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         { (char *)0, }
 145 };
 146
 147 static struct command_table db_command_table = {
 148         db_commands,
 149         SET_BEGIN(db_cmd_set),
 150         SET_LIMIT(db_cmd_set)
 151 };
 152
 153 static struct command   *db_last_command = 0;
 154
 155 /*
 156  * if 'ed' style: 'dot' is set at start of last item printed,
 157  * and '+' points to next line.
 158  * Otherwise: 'dot' points to next item, '..' points to last.
 159  */
 160 static boolean_t        db_ed_style = TRUE;
 161
 162 /*
 163  * Utility routine - discard tokens through end-of-line.
 164  */
 165 void
 166 db_skip_to_eol()
 167 {
 168         int     t;
 169         do {
 170             t = db_read_token();
 171         } while (t != tEOL);
 172 }
 173
 174 /*
 175  * Results of command search.
 176  */
 177 #define CMD_UNIQUE      0
 178 #define CMD_FOUND       1
 179 #define CMD_NONE        2
 180 #define CMD_AMBIGUOUS   3
 181 #define CMD_HELP        4
 182
 183 static void     db_cmd_match(char *name, struct command *cmd,
 184                     struct command **cmdp, int *resultp);
 185 static void     db_cmd_list(struct command_table *table);
 186 static int      db_cmd_search(char *name, struct command_table *table,
 187                     struct command **cmdp);
 188 static void     db_command(struct command **last_cmdp,
 189                     struct command_table *cmd_table);
 190
 191 /*
 192  * Helper function to match a single command.
 193  */
 194 static void
 195 db_cmd_match(name, cmd, cmdp, resultp)
 196         char *          name;
 197         struct command  *cmd;
 198         struct command  **cmdp; /* out */
 199         int *           resultp;
 200 {
 201         char *lp, *rp;
 202         int c;
 203
 204         lp = name;
 205         rp = cmd->name;
 206         while ((c = *lp) == *rp) {
 207                 if (c == 0) {
 208                         /* complete match */
 209                         *cmdp = cmd;
 210                         *resultp = CMD_UNIQUE;
 211                         return;
 212                 }
 213                 lp++;
 214                 rp++;
 215         }
 216         if (c == 0) {
 217                 /* end of name, not end of command -
 218                    partial match */
 219                 if (*resultp == CMD_FOUND) {
 220                         *resultp = CMD_AMBIGUOUS;
 221                         /* but keep looking for a full match -
 222                            this lets us match single letters */
 223                 } else {
 224                         *cmdp = cmd;
 225                         *resultp = CMD_FOUND;
 226                 }
 227         }
 228 }
 229
 230 /*
 231  * Search for command prefix.
 232  */
 233 static int
 234 db_cmd_search(name, table, cmdp)
 235         char *          name;
 236         struct command_table *table;
 237         struct command  **cmdp; /* out */
 238 {
 239         struct command  *cmd;
 240         struct command  **aux_cmdp;
 241         int             result = CMD_NONE;
 242
 243         for (cmd = table->table; cmd->name != 0; cmd++) {
 244                 db_cmd_match(name, cmd, cmdp, &result);
 245                 if (result == CMD_UNIQUE)
 246                         return (CMD_UNIQUE);
 247         }
 248         if (table->aux_tablep != NULL)
 249                 for (aux_cmdp = table->aux_tablep;
 250                      aux_cmdp < table->aux_tablep_end;
 251                      aux_cmdp++) {
 252                         db_cmd_match(name, *aux_cmdp, cmdp, &result);
 253                         if (result == CMD_UNIQUE)
 254                                 return (CMD_UNIQUE);
 255                 }
 256         if (result == CMD_NONE) {
 257                 /* check for 'help' */
 258                 if (name[0] == 'h' && name[1] == 'e'
 259                     && name[2] == 'l' && name[3] == 'p')
 260                         result = CMD_HELP;
 261         }
 262         return (result);
 263 }
 264
 265 static void
 266 db_cmd_list(table)
 267         struct command_table *table;
 268 {
 269         register struct command *cmd;
 270         register struct command **aux_cmdp;
 271
 272         for (cmd = table->table; cmd->name != 0; cmd++) {
 273             db_printf("%-12s", cmd->name);
 274             db_end_line(12);
 275         }
 276         if (table->aux_tablep == NULL)
 277             return;
 278         for (aux_cmdp = table->aux_tablep; aux_cmdp < table->aux_tablep_end;
 279              aux_cmdp++) {
 280             db_printf("%-12s", (*aux_cmdp)->name);
 281             db_end_line(12);
 282         }
 283 }
 284
 285 static void
 286 db_command(last_cmdp, cmd_table)
 287         struct command  **last_cmdp;    /* IN_OUT */
 288         struct command_table *cmd_table;
 289 {
 290         struct command  *cmd;
 291         int             t;
 292         char            modif[TOK_STRING_SIZE];
 293         db_expr_t       addr, count;
 294         boolean_t       have_addr = FALSE;
 295         int             result;
 296
 297         t = db_read_token();
 298         if (t == tEOL) {
 299             /* empty line repeats last command, at 'next' */
 300             cmd = *last_cmdp;
 301             addr = (db_expr_t)db_next;
 302             have_addr = FALSE;
 303             count = 1;
 304             modif[0] = '\0';
 305         }
 306         else if (t == tEXCL) {
 307             db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
 308             return;
 309         }
 310         else if (t != tIDENT) {
 311             db_printf("?\n");
 312             db_flush_lex();
 313             return;
 314         }
 315         else {
 316             /*
 317              * Search for command
 318              */
 319             while (cmd_table) {
 320                 result = db_cmd_search(db_tok_string,
 321                                        cmd_table,
 322                                        &cmd);
 323                 switch (result) {
 324                     case CMD_NONE:
 325                         db_printf("No such command\n");
 326                         db_flush_lex();
 327                         return;
 328                     case CMD_AMBIGUOUS:
 329                         db_printf("Ambiguous\n");
 330                         db_flush_lex();
 331                         return;
 332                     case CMD_HELP:
 333                         db_cmd_list(cmd_table);
 334                         db_flush_lex();
 335                         return;
 336                     default:
 337                         break;
 338                 }
 339                 if ((cmd_table = cmd->more) != NULL) {
 340                     t = db_read_token();
 341                     if (t != tIDENT) {
 342                         db_cmd_list(cmd_table);
 343                         db_flush_lex();
 344                         return;
 345                     }
 346                 }
 347             }
 348
 349             if ((cmd->flag & CS_OWN) == 0) {
 350                 /*
 351                  * Standard syntax:
 352                  * command [/modifier] [addr] [,count]
 353                  */
 354                 t = db_read_token();
 355                 if (t == tSLASH) {
 356                     t = db_read_token();
 357                     if (t != tIDENT) {
 358                         db_printf("Bad modifier\n");
 359                         db_flush_lex();
 360                         return;
 361                     }
 362                     db_strcpy(modif, db_tok_string);
 363                 }
 364                 else {
 365                     db_unread_token(t);
 366                     modif[0] = '\0';
 367                 }
 368
 369                 if (db_expression(&addr)) {
 370                     db_dot = (db_addr_t) addr;
 371                     db_last_addr = db_dot;
 372                     have_addr = TRUE;
 373                 }
 374                 else {
 375                     addr = (db_expr_t) db_dot;
 376                     have_addr = FALSE;
 377                 }
 378                 t = db_read_token();
 379                 if (t == tCOMMA) {
 380                     if (!db_expression(&count)) {
 381                         db_printf("Count missing\n");
 382                         db_flush_lex();
 383                         return;
 384                     }
 385                 }
 386                 else {
 387                     db_unread_token(t);
 388                     count = -1;
 389                 }
 390                 if ((cmd->flag & CS_MORE) == 0) {
 391                     db_skip_to_eol();
 392                 }
 393             }
 394         }
 395         *last_cmdp = cmd;
 396         if (cmd != 0) {
 397             /*
 398              * Execute the command.
 399              */
 400             db_enable_pager();
 401             (*cmd->fcn)(addr, have_addr, count, modif);
 402             db_disable_pager();
 403
 404             if (cmd->flag & CS_SET_DOT) {
 405                 /*
 406                  * If command changes dot, set dot to
 407                  * previous address displayed (if 'ed' style).
 408                  */
 409                 if (db_ed_style) {
 410                     db_dot = db_prev;
 411                 }
 412                 else {
 413                     db_dot = db_next;
 414                 }
 415             }
 416             else {
 417                 /*
 418                  * If command does not change dot,
 419                  * set 'next' location to be the same.
 420                  */
 421                 db_next = db_dot;
 422             }
 423         }
 424 }
 425
 426 /*
 427  * At least one non-optional command must be implemented using
 428  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
 429  */
 430 DB_COMMAND(panic, db_panic)
 431 {
 432         db_disable_pager();
 433         panic("from debugger");
 434 }
 435
 436 void
 437 db_command_loop()
 438 {
 439         /*
 440          * Initialize 'prev' and 'next' to dot.
 441          */
 442         db_prev = db_dot;
 443         db_next = db_dot;
 444
 445         db_cmd_loop_done = 0;
 446         while (!db_cmd_loop_done) {
 447             if (db_print_position() != 0)
 448                 db_printf("\n");
 449
 450             db_printf("db> ");
 451             (void) db_read_line();
 452
 453             db_command(&db_last_command, &db_command_table);
 454         }
 455 }
 456
 457 void
 458 db_error(s)
 459         const char *s;
 460 {
 461         if (s)
 462             db_printf("%s", s);
 463         db_flush_lex();
 464         kdb_reenter();
 465 }
 466
 467
 468 /*
 469  * Call random function:
 470  * !expr(arg,arg,arg)
 471  */
 472
 473 /* The generic implementation supports a maximum of 10 arguments. */
 474 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
 475     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
 476
 477 static __inline int
 478 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
 479 {
 480         __db_f *f = (__db_f *)addr;
 481
 482         if (nargs > 10) {
 483                 db_printf("Too many arguments (max 10)\n");
 484                 return (0);
 485         }
 486         *rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
 487             args[6], args[7], args[8], args[9]);
 488         return (1);
 489 }
 490
 491 static void
 492 db_fncall(dummy1, dummy2, dummy3, dummy4)
 493         db_expr_t       dummy1;
 494         boolean_t       dummy2;
 495         db_expr_t       dummy3;
 496         char *          dummy4;
 497 {
 498         db_expr_t       fn_addr;
 499         db_expr_t       args[DB_MAXARGS];
 500         int             nargs = 0;
 501         db_expr_t       retval;
 502         int             t;
 503
 504         if (!db_expression(&fn_addr)) {
 505             db_printf("Bad function\n");
 506             db_flush_lex();
 507             return;
 508         }
 509
 510         t = db_read_token();
 511         if (t == tLPAREN) {
 512             if (db_expression(&args[0])) {
 513                 nargs++;
 514                 while ((t = db_read_token()) == tCOMMA) {
 515                     if (nargs == DB_MAXARGS) {
 516                         db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
 517                         db_flush_lex();
 518                         return;
 519                     }
 520                     if (!db_expression(&args[nargs])) {
 521                         db_printf("Argument missing\n");
 522                         db_flush_lex();
 523                         return;
 524                     }
 525                     nargs++;
 526                 }
 527                 db_unread_token(t);
 528             }
 529             if (db_read_token() != tRPAREN) {
 530                 db_printf("?\n");
 531                 db_flush_lex();
 532                 return;
 533             }
 534         }
 535         db_skip_to_eol();
 536         db_disable_pager();
 537
 538         if (DB_CALL(fn_addr, &retval, nargs, args))
 539                 db_printf("= %#lr\n", (long)retval);
 540 }
 541
 542 static void
 543 db_halt(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
 544 {
 545
 546         cpu_halt();
 547 }
 548
 549 static void
 550 db_kill(dummy1, dummy2, dummy3, dummy4)
 551         db_expr_t       dummy1;
 552         boolean_t       dummy2;
 553         db_expr_t       dummy3;
 554         char *          dummy4;
 555 {
 556         db_expr_t old_radix, pid, sig;
 557         struct proc *p;
 558
 559 #define DB_ERROR(f)     do { db_printf f; db_flush_lex(); goto out; } while (0)
 560
 561         /*
 562          * PIDs and signal numbers are typically represented in base
 563          * 10, so make that the default here.  It can, of course, be
 564          * overridden by specifying a prefix.
 565          */
 566         old_radix = db_radix;
 567         db_radix = 10;
 568         /* Retrieve arguments. */
 569         if (!db_expression(&sig))
 570                 DB_ERROR(("Missing signal number\n"));
 571         if (!db_expression(&pid))
 572                 DB_ERROR(("Missing process ID\n"));
 573         db_skip_to_eol();
 574         if (sig < 0 || sig > _SIG_MAXSIG)
 575                 DB_ERROR(("Signal number out of range\n"));
 576
 577         /*
 578          * Find the process in question.  allproc_lock is not needed
 579          * since we're in DDB.
 580          */
 581         /* sx_slock(&allproc_lock); */
 582         LIST_FOREACH(p, &allproc, p_list)
 583             if (p->p_pid == pid)
 584                     break;
 585         /* sx_sunlock(&allproc_lock); */
 586         if (p == NULL)
 587                 DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
 588
 589         /* If it's already locked, bail; otherwise, do the deed. */
 590         if (PROC_TRYLOCK(p) == 0)
 591                 DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
 592         else {
 593                 psignal(p, sig);
 594                 PROC_UNLOCK(p);
 595         }
 596
 597 out:
 598         db_radix = old_radix;
 599 #undef DB_ERROR
 600 }
 601
 602 static void
 603 db_reset(dummy1, dummy2, dummy3, dummy4)
 604         db_expr_t       dummy1;
 605         boolean_t       dummy2;
 606         db_expr_t       dummy3;
 607         char *          dummy4;
 608 {
 609
 610         cpu_reset();
 611 }
 612
 613 static void
 614 db_watchdog(dummy1, dummy2, dummy3, dummy4)
 615         db_expr_t       dummy1;
 616         boolean_t       dummy2;
 617         db_expr_t       dummy3;
 618         char *          dummy4;
 619 {
 620         int i;
 621
 622         /*
 623          * XXX: It might make sense to be able to set the watchdog to a
 624          * XXX: timeout here so that failure or hang as a result of subsequent
 625          * XXX: ddb commands could be recovered by a reset.
 626          */
 627
 628         EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
 629 }
 630
 631 static void
 632 db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
 633 {
 634
 635         if (kdb_dbbe_select("gdb") != 0)
 636                 db_printf("The remote GDB backend could not be selected.\n");
 637         else
 638                 db_printf("Step to enter the remote GDB backend.\n");
 639 }
 640
 641 static void
 642 db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
 643 {
 644         struct thread *td;
 645         db_expr_t radix;
 646         pid_t pid;
 647         int t;
 648
 649         /*
 650          * We parse our own arguments. We don't like the default radix.
 651          */
 652         radix = db_radix;
 653         db_radix = 10;
 654         hastid = db_expression(&tid);
 655         t = db_read_token();
 656         if (t == tCOMMA) {
 657                 if (!db_expression(&count)) {
 658                         db_printf("Count missing\n");
 659                         db_flush_lex();
 660                         return;
 661                 }
 662         } else {
 663                 db_unread_token(t);
 664                 count = -1;
 665         }
 666         db_skip_to_eol();
 667         db_radix = radix;
 668
 669         if (hastid) {
 670                 td = kdb_thr_lookup((lwpid_t)tid);
 671                 if (td == NULL)
 672                         td = kdb_thr_from_pid((pid_t)tid);
 673                 if (td == NULL) {
 674                         db_printf("Thread %d not found\n", (int)tid);
 675                         return;
 676                 }
 677         } else
 678                 td = kdb_thread;
 679         if (td->td_proc != NULL)
 680                 pid = td->td_proc->p_pid;
 681         else
 682                 pid = -1;
 683         db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
 684         db_trace_thread(td, count);
 685 }
 686
 687 static void
 688 db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
 689     char *dummy4)
 690 {
 691         struct proc *p;
 692         struct thread *td;
 693
 694         LIST_FOREACH(p, &allproc, p_list) {
 695                 FOREACH_THREAD_IN_PROC(p, td) {
 696                         db_printf("\nTracing command %s pid %d tid %ld td %p\n",
 697                             p->p_comm, p->p_pid, (long)td->td_tid, td);
 698                         db_trace_thread(td, -1);
 699                         if (db_pager_quit)
 700                                 return;
 701                 }
 702         }
 703 }