usr/src/cmd/mdb/common/kmdb/kmdb_fault.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  * Copyright 2016 Joyent, Inc.
  26  */
  27
  28 /*
  29  * Handling of unintentional faults (i.e. bugs) in the debugger.
  30  */
  31
  32 #include <stdlib.h>
  33
  34 #include <kmdb/kmdb_fault.h>
  35 #include <kmdb/kmdb_promif.h>
  36 #include <kmdb/kmdb_kdi.h>
  37 #include <kmdb/kmdb_dpi.h>
  38 #include <mdb/mdb_debug.h>
  39 #include <mdb/mdb_kreg.h>
  40 #include <mdb/mdb_io_impl.h>
  41 #include <mdb/mdb.h>
  42
  43 void
  44 kmdb_fault(kreg_t tt, kreg_t pc, kreg_t sp, int cpuid)
  45 {
  46         int debug_self_confirm = 0;
  47         volatile int try;
  48         jmp_buf pcb, *old;
  49         char c;
  50
  51         /* Make absolutely sure */
  52         kmdb_kdi_system_claim();
  53
  54         try = 1;
  55         if (setjmp(pcb) != 0) {
  56                 if (++try == 2) {
  57                         mdb_iob_printf(mdb.m_err,
  58                             "\n*** First stack trace attempt failed.  "
  59                             "Trying safe mode.\n\n");
  60
  61                         kmdb_fault_display(tt, pc, sp, 1);
  62                 } else {
  63                         mdb_iob_printf(mdb.m_err,
  64                             "\n*** Unable to print stack trace.\n");
  65                 }
  66
  67         } else {
  68                 old = kmdb_dpi_set_fault_hdlr(&pcb);
  69
  70                 mdb_iob_printf(mdb.m_err, "\n*** Debugger Fault (CPU %d)\n\n",
  71                     cpuid);
  72                 kmdb_fault_display(tt, pc, sp, 0);
  73         }
  74
  75         kmdb_dpi_restore_fault_hdlr(old);
  76
  77         if (mdb.m_term != NULL) {
  78                 for (;;) {
  79                         mdb_iob_printf(mdb.m_err, "\n%s: "
  80                             "reboo(t)"
  81                             ", or (d)ebug with self? ", mdb.m_pname);
  82                         mdb_iob_flush(mdb.m_err);
  83
  84                         if (IOP_READ(mdb.m_term, &c, sizeof (c)) != sizeof (c))
  85                                 goto fault_obp;
  86
  87                         mdb_iob_printf(mdb.m_err, "\n");
  88
  89                         switch (c) {
  90
  91 #ifndef sun4v
  92                         case 'o':
  93                         case 'O':
  94 #endif /* sun4v */
  95                         case 't':
  96                         case 'T':
  97                                 kmdb_dpi_enter_mon();
  98                                 continue;
  99
 100                         case 'd':
 101                         case 'D':
 102                                 /*
 103                                  * Debug self - get confirmation, because they
 104                                  * can't go back to their running system if
 105                                  * they choose this one.
 106                                  */
 107                                 if (debug_self_confirm == 0) {
 108                                         mdb_iob_printf(mdb.m_err,
 109                                             "NOTE: You will not be able to "
 110                                             "resume your system if you "
 111                                             "choose this option.\nPlease "
 112                                             "select 'd' again to confirm.\n");
 113                                         debug_self_confirm = 1;
 114                                         continue;
 115                                 }
 116
 117                                 kmdb_dpi_set_state(DPI_STATE_LOST, 0);
 118                                 return;
 119                         }
 120                 }
 121         }
 122
 123 fault_obp:
 124         exit(1);
 125         /*NOTREACHED*/
 126 }