The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_command.c

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    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: releng/11.2/sys/ddb/db_command.c 324267 2017-10-04 11:55:34Z trasz $");
   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/conf.h>
   48 #include <sys/watchdog.h>
   49 #include <sys/kernel.h>
   50 
   51 #include <ddb/ddb.h>
   52 #include <ddb/db_command.h>
   53 #include <ddb/db_lex.h>
   54 #include <ddb/db_output.h>
   55 
   56 #include <machine/cpu.h>
   57 #include <machine/setjmp.h>
   58 
   59 /*
   60  * Exported global variables
   61  */
   62 bool            db_cmd_loop_done;
   63 db_addr_t       db_dot;
   64 db_addr_t       db_last_addr;
   65 db_addr_t       db_prev;
   66 db_addr_t       db_next;
   67 
   68 static db_cmdfcn_t      db_dump;
   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         { "trace",      db_stack_trace_all,     0,      NULL },
   84 };
   85 struct command_table db_show_all_table =
   86     LIST_HEAD_INITIALIZER(db_show_all_table);
   87 
   88 static struct command db_show_cmds[] = {
   89         { "all",        0,                      0,      &db_show_all_table },
   90         { "registers",  db_show_regs,           0,      NULL },
   91         { "breaks",     db_listbreak_cmd,       0,      NULL },
   92         { "threads",    db_show_threads,        0,      NULL },
   93 };
   94 struct command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
   95 
   96 static struct command db_cmds[] = {
   97         { "print",      db_print_cmd,           0,      NULL },
   98         { "p",          db_print_cmd,           0,      NULL },
   99         { "examine",    db_examine_cmd,         CS_SET_DOT, NULL },
  100         { "x",          db_examine_cmd,         CS_SET_DOT, NULL },
  101         { "search",     db_search_cmd,          CS_OWN|CS_SET_DOT, NULL },
  102         { "set",        db_set_cmd,             CS_OWN, NULL },
  103         { "write",      db_write_cmd,           CS_MORE|CS_SET_DOT, NULL },
  104         { "w",          db_write_cmd,           CS_MORE|CS_SET_DOT, NULL },
  105         { "delete",     db_delete_cmd,          0,      NULL },
  106         { "d",          db_delete_cmd,          0,      NULL },
  107         { "dump",       db_dump,                0,      NULL },
  108         { "break",      db_breakpoint_cmd,      0,      NULL },
  109         { "b",          db_breakpoint_cmd,      0,      NULL },
  110         { "dwatch",     db_deletewatch_cmd,     0,      NULL },
  111         { "watch",      db_watchpoint_cmd,      CS_MORE,NULL },
  112         { "dhwatch",    db_deletehwatch_cmd,    0,      NULL },
  113         { "hwatch",     db_hwatchpoint_cmd,     0,      NULL },
  114         { "step",       db_single_step_cmd,     0,      NULL },
  115         { "s",          db_single_step_cmd,     0,      NULL },
  116         { "continue",   db_continue_cmd,        0,      NULL },
  117         { "c",          db_continue_cmd,        0,      NULL },
  118         { "until",      db_trace_until_call_cmd,0,      NULL },
  119         { "next",       db_trace_until_matching_cmd,0,  NULL },
  120         { "match",      db_trace_until_matching_cmd,0,  NULL },
  121         { "trace",      db_stack_trace,         CS_OWN, NULL },
  122         { "t",          db_stack_trace,         CS_OWN, NULL },
  123         /* XXX alias for all trace */
  124         { "alltrace",   db_stack_trace_all,     0,      NULL },
  125         { "where",      db_stack_trace,         CS_OWN, NULL },
  126         { "bt",         db_stack_trace,         CS_OWN, NULL },
  127         { "call",       db_fncall,              CS_OWN, NULL },
  128         { "show",       0,                      0,      &db_show_table },
  129         { "ps",         db_ps,                  0,      NULL },
  130         { "gdb",        db_gdb,                 0,      NULL },
  131         { "halt",       db_halt,                0,      NULL },
  132         { "reboot",     db_reset,               0,      NULL },
  133         { "reset",      db_reset,               0,      NULL },
  134         { "kill",       db_kill,                CS_OWN, NULL },
  135         { "watchdog",   db_watchdog,            CS_OWN, NULL },
  136         { "thread",     db_set_thread,          CS_OWN, NULL },
  137         { "run",        db_run_cmd,             CS_OWN, NULL },
  138         { "script",     db_script_cmd,          CS_OWN, NULL },
  139         { "scripts",    db_scripts_cmd,         0,      NULL },
  140         { "unscript",   db_unscript_cmd,        CS_OWN, NULL },
  141         { "capture",    db_capture_cmd,         CS_OWN, NULL },
  142         { "textdump",   db_textdump_cmd,        CS_OWN, NULL },
  143         { "findstack",  db_findstack_cmd,       0,      NULL },
  144 };
  145 struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
  146 
  147 static struct command   *db_last_command = NULL;
  148 
  149 /*
  150  * if 'ed' style: 'dot' is set at start of last item printed,
  151  * and '+' points to next line.
  152  * Otherwise: 'dot' points to next item, '..' points to last.
  153  */
  154 static bool     db_ed_style = true;
  155 
  156 /*
  157  * Utility routine - discard tokens through end-of-line.
  158  */
  159 void
  160 db_skip_to_eol(void)
  161 {
  162         int     t;
  163         do {
  164             t = db_read_token();
  165         } while (t != tEOL);
  166 }
  167 
  168 /*
  169  * Results of command search.
  170  */
  171 #define CMD_UNIQUE      0
  172 #define CMD_FOUND       1
  173 #define CMD_NONE        2
  174 #define CMD_AMBIGUOUS   3
  175 #define CMD_HELP        4
  176 
  177 static void     db_cmd_match(char *name, struct command *cmd,
  178                     struct command **cmdp, int *resultp);
  179 static void     db_cmd_list(struct command_table *table);
  180 static int      db_cmd_search(char *name, struct command_table *table,
  181                     struct command **cmdp);
  182 static void     db_command(struct command **last_cmdp,
  183                     struct command_table *cmd_table, int dopager);
  184 
  185 /*
  186  * Initialize the command lists from the static tables.
  187  */
  188 void
  189 db_command_init(void)
  190 {
  191 #define N(a)    (sizeof(a) / sizeof(a[0]))
  192         int i;
  193 
  194         for (i = 0; i < N(db_cmds); i++)
  195                 db_command_register(&db_cmd_table, &db_cmds[i]);
  196         for (i = 0; i < N(db_show_cmds); i++)
  197                 db_command_register(&db_show_table, &db_show_cmds[i]);
  198         for (i = 0; i < N(db_show_all_cmds); i++)
  199                 db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
  200 #undef N
  201 }
  202 
  203 /*
  204  * Register a command.
  205  */
  206 void
  207 db_command_register(struct command_table *list, struct command *cmd)
  208 {
  209         struct command *c, *last;
  210 
  211         last = NULL;
  212         LIST_FOREACH(c, list, next) {
  213                 int n = strcmp(cmd->name, c->name);
  214 
  215                 /* Check that the command is not already present. */
  216                 if (n == 0) {
  217                         printf("%s: Warning, the command \"%s\" already exists;"
  218                              " ignoring request\n", __func__, cmd->name);
  219                         return;
  220                 }
  221                 if (n < 0) {
  222                         /* NB: keep list sorted lexicographically */
  223                         LIST_INSERT_BEFORE(c, cmd, next);
  224                         return;
  225                 }
  226                 last = c;
  227         }
  228         if (last == NULL)
  229                 LIST_INSERT_HEAD(list, cmd, next);
  230         else
  231                 LIST_INSERT_AFTER(last, cmd, next);
  232 }
  233 
  234 /*
  235  * Remove a command previously registered with db_command_register.
  236  */
  237 void
  238 db_command_unregister(struct command_table *list, struct command *cmd)
  239 {
  240         struct command *c;
  241 
  242         LIST_FOREACH(c, list, next) {
  243                 if (cmd == c) {
  244                         LIST_REMOVE(cmd, next);
  245                         return;
  246                 }
  247         }
  248         /* NB: intentionally quiet */
  249 }
  250 
  251 /*
  252  * Helper function to match a single command.
  253  */
  254 static void
  255 db_cmd_match(char *name, struct command *cmd, struct command **cmdp,
  256     int *resultp)
  257 {
  258         char *lp, *rp;
  259         int c;
  260 
  261         lp = name;
  262         rp = cmd->name;
  263         while ((c = *lp) == *rp) {
  264                 if (c == 0) {
  265                         /* complete match */
  266                         *cmdp = cmd;
  267                         *resultp = CMD_UNIQUE;
  268                         return;
  269                 }
  270                 lp++;
  271                 rp++;
  272         }
  273         if (c == 0) {
  274                 /* end of name, not end of command -
  275                    partial match */
  276                 if (*resultp == CMD_FOUND) {
  277                         *resultp = CMD_AMBIGUOUS;
  278                         /* but keep looking for a full match -
  279                            this lets us match single letters */
  280                 } else {
  281                         *cmdp = cmd;
  282                         *resultp = CMD_FOUND;
  283                 }
  284         }
  285 }
  286 
  287 /*
  288  * Search for command prefix.
  289  */
  290 static int
  291 db_cmd_search(char *name, struct command_table *table, struct command **cmdp)
  292 {
  293         struct command  *cmd;
  294         int             result = CMD_NONE;
  295 
  296         LIST_FOREACH(cmd, table, next) {
  297                 db_cmd_match(name,cmd,cmdp,&result);
  298                 if (result == CMD_UNIQUE)
  299                         break;
  300         }
  301 
  302         if (result == CMD_NONE) {
  303                 /* check for 'help' */
  304                 if (name[0] == 'h' && name[1] == 'e'
  305                     && name[2] == 'l' && name[3] == 'p')
  306                         result = CMD_HELP;
  307         }
  308         return (result);
  309 }
  310 
  311 static void
  312 db_cmd_list(struct command_table *table)
  313 {
  314         struct command  *cmd;
  315         int have_subcommands;
  316 
  317         have_subcommands = 0;
  318         LIST_FOREACH(cmd, table, next) {
  319                 if (cmd->more != NULL)
  320                         have_subcommands++;
  321                 db_printf("%-16s", cmd->name);
  322                 db_end_line(16);
  323         }
  324 
  325         if (have_subcommands > 0) {
  326                 db_printf("\nThe following have subcommands; append \"help\" "
  327                     "to list (e.g. \"show help\"):\n");
  328                 LIST_FOREACH(cmd, table, next) {
  329                         if (cmd->more == NULL)
  330                                 continue;
  331                         db_printf("%-16s", cmd->name);
  332                         db_end_line(16);
  333                 }
  334         }
  335 }
  336 
  337 static void
  338 db_command(struct command **last_cmdp, struct command_table *cmd_table,
  339     int dopager)
  340 {
  341         struct command  *cmd = NULL;
  342         int             t;
  343         char            modif[TOK_STRING_SIZE];
  344         db_expr_t       addr, count;
  345         bool            have_addr = false;
  346         int             result;
  347 
  348         t = db_read_token();
  349         if (t == tEOL) {
  350             /* empty line repeats last command, at 'next' */
  351             cmd = *last_cmdp;
  352             addr = (db_expr_t)db_next;
  353             have_addr = false;
  354             count = 1;
  355             modif[0] = '\0';
  356         }
  357         else if (t == tEXCL) {
  358             db_fncall((db_expr_t)0, (bool)false, (db_expr_t)0, (char *)0);
  359             return;
  360         }
  361         else if (t != tIDENT) {
  362             db_printf("Unrecognized input; use \"help\" "
  363                 "to list available commands\n");
  364             db_flush_lex();
  365             return;
  366         }
  367         else {
  368             /*
  369              * Search for command
  370              */
  371             while (cmd_table) {
  372                 result = db_cmd_search(db_tok_string,
  373                                        cmd_table,
  374                                        &cmd);
  375                 switch (result) {
  376                     case CMD_NONE:
  377                         db_printf("No such command; use \"help\" "
  378                             "to list available commands\n");
  379                         db_flush_lex();
  380                         return;
  381                     case CMD_AMBIGUOUS:
  382                         db_printf("Ambiguous\n");
  383                         db_flush_lex();
  384                         return;
  385                     case CMD_HELP:
  386                         if (cmd_table == &db_cmd_table) {
  387                             db_printf("This is ddb(4), the kernel debugger; "
  388                                 "see http://man.freebsd.org/ddb/4 for help.\n");
  389                             db_printf("Use \"bt\" for backtrace, \"dump\" for "
  390                                 "kernel core dump, \"reset\" to reboot.\n");
  391                             db_printf("Available commands:\n");
  392                         }
  393                         db_cmd_list(cmd_table);
  394                         db_flush_lex();
  395                         return;
  396                     default:
  397                         break;
  398                 }
  399                 if ((cmd_table = cmd->more) != NULL) {
  400                     t = db_read_token();
  401                     if (t != tIDENT) {
  402                         db_printf("Subcommand required; "
  403                             "available subcommands:\n");
  404                         db_cmd_list(cmd_table);
  405                         db_flush_lex();
  406                         return;
  407                     }
  408                 }
  409             }
  410 
  411             if ((cmd->flag & CS_OWN) == 0) {
  412                 /*
  413                  * Standard syntax:
  414                  * command [/modifier] [addr] [,count]
  415                  */
  416                 t = db_read_token();
  417                 if (t == tSLASH) {
  418                     t = db_read_token();
  419                     if (t != tIDENT) {
  420                         db_printf("Bad modifier\n");
  421                         db_flush_lex();
  422                         return;
  423                     }
  424                     db_strcpy(modif, db_tok_string);
  425                 }
  426                 else {
  427                     db_unread_token(t);
  428                     modif[0] = '\0';
  429                 }
  430 
  431                 if (db_expression(&addr)) {
  432                     db_dot = (db_addr_t) addr;
  433                     db_last_addr = db_dot;
  434                     have_addr = true;
  435                 }
  436                 else {
  437                     addr = (db_expr_t) db_dot;
  438                     have_addr = false;
  439                 }
  440                 t = db_read_token();
  441                 if (t == tCOMMA) {
  442                     if (!db_expression(&count)) {
  443                         db_printf("Count missing\n");
  444                         db_flush_lex();
  445                         return;
  446                     }
  447                 }
  448                 else {
  449                     db_unread_token(t);
  450                     count = -1;
  451                 }
  452                 if ((cmd->flag & CS_MORE) == 0) {
  453                     db_skip_to_eol();
  454                 }
  455             }
  456         }
  457         *last_cmdp = cmd;
  458         if (cmd != NULL) {
  459             /*
  460              * Execute the command.
  461              */
  462             if (dopager)
  463                 db_enable_pager();
  464             else
  465                 db_disable_pager();
  466             (*cmd->fcn)(addr, have_addr, count, modif);
  467             if (dopager)
  468                 db_disable_pager();
  469 
  470             if (cmd->flag & CS_SET_DOT) {
  471                 /*
  472                  * If command changes dot, set dot to
  473                  * previous address displayed (if 'ed' style).
  474                  */
  475                 if (db_ed_style) {
  476                     db_dot = db_prev;
  477                 }
  478                 else {
  479                     db_dot = db_next;
  480                 }
  481             }
  482             else {
  483                 /*
  484                  * If command does not change dot,
  485                  * set 'next' location to be the same.
  486                  */
  487                 db_next = db_dot;
  488             }
  489         }
  490 }
  491 
  492 /*
  493  * At least one non-optional command must be implemented using
  494  * DB_COMMAND() so that db_cmd_set gets created.  Here is one.
  495  */
  496 DB_COMMAND(panic, db_panic)
  497 {
  498         db_disable_pager();
  499         panic("from debugger");
  500 }
  501 
  502 void
  503 db_command_loop(void)
  504 {
  505         /*
  506          * Initialize 'prev' and 'next' to dot.
  507          */
  508         db_prev = db_dot;
  509         db_next = db_dot;
  510 
  511         db_cmd_loop_done = 0;
  512         while (!db_cmd_loop_done) {
  513             if (db_print_position() != 0)
  514                 db_printf("\n");
  515 
  516             db_printf("db> ");
  517             (void) db_read_line();
  518 
  519             db_command(&db_last_command, &db_cmd_table, /* dopager */ 1);
  520         }
  521 }
  522 
  523 /*
  524  * Execute a command on behalf of a script.  The caller is responsible for
  525  * making sure that the command string is < DB_MAXLINE or it will be
  526  * truncated.
  527  *
  528  * XXXRW: Runs by injecting faked input into DDB input stream; it would be
  529  * nicer to use an alternative approach that didn't mess with the previous
  530  * command buffer.
  531  */
  532 void
  533 db_command_script(const char *command)
  534 {
  535         db_prev = db_next = db_dot;
  536         db_inject_line(command);
  537         db_command(&db_last_command, &db_cmd_table, /* dopager */ 0);
  538 }
  539 
  540 void
  541 db_error(const char *s)
  542 {
  543         if (s)
  544             db_printf("%s", s);
  545         db_flush_lex();
  546         kdb_reenter();
  547 }
  548 
  549 static void
  550 db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
  551 {
  552         int error;
  553 
  554         if (textdump_pending) {
  555                 db_printf("textdump_pending set.\n"
  556                     "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
  557                 return;
  558         }
  559         error = doadump(false);
  560         if (error) {
  561                 db_printf("Cannot dump: ");
  562                 switch (error) {
  563                 case EBUSY:
  564                         db_printf("debugger got invoked while dumping.\n");
  565                         break;
  566                 case ENXIO:
  567                         db_printf("no dump device specified.\n");
  568                         break;
  569                 default:
  570                         db_printf("unknown error (error=%d).\n", error);
  571                         break;
  572                 }
  573         }
  574 }
  575 
  576 /*
  577  * Call random function:
  578  * !expr(arg,arg,arg)
  579  */
  580 
  581 /* The generic implementation supports a maximum of 10 arguments. */
  582 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
  583     db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
  584 
  585 static __inline int
  586 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
  587 {
  588         __db_f *f = (__db_f *)addr;
  589 
  590         if (nargs > 10) {
  591                 db_printf("Too many arguments (max 10)\n");
  592                 return (0);
  593         }
  594         *rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
  595             args[6], args[7], args[8], args[9]);
  596         return (1);
  597 }
  598 
  599 static void
  600 db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
  601 {
  602         db_expr_t       fn_addr;
  603         db_expr_t       args[DB_MAXARGS];
  604         int             nargs = 0;
  605         db_expr_t       retval;
  606         int             t;
  607 
  608         if (!db_expression(&fn_addr)) {
  609             db_printf("Bad function\n");
  610             db_flush_lex();
  611             return;
  612         }
  613 
  614         t = db_read_token();
  615         if (t == tLPAREN) {
  616             if (db_expression(&args[0])) {
  617                 nargs++;
  618                 while ((t = db_read_token()) == tCOMMA) {
  619                     if (nargs == DB_MAXARGS) {
  620                         db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
  621                         db_flush_lex();
  622                         return;
  623                     }
  624                     if (!db_expression(&args[nargs])) {
  625                         db_printf("Argument missing\n");
  626                         db_flush_lex();
  627                         return;
  628                     }
  629                     nargs++;
  630                 }
  631                 db_unread_token(t);
  632             }
  633             if (db_read_token() != tRPAREN) {
  634                 db_printf("Mismatched parens\n");
  635                 db_flush_lex();
  636                 return;
  637             }
  638         }
  639         db_skip_to_eol();
  640         db_disable_pager();
  641 
  642         if (DB_CALL(fn_addr, &retval, nargs, args))
  643                 db_printf("= %#lr\n", (long)retval);
  644 }
  645 
  646 static void
  647 db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
  648 {
  649 
  650         cpu_halt();
  651 }
  652 
  653 static void
  654 db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
  655 {
  656         db_expr_t old_radix, pid, sig;
  657         struct proc *p;
  658 
  659 #define DB_ERROR(f)     do { db_printf f; db_flush_lex(); goto out; } while (0)
  660 
  661         /*
  662          * PIDs and signal numbers are typically represented in base
  663          * 10, so make that the default here.  It can, of course, be
  664          * overridden by specifying a prefix.
  665          */
  666         old_radix = db_radix;
  667         db_radix = 10;
  668         /* Retrieve arguments. */
  669         if (!db_expression(&sig))
  670                 DB_ERROR(("Missing signal number\n"));
  671         if (!db_expression(&pid))
  672                 DB_ERROR(("Missing process ID\n"));
  673         db_skip_to_eol();
  674         if (!_SIG_VALID(sig))
  675                 DB_ERROR(("Signal number out of range\n"));
  676 
  677         /*
  678          * Find the process in question.  allproc_lock is not needed
  679          * since we're in DDB.
  680          */
  681         /* sx_slock(&allproc_lock); */
  682         FOREACH_PROC_IN_SYSTEM(p)
  683             if (p->p_pid == pid)
  684                     break;
  685         /* sx_sunlock(&allproc_lock); */
  686         if (p == NULL)
  687                 DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
  688 
  689         /* If it's already locked, bail; otherwise, do the deed. */
  690         if (PROC_TRYLOCK(p) == 0)
  691                 DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
  692         else {
  693                 pksignal(p, sig, NULL);
  694                 PROC_UNLOCK(p);
  695         }
  696 
  697 out:
  698         db_radix = old_radix;
  699 #undef DB_ERROR
  700 }
  701 
  702 /*
  703  * Reboot.  In case there is an additional argument, take it as delay in
  704  * seconds.  Default to 15s if we cannot parse it and make sure we will
  705  * never wait longer than 1 week.  Some code is similar to
  706  * kern_shutdown.c:shutdown_panic().
  707  */
  708 #ifndef DB_RESET_MAXDELAY
  709 #define DB_RESET_MAXDELAY       (3600 * 24 * 7)
  710 #endif
  711 
  712 static void
  713 db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
  714     char *modif __unused)
  715 {
  716         int delay, loop;
  717 
  718         if (have_addr) {
  719                 delay = (int)db_hex2dec(addr);
  720 
  721                 /* If we parse to fail, use 15s. */
  722                 if (delay == -1)
  723                         delay = 15;
  724 
  725                 /* Cap at one week. */
  726                 if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
  727                         delay = DB_RESET_MAXDELAY;
  728 
  729                 db_printf("Automatic reboot in %d seconds - "
  730                     "press a key on the console to abort\n", delay);
  731                 for (loop = delay * 10; loop > 0; --loop) {
  732                         DELAY(1000 * 100); /* 1/10th second */
  733                         /* Did user type a key? */
  734                         if (cncheckc() != -1)
  735                                 return;
  736                 }
  737         }
  738 
  739         cpu_reset();
  740 }
  741 
  742 static void
  743 db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
  744 {
  745         db_expr_t old_radix, tout;
  746         int err, i;
  747 
  748         old_radix = db_radix;
  749         db_radix = 10;
  750         err = db_expression(&tout);
  751         db_skip_to_eol();
  752         db_radix = old_radix;
  753 
  754         /* If no argument is provided the watchdog will just be disabled. */
  755         if (err == 0) {
  756                 db_printf("No argument provided, disabling watchdog\n");
  757                 tout = 0;
  758         } else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
  759                 db_error("Out of range watchdog interval\n");
  760                 return;
  761         }
  762         EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
  763 }
  764 
  765 static void
  766 db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
  767 {
  768 
  769         if (kdb_dbbe_select("gdb") != 0) {
  770                 db_printf("The remote GDB backend could not be selected.\n");
  771                 return;
  772         }
  773         /*
  774          * Mark that we are done in the debugger.  kdb_trap()
  775          * should re-enter with the new backend.
  776          */
  777         db_cmd_loop_done = 1;
  778         db_printf("(ctrl-c will return control to ddb)\n");
  779 }
  780 
  781 static void
  782 db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
  783 {
  784         struct thread *td;
  785         db_expr_t radix;
  786         pid_t pid;
  787         int t;
  788 
  789         /*
  790          * We parse our own arguments. We don't like the default radix.
  791          */
  792         radix = db_radix;
  793         db_radix = 10;
  794         hastid = db_expression(&tid);
  795         t = db_read_token();
  796         if (t == tCOMMA) {
  797                 if (!db_expression(&count)) {
  798                         db_printf("Count missing\n");
  799                         db_flush_lex();
  800                         return;
  801                 }
  802         } else {
  803                 db_unread_token(t);
  804                 count = -1;
  805         }
  806         db_skip_to_eol();
  807         db_radix = radix;
  808 
  809         if (hastid) {
  810                 td = kdb_thr_lookup((lwpid_t)tid);
  811                 if (td == NULL)
  812                         td = kdb_thr_from_pid((pid_t)tid);
  813                 if (td == NULL) {
  814                         db_printf("Thread %d not found\n", (int)tid);
  815                         return;
  816                 }
  817         } else
  818                 td = kdb_thread;
  819         if (td->td_proc != NULL)
  820                 pid = td->td_proc->p_pid;
  821         else
  822                 pid = -1;
  823         db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
  824         db_trace_thread(td, count);
  825 }
  826 
  827 static void
  828 db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
  829     char *dummy4)
  830 {
  831         struct proc *p;
  832         struct thread *td;
  833         jmp_buf jb;
  834         void *prev_jb;
  835 
  836         FOREACH_PROC_IN_SYSTEM(p) {
  837                 prev_jb = kdb_jmpbuf(jb);
  838                 if (setjmp(jb) == 0) {
  839                         FOREACH_THREAD_IN_PROC(p, td) {
  840                                 db_printf("\nTracing command %s pid %d tid %ld td %p\n",
  841                                           p->p_comm, p->p_pid, (long)td->td_tid, td);
  842                                 db_trace_thread(td, -1);
  843                                 if (db_pager_quit) {
  844                                         kdb_jmpbuf(prev_jb);
  845                                         return;
  846                                 }
  847                         }
  848                 }
  849                 kdb_jmpbuf(prev_jb);
  850         }
  851 }
  852 
  853 /*
  854  * Take the parsed expression value from the command line that was parsed
  855  * as a hexadecimal value and convert it as if the expression was parsed
  856  * as a decimal value.  Returns -1 if the expression was not a valid
  857  * decimal value.
  858  */
  859 db_expr_t
  860 db_hex2dec(db_expr_t expr)
  861 {
  862         uintptr_t x, y;
  863         db_expr_t val;
  864 
  865         y = 1;
  866         val = 0;
  867         x = expr;
  868         while (x != 0) {
  869                 if (x % 16 > 9)
  870                         return (-1);
  871                 val += (x % 16) * (y);
  872                 x >>= 4;
  873                 y *= 10;
  874         }
  875         return (val);
  876 }

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