/*++
Copyright (c) 1990 Microsoft Corporation
Module Name:
context.c
Abstract:
This module implements user-mode callable context manipulation routines.
Author:
Mark Lucovsky (markl) 20-Jun-1989
Revision History:
David N. Cutler (davec) 18-Apr-1990
Revise for MIPS environment.
Thomas Van Baak (tvb) 11-May-1992
Adapted for Alpha AXP.
--*/
#include <nt.h>
#include <ntrtl.h>
#include <alphaops.h>
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:
Process - Supplies an open handle to the target process. This argument
is ignored by this function.
Context - Supplies a pointer to a context record that is to be initialized.
Parameter - Supplies an initial value for register A0.
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.
--*/
{
//
// Check for proper initial stack and PC alignment.
//
if (((ULONG)InitialSp & 0xF) != 0) {
RtlRaiseStatus(STATUS_BAD_INITIAL_STACK);
}
if (((ULONG)InitialPc & 0x3) != 0) {
RtlRaiseStatus(STATUS_BAD_INITIAL_PC);
}
//
// Initialize the integer registers to contain their register number
// (they must be initialized and using register numbers instead of 0
// can be useful for debugging). Integer registers a0, ra, gp, and sp
// are set later.
//
Context->IntV0 = 0;
Context->IntT0 = 1;
Context->IntT1 = 2;
Context->IntT2 = 3;
Context->IntT3 = 4;
Context->IntT4 = 5;
Context->IntT5 = 6;
Context->IntT6 = 7;
Context->IntT7 = 8;
Context->IntS0 = 9;
Context->IntS1 = 10;
Context->IntS2 = 11;
Context->IntS3 = 12;
Context->IntS4 = 13;
Context->IntS5 = 14;
Context->IntFp = 15;
Context->IntA1 = 17;
Context->IntA2 = 18;
Context->IntA3 = 19;
Context->IntA4 = 20;
Context->IntA5 = 21;
Context->IntT8 = 22;
Context->IntT9 = 23;
Context->IntT10 = 24;
Context->IntT11 = 25;
Context->IntT12 = 27;
Context->IntAt = 28;
//
// Initialize the floating point registers to contain the integer value
// of their register number (they must be initialized and using register
// numbers instead of 0 can be useful for debugging).
//
Context->FltF0 = 0;
Context->FltF1 = 1;
Context->FltF2 = 2;
Context->FltF3 = 3;
Context->FltF4 = 4;
Context->FltF5 = 5;
Context->FltF6 = 6;
Context->FltF7 = 7;
Context->FltF8 = 8;
Context->FltF9 = 9;
Context->FltF10 = 10;
Context->FltF11 = 11;
Context->FltF12 = 12;
Context->FltF13 = 13;
Context->FltF14 = 14;
Context->FltF15 = 15;
Context->FltF16 = 16;
Context->FltF17 = 17;
Context->FltF18 = 18;
Context->FltF19 = 19;
Context->FltF20 = 20;
Context->FltF21 = 21;
Context->FltF22 = 22;
Context->FltF23 = 23;
Context->FltF24 = 24;
Context->FltF25 = 25;
Context->FltF26 = 26;
Context->FltF27 = 27;
Context->FltF28 = 28;
Context->FltF29 = 29;
Context->FltF30 = 30;
Context->FltF31 = 0;
//
// Initialize the control registers.
//
// Gp: will be set in LdrpInitialize at thread startup.
// Ra: some debuggers compare for 1 as a top-of-stack indication.
//
// N.B. ULONG becomes canonical longword with (ULONGLONG)(LONG) cast.
//
Context->IntGp = 0;
Context->IntSp = (ULONGLONG)(LONG)InitialSp;
Context->IntRa = 1;
Context->Fir = (ULONGLONG)(LONG)InitialPc;
//
// Set default Alpha floating point control register values.
//
Context->Fpcr = (ULONGLONG)0;
((PFPCR)(&Context->Fpcr))->DynamicRoundingMode = ROUND_TO_NEAREST;
Context->SoftFpcr = (ULONGLONG)0;
Context->Psr = 0;
Context->ContextFlags = CONTEXT_FULL;
//
// Set the initial context of the thread in a machine specific way.
//
Context->IntA0 = (ULONGLONG)(LONG)Parameter;
}
NTSTATUS
RtlRemoteCall(
HANDLE Process,
HANDLE Thread,
PVOID CallSite,
ULONG ArgumentCount,
PULONG Arguments,
BOOLEAN PassContext,
BOOLEAN AlreadySuspended
)
/*++
Routine Description:
This function calls a procedure in another thread/process by using
NtGetContext and NtSetContext. Parameters are passed to the target
procedure via the nonvolatile registers (s0 - s5).
Arguments:
Process - Supplies an open handle to the target process.
Thread - Supplies an open handle to the target thread within the target
process.
CallSite - Supplies the address of the procedure to call in the target
process.
ArgumentCount - Supplies the number of 32 bit parameters to pass to the
target procedure.
Arguments - Supplies a pointer to the array of 32 bit parameters to pass.
PassContext - Supplies a boolean value that determines whether a parameter
is to be passed that points to a context record. This parameter is
ignored on MIPS and Alpha hosts.
AlreadySuspended - Supplies a boolean value that determines whether the
target thread is already in a suspended or waiting state.
Return Value:
Status - Status value.
--*/
{
NTSTATUS Status;
CONTEXT Context;
ULONG Index;
ULONGLONG NewSp;
if ((ArgumentCount > 6) ||
(PassContext && (ArgumentCount > 5))) {
return(STATUS_INVALID_PARAMETER);
}
//
// If necessary, suspend the target thread before getting the thread's
// current state.
//
if (AlreadySuspended == FALSE) {
Status = NtSuspendThread(Thread, NULL);
if (NT_SUCCESS(Status) == FALSE) {
return(Status);
}
}
//
// Get the current state 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 non-volatile registers
// s0 - s5. The context record is passed on the stack of the target thread.
//
NewSp = Context.IntSp - sizeof(CONTEXT);
Status = NtWriteVirtualMemory(Process, (PVOID)NewSp, &Context,
sizeof(CONTEXT), NULL);
if (NT_SUCCESS(Status) == FALSE) {
if (AlreadySuspended == FALSE) {
NtResumeThread(Thread, NULL);
}
return(Status);
}
//
// N.B. Each ULONG argument is converted to canonical form with the
// (ULONGLONG)(LONG) cast as required by the calling standard.
//
// N.B. Given the PULONG Arguments prototype, this function cannot pass
// quadword arguments (including structures such as LARGE_INTEGER).
//
Context.IntSp = NewSp;
if (PassContext) {
Context.IntS0 = NewSp;
for (Index = 0; Index < ArgumentCount; Index += 1) {
(&Context.IntS1)[Index] = (ULONGLONG)(LONG)Arguments[Index];
}
} else {
for (Index = 0; Index < ArgumentCount; Index += 1) {
(&Context.IntS0)[Index] = (ULONGLONG)(LONG)Arguments[Index];
}
}
//
// Set the address of the target code into FIR and set the thread context
// to cause the target procedure to be executed.
//
// N.B. The PVOID CallSite is stored as a canonical longword in order
// for Fir to be a valid 64-bit address.
//
Context.Fir = (ULONGLONG)(LONG)CallSite;
Status = NtSetContextThread(Thread, &Context);
if (AlreadySuspended == FALSE) {
NtResumeThread(Thread, NULL);
}
return(Status);
}
