/*++
Module Name:
context.c
Abstract:
This module implements user-mode callable context manipulation routines.
The interfaces exported from this module are portable, but they must
be re-implemented for each architecture.
Author:
Revision History:
Ported to the IA64
27-Feb-1996 Revised to pass arguments to target thread by injecting
arguments into the backing store.
--*/
#include "ntrtlp.h"
#include "kxia64.h"
#if defined(ALLOC_PRAGMA) && defined(NTOS_KERNEL_RUNTIME)
#pragma alloc_text(PAGE,RtlInitializeContext)
#pragma alloc_text(PAGE,RtlRemoteCall)
#endif
VOID
RtlInitializeContext(
IN HANDLE Process,
OUT PCONTEXT Context,
IN PVOID Parameter OPTIONAL,
IN PVOID InitialPc OPTIONAL,
IN PVOID InitialSp OPTIONAL
)
/*++
Routine Description:
This function initializes a context structure so that it can
be used in a subsequent call to NtCreateThread.
Arguments:
Context - Supplies a context buffer to be initialized by this routine.
InitialPc - Supplies an initial program counter value.
InitialSp - Supplies an initial stack pointer value.
Return Value:
Raises STATUS_BAD_INITIAL_STACK if the value of InitialSp is not properly
aligned.
Raises STATUS_BAD_INITIAL_PC if the value of InitialPc is not properly
aligned.
--*/
{
ULONGLONG Argument;
ULONG_PTR Wow64Info;
NTSTATUS Status;
RTL_PAGED_CODE();
//
// Check for proper initial stack (0 mod 16).
//
if (((ULONG_PTR)InitialSp & 0xf) != 0) {
RtlRaiseStatus(STATUS_BAD_INITIAL_STACK);
}
//
// Check for proper plabel address alignment.
// Assumes InitialPc points to a plabel that must be 8-byte aligned.
//
if (((ULONG_PTR)InitialPc & 0x7) != 0) {
//
// Misaligned, See if we are running in a Wow64 process
//
Status = ZwQueryInformationProcess(Process,
ProcessWow64Information,
&Wow64Info,
sizeof(Wow64Info),
NULL);
if (NT_SUCCESS(Status) && (Wow64Info == 0))
{
//
// Native IA64 process must not be misaligned.
//
RtlRaiseStatus(STATUS_BAD_INITIAL_PC);
}
}
//
// Initialize the integer and floating registers to contain zeroes.
//
RtlZeroMemory(Context, sizeof(CONTEXT));
//
// Setup integer and control context.
//
Context->ContextFlags = CONTEXT_INTEGER | CONTEXT_CONTROL;
Context->RsBSPSTORE = Context->IntSp = (ULONG_PTR)InitialSp;
Context->IntSp -= STACK_SCRATCH_AREA;
//
// InitialPc is the module entry point which is a function pointer
// in IA64. StIIP and IntGp are initiailized with actual IP and GP
// from the plabel in LdrInitializeThunk after the loader runs.
//
Context->IntS1 = Context->IntS0 = Context->StIIP = (ULONG_PTR)InitialPc;
Context->IntGp = 0;
//
// Setup FPSR, PSR, and DCR
// N.B. Values to be determined.
//
Context->StFPSR = USER_FPSR_INITIAL;
Context->StIPSR = USER_PSR_INITIAL;
Context->ApDCR = USER_DCR_INITIAL;
//
// Set the initial context of the thread in a machine specific way.
// ie, pass the initial parameter to the RSE by saving it at the
// bottom of the backing store.
//
// Setup Frame Marker after RFI
// And other RSE states.
//
Argument = (ULONGLONG)Parameter;
ZwWriteVirtualMemory(Process,
(PVOID)((ULONG_PTR)Context->RsBSPSTORE),
(PVOID)&Argument,
sizeof(Argument),
NULL);
//
// N.b. The IFS must be reinitialized in LdrInitializeThunk
//
Context->StIFS = 0x8000000000000081ULL; // Valid, 1 local register, 0 output register
Context->RsBSP = Context->RsBSPSTORE;
Context->RsRSC = USER_RSC_INITIAL;
Context->ApUNAT = 0xFFFFFFFFFFFFFFFF;
}
NTSTATUS
RtlRemoteCall(
HANDLE Process,
HANDLE Thread,
PVOID CallSite,
ULONG ArgumentCount,
PULONG_PTR Arguments,
BOOLEAN PassContext,
BOOLEAN AlreadySuspended
)
/*++
Routine Description:
This function calls a procedure in another thread/process, using
NtGetContext and NtSetContext. Parameters are passed to the
target procedure via its stack.
Arguments:
Process - Handle of the target process
Thread - Handle of the target thread within that process
CallSite - Address of the procedure to call in the target process.
ArgumentCount - Number of parameters to pass to the target
procedure.
Arguments - Pointer to the array of parameters to pass.
PassContext - TRUE if an additional parameter is to be passed that
points to a context record.
AlreadySuspended - TRUE if the target thread is already in a suspended
or waiting state.
Return Value:
Status - Status value
--*/
{
NTSTATUS Status;
CONTEXT Context;
ULONG_PTR ContextAddress;
ULONG_PTR NewSp;
ULONG_PTR NewBsp;
ULONGLONG ArgumentsCopy[9];
PVOID ptr;
ULONG ShiftCount;
SHORT RNatSaveIndex, TotalFrameSize, Temp;
BOOLEAN RnatSaved = FALSE;
ULONG Count = 0;
RTL_PAGED_CODE();
if ((ArgumentCount > 8) || (PassContext && (ArgumentCount > 7))) {
return STATUS_INVALID_PARAMETER;
}
//
// If necessary, suspend the guy before with we mess with his stack.
//
if (AlreadySuspended == FALSE) {
Status = NtSuspendThread(Thread, NULL);
if (NT_SUCCESS(Status) == FALSE) {
return(Status);
}
}
//
// Get the context record of the target thread.
//
Context.ContextFlags = CONTEXT_FULL;
Status = NtGetContextThread(Thread, &Context);
if (NT_SUCCESS(Status) == FALSE) {
if (AlreadySuspended == FALSE) {
NtResumeThread(Thread, NULL);
}
return(Status);
}
if (AlreadySuspended) {
Context.IntV0 = STATUS_ALERTED;
}
//
// Pass the parameters to the other thread via the backing store (r32-r39).
// The context record is passed on the stack of the target thread.
// N.B. Align the context record address, stack pointer, and allocate
// stack scratch area.
//
ContextAddress = (((ULONG_PTR)Context.IntSp + 0xf) & ~0xfi64) - sizeof(CONTEXT);
NewSp = ContextAddress - STACK_SCRATCH_AREA;
Status = NtWriteVirtualMemory(Process, (PVOID)ContextAddress, &Context,
sizeof(CONTEXT), NULL);
if (NT_SUCCESS(Status) == FALSE) {
if (AlreadySuspended == FALSE) {
NtResumeThread(Thread, NULL);
}
return(Status);
}
RtlZeroMemory((PVOID)ArgumentsCopy, sizeof(ArgumentsCopy));
TotalFrameSize = (SHORT)(Context.StIFS & PFS_SIZE_MASK);
RNatSaveIndex = (SHORT)((Context.RsBSP >> 3) & NAT_BITS_PER_RNAT_REG);
Temp = RNatSaveIndex + TotalFrameSize - NAT_BITS_PER_RNAT_REG;
while (Temp >= 0) {
TotalFrameSize++;
Temp -= NAT_BITS_PER_RNAT_REG;
}
NewBsp = Context.RsBSP + TotalFrameSize * sizeof(ULONGLONG);
Context.RsBSP = NewBsp;
if (PassContext) {
ShiftCount = (ULONG) (NewBsp & 0x1F8) >> 3;
Context.RsRNAT &= ~(0x1i64 << ShiftCount);
ArgumentsCopy[Count++] = ContextAddress;
NewBsp += sizeof(ULONGLONG);
}
for (; ArgumentCount != 0 ; ArgumentCount--) {
if ((NewBsp & 0x1F8) == 0x1F8) {
ArgumentsCopy[Count++] = Context.RsRNAT;
Context.RsRNAT = -1i64;
NewBsp += sizeof(ULONGLONG);
}
ShiftCount = (ULONG)(NewBsp & 0x1F8) >> 3;
Context.RsRNAT &= ~(0x1i64 << ShiftCount);
ArgumentsCopy[Count++] = (ULONGLONG)(*Arguments++);
NewBsp += sizeof(ULONGLONG);
}
if ((NewBsp & 0x1F8) == 0x1F8) {
ArgumentsCopy[Count++] = Context.RsRNAT;
Context.RsRNAT = -1i64;
NewBsp += sizeof(ULONGLONG);
}
//
// Copy the arguments onto the target backing store.
//
if (Count) {
Status = NtWriteVirtualMemory(Process,
(PVOID)Context.RsBSP,
ArgumentsCopy,
Count * sizeof(ULONGLONG),
NULL
);
if (NT_SUCCESS(Status) == FALSE) {
if (AlreadySuspended == FALSE) {
NtResumeThread(Thread, NULL);
}
return(Status);
}
}
//
// set up RSE
//
Context.RsRSC = (RSC_MODE_LY<<RSC_MODE)
| (RSC_BE_LITTLE<<RSC_BE)
| (0x3<<RSC_PL);
Count = ArgumentCount + (PassContext ? 1 : 0);
//
// Inject all arguments as local stack registers in the target RSE frame
//
Context.StIFS = (0x3i64 << 62) | Count | (Count << PFS_SIZE_SHIFT);
//
// Set the address of the target code into IIP, the new target stack
// into sp, setup ap, and reload context to make it happen.
//
Context.IntSp = (ULONG_PTR)NewSp;
//
// Set IP to the target call site PLABEL and GP to zero. IIP and GP
// will be computed inside NtSetContextThread.
//
Context.StIIP = (ULONGLONG)CallSite;
Context.IntGp = 0;
//
// sanitize the floating pointer status register
//
SANITIZE_FSR(Context.StFPSR, UserMode);
Status = NtSetContextThread(Thread, &Context);
if (!AlreadySuspended) {
NtResumeThread(Thread, NULL);
}
return( Status );
}