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reactos/ntoskrnl/ke/i386/v86vdm.c
Thomas Faber 07de9d1da3
[NTOS:KE] In KiExitV86Mode, restore KTSS::Esp0 to its standard value. CORE-16531 
The trap frame is in a random location on the stack, and setting Esp0 there
wastes significant amounts of space and may lead to unexpected stack overflows.

Also use a more descriptive expression for the V86 members of the KTRAP_FRAME.
2020-01-03 11:28:09 +01:00

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/*
* PROJECT: ReactOS Kernel
* LICENSE: BSD - See COPYING.ARM in the top level directory
* FILE: ntoskrnl/ke/i386/v86vdm.c
* PURPOSE: V8086 and VDM Trap Emulation
* PROGRAMMERS: ReactOS Portable Systems Group
* Alex Ionescu (alex.ionescu@reactos.org)
*/
/* INCLUDES *******************************************************************/
#include <ntoskrnl.h>
#define NDEBUG
#include <debug.h>
#define KiVdmGetInstructionSize(x) ((x) & 0xFF)
#define KiVdmGetPrefixFlags(x) ((x) & 0xFFFFFF00)
/* GLOBALS ********************************************************************/
ULONG KeI386EFlagsAndMaskV86 = EFLAGS_USER_SANITIZE;
ULONG KeI386EFlagsOrMaskV86 = EFLAGS_INTERRUPT_MASK;
PVOID Ki386IopmSaveArea;
BOOLEAN KeI386VirtualIntExtensions = FALSE;
const PULONG KiNtVdmState = (PULONG)FIXED_NTVDMSTATE_LINEAR_PC_AT;
/* UNHANDLED OPCODES **********************************************************/
KiVdmUnhandledOpcode(F);
KiVdmUnhandledOpcode(OUTSW);
KiVdmUnhandledOpcode(OUTSB);
KiVdmUnhandledOpcode(INSB);
KiVdmUnhandledOpcode(INSW);
KiVdmUnhandledOpcode(NPX);
KiVdmUnhandledOpcode(INBimm);
KiVdmUnhandledOpcode(INWimm);
KiVdmUnhandledOpcode(OUTBimm);
KiVdmUnhandledOpcode(OUTWimm);
KiVdmUnhandledOpcode(INB);
KiVdmUnhandledOpcode(INW);
KiVdmUnhandledOpcode(OUTB);
KiVdmUnhandledOpcode(OUTW);
KiVdmUnhandledOpcode(HLT);
KiVdmUnhandledOpcode(INTO);
KiVdmUnhandledOpcode(INV);
/* OPCODE HANDLERS ************************************************************/
BOOLEAN
FASTCALL
KiVdmOpcodePUSHF(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
ULONG Esp, V86EFlags, TrapEFlags;
/* Get current V8086 flags and mask out interrupt flag */
V86EFlags = *KiNtVdmState;
V86EFlags &= ~EFLAGS_INTERRUPT_MASK;
/* Get trap frame EFLags */
TrapEFlags = TrapFrame->EFlags;
/* Check for VME support */
if(KeI386VirtualIntExtensions)
{
/* Copy the virtual interrupt flag to the interrupt flag */
TrapEFlags &= ~EFLAGS_INTERRUPT_MASK;
if(TrapEFlags & EFLAGS_VIF)
TrapEFlags |= EFLAGS_INTERRUPT_MASK;
}
/* Leave only align, nested task and interrupt */
TrapEFlags &= (EFLAGS_ALIGN_CHECK | EFLAGS_NESTED_TASK | EFLAGS_INTERRUPT_MASK);
/* Add in those flags if they exist, and add in the IOPL flag */
V86EFlags |= TrapEFlags;
V86EFlags |= EFLAGS_IOPL;
/* Build flat ESP */
Esp = (TrapFrame->HardwareSegSs << 4) + (USHORT)TrapFrame->HardwareEsp;
/* Check for OPER32 */
if (KiVdmGetPrefixFlags(Flags) & PFX_FLAG_OPER32)
{
/* Save EFlags */
Esp -= 4;
*(PULONG)Esp = V86EFlags;
}
else
{
/* Save EFLags */
Esp -= 2;
*(PUSHORT)Esp = (USHORT)V86EFlags;
}
/* Set new ESP and EIP */
TrapFrame->HardwareEsp = Esp - (TrapFrame->HardwareSegSs << 4);
TrapFrame->Eip += KiVdmGetInstructionSize(Flags);
/* We're done */
return TRUE;
}
BOOLEAN
FASTCALL
KiVdmOpcodePOPF(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
ULONG Esp, V86EFlags, EFlags, TrapEFlags;
/* Build flat ESP */
Esp = (TrapFrame->HardwareSegSs << 4) + (USHORT)TrapFrame->HardwareEsp;
/* Check for OPER32 */
if (KiVdmGetPrefixFlags(Flags) & PFX_FLAG_OPER32)
{
/* Read EFlags */
EFlags = *(PULONG)Esp;
Esp += 4;
}
else
{
/* Read EFlags */
EFlags = *(PUSHORT)Esp;
Esp += 2;
}
/* Set new ESP */
TrapFrame->HardwareEsp = Esp - (TrapFrame->HardwareSegSs << 4);
/* Mask out IOPL from the flags */
EFlags &= ~EFLAGS_IOPL;
/* Save the V86 flags, but mask out the nested task flag */
V86EFlags = EFlags & ~EFLAGS_NESTED_TASK;
/* Now leave only alignment, nested task and interrupt flag */
EFlags &= (EFLAGS_ALIGN_CHECK | EFLAGS_NESTED_TASK | EFLAGS_INTERRUPT_MASK);
/* Get trap EFlags */
TrapEFlags = TrapFrame->EFlags;
/* Check for VME support */
if(KeI386VirtualIntExtensions)
{
/* Copy the IF flag into the VIF one */
V86EFlags &= ~EFLAGS_VIF;
if(V86EFlags & EFLAGS_INTERRUPT_MASK)
{
V86EFlags |= EFLAGS_VIF;
/* Don't set the interrupt flag */
V86EFlags &= ~EFLAGS_INTERRUPT_MASK;
}
}
/* Add V86 flag */
V86EFlags |= EFLAGS_V86_MASK;
/* Update EFlags in trap frame */
TrapFrame->EFlags |= V86EFlags;
/* Check if ESP0 needs to be fixed up */
if (TrapEFlags & EFLAGS_V86_MASK) Ki386AdjustEsp0(TrapFrame);
/* Update the V8086 EFlags state */
KiVdmClearVdmEFlags(EFLAGS_ALIGN_CHECK | EFLAGS_NESTED_TASK | EFLAGS_INTERRUPT_MASK);
KiVdmSetVdmEFlags(EFlags);
/* FIXME: Check for VDM interrupts */
/* Update EIP */
TrapFrame->Eip += KiVdmGetInstructionSize(Flags);
/* We're done */
return TRUE;
}
BOOLEAN
FASTCALL
KiVdmOpcodeINTnn(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
ULONG Esp, V86EFlags, TrapEFlags, Eip, Interrupt;
/* Read trap frame EFlags */
TrapEFlags = TrapFrame->EFlags;
/* Remove interrupt flag from V8086 EFlags */
V86EFlags = *KiNtVdmState;
KiVdmClearVdmEFlags(EFLAGS_INTERRUPT_MASK);
/* Keep only alignment and interrupt flag from the V8086 state */
V86EFlags &= (EFLAGS_ALIGN_CHECK | EFLAGS_INTERRUPT_MASK);
/* Check for VME support */
ASSERT(KeI386VirtualIntExtensions == FALSE);
/* Mask in the relevant V86 EFlags into the trap flags */
V86EFlags |= (TrapEFlags & ~EFLAGS_INTERRUPT_MASK);
/* And mask out the VIF, nested task and TF flag from the trap flags */
TrapFrame->EFlags = TrapEFlags &~ (EFLAGS_VIF | EFLAGS_NESTED_TASK | EFLAGS_TF);
/* Add the IOPL flag to the local trap flags */
V86EFlags |= EFLAGS_IOPL;
/* Build flat ESP */
Esp = (TrapFrame->HardwareSegSs << 4) + TrapFrame->HardwareEsp;
/* Push EFlags */
Esp -= 2;
*(PUSHORT)(Esp) = (USHORT)V86EFlags;
/* Push CS */
Esp -= 2;
*(PUSHORT)(Esp) = (USHORT)TrapFrame->SegCs;
/* Push IP */
Esp -= 2;
*(PUSHORT)(Esp) = (USHORT)TrapFrame->Eip + KiVdmGetInstructionSize(Flags) + 1;
/* Update ESP */
TrapFrame->HardwareEsp = (USHORT)Esp;
/* Get flat EIP */
Eip = (TrapFrame->SegCs << 4) + TrapFrame->Eip;
/* Now get the *next* EIP address (current is original + the count - 1) */
Eip += KiVdmGetInstructionSize(Flags);
/* Now read the interrupt number */
Interrupt = *(PUCHAR)Eip;
/* Read the EIP from its IVT entry */
Interrupt = *(PULONG)(Interrupt * 4);
TrapFrame->Eip = (USHORT)Interrupt;
/* Now get the CS segment */
Interrupt = (USHORT)(Interrupt >> 16);
/* Check if the trap was not V8086 trap */
if (!(TrapFrame->EFlags & EFLAGS_V86_MASK))
{
/* Was it a kernel CS? */
Interrupt |= RPL_MASK;
if (TrapFrame->SegCs == KGDT_R0_CODE)
{
/* Add the RPL mask */
TrapFrame->SegCs = Interrupt;
}
else
{
/* Set user CS */
TrapFrame->SegCs = KGDT_R3_CODE | RPL_MASK;
}
}
else
{
/* Set IVT CS */
TrapFrame->SegCs = Interrupt;
}
/* We're done */
return TRUE;
}
BOOLEAN
FASTCALL
KiVdmOpcodeIRET(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
ULONG Esp, V86EFlags, EFlags, TrapEFlags, Eip;
/* Build flat ESP */
Esp = (TrapFrame->HardwareSegSs << 4) + TrapFrame->HardwareEsp;
/* Check for OPER32 */
if (KiVdmGetPrefixFlags(Flags) & PFX_FLAG_OPER32)
{
/* Build segmented EIP */
TrapFrame->Eip = *(PULONG)Esp;
TrapFrame->SegCs = *(PUSHORT)(Esp + 4);
/* Set new ESP */
TrapFrame->HardwareEsp += 12;
/* Get EFLAGS */
EFlags = *(PULONG)(Esp + 8);
}
else
{
/* Build segmented EIP */
TrapFrame->Eip = *(PUSHORT)Esp;
TrapFrame->SegCs = *(PUSHORT)(Esp + 2);
/* Set new ESP */
TrapFrame->HardwareEsp += 6;
/* Get EFLAGS */
EFlags = *(PUSHORT)(Esp + 4);
}
/* Mask out EFlags */
EFlags &= ~(EFLAGS_IOPL + EFLAGS_VIF + EFLAGS_NESTED_TASK + EFLAGS_VIP);
V86EFlags = EFlags;
/* Check for VME support */
ASSERT(KeI386VirtualIntExtensions == FALSE);
/* Add V86 and Interrupt flag */
EFlags |= EFLAGS_V86_MASK | EFLAGS_INTERRUPT_MASK;
/* Update EFlags in trap frame */
TrapEFlags = TrapFrame->EFlags;
TrapFrame->EFlags = (TrapFrame->EFlags & EFLAGS_VIP) | EFlags;
/* Check if ESP0 needs to be fixed up */
if (!(TrapEFlags & EFLAGS_V86_MASK)) Ki386AdjustEsp0(TrapFrame);
/* Update the V8086 EFlags state */
KiVdmClearVdmEFlags(EFLAGS_INTERRUPT_MASK);
KiVdmSetVdmEFlags(V86EFlags);
/* Build flat EIP and check if this is the BOP instruction */
Eip = (TrapFrame->SegCs << 4) + TrapFrame->Eip;
if (*(PUSHORT)Eip == 0xC4C4)
{
/* Dispatch the BOP */
VdmDispatchBop(TrapFrame);
}
else
{
/* FIXME: Check for VDM interrupts */
DPRINT("FIXME: Check for VDM interrupts\n");
}
/* We're done */
return TRUE;
}
BOOLEAN
FASTCALL
KiVdmOpcodeCLI(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
/* Check for VME support */
ASSERT(KeI386VirtualIntExtensions == FALSE);
/* Disable interrupts */
KiVdmClearVdmEFlags(EFLAGS_INTERRUPT_MASK);
/* Skip instruction */
TrapFrame->Eip += KiVdmGetInstructionSize(Flags);
/* Done */
return TRUE;
}
BOOLEAN
FASTCALL
KiVdmOpcodeSTI(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
/* Check for VME support */
ASSERT(KeI386VirtualIntExtensions == FALSE);
/* Enable interrupts */
KiVdmSetVdmEFlags(EFLAGS_INTERRUPT_MASK);
/* Skip instruction */
TrapFrame->Eip += KiVdmGetInstructionSize(Flags);
/* Done */
return TRUE;
}
/* MASTER OPCODE HANDLER ******************************************************/
BOOLEAN
FASTCALL
KiVdmHandleOpcode(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
ULONG Eip;
/* Get flat EIP of the *current* instruction (not the original EIP) */
Eip = (TrapFrame->SegCs << 4) + TrapFrame->Eip;
Eip += KiVdmGetInstructionSize(Flags) - 1;
/* Read the opcode entry */
switch (*(PUCHAR)Eip)
{
case 0xF: return KiCallVdmHandler(F);
case 0x26: return KiCallVdmPrefixHandler(PFX_FLAG_ES);
case 0x2E: return KiCallVdmPrefixHandler(PFX_FLAG_CS);
case 0x36: return KiCallVdmPrefixHandler(PFX_FLAG_SS);
case 0x3E: return KiCallVdmPrefixHandler(PFX_FLAG_DS);
case 0x64: return KiCallVdmPrefixHandler(PFX_FLAG_FS);
case 0x65: return KiCallVdmPrefixHandler(PFX_FLAG_GS);
case 0x66: return KiCallVdmPrefixHandler(PFX_FLAG_OPER32);
case 0x67: return KiCallVdmPrefixHandler(PFX_FLAG_ADDR32);
case 0xF0: return KiCallVdmPrefixHandler(PFX_FLAG_LOCK);
case 0xF2: return KiCallVdmPrefixHandler(PFX_FLAG_REPNE);
case 0xF3: return KiCallVdmPrefixHandler(PFX_FLAG_REP);
case 0x6C: return KiCallVdmHandler(INSB);
case 0x6D: return KiCallVdmHandler(INSW);
case 0x6E: return KiCallVdmHandler(OUTSB);
case 0x6F: return KiCallVdmHandler(OUTSW);
case 0x98: return KiCallVdmHandler(NPX);
case 0xD8: return KiCallVdmHandler(NPX);
case 0xD9: return KiCallVdmHandler(NPX);
case 0xDA: return KiCallVdmHandler(NPX);
case 0xDB: return KiCallVdmHandler(NPX);
case 0xDC: return KiCallVdmHandler(NPX);
case 0xDD: return KiCallVdmHandler(NPX);
case 0xDE: return KiCallVdmHandler(NPX);
case 0xDF: return KiCallVdmHandler(NPX);
case 0x9C: return KiCallVdmHandler(PUSHF);
case 0x9D: return KiCallVdmHandler(POPF);
case 0xCD: return KiCallVdmHandler(INTnn);
case 0xCE: return KiCallVdmHandler(INTO);
case 0xCF: return KiCallVdmHandler(IRET);
case 0xE4: return KiCallVdmHandler(INBimm);
case 0xE5: return KiCallVdmHandler(INWimm);
case 0xE6: return KiCallVdmHandler(OUTBimm);
case 0xE7: return KiCallVdmHandler(OUTWimm);
case 0xEC: return KiCallVdmHandler(INB);
case 0xED: return KiCallVdmHandler(INW);
case 0xEE: return KiCallVdmHandler(OUTB);
case 0xEF: return KiCallVdmHandler(OUTW);
case 0xF4: return KiCallVdmHandler(HLT);
case 0xFA: return KiCallVdmHandler(CLI);
case 0xFB: return KiCallVdmHandler(STI);
default:
DPRINT1("Unhandled instruction: 0x%02x.\n", *(PUCHAR)Eip);
return KiCallVdmHandler(INV);
}
}
/* PREFIX HANDLER *************************************************************/
BOOLEAN
FASTCALL
KiVdmOpcodePrefix(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
/* Increase instruction size */
Flags++;
/* Handle the next opcode */
return KiVdmHandleOpcode(TrapFrame, Flags);
}
/* TRAP HANDLER ***************************************************************/
BOOLEAN
FASTCALL
Ki386HandleOpcodeV86(IN PKTRAP_FRAME TrapFrame)
{
/* Clean up */
TrapFrame->Eip &= 0xFFFF;
TrapFrame->HardwareEsp &= 0xFFFF;
/* We start with only 1 byte per instruction */
return KiVdmHandleOpcode(TrapFrame, 1);
}
ULONG_PTR
FASTCALL
KiExitV86Mode(IN PKTRAP_FRAME TrapFrame)
{
PKPCR Pcr = KeGetPcr();
ULONG_PTR StackFrameUnaligned;
PKV8086_STACK_FRAME StackFrame;
PKTHREAD Thread;
PKV86_FRAME V86Frame;
PFX_SAVE_AREA NpxFrame;
/* Get the stack frame back */
StackFrameUnaligned = TrapFrame->Esi;
StackFrame = (PKV8086_STACK_FRAME)(ROUND_UP(StackFrameUnaligned - 4, 16) + 4);
V86Frame = &StackFrame->V86Frame;
NpxFrame = &StackFrame->NpxArea;
ASSERT((ULONG_PTR)NpxFrame % 16 == 0);
/* Copy the FPU frame back */
Thread = KeGetCurrentThread();
RtlCopyMemory(KiGetThreadNpxArea(Thread), NpxFrame, sizeof(FX_SAVE_AREA));
/* Set initial stack back */
Thread->InitialStack = (PVOID)((ULONG_PTR)V86Frame->ThreadStack + sizeof(FX_SAVE_AREA));
/* Set ESP0 back in the KTSS */
Pcr->TSS->Esp0 = (ULONG_PTR)Thread->InitialStack;
Pcr->TSS->Esp0 -= sizeof(KTRAP_FRAME) - FIELD_OFFSET(KTRAP_FRAME, V86Es);
Pcr->TSS->Esp0 -= NPX_FRAME_LENGTH;
/* Restore TEB addresses */
Thread->Teb = V86Frame->ThreadTeb;
KiSetTebBase(KeGetPcr(), V86Frame->ThreadTeb);
/* Enable interrupts and return a pointer to the trap frame */
_enable();
return StackFrameUnaligned;
}
VOID
FASTCALL
KiEnterV86Mode(IN ULONG_PTR StackFrameUnaligned)
{
PKTHREAD Thread;
PKV8086_STACK_FRAME StackFrame = (PKV8086_STACK_FRAME)(ROUND_UP(StackFrameUnaligned - 4, 16) + 4);
PKTRAP_FRAME TrapFrame = &StackFrame->TrapFrame;
PKV86_FRAME V86Frame = &StackFrame->V86Frame;
PFX_SAVE_AREA NpxFrame = &StackFrame->NpxArea;
ASSERT((ULONG_PTR)NpxFrame % 16 == 0);
/* Build fake user-mode trap frame */
TrapFrame->SegCs = KGDT_R0_CODE | RPL_MASK;
TrapFrame->SegEs = TrapFrame->SegDs = TrapFrame->SegFs = TrapFrame->SegGs = 0;
TrapFrame->ErrCode = 0;
/* Get the current thread's initial stack */
Thread = KeGetCurrentThread();
V86Frame->ThreadStack = KiGetThreadNpxArea(Thread);
/* Save TEB addresses */
V86Frame->ThreadTeb = Thread->Teb;
V86Frame->PcrTeb = KeGetPcr()->NtTib.Self;
/* Save return EIP */
TrapFrame->Eip = (ULONG_PTR)Ki386BiosCallReturnAddress;
/* Save our stack (after the frames) */
TrapFrame->Esi = StackFrameUnaligned;
TrapFrame->Edi = (ULONG_PTR)_AddressOfReturnAddress() + 4;
/* Sanitize EFlags and enable interrupts */
TrapFrame->EFlags = __readeflags() & 0x60DD7;
TrapFrame->EFlags |= EFLAGS_INTERRUPT_MASK;
/* Fill out the rest of the frame */
TrapFrame->HardwareSegSs = KGDT_R3_DATA | RPL_MASK;
TrapFrame->HardwareEsp = 0x11FFE;
TrapFrame->ExceptionList = EXCEPTION_CHAIN_END;
TrapFrame->Dr7 = 0;
/* Set some debug fields if trap debugging is enabled */
KiFillTrapFrameDebug(TrapFrame);
/* Disable interrupts */
_disable();
/* Copy the thread's NPX frame */
RtlCopyMemory(NpxFrame, V86Frame->ThreadStack, sizeof(FX_SAVE_AREA));
/* Clear exception list */
KeGetPcr()->NtTib.ExceptionList = EXCEPTION_CHAIN_END;
/* Set new ESP0 */
KeGetPcr()->TSS->Esp0 = (ULONG_PTR)&TrapFrame->V86Es;
/* Set new initial stack */
Thread->InitialStack = V86Frame;
/* Set VDM TEB */
Thread->Teb = (PTEB)TRAMPOLINE_TEB;
KiSetTebBase(KeGetPcr(), (PVOID)TRAMPOLINE_TEB);
/* Enable interrupts */
_enable();
/* Start VDM execution */
NtVdmControl(VdmStartExecution, NULL);
/* Exit to V86 mode */
KiEoiHelper(TrapFrame);
}
VOID
NTAPI
Ke386SetIOPL(VOID)
{
PKTHREAD Thread = KeGetCurrentThread();
PKPROCESS Process = Thread->ApcState.Process;
PKTRAP_FRAME TrapFrame;
CONTEXT Context;
/* IOPL was enabled for this process/thread */
Process->Iopl = TRUE;
Thread->Iopl = TRUE;
/* Get the trap frame on exit */
TrapFrame = KeGetTrapFrame(Thread);
/* Convert to a context */
Context.ContextFlags = CONTEXT_CONTROL;
KeTrapFrameToContext(TrapFrame, NULL, &Context);
/* Set the IOPL flag */
Context.EFlags |= EFLAGS_IOPL;
/* Convert back to a trap frame */
KeContextToTrapFrame(&Context, NULL, TrapFrame, CONTEXT_CONTROL, UserMode);
}
/* PUBLIC FUNCTIONS ***********************************************************/
/*
* @implemented
*/
NTSTATUS
NTAPI
Ke386CallBios(IN ULONG Int,
OUT PCONTEXT Context)
{
PUCHAR Trampoline = (PUCHAR)TRAMPOLINE_BASE;
PTEB VdmTeb = (PTEB)TRAMPOLINE_TEB;
PVDM_TIB VdmTib = (PVDM_TIB)TRAMPOLINE_TIB;
ULONG ContextSize = FIELD_OFFSET(CONTEXT, ExtendedRegisters);
PKTHREAD Thread = KeGetCurrentThread();
PKTSS Tss = KeGetPcr()->TSS;
PKPROCESS Process = Thread->ApcState.Process;
PVDM_PROCESS_OBJECTS VdmProcessObjects;
USHORT OldOffset, OldBase;
/* Start with a clean TEB */
RtlZeroMemory(VdmTeb, sizeof(TEB));
/* Write the interrupt and bop */
*Trampoline++ = 0xCD;
*Trampoline++ = (UCHAR)Int;
*(PULONG)Trampoline = TRAMPOLINE_BOP;
/* Setup the VDM TEB and TIB */
VdmTeb->Vdm = (PVOID)TRAMPOLINE_TIB;
RtlZeroMemory(VdmTib, sizeof(VDM_TIB));
VdmTib->Size = sizeof(VDM_TIB);
/* Set a blank VDM state */
*VdmState = 0;
/* Copy the context */
RtlCopyMemory(&VdmTib->VdmContext, Context, ContextSize);
VdmTib->VdmContext.SegCs = (ULONG_PTR)Trampoline >> 4;
VdmTib->VdmContext.SegSs = (ULONG_PTR)Trampoline >> 4;
VdmTib->VdmContext.Eip = 0;
VdmTib->VdmContext.Esp = 2 * PAGE_SIZE - sizeof(ULONG_PTR);
VdmTib->VdmContext.EFlags |= EFLAGS_V86_MASK | EFLAGS_INTERRUPT_MASK;
VdmTib->VdmContext.ContextFlags = CONTEXT_FULL;
/* This can't be a real VDM process */
ASSERT(PsGetCurrentProcess()->VdmObjects == NULL);
/* Allocate VDM structure */
VdmProcessObjects = ExAllocatePoolWithTag(NonPagedPool,
sizeof(VDM_PROCESS_OBJECTS),
' eK');
if (!VdmProcessObjects) return STATUS_NO_MEMORY;
/* Set it up */
RtlZeroMemory(VdmProcessObjects, sizeof(VDM_PROCESS_OBJECTS));
VdmProcessObjects->VdmTib = VdmTib;
PsGetCurrentProcess()->VdmObjects = VdmProcessObjects;
/* Set the system affinity for the current thread */
KeSetSystemAffinityThread(1);
/* Make sure there's space for two IOPMs, then copy & clear the current */
ASSERT(((PKIPCR)KeGetPcr())->GDT[KGDT_TSS / 8].LimitLow >=
(0x2000 + IOPM_OFFSET - 1));
RtlCopyMemory(Ki386IopmSaveArea, &Tss->IoMaps[0].IoMap, IOPM_SIZE);
RtlZeroMemory(&Tss->IoMaps[0].IoMap, IOPM_SIZE);
/* Save the old offset and base, and set the new ones */
OldOffset = Process->IopmOffset;
OldBase = Tss->IoMapBase;
Process->IopmOffset = (USHORT)IOPM_OFFSET;
Tss->IoMapBase = (USHORT)IOPM_OFFSET;
/* Switch stacks and work the magic */
Ki386SetupAndExitToV86Mode(VdmTeb);
/* Restore IOPM */
RtlCopyMemory(&Tss->IoMaps[0].IoMap, Ki386IopmSaveArea, IOPM_SIZE);
Process->IopmOffset = OldOffset;
Tss->IoMapBase = OldBase;
/* Restore affinity */
KeRevertToUserAffinityThread();
/* Restore context */
RtlCopyMemory(Context, &VdmTib->VdmContext, ContextSize);
Context->ContextFlags = CONTEXT_FULL;
/* Free VDM objects */
ExFreePoolWithTag(PsGetCurrentProcess()->VdmObjects, ' eK');
PsGetCurrentProcess()->VdmObjects = NULL;
/* Return status */
return STATUS_SUCCESS;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
Ke386IoSetAccessProcess(IN PKPROCESS Process,
IN ULONG MapNumber)
{
USHORT MapOffset;
PKPRCB Prcb;
KAFFINITY TargetProcessors;
if(MapNumber > IOPM_COUNT)
return FALSE;
MapOffset = KiComputeIopmOffset(MapNumber);
Process->IopmOffset = MapOffset;
TargetProcessors = Process->ActiveProcessors;
Prcb = KeGetCurrentPrcb();
if (TargetProcessors & Prcb->SetMember)
KeGetPcr()->TSS->IoMapBase = MapOffset;
return TRUE;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
Ke386SetIoAccessMap(IN ULONG MapNumber,
IN PKIO_ACCESS_MAP IopmBuffer)
{
PKPROCESS CurrentProcess;
PKPRCB Prcb;
PVOID pt;
if ((MapNumber > IOPM_COUNT) || (MapNumber == IO_ACCESS_MAP_NONE))
return FALSE;
Prcb = KeGetCurrentPrcb();
// Copy the IOP map and load the map for the current process.
pt = &(KeGetPcr()->TSS->IoMaps[MapNumber-1].IoMap);
RtlMoveMemory(pt, (PVOID)IopmBuffer, IOPM_SIZE);
CurrentProcess = Prcb->CurrentThread->ApcState.Process;
KeGetPcr()->TSS->IoMapBase = CurrentProcess->IopmOffset;
return TRUE;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
Ke386QueryIoAccessMap(IN ULONG MapNumber,
IN PKIO_ACCESS_MAP IopmBuffer)
{
ULONG i;
PVOID Map;
PUCHAR p;
if (MapNumber > IOPM_COUNT)
return FALSE;
if (MapNumber == IO_ACCESS_MAP_NONE)
{
// no access, simply return a map of all 1s
p = (PUCHAR)IopmBuffer;
for (i = 0; i < IOPM_SIZE; i++) {
p[i] = (UCHAR)-1;
}
}
else
{
// copy the bits
Map = (PVOID)&(KeGetPcr()->TSS->IoMaps[MapNumber-1].IoMap);
RtlMoveMemory((PVOID)IopmBuffer, Map, IOPM_SIZE);
}
return TRUE;
}
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