// entry in the IDT, this is sometimes called
// an "interrupt gate"
typedef struct
{
unsigned short LowOffset;
unsigned short selector;
unsigned char unused_lo;
unsigned char segment_type:4; //0x0E is an interrupt gate
unsigned char system_segment_flag:1;
unsigned char DPL:2; // descriptor privilege level
unsigned char P:1; /* present */
unsigned short HiOffset;
} IDTENTRY;
/* sidt returns idt in this format */
typedef struct
{
unsigned short IDTLimit;
unsigned short LowIDTbase;
unsigned short HiIDTbase;
} IDTINFO;
#pragma pack()
unsigned long old_ISR_pointer;
unsigned char keystroke_buffer[MAX_CHARS];
int kb_array_ptr=0;
// remember we disable interrupts while we patch the table
__asm cli
idt_entries[kb_int].LowOffset = (unsigned short)my_interrupt_hook;
idt_entries[kb_int].HiOffset = (unsigned short)((unsigned long)my_interrupt_hook >> 16);
__asm sti
DbgPrint("Hooking Interrupt complete: Old = 0x%08X, New = 0x%08X\n", old_ISR_pointer, my_interrupt_hook);
UNEXPECTED_KERNEL_MODE_TRAP (7f)
This means a trap occurred in kernel mode, and it's a trap of a kind
that the kernel isn't allowed to have/catch (bound trap) or that
is always instant death (double fault). The first number in the
bugcheck params is the number of the trap (8 = double fault, etc)
Consult an Intel x86 family manual to learn more about what these
traps are. Here is a *portion* of those codes:
If kv shows a taskGate
use .tss on the part before the colon, then kv.
Else if kv shows a trapframe
use .trap on that value
Else
.trap on the appropriate frame will show where the trap was taken
(on x86, this will be the ebp that goes with the procedure KiTrap)
Endif
kb will then show the corrected stack.
Arguments:
Arg1: 0000000d, EXCEPTION_GP_FAULT
Arg2: 00000000
Arg3: 00000000
Arg4: 00000000
Debugging Details:
------------------
*************************************************************************
*** ***
*** ***
*** Your debugger is not using the correct symbols ***
*** ***
*** In order for this command to work properly, your symbol path ***
*** must point to .pdb files that have full type information. ***
*** ***
*** Certain .pdb files (such as the public OS symbols) do not ***
*** contain the required information. Contact the group that ***
*** provided you with these symbols if you need this command to ***
*** work. ***
*** ***
*** Type referenced: kernel32!pNlsUserInfo ***
*** ***
*************************************************************************
*************************************************************************
*** ***
*** ***
*** Your debugger is not using the correct symbols ***
*** ***
*** In order for this command to work properly, your symbol path ***
*** must point to .pdb files that have full type information. ***
*** ***
*** Certain .pdb files (such as the public OS symbols) do not ***
*** contain the required information. Contact the group that ***
*** provided you with these symbols if you need this command to ***
*** work. ***
*** ***
*** Type referenced: kernel32!pNlsUserInfo ***
*** ***
*************************************************************************