* Copyright (c) 2009 The NetBSD Foundation, Inc.

/* $NetBSD: crash.c,v 1.17 2024/11/21 07:20:10 skrll Exp $ */

/*-
* Copyright (c) 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: crash.c,v 1.17 2024/11/21 07:20:10 skrll Exp $");
#endif /* not lint */

#include <sys/types.h>

#include <sys/fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/ioctl.h>

#ifndef __mips__
#include <machine/frame.h>
#endif

#include <ddb/ddb.h>

#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include <histedit.h>
#include <paths.h>
#include <kvm.h>
#include <err.h>
#include <ctype.h>
#include <util.h>

#include "extern.h"

#define MAXSTAB (16 * 1024 * 1024)

db_regs_t ddb_regs;

static kvm_t *kd;
static History *hist;
static HistEvent he;
static EditLine *elptr;
static char imgrelease[16];
static FILE *ofp;

static struct nlist nl[] = {
#define X_OSRELEASE 0
{ .n_name = "_osrelease" },
#define X_PANICSTR 1
{ .n_name = "_panicstr" },
#ifdef LOCKDEBUG
#define X_LOCKDEBUG 2
{ .n_name = "ld_all" },
#endif
{ .n_name = NULL },
};

#ifdef LOCKDEBUG
struct lockdebug;
TAILQ_HEAD(, lockdebug) ld_all;
#else
void lockdebug_lock_print(void);
void lockdebug_lock_print(void) {
warnx("No lockdebug support compiled in");
}
#endif

static void
cleanup(void)
{
if (ofp != stdout) {
(void)fflush(ofp);
(void)pclose(ofp);
ofp = stdout;
}
el_end(elptr);
history_end(hist);
}

void
db_vprintf(const char *fmt, va_list ap)
{
char buf[1024];
int b, c;

c = vsnprintf(buf, sizeof(buf), fmt, ap);
for (b = 0; b < c; b++) {
db_putchar(buf[b]);
}
}

void
db_printf(const char *fmt, ...)
{
va_list ap;

va_start(ap, fmt);
db_vprintf(fmt, ap);
va_end(ap);
}

void
db_write_bytes(db_addr_t addr, size_t size, const char *str)
{

if ((size_t)kvm_write(kd, addr, str, size) != size) {
warnx("kvm_write(%p, %zd): %s", (void *)addr, size,
kvm_geterr(kd));
longjmp(db_recover);
}
}

void
db_read_bytes(db_addr_t addr, size_t size, char *str)
{

if ((size_t)kvm_read(kd, addr, str, size) != size) {
warnx("kvm_read(%p, %zd): %s", (void *)addr, size,
kvm_geterr(kd));
longjmp(db_recover);
}
}

void *
db_alloc(size_t sz)
{

return emalloc(sz);
}

void *
db_zalloc(size_t sz)
{

return ecalloc(1, sz);
}

void
db_free(void *p, size_t sz)
{

free(p);
}

static void
punt(void)
{

db_printf("This command can only be used in-kernel.\n");
}

void
db_breakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{

punt();
}

void
db_continue_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{

db_cmd_loop_done = true;
}

void
db_delete_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{

punt();
}

void
db_deletewatch_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{

punt();
}

void
db_trace_until_matching_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{

punt();
}

void
db_single_step_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{

punt();
}

void
db_trace_until_call_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{

punt();
}

void
db_watchpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
const char *modif)
{

punt();
}

int
db_readline(char *lstart, int lsize)
{
const char *el;
char *pcmd;
int cnt;

db_force_whitespace();

/* Close any open pipe. */
if (ofp != stdout) {
(void)fflush(ofp);
(void)pclose(ofp);
ofp = stdout;
}

/* Read next command. */
el = el_gets(elptr, &cnt);
if (el == NULL) { /* EOF */
exit(EXIT_SUCCESS);
}

/* Save to history, and copy to caller's buffer. */
history(hist, &he, H_ENTER, el);
strlcpy(lstart, el, lsize);
if (cnt >= lsize) {
cnt = lsize - 1;
}
lstart[cnt] = '\0';
if (cnt > 0 && lstart[cnt - 1] == '\n') {
lstart[cnt - 1] = '\0';
}

/* Need to open a pipe? If not, return now. */
pcmd = strchr(lstart, '|');
if (pcmd == NULL) {
return strlen(lstart);
}

/* Open a pipe to specified command, redirect output. */
assert(ofp == stdout);
for (*pcmd++ = '\0'; isspace((unsigned char)*pcmd); pcmd++) {
/* nothing */
}
errno = 0;
ofp = popen(pcmd, "w");
if (ofp == NULL) {
warn("opening pipe for command `%s'", pcmd);
*lstart = '\0';
}
return strlen(lstart);
}

void
db_check_interrupt(void)
{

}

int
cngetc(void)
{
char ch;

if (el_getc(elptr, &ch) <= 0)
return 0;
return (unsigned char)ch;
}

void
cnputc(int c)
{

putc(c, ofp);
}

__dead static void
usage(void)
{

fprintf(stderr,
"usage: %s [-w] [-M core] [-N kernel]\n\n"
"-M core\tspecify memory file (default /dev/mem)\n"
"-N kernel\tspecify name list file (default /dev/ksyms)\n",
getprogname());
exit(EXIT_FAILURE);
}

static const char *
prompt(void)
{

return "crash> ";
}

int
main(int argc, char **argv)
{
const char *nlistf, *memf;
uintptr_t panicstr;
struct winsize ws;
struct stat sb;
size_t sz;
void *elf;
int fd, ch, flags;
char c;

nlistf = _PATH_KSYMS;
memf = _PATH_MEM;
ofp = stdout;
flags = O_RDONLY;

setprogname(argv[0]);

/*
* Parse options.
*/
while ((ch = getopt(argc, argv, "M:N:w")) != -1) {
switch (ch) {
case 'M':
memf = optarg;
break;
case 'N':
nlistf = optarg;
break;
case 'w':
flags = O_RDWR;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;

/*
* Print a list of images, and allow user to select.
*/
/* XXX */

/*
* Open the images (crash dump and symbol table).
*/
kd = kvm_open(nlistf, memf, NULL, flags, getprogname());
if (kd == NULL) {
return EXIT_FAILURE;
}
fd = open(nlistf, O_RDONLY);
if (fd == -1) {
err(EXIT_FAILURE, "open `%s'", nlistf);
}
if (fstat(fd, &sb) == -1) {
err(EXIT_FAILURE, "stat `%s'", nlistf);
}
if ((sb.st_mode & S_IFMT) != S_IFREG) { /* XXX ksyms */
sz = MAXSTAB;
elf = malloc(sz);
if (elf == NULL) {
err(EXIT_FAILURE, "malloc(%zu)", sz);
}
sz = read(fd, elf, sz);
if ((ssize_t)sz == -1) {
err(EXIT_FAILURE, "read `%s'", nlistf);
}
if (sz == MAXSTAB) {
errx(EXIT_FAILURE, "symbol table > %d bytes", MAXSTAB);
}
} else {
sz = sb.st_size;
elf = mmap(NULL, sz, PROT_READ, MAP_PRIVATE|MAP_FILE, fd, 0);
if (elf == MAP_FAILED) {
err(EXIT_FAILURE, "mmap `%s'", nlistf);
}
}

/*
* Print kernel & crash versions.
*/
if (kvm_nlist(kd, nl) == -1) {
errx(EXIT_FAILURE, "kvm_nlist: %s", kvm_geterr(kd));
}
if ((size_t)kvm_read(kd, nl[X_OSRELEASE].n_value, imgrelease,
sizeof(imgrelease)) != sizeof(imgrelease)) {
errx(EXIT_FAILURE, "cannot read osrelease: %s",
kvm_geterr(kd));
}
printf("Crash version %s, image version %s.\n", osrelease, imgrelease);
if (strcmp(osrelease, imgrelease) != 0) {
printf("WARNING: versions differ, you may not be able to "
"examine this image.\n");
}
#ifdef LOCKDEBUG
if ((size_t)kvm_read(kd, nl[X_LOCKDEBUG].n_value, &ld_all,
sizeof(ld_all)) != sizeof(ld_all))
printf("Kernel compiled without options LOCKDEBUG.\n");
#endif

/*
* Print the panic string, if any.
*/
if ((size_t)kvm_read(kd, nl[X_PANICSTR].n_value, &panicstr,
sizeof(panicstr)) != sizeof(panicstr)) {
errx(EXIT_FAILURE, "cannot read panicstr: %s",
kvm_geterr(kd));
}
if (strcmp(memf, _PATH_MEM) == 0) {
printf("Output from a running system is unreliable.\n");
} else if (panicstr == 0) {
printf("System does not appear to have panicked.\n");
} else {
printf("System panicked: ");
for (;;) {
if ((size_t)kvm_read(kd, panicstr, &c, sizeof(c)) !=
sizeof(c)) {
errx(EXIT_FAILURE, "cannot read *panicstr: %s",
kvm_geterr(kd));
}
if (c == '\0') {
break;
}
putchar(c);
panicstr++;
}
putchar('\n');
}

/*
* Initialize line editing.
*/
hist = history_init();
history(hist, &he, H_SETSIZE, 100);
elptr = el_init(getprogname(), stdin, stdout, stderr);
el_set(elptr, EL_EDITOR, "emacs");
el_set(elptr, EL_SIGNAL, 1);
el_set(elptr, EL_HIST, history, hist);
el_set(elptr, EL_PROMPT, prompt);
el_source(elptr, NULL);

atexit(cleanup);

/*
* Initialize ddb.
*/
if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1) {
db_max_width = ws.ws_col;
}
db_mach_init(kd);
ddb_init(sz, elf, (char *)elf + sz);

/*
* Debug it!
*/
db_command_loop();

/*
* Finish.
*/
return EXIT_SUCCESS;
}