rom/exec/alert.c

   1 /*
   2     Copyright © 1995-2016, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Display an alert.
   6     Lang: english
   7 */
   8
   9 #include <aros/debug.h>
  10 #include <exec/alerts.h>
  11 #include <exec/execbase.h>
  12 #include <exec/rawfmt.h>
  13 #include <proto/exec.h>
  14 #include <proto/kernel.h>
  15 #include <string.h>
  16
  17 #include "exec_intern.h"
  18 #include "exec_util.h"
  19 #include "etask.h"
  20
  21 /*****************************************************************************
  22
  23     NAME */
  24
  25         AROS_LH1(void, Alert,
  26
  27 /*  SYNOPSIS */
  28         AROS_LHA(ULONG, alertNum, D7),
  29
  30 /*  LOCATION */
  31         struct ExecBase *, SysBase, 18, Exec)
  32
  33 /*  FUNCTION
  34         Alerts the user of a serious system problem.
  35
  36     INPUTS
  37         alertNum - This is a number which contains information about
  38                 the reason for the call.
  39
  40     RESULT
  41         This routine may return, if the alert is not a dead-end one.
  42
  43     NOTES
  44         You should not call this routine because it halts the machine,
  45         displays the message and then may reboot it.
  46
  47     EXAMPLE
  48         // Dead-End alert: 680x0 Access To Odd Address
  49         Alert (0x80000003);
  50
  51     BUGS
  52
  53     SEE ALSO
  54
  55     INTERNALS
  56
  57 ******************************************************************************/
  58 {
  59     AROS_LIBFUNC_INIT
  60
  61     Exec_ExtAlert(alertNum, __builtin_return_address(0), CALLER_FRAME, AT_NONE, NULL, SysBase);
  62
  63     AROS_LIBFUNC_EXIT
  64 }
  65
  66 static const ULONG contextSizes[] =
  67 {
  68     0,
  69     sizeof(struct ExceptionContext),
  70     sizeof(struct MungwallContext),
  71     sizeof(struct MMContext)
  72 };
  73
  74 void Exec_ExtAlert(ULONG alertNum, APTR location, APTR stack, UBYTE type, APTR data, struct ExecBase *SysBase)
  75 {
  76     struct Task *task = GET_THIS_TASK;
  77     int supervisor = KrnIsSuper();
  78     BOOL usesystemalert = !!supervisor;
  79     struct IntETask *iet = NULL;
  80
  81     D(bug("[exec] Alert 0x%08X, supervisor %d\n", alertNum, supervisor));
  82
  83     if (task && (task->tc_Flags & TF_ETASK) && (task->tc_State != TS_REMOVED))
  84     {
  85         iet = GetIntETask(task);
  86
  87         D(bug("[Alert] Task 0x%p, ETask 0x%p\n", task, iet));
  88
  89         /* Do we already have location set? */
  90         if (iet->iet_AlertFlags & AF_Location)
  91         {
  92             /* If yes, pick it up */
  93             location = iet->iet_AlertLocation;
  94             stack    = iet->iet_AlertStack;
  95         }
  96         else
  97         {
  98             if (supervisor && ((alertNum & ~AT_DeadEnd) == AN_StackProbe))
  99             {
 100                 /*
 101                  * Special case: AN_StackProbe issued by kernel's task dispatcher.
 102                  * Pick up data from task's context.
 103                  */
 104                 struct ExceptionContext *ctx = iet->iet_ETask.et_RegFrame;
 105
 106                 location = (APTR)ctx->PC;
 107                 stack    = (APTR)ctx->FP;
 108                 type     = AT_CPU;
 109                 data     = ctx;
 110             }
 111
 112             /* Set location */
 113             iet->iet_AlertFlags   |= AF_Location;
 114             iet->iet_AlertLocation = location;
 115             iet->iet_AlertStack    = stack;
 116
 117             D(bug("[Alert] Previous frame 0x%p, caller 0x%p\n", iet->iet_AlertStack, iet->iet_AlertLocation));
 118         }
 119
 120         /* If this is not a nested call, set the supplementary data if specified */
 121         if (data && !(iet->iet_AlertFlags & AF_Alert))
 122         {
 123             D(bug("[Alert] Setting alert context, type %u, data 0x%p\n", type, data));
 124
 125             iet->iet_AlertType = type;
 126             CopyMem(data, &iet->iet_AlertData, contextSizes[type]);
 127         }
 128         else
 129         {
 130             /* Either no data or already present */
 131             type = iet->iet_AlertType;
 132             data = &iet->iet_AlertData;
 133
 134             D(bug("[Alert] Got stored alert context, type %u, data 0x%p\n", type, data));
 135         }
 136     }
 137     else
 138     {
 139         /*
 140          * If we have no task, or the task is being removed,
 141          * we can't use the user-mode routine.
 142          */
 143         usesystemalert = TRUE;
 144     }
 145
 146     /*
 147      * If we are running in user mode we should first try to report a problem
 148      * using Intuition display.
 149      */
 150     if (!usesystemalert)
 151     {
 152         alertNum = Exec_UserAlert(alertNum, SysBase);
 153         if (!alertNum)
 154         {
 155             /*
 156              * UserAlert() succeeded and the user decided to continue the task.
 157              * Clear crash status and return happily
 158              */
 159             if (iet)
 160                 ResetETask(iet);
 161             return;
 162         }
 163     }
 164
 165     /* Hint for SystemAlert() - if AlertType is AT_NONE, we don't have AlertData */
 166     if (type == AT_NONE)
 167         data = NULL;
 168
 169     /*
 170      * We're here if Intuition failed. Use safe (but not so
 171      * system and user-friendly) way to post alerts.
 172      */
 173     Disable();
 174     Exec_SystemAlert(alertNum, location, stack, type, data, SysBase);
 175
 176     if (alertNum & AT_DeadEnd)
 177     {
 178         /* Um, we have to do something here in order to prevent the
 179            computer from continuing... */
 180         ColdReboot();
 181         ShutdownA(SD_ACTION_COLDREBOOT);
 182     }
 183
 184     Enable();
 185
 186     /*
 187      * We successfully displayed an alert in supervisor mode.
 188      * Clear alert status by clearing respective fields in ETask.
 189      */
 190     if (iet)
 191         ResetETask(iet);
 192 }