/*
 * 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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright 2016 Joyent, Inc.
 */

/*
 * Handling of unintentional faults (i.e. bugs) in the debugger.
 */

#include <stdlib.h>

#include <kmdb/kmdb_fault.h>
#include <kmdb/kmdb_promif.h>
#include <kmdb/kmdb_kdi.h>
#include <kmdb/kmdb_dpi.h>
#include <mdb/mdb_debug.h>
#include <mdb/mdb_kreg.h>
#include <mdb/mdb_io_impl.h>
#include <mdb/mdb.h>

void
kmdb_fault(kreg_t tt, kreg_t pc, kreg_t sp, int cpuid)
{
        int debug_self_confirm = 0;
        volatile int try;
        jmp_buf pcb, *old;
        char c;

        /* Make absolutely sure */
        kmdb_kdi_system_claim();

        try = 1;
        if (setjmp(pcb) != 0) {
                if (++try == 2) {
                        mdb_iob_printf(mdb.m_err,
                            "\n*** First stack trace attempt failed.  "
                            "Trying safe mode.\n\n");

                        kmdb_fault_display(tt, pc, sp, 1);
                } else {
                        mdb_iob_printf(mdb.m_err,
                            "\n*** Unable to print stack trace.\n");
                }

        } else {
                old = kmdb_dpi_set_fault_hdlr(&pcb);

                mdb_iob_printf(mdb.m_err, "\n*** Debugger Fault (CPU %d)\n\n",
                    cpuid);
                kmdb_fault_display(tt, pc, sp, 0);
        }

        kmdb_dpi_restore_fault_hdlr(old);

        if (mdb.m_term != NULL) {
                for (;;) {
                        mdb_iob_printf(mdb.m_err, "\n%s: "
#if defined(__sparc)
#ifndef sun4v
                            "(o)bp, "
#endif /* sun4v */
                            "(p)anic"
#else
                            "reboo(t)"
#endif
                            ", or (d)ebug with self? ", mdb.m_pname);
                        mdb_iob_flush(mdb.m_err);

                        if (IOP_READ(mdb.m_term, &c, sizeof (c)) != sizeof (c))
                                goto fault_obp;

                        mdb_iob_printf(mdb.m_err, "\n");

                        switch (c) {
#ifdef __sparc
                        case 'p':
                                kmdb_dpi_kernpanic(cpuid);
                                /*NOTREACHED*/
                                continue;
#endif

#ifndef sun4v
                        case 'o':
                        case 'O':
#endif /* sun4v */
                        case 't':
                        case 'T':
                                kmdb_dpi_enter_mon();
                                continue;

                        case 'd':
                        case 'D':
                                /*
                                 * Debug self - get confirmation, because they
                                 * can't go back to their running system if
                                 * they choose this one.
                                 */
                                if (debug_self_confirm == 0) {
                                        mdb_iob_printf(mdb.m_err,
                                            "NOTE: You will not be able to "
                                            "resume your system if you "
                                            "choose this option.\nPlease "
                                            "select 'd' again to confirm.\n");
                                        debug_self_confirm = 1;
                                        continue;
                                }

                                kmdb_dpi_set_state(DPI_STATE_LOST, 0);
                                return;
                        }
                }
        }

fault_obp:
        exit(1);
        /*NOTREACHED*/
}