rosapps/applications/sysutils/utils/pice/module/hooks.c

   1 /*++
   2
   3 Copyright (c) 1998-2001 Klaus P. Gerlicher
   4
   5 Module Name:
   6
   7     hooks.c
   8
   9 Abstract:
  10
  11     hooking of interrupts
  12
  13 Environment:
  14
  15     Kernel mode only
  16
  17 Author:
  18
  19     Klaus P. Gerlicher
  20
  21 Revision History:
  22
  23     16-Jul-1998:        created
  24     15-Nov-2000:    general cleanup of source files
  25
  26 Copyright notice:
  27
  28   This file may be distributed under the terms of the GNU Public License.
  29
  30 --*/
  31
  32 ////////////////////////////////////////////////////
  33 // INCLUDES
  34 ////
  35 #include "remods.h"
  36 #include "precomp.h"
  37
  38 ////////////////////////////////////////////////////
  39 // PROTOTYPES
  40 ////
  41 void DeinstallHooks(void);
  42
  43 ////////////////////////////////////////////////////
  44 // DEFINES
  45 ////
  46
  47 ////////////////////////////////////////////////////
  48 // GLOBALS
  49 ////
  50
  51 // IDT entries
  52 //PIDTENTRY pidt[256];
  53 IDTENTRY oldidt[256]={{0},};
  54
  55 IDTENTRY idt_snapshot[256]={{0},};
  56
  57 // processor flag for interrupt suspension
  58 ULONG ulOldFlags;
  59
  60 ////////////////////////////////////////////////////
  61 // PROCEDURES
  62 ////
  63
  64 //*************************************************************************
  65 // MaskIrqs()
  66 //
  67 //*************************************************************************
  68 void MaskIrqs(void)
  69 {
  70     ENTER_FUNC();
  71
  72     save_flags(ulOldFlags);
  73     cli();
  74
  75     LEAVE_FUNC();
  76 }
  77
  78 //*************************************************************************
  79 // UnmaskIrqs()
  80 //
  81 //*************************************************************************
  82 void UnmaskIrqs(void)
  83 {
  84     ENTER_FUNC();
  85
  86     restore_flags(ulOldFlags);
  87
  88     LEAVE_FUNC();
  89 }
  90
  91 //*************************************************************************
  92 // SetGlobalInt()
  93 //
  94 //*************************************************************************
  95 ULONG SetGlobalInt(ULONG dwInt,ULONG NewIntHandler)
  96 {
  97     ULONG idt[2];
  98     ULONG OldIntHandler;
  99     struct IdtEntry* pidt;
 100     struct IdtEntry oldidt;
 101
 102     ENTER_FUNC();
 103
 104         // get linear location of IDT
 105         __asm__("sidt %0":"=m" (idt));
 106
 107         // get pointer to idte for int 3
 108         pidt=((struct IdtEntry*)((idt[1]<<16)|((idt[0]>>16)&0x0000FFFF)))+dwInt;
 109
 110         oldidt=*pidt;
 111
 112     // set new handler address
 113         pidt->HiOffset=(USHORT)(((ULONG)NewIntHandler)>>16);
 114         pidt->LoOffset=(USHORT)(((ULONG)NewIntHandler)&0x0000FFFF);
 115
 116     DPRINT((0,"new INT(%0.2x) handler = %0.4x:%x\n",dwInt,pidt->SegSel,(pidt->HiOffset<<16)|(pidt->LoOffset&0x0000FFFF)));
 117
 118         OldIntHandler=(oldidt.HiOffset<<16)|(oldidt.LoOffset&0x0000FFFF);
 119
 120     DPRINT((0,"old INT(%0.2x) handler = %0.4x:%x\n",dwInt,pidt->SegSel,OldIntHandler));
 121
 122     LEAVE_FUNC();
 123
 124         return OldIntHandler;
 125 }
 126
 127 //*************************************************************************
 128 // TakeIdtSnapshot()
 129 //
 130 //*************************************************************************
 131 void TakeIdtSnapshot(void)
 132 {
 133     ULONG idt[2],i;
 134     struct IdtEntry* pidt;
 135
 136         __asm__("sidt %0":"=m" (idt));
 137
 138         // get pointer to idte for int 3
 139         pidt=((struct IdtEntry*)((idt[1]<<16)|((idt[0]>>16)&0x0000FFFF)));
 140
 141     for(i=0;i<256;i++)
 142     {
 143         DPRINT((11,"TakeIdtSnapShot(): saving vector %u\n",i));
 144         if(IsRangeValid((ULONG)pidt,sizeof(*pidt)) )
 145         {
 146             DPRINT((11,"TakeIdtSnapShot(): vector %u valid\n",i));
 147             idt_snapshot[i] = *pidt++;
 148         }
 149     }
 150 }
 151
 152 //*************************************************************************
 153 // RestoreIdt()
 154 //
 155 //*************************************************************************
 156 void RestoreIdt(void)
 157 {
 158     ULONG idt[2],i;
 159     struct IdtEntry* pidt;
 160
 161         __asm__("sidt %0":"=m" (idt));
 162
 163     // get pointer to idte for int 3
 164         pidt=((struct IdtEntry*)((idt[1]<<16)|((idt[0]>>16)&0x0000FFFF)));
 165
 166     for(i=0;i<256;i++)
 167     {
 168         DPRINT((11,"TakeIdtSnapShot(): restoring vector %u\n",i));
 169         if(IsRangeValid((ULONG)pidt,sizeof(*pidt)) )
 170         {
 171             DPRINT((11,"TakeIdtSnapShot(): vector %u valid\n",i));
 172             *pidt++ = idt_snapshot[i];
 173         }
 174     }
 175 }
 176
 177 // EOF