BOOLEAN
KdpTrap (
IN PKTRAP_FRAME TrapFrame,
IN PKEXCEPTION_FRAME ExceptionFrame,
IN PEXCEPTION_RECORD ExceptionRecord,
IN PCONTEXT ContextRecord,
IN KPROCESSOR_MODE PreviousMode,
IN BOOLEAN SecondChance
)
/*++
Routine Description:
This routine is called whenever a exception is dispatched and the kernel
debugger is active.
Arguments:
TrapFrame - Supplies a pointer to a trap frame that describes the
trap.
ExceptionFrame - Supplies a pointer to a exception frame that describes
the trap.
ExceptionRecord - Supplies a pointer to an exception record that
describes the exception.
ContextRecord - Supplies the context at the time of the exception.
PreviousMode - Supplies the previous processor mode.
SecondChance - Supplies a boolean value that determines whether this is
the second chance (TRUE) that the exception has been raised.
Return Value:
A value of TRUE is returned if the exception is handled. Otherwise a
value of FALSE is returned.
--*/
{
BOOLEAN Completion;
BOOLEAN Enable;
BOOLEAN UnloadSymbols = FALSE;
ULONG OldIar;
STRING Input;
STRING Output;
PKPRCB Prcb;
//
// Synchronize processor execution, save processor state, enter debugger,
// and flush the current TB.
//
re_enter_debugger:
Enable = KdEnterDebugger(TrapFrame, ExceptionFrame);
Prcb = KeGetCurrentPrcb();
KiSaveProcessorState(TrapFrame, ExceptionFrame);
KeFlushCurrentTb();
//
// If this is a breakpoint instruction, then check to determine if is
// an internal command.
//
if ((ExceptionRecord->ExceptionCode == STATUS_BREAKPOINT) &&
((ExceptionRecord->ExceptionInformation[0] & BREAKPOINT_CODE_MASK)
>= DEBUG_PRINT_BREAKPOINT)) {
//
// Switch on the breakpoint code.
//
switch (ExceptionRecord->ExceptionInformation[0] & BREAKPOINT_CODE_MASK) {
//
// Print a debug string.
//
// Arguments:
//
// a0 - Supplies a pointer to an output string buffer.
// a1 - Supplies the length of the output string buffer.
//
case DEBUG_PRINT_BREAKPOINT:
ContextRecord->Iar += 4;
Output.Buffer = (PCHAR)ContextRecord->Gpr3;
Output.Length = (USHORT)ContextRecord->Gpr4;
if (KdDebuggerNotPresent == FALSE) {
if (KdpPrintString(&Output)) {
ContextRecord->Gpr3 = (ULONG)STATUS_BREAKPOINT;
} else {
ContextRecord->Gpr3 = (ULONG)STATUS_SUCCESS;
}
} else {
ContextRecord->Gpr3 = (ULONG)STATUS_DEVICE_NOT_CONNECTED;
}
KiRestoreProcessorState(TrapFrame, ExceptionFrame);
KdExitDebugger(Enable);
return TRUE;
//
// Print a debug prompt string, then input a string.
//
// r.3 - Supplies a pointer to an output string buffer.
// r.4 - Supplies the length of the output string buffer..
// r.5 - supplies a pointer to an input string buffer.
// r.6 - Supplies the length of the input string bufffer.
//
case DEBUG_PROMPT_BREAKPOINT:
ContextRecord->Iar += 4;
Output.Buffer = (PCHAR)ContextRecord->Gpr3;
Output.Length = (USHORT)ContextRecord->Gpr4;
Input.Buffer = (PCHAR)ContextRecord->Gpr5;
Input.MaximumLength = (USHORT)ContextRecord->Gpr6;
KdpPromptString(&Output, &Input);
ContextRecord->Gpr3 = Input.Length;
KiRestoreProcessorState(TrapFrame, ExceptionFrame);
KdExitDebugger(Enable);
return TRUE;
//
// Load the symbolic information for an image.
//
// Arguments:
//
// r.3 - Supplies a pointer to an output string descriptor.
// r.4 - Supplies a the base address of the image.
//
case DEBUG_UNLOAD_SYMBOLS_BREAKPOINT:
UnloadSymbols = TRUE;
//
// Fall through
//
case DEBUG_LOAD_SYMBOLS_BREAKPOINT:
OldIar = ContextRecord->Iar;
if (KdDebuggerNotPresent == FALSE) {
KdpReportLoadSymbolsStateChange((PSTRING)ContextRecord->Gpr3,
(PKD_SYMBOLS_INFO) ContextRecord->Gpr4,
UnloadSymbols,
&Prcb->ProcessorState.ContextFrame);
}
RtlCopyMemory(ContextRecord,
&Prcb->ProcessorState.ContextFrame,
sizeof(CONTEXT));
KiRestoreProcessorState(TrapFrame, ExceptionFrame);
KdExitDebugger(Enable);
//
// If the kernel debugger did not update the IAR, then increment
// past the breakpoint instruction.
//
if (ContextRecord->Iar == OldIar) {
ContextRecord->Iar += 4;
}
return TRUE;
//
// Unknown internal command.
//
default:
break;
}
}
//
// Report state change to kernel debugger on host machine.
//
Completion = KdpReportExceptionStateChange(
ExceptionRecord,
&Prcb->ProcessorState.ContextFrame,
SecondChance);
RtlCopyMemory(ContextRecord,
&Prcb->ProcessorState.ContextFrame,
sizeof(CONTEXT));
KiRestoreProcessorState(TrapFrame, ExceptionFrame);
KdExitDebugger(Enable);
//
// check to see if the user of the remote debugger
// requested memory to be paged in
//
if (KdpPageInAddress) {
if (KeGetCurrentIrql() <= APC_LEVEL) {
//
// if the IQRL is below DPC level then cause
// the page fault to occur and then re-enter
// the debugger. this whole process is transparent
// to the user.
//
KdpPageInData( (PUCHAR)KdpPageInAddress );
KdpPageInAddress = 0;
KdpControlCPending = FALSE;
goto re_enter_debugger;
} else {
//
// we cannot take a page fault
// here so a worker item is queued to take the
// page fault. after the worker item takes the
// page fault it sets the contol-c flag so that
// the user re-enters the debugger just as if
// control-c was pressed.
//
if (KdpControlCPressed) {
ExInitializeWorkItem(
&KdpPageInWorkItem,
(PWORKER_THREAD_ROUTINE) KdpPageInData,
(PVOID) KdpPageInAddress
);
ExQueueWorkItem( &KdpPageInWorkItem, DelayedWorkQueue );
KdpPageInAddress = 0;
}
}
}
KdpControlCPressed = FALSE;
return Completion;
}
DECLSPEC_NORETURN
VOID
__cdecl
KiTrap02(VOID)
{
PKTSS Tss, NmiTss;
PKTHREAD Thread;
PKPROCESS Process;
PKGDTENTRY TssGdt;
KTRAP_FRAME TrapFrame;
KIRQL OldIrql;
//
// In some sort of strange recursion case, we might end up here with the IF
// flag incorrectly on the interrupt frame -- during a normal NMI this would
// normally already be set.
//
// For sanity's sake, make sure interrupts are disabled for sure.
// NMIs will already be since the CPU does it for us.
//
_disable();
//
// Get the current TSS, thread, and process
//
Tss = PCR->TSS;
Thread = ((PKIPCR)PCR)->PrcbData.CurrentThread;
Process = Thread->ApcState.Process;
//
// Save data usually not in the TSS
//
Tss->CR3 = Process->DirectoryTableBase[0];
Tss->IoMapBase = Process->IopmOffset;
Tss->LDT = Process->LdtDescriptor.LimitLow ? KGDT_LDT : 0;
//
// Now get the base address of the NMI TSS
//
TssGdt = &((PKIPCR)KeGetPcr())->GDT[KGDT_NMI_TSS / sizeof(KGDTENTRY)];
NmiTss = (PKTSS)(ULONG_PTR)(TssGdt->BaseLow |
TssGdt->HighWord.Bytes.BaseMid << 16 |
TssGdt->HighWord.Bytes.BaseHi << 24);
//
// Switch to it and activate it, masking off the nested flag
//
// Note that in reality, we are already on the NMI tss -- we just need to
// update the PCR to reflect this
//
PCR->TSS = NmiTss;
__writeeflags(__readeflags() &~ EFLAGS_NESTED_TASK);
TssGdt->HighWord.Bits.Dpl = 0;
TssGdt->HighWord.Bits.Pres = 1;
TssGdt->HighWord.Bits.Type = I386_TSS;
//
// Now build the trap frame based on the original TSS
//
// The CPU does a hardware "Context switch" / task switch of sorts and so it
// takes care of saving our context in the normal TSS.
//
// We just have to go get the values...
//
RtlZeroMemory(&TrapFrame, sizeof(KTRAP_FRAME));
TrapFrame.HardwareSegSs = Tss->Ss0;
TrapFrame.HardwareEsp = Tss->Esp0;
TrapFrame.EFlags = Tss->EFlags;
TrapFrame.SegCs = Tss->Cs;
TrapFrame.Eip = Tss->Eip;
TrapFrame.Ebp = Tss->Ebp;
TrapFrame.Ebx = Tss->Ebx;
TrapFrame.Esi = Tss->Esi;
TrapFrame.Edi = Tss->Edi;
TrapFrame.SegFs = Tss->Fs;
TrapFrame.ExceptionList = PCR->NtTib.ExceptionList;
TrapFrame.PreviousPreviousMode = -1;
TrapFrame.Eax = Tss->Eax;
TrapFrame.Ecx = Tss->Ecx;
TrapFrame.Edx = Tss->Edx;
TrapFrame.SegDs = Tss->Ds;
TrapFrame.SegEs = Tss->Es;
TrapFrame.SegGs = Tss->Gs;
TrapFrame.DbgEip = Tss->Eip;
TrapFrame.DbgEbp = Tss->Ebp;
//
// Store the trap frame in the KPRCB
//
KiSaveProcessorState(&TrapFrame, NULL);
//
// Call any registered NMI handlers and see if they handled it or not
//
if (!KiHandleNmi())
{
//
// They did not, so call the platform HAL routine to bugcheck the system
//
// Make sure the HAL believes it's running at HIGH IRQL... we can't use
// the normal APIs here as playing with the IRQL could change the system
// state
//
OldIrql = PCR->Irql;
PCR->Irql = HIGH_LEVEL;
HalHandleNMI(NULL);
PCR->Irql = OldIrql;
}
//
// Although the CPU disabled NMIs, we just did a BIOS Call, which could've
// totally changed things.
//
// We have to make sure we're still in our original NMI -- a nested NMI
// will point back to the NMI TSS, and in that case we're hosed.
//
if (PCR->TSS->Backlink != KGDT_NMI_TSS)
{
//
// Restore original TSS
//
PCR->TSS = Tss;
//
// Set it back to busy
//
TssGdt->HighWord.Bits.Dpl = 0;
TssGdt->HighWord.Bits.Pres = 1;
TssGdt->HighWord.Bits.Type = I386_ACTIVE_TSS;
//
// Restore nested flag
//
__writeeflags(__readeflags() | EFLAGS_NESTED_TASK);
//
// Handled, return from interrupt
//
KiIret();
}
//
// Unhandled: crash the system
//
KiSystemFatalException(EXCEPTION_NMI, NULL);
}
VOID
KiFreezeTargetExecution (
IN PKTRAP_FRAME TrapFrame,
IN PKEXCEPTION_FRAME ExceptionFrame
)
/*++
Routine Description:
This function freezes the execution of the current running processor.
If a trapframe is supplied to current state is saved into the prcb
for the debugger.
Arguments:
TrapFrame - Supplies a pointer to the trap frame that describes the
trap.
ExceptionFrame - Supplies a pointer to the exception frame that
describes the trap.
Return Value:
None.
--*/
{
#if !defined(NT_UP)
KIRQL OldIrql;
PKPRCB Prcb;
BOOLEAN Enable;
KCONTINUE_STATUS Status;
EXCEPTION_RECORD ExceptionRecord;
Enable = KiDisableInterrupts();
KeRaiseIrql(HIGH_LEVEL, &OldIrql);
Prcb = KeGetCurrentPrcb();
Prcb->IpiFrozen = TARGET_FROZEN;
Prcb->SkipTick = TRUE;
if (TrapFrame != NULL) {
KiSaveProcessorState(TrapFrame, ExceptionFrame);
}
//
// Sweep the data cache in case this is a system crash and the bug
// check code is attempting to write a crash dump file.
//
KeSweepCurrentDcache();
//
// Wait for person requesting us to freeze to
// clear our frozen flag
//
while (FrozenState(Prcb->IpiFrozen) == TARGET_FROZEN) {
if (Prcb->IpiFrozen & FREEZE_ACTIVE) {
//
// This processor has been made the active processor
//
if (TrapFrame) {
RtlZeroMemory (&ExceptionRecord, sizeof ExceptionRecord);
ExceptionRecord.ExceptionCode = STATUS_WAKE_SYSTEM_DEBUGGER;
ExceptionRecord.ExceptionRecord = &ExceptionRecord;
ExceptionRecord.ExceptionAddress =
(PVOID)CONTEXT_TO_PROGRAM_COUNTER (&Prcb->ProcessorState.ContextFrame);
Status = (KiDebugSwitchRoutine) (
&ExceptionRecord,
&Prcb->ProcessorState.ContextFrame,
FALSE
);
} else {
Status = ContinueError;
}
//
// If status is anything other then, continue with next
// processor then reselect master
//
if (Status != ContinueNextProcessor) {
Prcb->IpiFrozen &= ~FREEZE_ACTIVE;
KiFreezeOwner->IpiFrozen |= FREEZE_ACTIVE;
}
}
KeYieldProcessor();
}
if (TrapFrame != NULL) {
KiRestoreProcessorState(TrapFrame, ExceptionFrame);
}
Prcb->IpiFrozen = RUNNING;
KeFlushCurrentTb();
KeSweepCurrentIcache();
KeLowerIrql(OldIrql);
KiRestoreInterrupts(Enable);
#endif // !define(NT_UP)
return;
}
