freebsd-dev/sys/ddb/db_command.c
Edward Tomasz Napierala 9990da25ea Improve ddb(4) error reporting a bit.
Obtained from:	CheriBSD
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-07-06 12:30:39 +00:00

915 lines
21 KiB
C

/*-
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* Author: David B. Golub, Carnegie Mellon University
* Date: 7/90
*/
/*
* Command dispatcher.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/linker_set.h>
#include <sys/lock.h>
#include <sys/kdb.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/signalvar.h>
#include <sys/systm.h>
#include <sys/cons.h>
#include <sys/conf.h>
#include <sys/watchdog.h>
#include <sys/kernel.h>
#include <ddb/ddb.h>
#include <ddb/db_command.h>
#include <ddb/db_lex.h>
#include <ddb/db_output.h>
#include <machine/cpu.h>
#include <machine/setjmp.h>
/*
* Exported global variables
*/
int db_cmd_loop_done;
db_addr_t db_dot;
db_addr_t db_last_addr;
db_addr_t db_prev;
db_addr_t db_next;
static db_cmdfcn_t db_dump;
static db_cmdfcn_t db_fncall;
static db_cmdfcn_t db_gdb;
static db_cmdfcn_t db_halt;
static db_cmdfcn_t db_kill;
static db_cmdfcn_t db_reset;
static db_cmdfcn_t db_stack_trace;
static db_cmdfcn_t db_stack_trace_active;
static db_cmdfcn_t db_stack_trace_all;
static db_cmdfcn_t db_watchdog;
/*
* 'show' commands
*/
static struct command db_show_active_cmds[] = {
{ "trace", db_stack_trace_active, 0, NULL },
};
struct command_table db_show_active_table =
LIST_HEAD_INITIALIZER(db_show_active_table);
static struct command db_show_all_cmds[] = {
{ "trace", db_stack_trace_all, 0, NULL },
};
struct command_table db_show_all_table =
LIST_HEAD_INITIALIZER(db_show_all_table);
static struct command db_show_cmds[] = {
{ "active", 0, 0, &db_show_active_table },
{ "all", 0, 0, &db_show_all_table },
{ "registers", db_show_regs, 0, NULL },
{ "breaks", db_listbreak_cmd, 0, NULL },
{ "threads", db_show_threads, 0, NULL },
};
struct command_table db_show_table = LIST_HEAD_INITIALIZER(db_show_table);
static struct command db_cmds[] = {
{ "print", db_print_cmd, 0, NULL },
{ "p", db_print_cmd, 0, NULL },
{ "examine", db_examine_cmd, CS_SET_DOT, NULL },
{ "x", db_examine_cmd, CS_SET_DOT, NULL },
{ "search", db_search_cmd, CS_OWN|CS_SET_DOT, NULL },
{ "set", db_set_cmd, CS_OWN, NULL },
{ "write", db_write_cmd, CS_MORE|CS_SET_DOT, NULL },
{ "w", db_write_cmd, CS_MORE|CS_SET_DOT, NULL },
{ "delete", db_delete_cmd, 0, NULL },
{ "d", db_delete_cmd, 0, NULL },
{ "dump", db_dump, 0, NULL },
{ "break", db_breakpoint_cmd, 0, NULL },
{ "b", db_breakpoint_cmd, 0, NULL },
{ "dwatch", db_deletewatch_cmd, 0, NULL },
{ "watch", db_watchpoint_cmd, CS_MORE,NULL },
{ "dhwatch", db_deletehwatch_cmd, 0, NULL },
{ "hwatch", db_hwatchpoint_cmd, 0, NULL },
{ "step", db_single_step_cmd, 0, NULL },
{ "s", db_single_step_cmd, 0, NULL },
{ "continue", db_continue_cmd, 0, NULL },
{ "c", db_continue_cmd, 0, NULL },
{ "until", db_trace_until_call_cmd,0, NULL },
{ "next", db_trace_until_matching_cmd,0, NULL },
{ "match", db_trace_until_matching_cmd,0, NULL },
{ "trace", db_stack_trace, CS_OWN, NULL },
{ "t", db_stack_trace, CS_OWN, NULL },
/* XXX alias for active trace */
{ "acttrace", db_stack_trace_active, 0, NULL },
/* XXX alias for all trace */
{ "alltrace", db_stack_trace_all, 0, NULL },
{ "where", db_stack_trace, CS_OWN, NULL },
{ "bt", db_stack_trace, CS_OWN, NULL },
{ "call", db_fncall, CS_OWN, NULL },
{ "show", 0, 0, &db_show_table },
{ "ps", db_ps, 0, NULL },
{ "gdb", db_gdb, 0, NULL },
{ "halt", db_halt, 0, NULL },
{ "reboot", db_reset, 0, NULL },
{ "reset", db_reset, 0, NULL },
{ "kill", db_kill, CS_OWN, NULL },
{ "watchdog", db_watchdog, CS_OWN, NULL },
{ "thread", db_set_thread, CS_OWN, NULL },
{ "run", db_run_cmd, CS_OWN, NULL },
{ "script", db_script_cmd, CS_OWN, NULL },
{ "scripts", db_scripts_cmd, 0, NULL },
{ "unscript", db_unscript_cmd, CS_OWN, NULL },
{ "capture", db_capture_cmd, CS_OWN, NULL },
{ "textdump", db_textdump_cmd, CS_OWN, NULL },
{ "findstack", db_findstack_cmd, 0, NULL },
};
struct command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
static struct command *db_last_command = NULL;
/*
* if 'ed' style: 'dot' is set at start of last item printed,
* and '+' points to next line.
* Otherwise: 'dot' points to next item, '..' points to last.
*/
static bool db_ed_style = true;
/*
* Utility routine - discard tokens through end-of-line.
*/
void
db_skip_to_eol(void)
{
int t;
do {
t = db_read_token();
} while (t != tEOL);
}
/*
* Results of command search.
*/
#define CMD_UNIQUE 0
#define CMD_FOUND 1
#define CMD_NONE 2
#define CMD_AMBIGUOUS 3
#define CMD_HELP 4
static void db_cmd_match(char *name, struct command *cmd,
struct command **cmdp, int *resultp);
static void db_cmd_list(struct command_table *table);
static int db_cmd_search(char *name, struct command_table *table,
struct command **cmdp);
static void db_command(struct command **last_cmdp,
struct command_table *cmd_table, int dopager);
/*
* Initialize the command lists from the static tables.
*/
void
db_command_init(void)
{
#define N(a) (sizeof(a) / sizeof(a[0]))
int i;
for (i = 0; i < N(db_cmds); i++)
db_command_register(&db_cmd_table, &db_cmds[i]);
for (i = 0; i < N(db_show_cmds); i++)
db_command_register(&db_show_table, &db_show_cmds[i]);
for (i = 0; i < N(db_show_active_cmds); i++)
db_command_register(&db_show_active_table,
&db_show_active_cmds[i]);
for (i = 0; i < N(db_show_all_cmds); i++)
db_command_register(&db_show_all_table, &db_show_all_cmds[i]);
#undef N
}
/*
* Register a command.
*/
void
db_command_register(struct command_table *list, struct command *cmd)
{
struct command *c, *last;
last = NULL;
LIST_FOREACH(c, list, next) {
int n = strcmp(cmd->name, c->name);
/* Check that the command is not already present. */
if (n == 0) {
printf("%s: Warning, the command \"%s\" already exists;"
" ignoring request\n", __func__, cmd->name);
return;
}
if (n < 0) {
/* NB: keep list sorted lexicographically */
LIST_INSERT_BEFORE(c, cmd, next);
return;
}
last = c;
}
if (last == NULL)
LIST_INSERT_HEAD(list, cmd, next);
else
LIST_INSERT_AFTER(last, cmd, next);
}
/*
* Remove a command previously registered with db_command_register.
*/
void
db_command_unregister(struct command_table *list, struct command *cmd)
{
struct command *c;
LIST_FOREACH(c, list, next) {
if (cmd == c) {
LIST_REMOVE(cmd, next);
return;
}
}
/* NB: intentionally quiet */
}
/*
* Helper function to match a single command.
*/
static void
db_cmd_match(char *name, struct command *cmd, struct command **cmdp,
int *resultp)
{
char *lp, *rp;
int c;
lp = name;
rp = cmd->name;
while ((c = *lp) == *rp) {
if (c == 0) {
/* complete match */
*cmdp = cmd;
*resultp = CMD_UNIQUE;
return;
}
lp++;
rp++;
}
if (c == 0) {
/* end of name, not end of command -
partial match */
if (*resultp == CMD_FOUND) {
*resultp = CMD_AMBIGUOUS;
/* but keep looking for a full match -
this lets us match single letters */
} else {
*cmdp = cmd;
*resultp = CMD_FOUND;
}
}
}
/*
* Search for command prefix.
*/
static int
db_cmd_search(char *name, struct command_table *table, struct command **cmdp)
{
struct command *cmd;
int result = CMD_NONE;
LIST_FOREACH(cmd, table, next) {
db_cmd_match(name,cmd,cmdp,&result);
if (result == CMD_UNIQUE)
break;
}
if (result == CMD_NONE) {
/* check for 'help' */
if (name[0] == 'h' && name[1] == 'e'
&& name[2] == 'l' && name[3] == 'p')
result = CMD_HELP;
}
return (result);
}
static void
db_cmd_list(struct command_table *table)
{
struct command *cmd;
int have_subcommands;
have_subcommands = 0;
LIST_FOREACH(cmd, table, next) {
if (cmd->more != NULL)
have_subcommands++;
db_printf("%-16s", cmd->name);
db_end_line(16);
}
if (have_subcommands > 0) {
db_printf("\nThe following have subcommands; append \"help\" "
"to list (e.g. \"show help\"):\n");
LIST_FOREACH(cmd, table, next) {
if (cmd->more == NULL)
continue;
db_printf("%-16s", cmd->name);
db_end_line(16);
}
}
}
static void
db_command(struct command **last_cmdp, struct command_table *cmd_table,
int dopager)
{
struct command *cmd = NULL;
int t;
char modif[TOK_STRING_SIZE];
db_expr_t addr, count;
bool have_addr = false;
int result;
t = db_read_token();
if (t == tEOL) {
/* empty line repeats last command, at 'next' */
cmd = *last_cmdp;
addr = (db_expr_t)db_next;
have_addr = false;
count = 1;
modif[0] = '\0';
}
else if (t == tEXCL) {
db_fncall((db_expr_t)0, (bool)false, (db_expr_t)0, (char *)0);
return;
}
else if (t != tIDENT) {
db_printf("Unrecognized input; use \"help\" "
"to list available commands\n");
db_flush_lex();
return;
}
else {
/*
* Search for command
*/
while (cmd_table) {
result = db_cmd_search(db_tok_string,
cmd_table,
&cmd);
switch (result) {
case CMD_NONE:
db_printf("No such command; use \"help\" "
"to list available commands\n");
db_flush_lex();
return;
case CMD_AMBIGUOUS:
db_printf("Ambiguous\n");
db_flush_lex();
return;
case CMD_HELP:
if (cmd_table == &db_cmd_table) {
db_printf("This is ddb(4), the kernel debugger; "
"see http://man.freebsd.org/ddb/4 for help.\n");
db_printf("Use \"bt\" for backtrace, \"dump\" for "
"kernel core dump, \"reset\" to reboot.\n");
db_printf("Available commands:\n");
}
db_cmd_list(cmd_table);
db_flush_lex();
return;
default:
break;
}
if ((cmd_table = cmd->more) != NULL) {
t = db_read_token();
if (t != tIDENT) {
db_printf("Subcommand required; "
"available subcommands:\n");
db_cmd_list(cmd_table);
db_flush_lex();
return;
}
}
}
if ((cmd->flag & CS_OWN) == 0) {
/*
* Standard syntax:
* command [/modifier] [addr] [,count]
*/
t = db_read_token();
if (t == tSLASH) {
t = db_read_token();
if (t != tIDENT) {
db_printf("Bad modifier\n");
db_flush_lex();
return;
}
db_strcpy(modif, db_tok_string);
}
else {
db_unread_token(t);
modif[0] = '\0';
}
if (db_expression(&addr)) {
db_dot = (db_addr_t) addr;
db_last_addr = db_dot;
have_addr = true;
}
else {
addr = (db_expr_t) db_dot;
have_addr = false;
}
t = db_read_token();
if (t == tCOMMA) {
if (!db_expression(&count)) {
db_printf("Count missing\n");
db_flush_lex();
return;
}
}
else {
db_unread_token(t);
count = -1;
}
if ((cmd->flag & CS_MORE) == 0) {
db_skip_to_eol();
}
}
}
*last_cmdp = cmd;
if (cmd != NULL) {
/*
* Execute the command.
*/
if (dopager)
db_enable_pager();
else
db_disable_pager();
(*cmd->fcn)(addr, have_addr, count, modif);
if (dopager)
db_disable_pager();
if (cmd->flag & CS_SET_DOT) {
/*
* If command changes dot, set dot to
* previous address displayed (if 'ed' style).
*/
if (db_ed_style) {
db_dot = db_prev;
}
else {
db_dot = db_next;
}
}
else {
/*
* If command does not change dot,
* set 'next' location to be the same.
*/
db_next = db_dot;
}
}
}
/*
* At least one non-optional command must be implemented using
* DB_COMMAND() so that db_cmd_set gets created. Here is one.
*/
DB_COMMAND(panic, db_panic)
{
db_disable_pager();
panic("from debugger");
}
void
db_command_loop(void)
{
/*
* Initialize 'prev' and 'next' to dot.
*/
db_prev = db_dot;
db_next = db_dot;
db_cmd_loop_done = 0;
while (!db_cmd_loop_done) {
if (db_print_position() != 0)
db_printf("\n");
db_printf("db> ");
(void) db_read_line();
db_command(&db_last_command, &db_cmd_table, /* dopager */ 1);
}
}
/*
* Execute a command on behalf of a script. The caller is responsible for
* making sure that the command string is < DB_MAXLINE or it will be
* truncated.
*
* XXXRW: Runs by injecting faked input into DDB input stream; it would be
* nicer to use an alternative approach that didn't mess with the previous
* command buffer.
*/
void
db_command_script(const char *command)
{
db_prev = db_next = db_dot;
db_inject_line(command);
db_command(&db_last_command, &db_cmd_table, /* dopager */ 0);
}
void
db_error(const char *s)
{
if (s)
db_printf("%s", s);
db_flush_lex();
kdb_reenter();
}
static void
db_dump(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
{
int error;
if (textdump_pending) {
db_printf("textdump_pending set.\n"
"run \"textdump unset\" first or \"textdump dump\" for a textdump.\n");
return;
}
error = doadump(false);
if (error) {
db_printf("Cannot dump: ");
switch (error) {
case EBUSY:
db_printf("debugger got invoked while dumping.\n");
break;
case ENXIO:
db_printf("no dump device specified.\n");
break;
default:
db_printf("unknown error (error=%d).\n", error);
break;
}
}
}
/*
* Call random function:
* !expr(arg,arg,arg)
*/
/* The generic implementation supports a maximum of 10 arguments. */
typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t,
db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t);
static __inline int
db_fncall_generic(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
{
__db_f *f = (__db_f *)addr;
if (nargs > 10) {
db_printf("Too many arguments (max 10)\n");
return (0);
}
*rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
args[6], args[7], args[8], args[9]);
return (1);
}
static void
db_fncall(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
{
db_expr_t fn_addr;
db_expr_t args[DB_MAXARGS];
int nargs = 0;
db_expr_t retval;
int t;
if (!db_expression(&fn_addr)) {
db_printf("Bad function\n");
db_flush_lex();
return;
}
t = db_read_token();
if (t == tLPAREN) {
if (db_expression(&args[0])) {
nargs++;
while ((t = db_read_token()) == tCOMMA) {
if (nargs == DB_MAXARGS) {
db_printf("Too many arguments (max %d)\n", DB_MAXARGS);
db_flush_lex();
return;
}
if (!db_expression(&args[nargs])) {
db_printf("Argument missing\n");
db_flush_lex();
return;
}
nargs++;
}
db_unread_token(t);
}
if (db_read_token() != tRPAREN) {
db_printf("Mismatched parens\n");
db_flush_lex();
return;
}
}
db_skip_to_eol();
db_disable_pager();
if (DB_CALL(fn_addr, &retval, nargs, args))
db_printf("= %#lr\n", (long)retval);
}
static void
db_halt(db_expr_t dummy, bool dummy2, db_expr_t dummy3, char *dummy4)
{
cpu_halt();
}
static void
db_kill(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
{
db_expr_t old_radix, pid, sig;
struct proc *p;
#define DB_ERROR(f) do { db_printf f; db_flush_lex(); goto out; } while (0)
/*
* PIDs and signal numbers are typically represented in base
* 10, so make that the default here. It can, of course, be
* overridden by specifying a prefix.
*/
old_radix = db_radix;
db_radix = 10;
/* Retrieve arguments. */
if (!db_expression(&sig))
DB_ERROR(("Missing signal number\n"));
if (!db_expression(&pid))
DB_ERROR(("Missing process ID\n"));
db_skip_to_eol();
if (!_SIG_VALID(sig))
DB_ERROR(("Signal number out of range\n"));
/*
* Find the process in question. allproc_lock is not needed
* since we're in DDB.
*/
/* sx_slock(&allproc_lock); */
FOREACH_PROC_IN_SYSTEM(p)
if (p->p_pid == pid)
break;
/* sx_sunlock(&allproc_lock); */
if (p == NULL)
DB_ERROR(("Can't find process with pid %ld\n", (long) pid));
/* If it's already locked, bail; otherwise, do the deed. */
if (PROC_TRYLOCK(p) == 0)
DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
else {
pksignal(p, sig, NULL);
PROC_UNLOCK(p);
}
out:
db_radix = old_radix;
#undef DB_ERROR
}
/*
* Reboot. In case there is an additional argument, take it as delay in
* seconds. Default to 15s if we cannot parse it and make sure we will
* never wait longer than 1 week. Some code is similar to
* kern_shutdown.c:shutdown_panic().
*/
#ifndef DB_RESET_MAXDELAY
#define DB_RESET_MAXDELAY (3600 * 24 * 7)
#endif
static void
db_reset(db_expr_t addr, bool have_addr, db_expr_t count __unused,
char *modif __unused)
{
int delay, loop;
if (have_addr) {
delay = (int)db_hex2dec(addr);
/* If we parse to fail, use 15s. */
if (delay == -1)
delay = 15;
/* Cap at one week. */
if ((uintmax_t)delay > (uintmax_t)DB_RESET_MAXDELAY)
delay = DB_RESET_MAXDELAY;
db_printf("Automatic reboot in %d seconds - "
"press a key on the console to abort\n", delay);
for (loop = delay * 10; loop > 0; --loop) {
DELAY(1000 * 100); /* 1/10th second */
/* Did user type a key? */
if (cncheckc() != -1)
return;
}
}
cpu_reset();
}
static void
db_watchdog(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
{
db_expr_t old_radix, tout;
int err, i;
old_radix = db_radix;
db_radix = 10;
err = db_expression(&tout);
db_skip_to_eol();
db_radix = old_radix;
/* If no argument is provided the watchdog will just be disabled. */
if (err == 0) {
db_printf("No argument provided, disabling watchdog\n");
tout = 0;
} else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
db_error("Out of range watchdog interval\n");
return;
}
EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
}
static void
db_gdb(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
{
if (kdb_dbbe_select("gdb") != 0) {
db_printf("The remote GDB backend could not be selected.\n");
return;
}
/*
* Mark that we are done in the debugger. kdb_trap()
* should re-enter with the new backend.
*/
db_cmd_loop_done = 1;
db_printf("(ctrl-c will return control to ddb)\n");
}
static void
db_stack_trace(db_expr_t tid, bool hastid, db_expr_t count, char *modif)
{
struct thread *td;
db_expr_t radix;
pid_t pid;
int t;
/*
* We parse our own arguments. We don't like the default radix.
*/
radix = db_radix;
db_radix = 10;
hastid = db_expression(&tid);
t = db_read_token();
if (t == tCOMMA) {
if (!db_expression(&count)) {
db_printf("Count missing\n");
db_flush_lex();
return;
}
} else {
db_unread_token(t);
count = -1;
}
db_skip_to_eol();
db_radix = radix;
if (hastid) {
td = kdb_thr_lookup((lwpid_t)tid);
if (td == NULL)
td = kdb_thr_from_pid((pid_t)tid);
if (td == NULL) {
db_printf("Thread %d not found\n", (int)tid);
return;
}
} else
td = kdb_thread;
if (td->td_proc != NULL)
pid = td->td_proc->p_pid;
else
pid = -1;
db_printf("Tracing pid %d tid %ld td %p\n", pid, (long)td->td_tid, td);
db_trace_thread(td, count);
}
static void
_db_stack_trace_all(bool active_only)
{
struct proc *p;
struct thread *td;
jmp_buf jb;
void *prev_jb;
FOREACH_PROC_IN_SYSTEM(p) {
prev_jb = kdb_jmpbuf(jb);
if (setjmp(jb) == 0) {
FOREACH_THREAD_IN_PROC(p, td) {
if (td->td_state == TDS_RUNNING)
db_printf("\nTracing command %s pid %d"
" tid %ld td %p (CPU %d)\n",
p->p_comm, p->p_pid,
(long)td->td_tid, td,
td->td_oncpu);
else if (active_only)
continue;
else
db_printf("\nTracing command %s pid %d"
" tid %ld td %p\n", p->p_comm,
p->p_pid, (long)td->td_tid, td);
db_trace_thread(td, -1);
if (db_pager_quit) {
kdb_jmpbuf(prev_jb);
return;
}
}
}
kdb_jmpbuf(prev_jb);
}
}
static void
db_stack_trace_active(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
char *dummy4)
{
_db_stack_trace_all(true);
}
static void
db_stack_trace_all(db_expr_t dummy, bool dummy2, db_expr_t dummy3,
char *dummy4)
{
_db_stack_trace_all(false);
}
/*
* Take the parsed expression value from the command line that was parsed
* as a hexadecimal value and convert it as if the expression was parsed
* as a decimal value. Returns -1 if the expression was not a valid
* decimal value.
*/
db_expr_t
db_hex2dec(db_expr_t expr)
{
uintptr_t x, y;
db_expr_t val;
y = 1;
val = 0;
x = expr;
while (x != 0) {
if (x % 16 > 9)
return (-1);
val += (x % 16) * (y);
x >>= 4;
y *= 10;
}
return (val);
}