sun4/os/forthdebug.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <sys/cmn_err.h>
#include <sys/modctl.h>
#include <sys/kobj.h>
#include <sys/kobj_impl.h>
#include <sys/promif.h>
#include <sys/promimpl.h>
#include <sys/reboot.h>
#include <sys/bootconf.h>
#include <sys/systm.h>      /* strstr */
#include <sys/machsystm.h>  /* obpdebug */

#define FDEBUGFILE  "misc/forthdebug"
#define INSTALL_DBP "kdbg-words dbp-install previous"
#define SYMBOL_END  "END OF SYMBOL"

#ifdef DEBUG
static int forthdebug   = 1;
#else
static int forthdebug   = 0;
#endif /* DEBUG */

static int forthdebug_dbp = 0;
int forthdebug_supported = 1;
int modreloc_flag = KOBJ_RELOCATED;

/*
 * basic_sym[] holds all essential symbols the symbol lookup
 * service requires. Forthdebug stub names appears in forthdebug
 * as place holders. They are replaced with the value of corresponding
 * kernel variables. For example, "modules-val-here" in forthdebug
 * is replaced with the address of "modules" variable.
 *
 * To improve performance, we mandate the records be in the same
 * sequence they appear in forthdebug, i.e "modules-val-here" is
 * ahead of "primaries-v-here" in misc/forthdebug.
 *
 * The last record must be all 0 to indicate end of the array.
 */
static char *basic_sym[] = {
    /* kernel variable */   /* forthdebug stub name - must be 16 chars */
    "modules",      "modules-val-here",
    "primaries",        "primaries-v-here",
    "modreloc_flag",    "modreloc-flagval",
    0,          0
};

static void fdbp_hook() {} /* null function for defer breakpoint operation */

/*ARGSUSED*/
static void fdbp_snoop(unsigned int i, struct modctl *modctl_p)
{
    promif_preprom();
    fdbp_hook();
    promif_postprom();
}

static kobj_notify_list_t knl_load = {
    fdbp_snoop, KOBJ_NOTIFY_MODLOADED, 0, 0
};

static kobj_notify_list_t knl_unload = {
    fdbp_snoop, KOBJ_NOTIFY_MODUNLOADING, 0, 0
};

void
forthdebug_init(void)
{
    char *fth_buf, *buf_p;
    ulong_t modsym;
    int i, sz;
    uint64_t fsz;
    struct _buf *file;

    if (!forthdebug_supported) {
        (void) modload("misc", "obpsym");
        return;
    }

    forthdebug_dbp |= boothowto & RB_FORTHDEBUGDBP;
    forthdebug |= (boothowto & RB_FORTHDEBUG) | forthdebug_dbp;

    file = kobj_open_path(FDEBUGFILE, 1, 1);
    if (file == (struct _buf *)-1) {
        cmn_err(CE_CONT, "Can't open %s\n", FDEBUGFILE);
        return;
    }

    i = kobj_get_filesize(file, &fsz);
    if (i || !fsz) {
        cmn_err(CE_CONT, "Can't stat %s stat=%x sz=%llx\n",
            FDEBUGFILE, i, (long long)fsz);
        goto err_stat;
    }

    fth_buf = (char *)kobj_zalloc(fsz + 1, KM_SLEEP);
    sz = kobj_read_file(file, fth_buf, fsz, 0); /* entire file */
    if (sz < 0) {
        cmn_err(CE_CONT, "Error(%d) reading %s\n", sz, FDEBUGFILE);
        goto done;
    }
    ASSERT(fsz == sz);
    fth_buf[sz] = 0;

    /* resolve all essential symbols in basic_sym[] */
    for (i = 0; basic_sym[i]; i += 2) {
        buf_p = strstr(fth_buf, basic_sym[i + 1]);
        modsym = kobj_getsymvalue(basic_sym[i], 0);
        if (buf_p && modsym) {
            (void) sprintf(buf_p, "%16p", (void *)modsym);
            buf_p += 16;
            *buf_p++ = ' '; /* erase null char by sprintf */
        } else {
            cmn_err(CE_CONT,
                "forthdebug_init: No %s symbol(%p,%p), aborted\n",
                basic_sym[i], (void *)buf_p, (void *)modsym);
            goto done;
        }
    }
    if (!forthdebug) {  /* symbol lookup services only */
        if (!(buf_p = strstr(fth_buf, SYMBOL_END))) {
            cmn_err(CE_CONT, "No %s in forthdebug\n", SYMBOL_END);
            goto done;
        }
        *buf_p = '\0';
#ifdef DEBUG
        cmn_err(CE_CONT, "symbol lookup service (%ld bytes)\n",
            (long)(buf_p - fth_buf));
#endif /* DEBUG */
        prom_interpret(fth_buf, 0, 0, 0, 0, 0);
        goto done;
    }

    cmn_err(CE_CONT, "%s (%d bytes) ", FDEBUGFILE, sz);
    prom_interpret(fth_buf, 0, 0, 0, 0, 0);
    cmn_err(CE_CONT, "loaded\n");
    obpdebug = 1;   /* backward compatibility */

    if (forthdebug_dbp) {
#ifdef NO_KOBJ_NOTIFY
        modsym = kobj_getsymvalue("kobj_notify_add", 0);
        (void) ((int (*)(kobj_notify_list_t *))modsym)(&knl_load);
        (void) ((int (*)(kobj_notify_list_t *))modsym)(&knl_unload);
#else
        (void) kobj_notify_add(&knl_load);
        (void) kobj_notify_add(&knl_unload);
#endif  /* NO_KOBJ_NOTIFY */
        prom_interpret(INSTALL_DBP, 0, 0, 0, 0, 0);
        debug_enter("Defer breakpoint enabled. Add breakpoints, then");
    }
done:
    kobj_free(fth_buf, fsz + 1);
err_stat:
    kobj_close_file(file);

    if (boothowto & RB_HALT)
        debug_enter("forthdebug: halt flag (-h) is set.\n");
}