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_kill;
  72 static db_cmdfcn_t      db_reset;
  73 static db_cmdfcn_t      db_stack_trace;
  74 static db_cmdfcn_t      db_stack_trace_all;
  75 static db_cmdfcn_t      db_watchdog;
  76
  77 /*
  78  * 'show' commands
  79  */
  80
  81 static struct command db_show_all_cmds[] = {
  82         { "procs",      db_ps,                  0,      0 },
  83         { (char *)0 }
  84 };
  85
  86 static struct command_table db_show_all_table = {
  87         db_show_all_cmds
  88 };
  89
  90 static struct command db_show_cmds[] = {
  91         { "all",        0,                      0,      &db_show_all_table },
  92         { "registers",  db_show_regs,           0,      0 },
  93         { "breaks",     db_listbreak_cmd,       0,      0 },
  94         { "threads",    db_show_threads,        0,      0 },
  95         { (char *)0, }
  96 };
  97
  98 static struct command_table db_show_table = {
  99         db_show_cmds,
 100         SET_BEGIN(db_show_cmd_set),
 101         SET_LIMIT(db_show_cmd_set)
 102 };
 103
 104 static struct command db_commands[] = {
 105         { "print",      db_print_cmd,           0,      0 },
 106         { "p",          db_print_cmd,           0,      0 },
 107         { "examine",    db_examine_cmd,         CS_SET_DOT, 0 },
 108         { "x",          db_examine_cmd,         CS_SET_DOT, 0 },
 109         { "search",     db_search_cmd,          CS_OWN|CS_SET_DOT, 0 },
 110         { "set",        db_set_cmd,             CS_OWN, 0 },
 111         { "write",      db_write_cmd,           CS_MORE|CS_SET_DOT, 0 },
 112         { "w",          db_write_cmd,           CS_MORE|CS_SET_DOT, 0 },
 113         { "delete",     db_delete_cmd,          0,      0 },
 114         { "d",          db_delete_cmd,          0,      0 },
 115         { "break",      db_breakpoint_cmd,      0,      0 },
 116         { "dwatch",     db_deletewatch_cmd,     0,      0 },
 117         { "watch",      db_watchpoint_cmd,      CS_MORE,0 },
 118         { "dhwatch",    db_deletehwatch_cmd,    0,      0 },
 119         { "hwatch",     db_hwatchpoint_cmd,     0,      0 },
 120         { "step",       db_single_step_cmd,     0,      0 },
 121         { "s",          db_single_step_cmd,     0,      0 },
 122         { "continue",   db_continue_cmd,        0,      0 },
 123         { "c",          db_continue_cmd,        0,      0 },
 124         { "until",      db_trace_until_call_cmd,0,      0 },
 125         { "next",       db_trace_until_matching_cmd,0,  0 },
 126         { "match",      db_trace_until_matching_cmd,0,  0 },
 127         { "trace",      db_stack_trace,         CS_OWN, 0 },
 128         { "alltrace",   db_stack_trace_all,     0,      0 },
 129         { "where",      db_stack_trace,         CS_OWN, 0 },
 130         { "bt",         db_stack_trace,         CS_OWN, 0 },
 131         { "call",       db_fncall,              CS_OWN, 0 },
 132         { "show",       0,                      0,      &db_show_table },
 133         { "ps",         db_ps,                  0,      0 },
 134         { "gdb",        db_gdb,                 0,      0 },
 135         { "reset",      db_reset,               0,      0 },
 136         { "kill",       db_kill,                CS_OWN, 0 },
 137         { "watchdog",   db_watchdog,            0,      0 },
 138         { "thread",     db_set_thread,          CS_OWN, 0 },
 139         { (char *)0, }
 140 };
 141
 142 static struct command_table db_command_table = {
 143         db_commands,
 144         SET_BEGIN(db_cmd_set),
 145         SET_LIMIT(db_cmd_set)
 146 };
 147
 148 static struct command   *db_last_command = 0;
 149
 150 /*
 151  * if 'ed' style: 'dot' is set at start of last item printed,
 152  * and '+' points to next line.
 153  * Otherwise: 'dot' points to next item, '..' points to last.
 154  */
 155 static boolean_t        db_ed_style = TRUE;
 156
 157 /*
 158  * Utility routine - discard tokens through end-of-line.
 159  */
 160 void
 161 db_skip_to_eol()
 162 {
 163         int     t;
 164         do {
 165             t = db_read_token();
 166         } while (t != tEOL);
 167 }
 168
 169 /*
 170  * Results of command search.
 171  */
 172 #define CMD_UNIQUE      0
 173 #define CMD_FOUND       1
 174 #define CMD_NONE        2
 175 #define CMD_AMBIGUOUS   3
 176 #define CMD_HELP        4
 177
 178 static void     db_cmd_match(char *name, struct command *cmd,
 179                     struct command **cmdp, int *resultp);
 180 static void     db_cmd_list(struct command_table *table);
 181 static int      db_cmd_search(char *name, struct command_table *table,
 182                     struct command **cmdp);
 183 static void     db_command(struct command **last_cmdp,
 184                     struct command_table *cmd_table);
 185
 186 /*
 187  * Helper function to match a single command.
 188  */
 189 static void
 190 db_cmd_match(name, cmd, cmdp, resultp)
 191         char *          name;
 192         struct command  *cmd;
 193         struct command  **cmdp; /* out */
 194         int *           resultp;
 195 {
 196         char *lp, *rp;
 197         int c;
 198
 199         lp = name;
 200         rp = cmd->name;
 201         while ((c = *lp) == *rp) {
 202                 if (c == 0) {
 203                         /* complete match */
 204                         *cmdp = cmd;
 205                         *resultp = CMD_UNIQUE;
 206                         return;
 207                 }
 208                 lp++;
 209                 rp++;
 210         }
 211         if (c == 0) {
 212                 /* end of name, not end of command -
 213                    partial match */
 214                 if (*resultp == CMD_FOUND) {
 215                         *resultp = CMD_AMBIGUOUS;
 216                         /* but keep looking for a full match -
 217                            this lets us match single letters */
 218                 } else {
 219                         *cmdp = cmd;
 220                         *resultp = CMD_FOUND;
 221                 }
 222         }
 223 }
 224
 225 /*
 226  * Search for command prefix.
 227  */
 228 static int
 229 db_cmd_search(name, table, cmdp)
 230         char *          name;
 231         struct command_table *table;
 232         struct command  **cmdp; /* out */
 233 {
 234         struct command  *cmd;
 235         struct command  **aux_cmdp;
 236         int             result = CMD_NONE;
 237
 238         for (cmd = table->table; cmd->name != 0; cmd++) {
 239                 db_cmd_match(name, cmd, cmdp, &result);
 240                 if (result == CMD_UNIQUE)
 241                         return (CMD_UNIQUE);
 242         }
 243         if (table->aux_tablep != NULL)
 244                 for (aux_cmdp = table->aux_tablep;
 245                      aux_cmdp < table->aux_tablep_end;
 246                      aux_cmdp++) {
 247                         db_cmd_match(name, *aux_cmdp, cmdp, &result);
 248                         if (result == CMD_UNIQUE)
 249                                 return (CMD_UNIQUE);
 250                 }
 251         if (result == CMD_NONE) {
 252                 /* check for 'help' */
 253                 if (name[0] == 'h' && name[1] == 'e'
 254                     && name[2] == 'l' && name[3] == 'p')
 255                         result = CMD_HELP;
 256         }
 257         return (result);
 258 }
 259
 260 static void
 261 db_cmd_list(table)
 262         struct command_table *table;
 263 {
 264         register struct command *cmd;
 265         register struct command **aux_cmdp;
 266
 267         for (cmd = table->table; cmd->name != 0; cmd++) {
 268             db_printf("%-12s", cmd->name);
 269             db_end_line();
 270         }
 271         if (table->aux_tablep == NULL)
 272             return;
 273         for (aux_cmdp = table->aux_tablep; aux_cmdp < table->aux_tablep_end;
 274              aux_cmdp++) {
 275             db_printf("%-12s", (*aux_cmdp)->name);
 276             db_end_line();
 277         }
 278 }
 279
 280 static void
 281 db_command(last_cmdp, cmd_table)
 282         struct command  **last_cmdp;    /* IN_OUT */
 283         struct command_table *cmd_table;
 284 {
 285         struct command  *cmd;
 286         int             t;
 287         char            modif[TOK_STRING_SIZE];
 288         db_expr_t       addr, count;
 289         boolean_t       have_addr = FALSE;
 290         int             result;
 291
 292         t = db_read_token();
 293         if (t == tEOL) {
 294             /* empty line repeats last command, at 'next' */
 295             cmd = *last_cmdp;
 296             addr = (db_expr_t)db_next;
 297             have_addr = FALSE;
 298             count = 1;
 299             modif[0] = '\0';
 300         }
 301         else if (t == tEXCL) {
 302             db_fncall((db_expr_t)0, (boolean_t)0, (db_expr_t)0, (char *)0);
 303             return;
 304         }
 305         else if (t != tIDENT) {
 306             db_printf("?\n");
 307             db_flush_lex();
 308             return;
 309         }
 310         else {
 311             /*
 312              * Search for command
 313              */
 314             while (cmd_table) {
 315                 result = db_cmd_search(db_tok_string,
 316                                        cmd_table,
 317                                        &cmd);
 318                 switch (result) {
 319                     case CMD_NONE:
 320                         db_printf("No such command\n");
 321                         db_flush_lex();
 322                         return;
 323                     case CMD_AMBIGUOUS:
 324                         db_printf("Ambiguous\n");
 325                         db_flush_lex();
 326                         return;
 327                     case CMD_HELP:
 328                         db_cmd_list(cmd_table);
 329                         db_flush_lex();
 330                         return;
 331                     default:
 332                         break;
 333                 }
 334                 if ((cmd_table = cmd->more) != NULL) {
 335                     t = db_read_token();
 336                     if (t != tIDENT) {
 337                         db_cmd_list(cmd_table);
 338                         db_flush_lex();
 339                         return;
 340                     }
 341                 }
 342             }
 343
 344             if ((cmd->flag & CS_OWN) == 0) {
 345                 /*
 346                  * Standard syntax:
 347                  * command [/modifier] [addr] [,count]
 348                  */
 349                 t = db_read_token();
 350                 if (t == tSLASH) {
 351                     t = db_read_token();
 352                     if (t != tIDENT) {
 353                         db_printf("Bad modifier\n");
 354                         db_flush_lex();
 355                         return;
 356                     }
 357                     db_strcpy(modif, db_tok_string);
 358                 }
 359                 else {
 360                     db_unread_token(t);
 361                     modif[0] = '\0';
 362                 }
 363
 364                 if (db_expression(&addr)) {
 365                     db_dot = (db_addr_t) addr;
 366                     db_last_addr = db_dot;
 367                     have_addr = TRUE;
 368                 }
 369                 else {
 370                     addr = (db_expr_t) db_dot;
 371                     have_addr = FALSE;
 372                 }
 373                 t = db_read_token();
 374                 if (t == tCOMMA) {
 375                     if (!db_expression(&count)) {
 376                         db_printf("Count missing\n");
 377                         db_flush_lex();
 378                         return;
 379                     }
 380                 }
 381                 else {
 382                     db_unread_token(t);
 383                     count = -1;
 384                 }
 385                 if ((cmd->flag & CS_MORE) == 0) {
 386                     db_skip_to_eol();
 387                 }
 388             }
 389         }
 390         *last_cmdp = cmd;
 391         if (cmd != 0) {
 392             /*
 393              * Execute the command.
 394              */
 395             (*cmd->fcn)(addr, have_addr, count, modif);
 396             db_setup_paging(NULL, NULL, -1);
 397
 398             if (cmd->flag & CS_SET_DOT) {
 399                 /*
 400                  * If command changes dot, set dot to
 401                  * previous address displayed (if 'ed' style).
 402                  */
 403                 if (db_ed_style) {
 404                     db_dot = db_prev;
 405                 }
 406                 else {
 407                     db_dot = db_next;
 408                 }
 409             }
 410             else {
 411                 /*
 412                  * If command does not change dot,
 413                  * set 'next' location to be the same.
 414                  */
 415                 db_next = db_dot;
 416             }
 417         }
 418 }
 419
 420 /*
 421  * At least one non-optional command must be implemented using
 422  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
 423  */
 424 DB_COMMAND(panic, db_panic)
 425 {
 426         panic("from debugger");
 427 }
 428
 429 void
 430 db_command_loop()
 431 {
 432         /*
 433          * Initialize 'prev' and 'next' to dot.
 434          */
 435         db_prev = db_dot;
 436         db_next = db_dot;
 437
 438         db_cmd_loop_done = 0;
 439         while (!db_cmd_loop_done) {
 440             if (db_print_position() != 0)
 441                 db_printf("\n");
 442
 443             db_printf("db> ");
 444             (void) db_read_line();
 445
 446             db_command(&db_last_command, &db_command_table);
 447         }
 448 }
 449
 450 void
 451 db_error(s)
 452         const char *s;
 453 {
 454         if (s)
 455             db_printf("%s", s);
 456         db_flush_lex();
 457         kdb_reenter();
 458 }
 459
 460
 461 /*
 462  * Call random function:
 463  * !expr(arg,arg,arg)
 464  */
 465
 466 /* The generic implementation supports a maximum of 10 arguments. */
 467 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
 468     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
 469
 470 static __inline int
 471 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
 472 {
 473         __db_f *f = (__db_f *)addr;
 474
 475         if (nargs > 10) {
 476                 db_printf("Too many arguments (max 10)\n");
 477                 return (0);
 478         }
 479         *rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
 480             args[6], args[7], args[8], args[9]);
 481         return (1);
 482 }
 483
 484 static void
 485 db_fncall(dummy1, dummy2, dummy3, dummy4)
 486         db_expr_t       dummy1;
 487         boolean_t       dummy2;
 488         db_expr_t       dummy3;
 489         char *          dummy4;
 490 {
 491         db_expr_t       fn_addr;
 492         db_expr_t       args[DB_MAXARGS];
 493         int             nargs = 0;
 494         db_expr_t       retval;
 495         int             t;
 496
 497         if (!db_expression(&fn_addr)) {
 498             db_printf("Bad function\n");
 499             db_flush_lex();
 500             return;
 501         }
 502
 503         t = db_read_token();
 504         if (t == tLPAREN) {
 505             if (db_expression(&args[0])) {
 506                 nargs++;
 507                 while ((t = db_read_token()) == tCOMMA) {
 508                     if (nargs == DB_MAXARGS) {
 509                         db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
 510                         db_flush_lex();
 511                         return;
 512                     }
 513                     if (!db_expression(&args[nargs])) {
 514                         db_printf("Argument missing\n");
 515                         db_flush_lex();
 516                         return;
 517                     }
 518                     nargs++;
 519                 }
 520                 db_unread_token(t);
 521             }
 522             if (db_read_token() != tRPAREN) {
 523                 db_printf("?\n");
 524                 db_flush_lex();
 525                 return;
 526             }
 527         }
 528         db_skip_to_eol();
 529
 530         if (DB_CALL(fn_addr, &retval, nargs, args))
 531                 db_printf("= %#lr\n", (long)retval);
 532 }
 533
 534 static void
 535 db_kill(dummy1, dummy2, dummy3, dummy4)
 536         db_expr_t       dummy1;
 537         boolean_t       dummy2;
 538         db_expr_t       dummy3;
 539         char *          dummy4;
 540 {
 541         db_expr_t old_radix, pid, sig;
 542         struct proc *p;
 543
 544 #define DB_ERROR(f)     do { db_printf f; db_flush_lex(); goto out; } while (0)
 545
 546         /*
 547          * PIDs and signal numbers are typically represented in base
 548          * 10, so make that the default here.  It can, of course, be
 549          * overridden by specifying a prefix.
 550          */
 551         old_radix = db_radix;
 552         db_radix = 10;
 553         /* Retrieve arguments. */
 554         if (!db_expression(&sig))
 555                 DB_ERROR(("Missing signal number\n"));
 556         if (!db_expression(&pid))
 557                 DB_ERROR(("Missing process ID\n"));
 558         db_skip_to_eol();
 559         if (sig < 0 || sig > _SIG_MAXSIG)
 560                 DB_ERROR(("Signal number out of range\n"));
 561
 562         /*
 563          * Find the process in question.  allproc_lock is not needed
 564          * since we're in DDB.
 565          */
 566         /* sx_slock(&allproc_lock); */
 567         LIST_FOREACH(p, &allproc, p_list)
 568             if (p->p_pid == pid)
 569                     break;
 570         /* sx_sunlock(&allproc_lock); */
 571         if (p == NULL)
 572                 DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
 573
 574         /* If it's already locked, bail; otherwise, do the deed. */
 575         if (PROC_TRYLOCK(p) == 0)
 576                 DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
 577         else {
 578                 psignal(p, sig);
 579                 PROC_UNLOCK(p);
 580         }
 581
 582 out:
 583         db_radix = old_radix;
 584 #undef DB_ERROR
 585 }
 586
 587 static void
 588 db_reset(dummy1, dummy2, dummy3, dummy4)
 589         db_expr_t       dummy1;
 590         boolean_t       dummy2;
 591         db_expr_t       dummy3;
 592         char *          dummy4;
 593 {
 594
 595         cpu_reset();
 596 }
 597
 598 static void
 599 db_watchdog(dummy1, dummy2, dummy3, dummy4)
 600         db_expr_t       dummy1;
 601         boolean_t       dummy2;
 602         db_expr_t       dummy3;
 603         char *          dummy4;
 604 {
 605         int i;
 606
 607         /*
 608          * XXX: It might make sense to be able to set the watchdog to a
 609          * XXX: timeout here so that failure or hang as a result of subsequent
 610          * XXX: ddb commands could be recovered by a reset.
 611          */
 612
 613         EVENTHANDLER_INVOKE(watchdog_list, 0, &i);
 614 }
 615
 616 static void
 617 db_gdb(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
 618 {
 619
 620         if (kdb_dbbe_select("gdb") != 0)
 621                 db_printf("The remote GDB backend could not be selected.\n");
 622         else
 623                 db_printf("Step to enter the remote GDB backend.\n");
 624 }
 625
 626 static void
 627 db_stack_trace(db_expr_t tid, boolean_t hastid, db_expr_t count, char *modif)
 628 {
 629         struct thread *td;
 630         db_expr_t radix;
 631         pid_t pid;
 632         int t;
 633
 634         /*
 635          * We parse our own arguments. We don't like the default radix.
 636          */
 637         radix = db_radix;
 638         db_radix = 10;
 639         hastid = db_expression(&tid);
 640         t = db_read_token();
 641         if (t == tCOMMA) {
 642                 if (!db_expression(&count)) {
 643                         db_printf("Count missing\n");
 644                         db_flush_lex();
 645                         return;
 646                 }
 647         } else {
 648                 db_unread_token(t);
 649                 count = -1;
 650         }
 651         db_skip_to_eol();
 652         db_radix = radix;
 653
 654         if (hastid) {
 655                 td = kdb_thr_lookup((lwpid_t)tid);
 656                 if (td == NULL)
 657                         td = kdb_thr_from_pid((pid_t)tid);
 658                 if (td == NULL) {
 659                         db_printf("Thread %d not found\n", (int)tid);
 660                         return;
 661                 }
 662         } else
 663                 td = kdb_thread;
 664         if (td->td_proc != NULL)
 665                 pid = td->td_proc->p_pid;
 666         else
 667                 pid = -1;
 668         db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
 669         db_trace_thread(td, count);
 670 }
 671
 672 static void
 673 db_stack_trace_all(db_expr_t dummy, boolean_t dummy2, db_expr_t dummy3,
 674     char *dummy4)
 675 {
 676         struct proc *p;
 677         struct thread *td;
 678         int quit;
 679
 680         quit = 0;
 681         db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
 682         LIST_FOREACH(p, &allproc, p_list) {
 683                 FOREACH_THREAD_IN_PROC(p, td) {
 684                         db_printf("\nTracing command %s pid %d tid %ld td %p\n",
 685                             p->p_comm, p->p_pid, (long)td->td_tid, td);
 686                         db_trace_thread(td, -1);
 687                         if (quit)
 688                                 return;
 689                 }
 690         }
 691 }