/*      $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;
}