rom/exec/alert.c

   1 /*
   2     Copyright © 1995-2011, 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 /* x86/64 kernel.resource doesn't have KrnIsSuper() */
  22 #ifndef KrnIsSuper
  23 #define KrnIsSuper() 0
  24 #endif
  25
  26 /*****************************************************************************
  27
  28     NAME */
  29
  30         AROS_LH1(void, Alert,
  31
  32 /*  SYNOPSIS */
  33         AROS_LHA(ULONG, alertNum, D7),
  34
  35 /*  LOCATION */
  36         struct ExecBase *, SysBase, 18, Exec)
  37
  38 /*  FUNCTION
  39         Alerts the user of a serious system problem.
  40
  41     INPUTS
  42         alertNum - This is a number which contains information about
  43                 the reason for the call.
  44
  45     RESULT
  46         This routine may return, if the alert is not a dead-end one.
  47
  48     NOTES
  49         You should not call this routine because it halts the machine,
  50         displays the message and then may reboot it.
  51
  52     EXAMPLE
  53         // Dead-End alert: 680x0 Access To Odd Address
  54         Alert (0x80000003);
  55
  56     BUGS
  57
  58     SEE ALSO
  59
  60     INTERNALS
  61
  62 ******************************************************************************/
  63 {
  64     AROS_LIBFUNC_INIT
  65
  66     struct Task *task = SysBase->ThisTask;
  67     struct IntETask *iet = NULL;
  68     int supervisor = KrnIsSuper();
  69
  70     D(bug("[exec] Alert 0x%08X\n", alertNum));
  71
  72     if (task)
  73     {
  74         iet = GetIntETask(task);
  75
  76         /* Do we already have location set? */
  77         if (!(iet->iet_AlertFlags & AF_Location))
  78         {
  79             /* If no, the location is where we were called from */
  80             iet->iet_AlertFlags |= AF_Location;
  81
  82             if (supervisor && ((alertNum & ~AT_DeadEnd) == AN_StackProbe))
  83             {
  84                 /*
  85                  * Special case: AN_StackProbe issued by kernel's task dispatcher.
  86                  * Pick up data from task's context.
  87                  */
  88                 struct ExceptionContext *ctx = iet->iet_Context;
  89
  90                 iet->iet_AlertLocation = (APTR)ctx->PC;
  91                 iet->iet_AlertStack    = (APTR)ctx->FP;
  92             }
  93             else
  94             {
  95                 iet->iet_AlertLocation = __builtin_return_address(0);
  96                 /*
  97                  * And backtrace starts at caller's frame.
  98                  * On ARM we don't have frame pointer so we can't do backtrace.
  99                  * __builtin_frame_address(1) will return garbage, so don't do this.
 100                  */
 101 #ifdef __arm__
 102                 iet->iet_AlertStack = NULL;
 103 #else
 104                 iet->iet_AlertStack = __builtin_frame_address(1);
 105 #endif
 106                 D(bug("[Alert] Previous frame 0x%p, caller 0x%p\n", iet->iet_AlertStack, iet->iet_AlertLocation));
 107             }
 108         }
 109     }
 110
 111     /*
 112      * If we are running in user mode we should first try to report a problem
 113      * using Intuition display.
 114      */
 115     if (!supervisor)
 116     {
 117         alertNum = Exec_UserAlert(alertNum, SysBase);
 118         if (!alertNum)
 119             return;
 120     }
 121
 122     /*
 123      * We're here if Intuition failed. Use safe (but not so
 124      * system and user-friendly) way to post alerts.
 125      */
 126     Disable();
 127     Exec_SystemAlert(alertNum, SysBase);
 128     Enable();
 129
 130     /*
 131      * We succesfully displayed an alert in supervisor mode.
 132      * Clear alert status by clearing respective fields in ETask.
 133      */
 134     if (iet)
 135     {
 136         ResetETask(iet);
 137     }
 138
 139     if (alertNum & AT_DeadEnd)
 140     {
 141         /* Um, we have to do something here in order to prevent the
 142            computer from continuing... */
 143         ColdReboot();
 144         ShutdownA(SD_ACTION_COLDREBOOT);
 145     }
 146
 147     AROS_LIBFUNC_EXIT
 148 }