_STRING_SIZE];
 300         db_expr_t       addr, count;
 301         boolean_t       have_addr = FALSE;
 302         int             result;
 303
 304         t = db_read_token();
 305         if (t == tEOL) {
 306             /* empty line repeats last command, at 'next' */
 307             cmd = *last_cmdp;
 308             addr = (db_expr_t)db_next;
 309             have_addr = FALSE;
 310             count = 1;
 311             modif[0] = '\0';
 312         }
 313         else if (t == tEXCL) {
 314             db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
 315             return;
 316         }
 317         else if (t != tIDENT) {
 318             db_printf("?\n");
 319             db_flush_lex();
 320             return;
 321         }
 322         else {
 323             /*
 324              * Search for command
 325              */
 326             while (cmd_table) {
 327                 result = db_cmd_search(db_tok_string,
 328                                        cmd_table,
 329                                        &cmd);
 330                 switch (result) {
 331                     case CMD_NONE:
 332                         db_printf("No such command\n");
 333                         db_flush_lex();
 334                         return;
 335                     case CMD_AMBIGUOUS:
 336                         db_printf("Ambiguous\n");
 337                         db_flush_lex();
 338                         return;
 339                     case CMD_HELP:
 340                         db_cmd_list(cmd_table);
 341                         db_flush_lex();
 342                         return;
 343                     default:
 344                         break;
 345                 }
 346                 if ((cmd_table = cmd->more) != NULL) {
 347                     t = db_read_token();
 348                     if (t != tIDENT) {
 349                         db_cmd_list(cmd_table);
 350                         db_flush_lex();
 351                         return;
 352                     }
 353                 }
 354             }
 355
 356             if ((cmd->flag & CS_OWN) == 0) {
 357                 /*
 358                  * Standard syntax:
 359                  * command [/modifier] [addr] [,count]
 360                  */
 361                 t = db_read_token();
 362                 if (t == tSLASH) {
 363                     t = db_read_token();
 364                     if (t != tIDENT) {
 365                         db_printf("Bad modifier\n");
 366                         db_flush_lex();
 367                         return;
 368                     }
 369                     db_strcpy(modif, db_tok_string);
 370                 }
 371                 else {
 372                     db_unread_token(t);
 373                     modif[0] = '\0';
 374                 }
 375
 376                 if (db_expression(&addr)) {
 377                     db_dot = (db_addr_t) addr;
 378                     db_last_addr = db_dot;
 379                     have_addr = TRUE;
 380                 }
 381                 else {
 382                     addr = (db_expr_t) db_dot;
 383                     have_addr = FALSE;
 384                 }
 385                 t = db_read_token();
 386                 if (t == tCOMMA) {
 387                     if (!db_expression(&count)) {
 388                         db_printf("Count missing\n");
 389                         db_flush_lex();
 390                         return;
 391                     }
 392                 }
 393                 else {
 394                     db_unread_token(t);
 395                     count = -1;
 396                 }
 397                 if ((cmd->flag & CS_MORE) == 0) {
 398                     db_skip_to_eol();
 399                 }
 400             }
 401         }
 402         *last_cmdp = cmd;
 403         if (cmd != 0) {
 404             /*
 405              * Execute the command.
 406              */
 407             if (dopager)
 408                 db_enable_pager();
 409             else
 410                 db_disable_pager();
 411             (*cmd->fcn)(addr, have_addr, count, modif);
 412             if (dopager)
 413                 db_disable_pager();
 414
 415             if (cmd->flag & CS_SET_DOT) {
 416                 /*
 417                  * If command changes dot, set dot to
 418                  * previous address displayed (if 'ed' style).
 419                  */
 420                 if (db_ed_style) {
 421                     db_dot = db_prev;
 422                 }
 423                 else {
 424                     db_dot = db_next;
 425                 }
 426             }
 427             else {
 428                 /*
 429                  * If command does not change dot,
 430                  * set 'next' location to be the same.
 431                  */
 432                 db_next = db_dot;
 433             }
 434         }
 435 }
 436
 437 /*
 438  * At least one non-optional command must be implemented using
 439  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
 440  */
 441 DB_COMMAND(panic, db_panic)
 442 {
 443         db_disable_pager();
 444         panic("from debugger");
 445 }
 446
 447 void
 448 db_command_loop()
 449 {
 450         /*
 451          * Initialize 'prev' and 'next' to dot.
 452          */
 453         db_prev = db_dot;
 454         db_next = db_dot;
 455
 456         db_cmd_loop_done = 0;
 457         while (!db_cmd_loop_done) {
 458             if (db_print_position() != 0)
 459                 db_printf("\n");
 460
 461             db_printf("db> ");
 462             (void) db_read_line();
 463
 464             db_command(&db_last_command, &db_command_table, /* dopager */ 1);
 465         }
 466 }
 467
 468 /*
 469  * Execute a command on behalf of a script.  The caller is responsible for
 470  * making sure that the command string is < DB_MAXLINE or it will be
 471  * truncated.
 472  *
 473  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
 474  * nicer to use an alternative approach that didn't mess with the previous
 475  * command buffer.
 476  */
 477 void
 478 db_command_script(const char *command)
 479 {
 480         db_prev = db_next = db_dot;
 481         db_inject_line(command);
 482         db_command(&db_last_command, &db_command_table, /* dopager */ 0);
 483 }
 484
 485 void
 486 db_error(s)
 487         const char *s;
 488 {
 489         if (s)
 490             db_printf("%s", s);
 491         db_flush_lex();
 492         kdb_reenter();
 493 }
 494
 495
 496 /*
 497  * Call random function:
 498  * !expr(arg,arg,arg)
 499  */
 500
 501 /* The generic implementation supports a maximum of 10 arguments. */
 502 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
 503     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
 504
 505 static __inline int
 506 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
 507 {
 508         __db_f *f = (__db_f *)addr;
 509
 510         if (nargs > 10) {
 511                 db_printf("Too many arguments (max 10)\n");
 512                 return (0);
 513         }
 514         *rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
 515             args[6], args[7], args[8], args[9]);
 516         return (1);
 517 }
 518
 519 static void
 520 db_fncall(dummy1, dummy2, dummy3, dummy4)
 521         db_expr_t       dummy1;
 522         boolean_t       dummy2;
 523         db_expr_t       dummy3;
 524         char *          dummy4;
 525 {
 526         db_expr_t       fn_addr;
 527         db_expr_t       args[DB_MAXARGS];
 528         int             nargs = 0;
 529         db_expr_t       retval;
 530         int             t;
 531
 532         if (!db_expression(&fn_addr)) {
 533             db_printf("Bad function\n");
 534             db_flush_lex();
 535             return;
 536         }
 537
 538         t = db_read_token();
 539         if (t == tLPAREN) {
 540             if (db_expression(&args[0])) {
 541                 nargs++;
 542                 while ((t = db_read_token()) == tCOMMA) {
 543                     if (nargs == DB_MAXARGS) {
 544                         db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
 545                         db_flush_lex();
 546                         return;
 547                     }
 548                     if (!db_expression(&args[nargs])) {
 549                         db_printf("Argument missing\n");
 550                         db_flush_lex();
 551                         return;
 552                     }
 553                     nargs++;
 554                 }
 555                 db_unread_token(t);
 556             }
 557             if (db_read_token() != tRPAREN) {
 558                 db_printf("?\n");
 559                 db_flush_lex();
 560                 return;
 561             }
 562         }
 563         db_skip_to_eol();
 564         db_disable_pager();
 565
 566         if (DB_CALL(fn_addr, &retval, nargs, args))
 567                 db_printf("= %#lr\n", (long)retval);
 568 }
 569
 570 static void
 571 db_halt(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
 572 {
 573
 574         cpu_halt();
 575 }
 576
 577 static void
 578 db_kill(dummy1, dummy2, dummy3, dummy4)
 579         db_expr_t       dummy1;
 580         boolean_t       dummy2;
 581         db_expr_t       dummy3;
 582         char *          dummy4;
 583 {
 584         db_expr_t old_radix, pid, sig;
 585         struct proc *p;
 586
 587 #define DB_ERROR(f)     do { db_printf f; db_flush_lex(); goto out; } while (0)
 588
 589         /*
 590          * PIDs and signal numbers are typically represented in base
 591          * 10, so make that the default here.  It can, of course, be
 592          * overridden by specifying a prefix.
 593          */
 594         old_radix = db_radix;
 595         db_radix = 10;
 596         /* Retrieve arguments. */
 597         if (!db_expression(&sig))
 598                 DB_ERROR(("Missing signal number\n"));
 599         if (!db_expression(&pid))
 600                 DB_ERROR(("Missing process ID\n"));
 601         db_skip_to_eol();
 602         if (sig < 0 || sig > _SIG_MAXSIG)
 603                 DB_ERROR(("Signal number out of range\n"));
 604
 605         /*
 606          * Find the process in question.  allproc_lock is not needed
 607          * since we're in DDB.
 608          */
 609         /* sx_slock(&allproc_lock); */
 610         FOREACH_PROC_IN_SYSTEM(p)
 611             if (p->p_pid == pid)
 612                     break;
 613         /* sx_sunlock(&allproc_lock); */
 614         if (p == NULL)
 615                 DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
 616
 617         /* If it's already locked, bail; otherwise, do the deed. */
 618         if (PROC_TRYLOCK(p) == 0)
 619                 DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
 620         else {
 621                 psignal(p, sig);
 622                 PROC_UNLOCK(p);
 623         }
 624
 625 out:
 626         db_radix = old_radix;
 627 #undef DB_ERROR
 628 }
 629
 630 static void
 631 db_reset(dummy1, dummy2, dummy3, dummy4)
 632         db_expr_t       dummy1;
 633         boolean_t       dummy2;
 634         db_expr_t       dummy3;
 635         char *          dummy4;
 636 {
 637
 638         cpu_reset();
 639 }
 640
 641 static void
 642 db_watchdog(dummy1, dummy2, dummy3, dummy4)
 643         db_expr_t       dummy1;
 644         boolean_t       dummy2;
 645         db_expr_t       dummy3;
 646         char *          dummy4;
 647 {
 648         int i;
 649
 650         /*
 651          * XXX: It might make sense to be able to set the watchdog to a
 652          * XXX: timeout here so that failure or hang as a result of subsequent
 653          * XXX: ddb commands could be recovered by a reset.
 654          */
 655
 656         EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
 657 }
 658
 659 static void
 660 db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
 661 {
 662
 663         if (kdb_dbbe_select("gdb") != 0)
 664                 db_printf("The remote GDB backend could not be selected.\n");
 665         else
 666                 db_printf("Step to enter the remote GDB backend.\n");
 667 }
 668
 669 static void
 670 db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
 671 {
 672         struct thread *td;
 673         db_expr_t radix;
 674         pid_t pid;
 675         int t;
 676
 677         /*
 678          * We parse our own arguments. We don't like the default radix.
 679          */
 680         radix = db_radix;
 681         db_radix = 10;
 682         hastid = db_expression(&tid);
 683         t = db_read_token();
 684         if (t == tCOMMA) {
 685                 if (!db_expression(&count)) {
 686                         db_printf("Count missing\n");
 687                         db_flush_lex();
 688                         return;
 689                 }
 690         } else {
 691                 db_unread_token(t);
 692                 count = -1;
 693         }
 694         db_skip_to_eol();
 695         db_radix = radix;
 696
 697         if (hastid) {
 698                 td = kdb_thr_lookup((lwpid_t)tid);
 699                 if (td == NULL)
 700                         td = kdb_thr_from_pid((pid_t)tid);
 701                 if (td == NULL) {
 702                         db_printf("Thread %d not found\n", (int)tid);
 703                         return;
 704                 }
 705         } else
 706                 td = kdb_thread;
 707         if (td->td_proc != NULL)
 708                 pid = td->td_proc->p_pid;
 709         else
 710                 pid = -1;
 711         db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
 712         db_trace_thread(td, count);
 713 }
 714
 715 static void
 716 db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
 717     char *dummy4)
 718 {
 719         struct proc *p;
 720         struct thread *td;
 721         jmp_buf jb;
 722         void *prev_jb;
 723
 724         FOREACH_PROC_IN_SYSTEM(p) {
 725                 prev_jb = kdb_jmpbuf(jb);
 726                 if (setjmp(jb) == 0) {
 727                         FOREACH_THREAD_IN_PROC(p, td) {
 728                                 db_printf("\nTracing command %s pid %d tid %ld td %p\n",
 729                                           p->p_comm, p->p_pid, (long)td->td_tid, td);
 730                                 db_trace_thread(td, -1);
 731                                 if (db_pager_quit) {
 732                                         kdb_jmpbuf(prev_jb);
 733                                         return;
 734                                 }
 735                         }
 736                 }
 737                 kdb_jmpbuf(prev_jb);
 738         }
 739 }