rom/exec/alert.c

   1 /*
   2     Copyright © 1995-2017, 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 <string.h>
  15
  16 #include "exec_intern.h"
  17 #include "exec_util.h"
  18 #include "etask.h"
  19
  20 /*****************************************************************************
  21
  22     NAME */
  23
  24         AROS_LH1(void, Alert,
  25
  26 /*  SYNOPSIS */
  27         AROS_LHA(ULONG, alertNum, D7),
  28
  29 /*  LOCATION */
  30         struct ExecBase *, SysBase, 18, Exec)
  31
  32 /*  FUNCTION
  33         Alerts the user of a serious system problem.
  34
  35     INPUTS
  36         alertNum - This is a number which contains information about
  37                 the reason for the call.
  38
  39     RESULT
  40         This routine may return, if the alert is not a dead-end one.
  41
  42     NOTES
  43         You should not call this routine because it halts the machine,
  44         displays the message and then may reboot it.
  45
  46     EXAMPLE
  47         // Dead-End alert: 680x0 Access To Odd Address
  48         Alert (0x80000003);
  49
  50     BUGS
  51
  52     SEE ALSO
  53
  54     INTERNALS
  55
  56 ******************************************************************************/
  57 {
  58     AROS_LIBFUNC_INIT
  59
  60     Exec_ExtAlert(alertNum, __builtin_return_address(0), CALLER_FRAME, AT_NONE, NULL, SysBase);
  61
  62     AROS_LIBFUNC_EXIT
  63 }
  64
  65 static const ULONG contextSizes[] =
  66 {
  67     0,
  68     sizeof(struct ExceptionContext),
  69     sizeof(struct MungwallContext),
  70     sizeof(struct MMContext)
  71 };
  72
  73 void Exec_ExtAlert(ULONG alertNum, APTR location, APTR stack, UBYTE type, APTR data, struct ExecBase *SysBase)
  74 {
  75     struct Task *task = GET_THIS_TASK;
  76     int supervisor = KrnIsSuper();
  77     BOOL usesystemalert = !!supervisor;
  78     struct IntETask *iet = NULL;
  79
  80     D(bug("[exec] Alert 0x%08X, supervisor %d\n", alertNum, supervisor));
  81
  82     if (task && (task->tc_Flags & TF_ETASK) && (task->tc_State != TS_REMOVED))
  83     {
  84         iet = GetIntETask(task);
  85
  86         D(bug("[Alert] Task 0x%p, ETask 0x%p\n", task, iet));
  87
  88         /* Do we already have location set? */
  89         if (iet->iet_AlertFlags & AF_Location)
  90         {
  91             /* If yes, pick it up */
  92             location = iet->iet_AlertLocation;
  93             stack    = iet->iet_AlertStack;
  94         }
  95         else
  96         {
  97             if (supervisor && ((alertNum & ~AT_DeadEnd) == AN_StackProbe))
  98             {
  99                 /*
 100                  * Special case: AN_StackProbe issued by kernel's task dispatcher.
 101                  * Pick up data from task's context.
 102                  */
 103                 struct ExceptionContext *ctx = iet->iet_ETask.et_RegFrame;
 104
 105                 location = (APTR)ctx->PC;
 106                 stack    = (APTR)ctx->FP;
 107                 type     = AT_CPU;
 108                 data     = ctx;
 109             }
 110
 111             /* Set location */
 112             iet->iet_AlertFlags   |= AF_Location;
 113             iet->iet_AlertLocation = location;
 114             iet->iet_AlertStack    = stack;
 115
 116             D(bug("[Alert] Previous frame 0x%p, caller 0x%p\n", iet->iet_AlertStack, iet->iet_AlertLocation));
 117         }
 118
 119         /* If this is not a nested call, set the supplementary data if specified */
 120         if (data && !(iet->iet_AlertFlags & AF_Alert))
 121         {
 122             D(bug("[Alert] Setting alert context, type %u, data 0x%p\n", type, data));
 123
 124             iet->iet_AlertType = type;
 125             CopyMem(data, &iet->iet_AlertData, contextSizes[type]);
 126         }
 127         else
 128         {
 129             /* Either no data or already present */
 130             type = iet->iet_AlertType;
 131             data = &iet->iet_AlertData;
 132
 133             D(bug("[Alert] Got stored alert context, type %u, data 0x%p\n", type, data));
 134         }
 135     }
 136     else
 137     {
 138         /*
 139          * If we have no task, or the task is being removed,
 140          * we can't use the user-mode routine.
 141          */
 142         usesystemalert = TRUE;
 143     }
 144
 145     /*
 146      * If we are running in user mode we should first try to report a problem
 147      * using Intuition display.
 148      */
 149     if (!usesystemalert)
 150     {
 151         alertNum = Exec_UserAlert(alertNum, SysBase);
 152         if (!alertNum)
 153         {
 154             /*
 155              * UserAlert() succeeded and the user decided to continue the task.
 156              * Clear crash status and return happily
 157              */
 158             if (iet)
 159                 ResetETask(iet);
 160             return;
 161         }
 162     }
 163
 164     /* Hint for SystemAlert() - if AlertType is AT_NONE, we don't have AlertData */
 165     if (type == AT_NONE)
 166         data = NULL;
 167
 168     /*
 169      * We're here if Intuition failed. Use safe (but not so
 170      * system and user-friendly) way to post alerts.
 171      */
 172     Disable();
 173     Exec_SystemAlert(alertNum, location, stack, type, data, SysBase);
 174
 175     if (alertNum & AT_DeadEnd)
 176     {
 177         /* Um, we have to do something here in order to prevent the
 178            computer from continuing... */
 179         ColdReboot();
 180         ShutdownA(SD_ACTION_COLDREBOOT);
 181     }
 182
 183     Enable();
 184
 185     /*
 186      * We successfully displayed an alert in supervisor mode.
 187      * Clear alert status by clearing respective fields in ETask.
 188      */
 189     if (iet)
 190         ResetETask(iet);
 191 }