2 * SPDX-License-Identifier: MIT-CMU
4 * Mach Operating System
5 * Copyright (c) 1991,1990 Carnegie Mellon University
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18 * Carnegie Mellon requests users of this software to return to
20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
29 * Author: David B. Golub, Carnegie Mellon University
36 #include <sys/param.h>
39 #include <sys/eventhandler.h>
41 #include <sys/kernel.h>
42 #include <sys/linker_set.h>
44 #include <sys/mutex.h>
46 #include <sys/reboot.h>
47 #include <sys/signalvar.h>
48 #include <sys/systm.h>
49 #include <sys/watchdog.h>
52 #include <ddb/db_command.h>
53 #include <ddb/db_lex.h>
54 #include <ddb/db_output.h>
56 #include <machine/cpu.h>
57 #include <machine/setjmp.h>
59 #include <security/mac/mac_framework.h>
62 * Exported global variables
66 db_addr_t db_last_addr;
70 static db_cmdfcn_t db_dump;
71 static db_cmdfcn_t db_fncall;
72 static db_cmdfcn_t db_gdb;
73 static db_cmdfcn_t db_halt;
74 static db_cmdfcn_t db_kill;
75 static db_cmdfcn_t db_reset;
76 static db_cmdfcn_t db_stack_trace;
77 static db_cmdfcn_t db_stack_trace_active;
78 static db_cmdfcn_t db_stack_trace_all;
79 static db_cmdfcn_t db_watchdog;
81 #define DB_CMD(_name, _func, _flags) \
88 #define DB_TABLE(_name, _more) \
95 static struct db_command db_show_active_cmds[] = {
96 DB_CMD("trace", db_stack_trace_active, DB_CMD_MEMSAFE),
98 struct db_command_table db_show_active_table =
99 LIST_HEAD_INITIALIZER(db_show_active_table);
101 static struct db_command db_show_all_cmds[] = {
102 DB_CMD("trace", db_stack_trace_all, DB_CMD_MEMSAFE),
104 struct db_command_table db_show_all_table =
105 LIST_HEAD_INITIALIZER(db_show_all_table);
107 static struct db_command db_show_cmds[] = {
108 DB_TABLE("active", &db_show_active_table),
109 DB_TABLE("all", &db_show_all_table),
110 DB_CMD("registers", db_show_regs, DB_CMD_MEMSAFE),
111 DB_CMD("breaks", db_listbreak_cmd, DB_CMD_MEMSAFE),
112 DB_CMD("threads", db_show_threads, DB_CMD_MEMSAFE),
114 struct db_command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
116 static struct db_command db_cmds[] = {
117 DB_TABLE("show", &db_show_table),
118 DB_CMD("print", db_print_cmd, 0),
119 DB_CMD("p", db_print_cmd, 0),
120 DB_CMD("examine", db_examine_cmd, CS_SET_DOT),
121 DB_CMD("x", db_examine_cmd, CS_SET_DOT),
122 DB_CMD("search", db_search_cmd, CS_OWN|CS_SET_DOT),
123 DB_CMD("set", db_set_cmd, CS_OWN|DB_CMD_MEMSAFE),
124 DB_CMD("write", db_write_cmd, CS_MORE|CS_SET_DOT),
125 DB_CMD("w", db_write_cmd, CS_MORE|CS_SET_DOT),
126 DB_CMD("delete", db_delete_cmd, 0),
127 DB_CMD("d", db_delete_cmd, 0),
128 DB_CMD("dump", db_dump, DB_CMD_MEMSAFE),
129 DB_CMD("break", db_breakpoint_cmd, 0),
130 DB_CMD("b", db_breakpoint_cmd, 0),
131 DB_CMD("dwatch", db_deletewatch_cmd, 0),
132 DB_CMD("watch", db_watchpoint_cmd, CS_MORE),
133 DB_CMD("dhwatch", db_deletehwatch_cmd, 0),
134 DB_CMD("hwatch", db_hwatchpoint_cmd, 0),
135 DB_CMD("step", db_single_step_cmd, DB_CMD_MEMSAFE),
136 DB_CMD("s", db_single_step_cmd, DB_CMD_MEMSAFE),
137 DB_CMD("continue", db_continue_cmd, DB_CMD_MEMSAFE),
138 DB_CMD("c", db_continue_cmd, DB_CMD_MEMSAFE),
139 DB_CMD("until", db_trace_until_call_cmd, DB_CMD_MEMSAFE),
140 DB_CMD("next", db_trace_until_matching_cmd, DB_CMD_MEMSAFE),
141 DB_CMD("match", db_trace_until_matching_cmd, 0),
142 DB_CMD("trace", db_stack_trace, CS_OWN|DB_CMD_MEMSAFE),
143 DB_CMD("t", db_stack_trace, CS_OWN|DB_CMD_MEMSAFE),
144 /* XXX alias for active trace */
145 DB_CMD("acttrace", db_stack_trace_active, DB_CMD_MEMSAFE),
146 /* XXX alias for all trace */
147 DB_CMD("alltrace", db_stack_trace_all, DB_CMD_MEMSAFE),
148 DB_CMD("where", db_stack_trace, CS_OWN|DB_CMD_MEMSAFE),
149 DB_CMD("bt", db_stack_trace, CS_OWN|DB_CMD_MEMSAFE),
150 DB_CMD("call", db_fncall, CS_OWN),
151 DB_CMD("ps", db_ps, DB_CMD_MEMSAFE),
152 DB_CMD("gdb", db_gdb, 0),
153 DB_CMD("halt", db_halt, DB_CMD_MEMSAFE),
154 DB_CMD("reboot", db_reset, DB_CMD_MEMSAFE),
155 DB_CMD("reset", db_reset, DB_CMD_MEMSAFE),
156 DB_CMD("kill", db_kill, CS_OWN|DB_CMD_MEMSAFE),
157 DB_CMD("watchdog", db_watchdog, CS_OWN|DB_CMD_MEMSAFE),
158 DB_CMD("thread", db_set_thread, 0),
159 DB_CMD("run", db_run_cmd, CS_OWN|DB_CMD_MEMSAFE),
160 DB_CMD("script", db_script_cmd, CS_OWN|DB_CMD_MEMSAFE),
161 DB_CMD("scripts", db_scripts_cmd, DB_CMD_MEMSAFE),
162 DB_CMD("unscript", db_unscript_cmd, CS_OWN|DB_CMD_MEMSAFE),
163 DB_CMD("capture", db_capture_cmd, CS_OWN|DB_CMD_MEMSAFE),
164 DB_CMD("textdump", db_textdump_cmd, CS_OWN|DB_CMD_MEMSAFE),
165 DB_CMD("findstack", db_findstack_cmd, 0),
167 struct db_command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
172 static struct db_command *db_last_command = NULL;
175 * if 'ed' style: 'dot' is set at start of last item printed,
176 * and '+' points to next line.
177 * Otherwise: 'dot' points to next item, '..' points to last.
179 static bool db_ed_style = true;
182 * Utility routine - discard tokens through end-of-line.
195 * Results of command search.
200 #define CMD_AMBIGUOUS 3
203 static void db_cmd_match(char *name, struct db_command *cmd,
204 struct db_command **cmdp, int *resultp);
205 static void db_cmd_list(struct db_command_table *table);
206 static int db_cmd_search(char *name, struct db_command_table *table,
207 struct db_command **cmdp);
208 static void db_command(struct db_command **last_cmdp,
209 struct db_command_table *cmd_table, bool dopager);
212 * Initialize the command lists from the static tables.
215 db_command_init(void)
219 for (i = 0; i < nitems(db_cmds); i++)
220 db_command_register(&db_cmd_table, &db_cmds[i]);
221 for (i = 0; i < nitems(db_show_cmds); i++)
222 db_command_register(&db_show_table, &db_show_cmds[i]);
223 for (i = 0; i < nitems(db_show_active_cmds); i++)
224 db_command_register(&db_show_active_table,
225 &db_show_active_cmds[i]);
226 for (i = 0; i < nitems(db_show_all_cmds); i++)
227 db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
231 * Register a command.
234 db_command_register(struct db_command_table *list, struct db_command *cmd)
236 struct db_command *c, *last;
239 if (mac_ddb_command_register(list, cmd)) {
240 printf("%s: MAC policy refused registration of command %s\n",
241 __func__, cmd->name);
246 LIST_FOREACH(c, list, next) {
247 int n = strcmp(cmd->name, c->name);
249 /* Check that the command is not already present. */
251 printf("%s: Warning, the command \"%s\" already exists;"
252 " ignoring request\n", __func__, cmd->name);
256 /* NB: keep list sorted lexicographically */
257 LIST_INSERT_BEFORE(c, cmd, next);
263 LIST_INSERT_HEAD(list, cmd, next);
265 LIST_INSERT_AFTER(last, cmd, next);
269 * Remove a command previously registered with db_command_register.
272 db_command_unregister(struct db_command_table *list, struct db_command *cmd)
274 struct db_command *c;
276 LIST_FOREACH(c, list, next) {
278 LIST_REMOVE(cmd, next);
282 /* NB: intentionally quiet */
286 * Helper function to match a single command.
289 db_cmd_match(char *name, struct db_command *cmd, struct db_command **cmdp,
297 while ((c = *lp) == *rp) {
301 *resultp = CMD_UNIQUE;
308 /* end of name, not end of command -
310 if (*resultp == CMD_FOUND) {
311 *resultp = CMD_AMBIGUOUS;
312 /* but keep looking for a full match -
313 this lets us match single letters */
314 } else if (*resultp == CMD_NONE) {
316 *resultp = CMD_FOUND;
322 * Search for command prefix.
325 db_cmd_search(char *name, struct db_command_table *table,
326 struct db_command **cmdp)
328 struct db_command *cmd;
329 int result = CMD_NONE;
331 LIST_FOREACH(cmd, table, next) {
332 db_cmd_match(name,cmd,cmdp,&result);
333 if (result == CMD_UNIQUE)
337 if (result == CMD_NONE) {
338 /* check for 'help' */
339 if (name[0] == 'h' && name[1] == 'e'
340 && name[2] == 'l' && name[3] == 'p')
347 db_cmd_list(struct db_command_table *table)
349 struct db_command *cmd;
350 int have_subcommands;
352 have_subcommands = 0;
353 LIST_FOREACH(cmd, table, next) {
354 if (cmd->more != NULL)
356 db_printf("%-16s", cmd->name);
360 if (have_subcommands > 0) {
361 db_printf("\nThe following have subcommands; append \"help\" "
362 "to list (e.g. \"show help\"):\n");
363 LIST_FOREACH(cmd, table, next) {
364 if (cmd->more == NULL)
366 db_printf("%-16s", cmd->name);
373 db_command(struct db_command **last_cmdp, struct db_command_table *cmd_table,
376 char modif[TOK_STRING_SIZE];
377 struct db_command *cmd = NULL;
378 db_expr_t addr, count;
380 bool have_addr = false;
384 /* empty line repeats last command, at 'next' */
386 addr = (db_expr_t)db_next;
390 } else if (t == tEXCL) {
391 db_fncall((db_expr_t)0, false, (db_expr_t)0, NULL);
393 } else if (t != tIDENT) {
394 db_printf("Unrecognized input; use \"help\" "
395 "to list available commands\n");
402 while (cmd_table != NULL) {
403 result = db_cmd_search(db_tok_string, cmd_table, &cmd);
406 db_printf("No such command; use \"help\" "
407 "to list available commands\n");
411 db_printf("Ambiguous\n");
415 if (cmd_table == &db_cmd_table) {
416 db_printf("This is ddb(4), the kernel debugger; "
417 "see https://man.FreeBSD.org/ddb/4 for help.\n");
418 db_printf("Use \"bt\" for backtrace, \"dump\" for "
419 "kernel core dump, \"reset\" to reboot.\n");
420 db_printf("Available commands:\n");
422 db_cmd_list(cmd_table);
429 if ((cmd_table = cmd->more) != NULL) {
432 db_printf("Subcommand required; "
433 "available subcommands:\n");
434 db_cmd_list(cmd_table);
441 if ((cmd->flag & CS_OWN) == 0) {
444 * command [/modifier] [addr] [,count]
450 db_printf("Bad modifier\n");
454 db_strcpy(modif, db_tok_string);
460 if (db_expression(&addr)) {
461 db_dot = (db_addr_t) addr;
462 db_last_addr = db_dot;
465 addr = (db_expr_t) db_dot;
471 if (!db_expression(&count)) {
472 db_printf("Count missing\n");
481 if ((cmd->flag & CS_MORE) == 0) {
490 if (mac_ddb_command_exec(cmd, addr, have_addr, count, modif)) {
491 db_printf("MAC prevented execution of command %s\n",
497 * Execute the command.
503 (*cmd->fcn)(addr, have_addr, count, modif);
507 if (cmd->flag & CS_SET_DOT) {
509 * If command changes dot, set dot to previous address
510 * displayed (if 'ed' style).
512 db_dot = db_ed_style ? db_prev : db_next;
515 * If command does not change dot, set 'next' location
524 * At least one non-optional command must be implemented using
525 * DB_COMMAND() so that db_cmd_set gets created. Here is one.
527 DB_COMMAND_FLAGS(panic, db_panic, DB_CMD_MEMSAFE)
530 panic("from debugger");
534 db_command_loop(void)
537 * Initialize 'prev' and 'next' to dot.
542 db_cmd_loop_done = 0;
543 while (!db_cmd_loop_done) {
544 if (db_print_position() != 0)
548 (void)db_read_line();
550 db_command(&db_last_command, &db_cmd_table, /* dopager */ true);
555 * Execute a command on behalf of a script. The caller is responsible for
556 * making sure that the command string is < DB_MAXLINE or it will be
559 * XXXRW: Runs by injecting faked input into DDB input stream; it would be
560 * nicer to use an alternative approach that didn't mess with the previous
564 db_command_script(const char *command)
566 db_prev = db_next = db_dot;
567 db_inject_line(command);
568 db_command(&db_last_command, &db_cmd_table, /* dopager */ false);
572 db_error(const char *s)
577 kdb_reenter_silent();
581 db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
585 if (textdump_pending) {
586 db_printf("textdump_pending set.\n"
587 "run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
590 error = doadump(false);
592 db_printf("Cannot dump: ");
595 db_printf("debugger got invoked while dumping.\n");
598 db_printf("no dump device specified.\n");
601 db_printf("unknown error (error=%d).\n", error);
608 * Call random function:
612 /* The generic implementation supports a maximum of 10 arguments. */
613 typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
614 db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
617 db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
619 __db_f *f = (__db_f *)addr;
622 db_printf("Too many arguments (max 10)\n");
625 *rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
626 args[6], args[7], args[8], args[9]);
631 db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
634 db_expr_t args[DB_MAXARGS];
639 if (!db_expression(&fn_addr)) {
640 db_printf("Bad function\n");
647 if (db_expression(&args[0])) {
649 while ((t = db_read_token()) == tCOMMA) {
650 if (nargs == DB_MAXARGS) {
651 db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
655 if (!db_expression(&args[nargs])) {
656 db_printf("Argument missing\n");
664 if (db_read_token() != tRPAREN) {
665 db_printf("Mismatched parens\n");
673 if (DB_CALL(fn_addr, &retval, nargs, args))
674 db_printf("= %#lr\n", (long)retval);
678 db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
685 db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
687 db_expr_t old_radix, pid, sig;
690 #define DB_ERROR(f) do { db_printf f; db_flush_lex(); goto out; } while (0)
693 * PIDs and signal numbers are typically represented in base
694 * 10, so make that the default here. It can, of course, be
695 * overridden by specifying a prefix.
697 old_radix = db_radix;
699 /* Retrieve arguments. */
700 if (!db_expression(&sig))
701 DB_ERROR(("Missing signal number\n"));
702 if (!db_expression(&pid))
703 DB_ERROR(("Missing process ID\n"));
705 if (!_SIG_VALID(sig))
706 DB_ERROR(("Signal number out of range\n"));
709 * Find the process in question. allproc_lock is not needed
710 * since we're in DDB.
712 /* sx_slock(&allproc_lock); */
713 FOREACH_PROC_IN_SYSTEM(p)
716 /* sx_sunlock(&allproc_lock); */
718 DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
720 /* If it's already locked, bail; otherwise, do the deed. */
721 if (PROC_TRYLOCK(p) == 0)
722 DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
724 pksignal(p, sig, NULL);
729 db_radix = old_radix;
734 * Reboot. In case there is an additional argument, take it as delay in
735 * seconds. Default to 15s if we cannot parse it and make sure we will
736 * never wait longer than 1 week. Some code is similar to
737 * kern_shutdown.c:shutdown_panic().
739 #ifndef DB_RESET_MAXDELAY
740 #define DB_RESET_MAXDELAY (3600 * 24 * 7)
744 db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
750 delay = (int)db_hex2dec(addr);
752 /* If we parse to fail, use 15s. */
756 /* Cap at one week. */
757 if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
758 delay = DB_RESET_MAXDELAY;
760 db_printf("Automatic reboot in %d seconds - "
761 "press a key on the console to abort\n", delay);
762 for (loop = delay * 10; loop > 0; --loop) {
763 DELAY(1000 * 100); /* 1/10th second */
764 /* Did user type a key? */
765 if (cncheckc() != -1)
771 * Conditionally try the standard reboot path, so any registered
772 * shutdown/reset handlers have a chance to run first. Some platforms
773 * may not support the machine-dependent mechanism used by cpu_reset()
774 * and rely on some other non-standard mechanism to perform the reset.
775 * For example, the BCM2835 watchdog driver or gpio-poweroff driver.
777 if (modif[0] != 's') {
778 kern_reboot(RB_NOSYNC);
786 db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
788 db_expr_t old_radix, tout;
791 old_radix = db_radix;
793 err = db_expression(&tout);
795 db_radix = old_radix;
797 /* If no argument is provided the watchdog will just be disabled. */
799 db_printf("No argument provided, disabling watchdog\n");
801 } else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
802 db_error("Out of range watchdog interval\n");
805 EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
809 db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
812 if (kdb_dbbe_select("gdb") != 0) {
813 db_printf("The remote GDB backend could not be selected.\n");
817 * Mark that we are done in the debugger. kdb_trap()
818 * should re-enter with the new backend.
820 db_cmd_loop_done = 1;
821 db_printf("(ctrl-c will return control to ddb)\n");
825 db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
833 * We parse our own arguments. We don't like the default radix.
837 hastid = db_expression(&tid);
840 if (!db_expression(&count)) {
841 db_printf("Count missing\n");
854 td = kdb_thr_lookup((lwpid_t)tid);
856 td = kdb_thr_from_pid((pid_t)tid);
858 db_printf("Thread %d not found\n", (int)tid);
863 if (td->td_proc != NULL)
864 pid = td->td_proc->p_pid;
867 db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
868 if (td->td_proc != NULL && (td->td_proc->p_flag & P_INMEM) == 0)
869 db_printf("--- swapped out\n");
871 db_trace_thread(td, count);
875 _db_stack_trace_all(bool active_only)
881 for (td = kdb_thr_first(); td != NULL; td = kdb_thr_next(td)) {
882 prev_jb = kdb_jmpbuf(jb);
883 if (setjmp(jb) == 0) {
884 if (TD_IS_RUNNING(td))
885 db_printf("\nTracing command %s pid %d"
886 " tid %ld td %p (CPU %d)\n",
887 td->td_proc->p_comm, td->td_proc->p_pid,
888 (long)td->td_tid, td, td->td_oncpu);
889 else if (active_only)
892 db_printf("\nTracing command %s pid %d"
893 " tid %ld td %p\n", td->td_proc->p_comm,
894 td->td_proc->p_pid, (long)td->td_tid, td);
895 if (td->td_proc->p_flag & P_INMEM)
896 db_trace_thread(td, -1);
898 db_printf("--- swapped out\n");
909 db_stack_trace_active(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
913 _db_stack_trace_all(true);
917 db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
921 _db_stack_trace_all(false);
925 * Take the parsed expression value from the command line that was parsed
926 * as a hexadecimal value and convert it as if the expression was parsed
927 * as a decimal value. Returns -1 if the expression was not a valid
931 db_hex2dec(db_expr_t expr)
942 val += (x % 16) * (y);