613 lines
16 KiB
NASM
613 lines
16 KiB
NASM
|
title "Miscellaneous Exception Handling"
|
||
|
|
||
|
|
||
|
; Copyright (c) 1989 Microsoft Corporation
|
||
|
|
||
|
; Module Name:
|
||
|
|
||
|
; xcptmisc.asm
|
||
|
|
||
|
; Abstract:
|
||
|
|
||
|
; This module implements miscellaneous routines that are required to
|
||
|
; support exception handling. Functions are provided to call an exception
|
||
|
; handler for an exception, call an exception handler for unwinding, get
|
||
|
; the caller's stack pointer, get the caller's frame pointer, get the
|
||
|
; caller's floating status, get the caller's processor state, get the
|
||
|
; caller's extended processor status, and get the current stack limits.
|
||
|
|
||
|
; Author:
|
||
|
|
||
|
; David N. Cutler (davec) 14-Aug-1989
|
||
|
|
||
|
; Environment:
|
||
|
|
||
|
; Any mode.
|
||
|
|
||
|
; Revision History:
|
||
|
|
||
|
; 6 April 90 bryanwi
|
||
|
|
||
|
; 386 version created
|
||
|
|
||
|
|
||
|
.386p
|
||
|
|
||
|
.xlist
|
||
|
include ks386.inc
|
||
|
include callconv.inc ; calling convention macros
|
||
|
.list
|
||
|
|
||
|
|
||
|
; Unwind flags.
|
||
|
|
||
|
|
||
|
Unwind equ EXCEPTION_UNWINDING OR EXCEPTION_EXIT_UNWIND
|
||
|
|
||
|
_TEXT$01 SEGMENT DWORD PUBLIC 'CODE'
|
||
|
ASSUME DS:FLAT, ES:FLAT, SS:NOTHING, FS:NOTHING, GS:NOTHING
|
||
|
|
||
|
page
|
||
|
subttl "Execute Handler for Exception"
|
||
|
|
||
|
|
||
|
; EXCEPTION_DISPOSITION
|
||
|
; RtlpExecuteHandlerForException (
|
||
|
; IN PEXCEPTION_RECORD ExceptionRecord,
|
||
|
; IN PVOID EstablisherFrame,
|
||
|
; IN OUT PCONTEXT ContextRecord,
|
||
|
; IN OUT PVOID DispatcherContext,
|
||
|
; IN PEXCEPTION_ROUTINE ExceptionRoutine
|
||
|
; )
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function allocates a call frame, stores the handler address and
|
||
|
; establisher frame pointer in the frame, establishes an exception
|
||
|
; handler, and then calls the specified exception handler as an exception
|
||
|
; handler. If a nested exception occurs, then the exception handler of
|
||
|
; of this function is called and the handler address and establisher
|
||
|
; frame pointer are returned to the exception dispatcher via the dispatcher
|
||
|
; context parameter. If control is returned to this routine, then the
|
||
|
; frame is deallocated and the disposition status is returned to the
|
||
|
; exception dispatcher.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; ExceptionRecord (ebp+8) - Supplies a pointer to an exception record.
|
||
|
|
||
|
; EstablisherFrame (ebp+12) - Supplies the frame pointer of the establisher
|
||
|
; of the exception handler that is to be called.
|
||
|
|
||
|
; ContextRecord (ebp+16) - Supplies a pointer to a context record.
|
||
|
|
||
|
; DispatcherContext (ebp+20) - Supplies a pointer to the dispatcher context
|
||
|
; record.
|
||
|
|
||
|
; ExceptionRoutine (ebp+24) - supplies a pointer to the exception handler
|
||
|
; that is to be called.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; The disposition value returned by the specified exception handler is
|
||
|
; returned as the function value.
|
||
|
|
||
|
|
||
|
|
||
|
cPublicProc _RtlpExecuteHandlerForException,5
|
||
|
|
||
|
mov edx,offset FLAT:ExceptionHandler ; Set who to register
|
||
|
jmp ExecuteHandler ; jump to common code
|
||
|
|
||
|
stdENDP _RtlpExecuteHandlerForException
|
||
|
|
||
|
|
||
|
page
|
||
|
subttl "Execute Handler for Unwind"
|
||
|
|
||
|
|
||
|
; EXCEPTION_DISPOSITION
|
||
|
; RtlpExecuteHandlerForUnwind (
|
||
|
; IN PEXCEPTION_RECORD ExceptionRecord,
|
||
|
; IN PVOID EstablisherFrame,
|
||
|
; IN OUT PCONTEXT ContextRecord,
|
||
|
; IN OUT PVOID DispatcherContext,
|
||
|
; IN PEXCEPTION_ROUTINE ExceptionRoutine
|
||
|
; )
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function allocates a call frame, stores the handler address and
|
||
|
; establisher frame pointer in the frame, establishes an exception
|
||
|
; handler, and then calls the specified exception handler as an unwind
|
||
|
; handler. If a collided unwind occurs, then the exception handler of
|
||
|
; of this function is called and the handler address and establisher
|
||
|
; frame pointer are returned to the unwind dispatcher via the dispatcher
|
||
|
; context parameter. If control is returned to this routine, then the
|
||
|
; frame is deallocated and the disposition status is returned to the
|
||
|
; unwind dispatcher.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; ExceptionRecord (ebp+8) - Supplies a pointer to an exception record.
|
||
|
|
||
|
; EstablisherFrame (ebp+12) - Supplies the frame pointer of the establisher
|
||
|
; of the exception handler that is to be called.
|
||
|
|
||
|
; ContextRecord (ebp+16) - Supplies a pointer to a context record.
|
||
|
|
||
|
; DispatcherContext (ebp+20) - Supplies a pointer to the dispatcher context
|
||
|
; record.
|
||
|
|
||
|
; ExceptionRoutine (ebp+24) - supplies a pointer to the exception handler
|
||
|
; that is to be called.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; The disposition value returned by the specified exception handler is
|
||
|
; returned as the function value.
|
||
|
|
||
|
|
||
|
|
||
|
cPublicProc _RtlpExecuteHandlerForUnwind ,5
|
||
|
|
||
|
mov edx,offset FLAT:UnwindHandler
|
||
|
|
||
|
;; N.B. - FALL into ExecuteHandler
|
||
|
|
||
|
stdENDP _RtlpExecuteHandlerForUnwind
|
||
|
|
||
|
|
||
|
|
||
|
|
||
|
; ExecuteHandler is the common tail for RtlpExecuteHandlerForException
|
||
|
; and RtlpExecuteHandlerForUnwind.
|
||
|
|
||
|
; (edx) = handler (Exception or Unwind) address
|
||
|
|
||
|
|
||
|
|
||
|
ExceptionRecord equ [ebp+8]
|
||
|
EstablisherFrame equ [ebp+12]
|
||
|
ContextRecord equ [ebp+16]
|
||
|
DispatcherContext equ [ebp+20]
|
||
|
ExceptionRoutine equ [ebp+24]
|
||
|
|
||
|
|
||
|
cPublicProc ExecuteHandler,5
|
||
|
|
||
|
push ebp
|
||
|
mov ebp,esp
|
||
|
|
||
|
push EstablisherFrame ; Save context of exception handler
|
||
|
; that we're about to call.
|
||
|
|
||
|
.errnz ErrHandler-4
|
||
|
push edx ; Set Handler address
|
||
|
|
||
|
.errnz ErrNext-0
|
||
|
push fs:PcExceptionList ; Set next pointer
|
||
|
|
||
|
|
||
|
mov fs:PcExceptionList,esp ; Link us on
|
||
|
|
||
|
; Call the specified exception handler.
|
||
|
|
||
|
push DispatcherContext
|
||
|
push ContextRecord
|
||
|
push EstablisherFrame
|
||
|
push ExceptionRecord
|
||
|
|
||
|
mov ecx,ExceptionRoutine
|
||
|
call ecx
|
||
|
mov esp,fs:PcExceptionList
|
||
|
|
||
|
; Don't clean stack here, code in front of ret will blow it off anyway
|
||
|
|
||
|
; Disposition is in eax, so all we do is deregister handler and return
|
||
|
|
||
|
.errnz ErrNext-0
|
||
|
pop fs:PcExceptionList
|
||
|
|
||
|
mov esp,ebp
|
||
|
pop ebp
|
||
|
stdRET ExecuteHandler
|
||
|
|
||
|
stdENDP ExecuteHandler
|
||
|
|
||
|
page
|
||
|
subttl "Local Exception Handler"
|
||
|
|
||
|
|
||
|
; EXCEPTION_DISPOSITION
|
||
|
; ExceptionHandler (
|
||
|
; IN PEXCEPTION_RECORD ExceptionRecord,
|
||
|
; IN PVOID EstablisherFrame,
|
||
|
; IN OUT PCONTEXT ContextRecord,
|
||
|
; IN OUT PVOID DispatcherContext
|
||
|
; )
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function is called when a nested exception occurs. Its function
|
||
|
; is to retrieve the establisher frame pointer and handler address from
|
||
|
; its establisher's call frame, store this information in the dispatcher
|
||
|
; context record, and return a disposition value of nested exception.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; ExceptionRecord (exp+4) - Supplies a pointer to an exception record.
|
||
|
|
||
|
; EstablisherFrame (esp+8) - Supplies the frame pointer of the establisher
|
||
|
; of this exception handler.
|
||
|
|
||
|
; ContextRecord (esp+12) - Supplies a pointer to a context record.
|
||
|
|
||
|
; DispatcherContext (esp+16) - Supplies a pointer to the dispatcher context
|
||
|
; record.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; A disposition value ExceptionNestedException is returned if an unwind
|
||
|
; is not in progress. Otherwise a value of ExceptionContinueSearch is
|
||
|
; returned.
|
||
|
|
||
|
|
||
|
|
||
|
stdPROC ExceptionHandler,4
|
||
|
|
||
|
mov ecx,dword ptr [esp+4] ; (ecx) -> ExceptionRecord
|
||
|
test dword ptr [ecx.ErExceptionFlags],Unwind
|
||
|
mov eax,ExceptionContinueSearch ; Assume unwind
|
||
|
jnz eh10 ; unwind, go return
|
||
|
|
||
|
|
||
|
; Unwind is not in progress - return nested exception disposition.
|
||
|
|
||
|
|
||
|
mov ecx,[esp+8] ; (ecx) -> EstablisherFrame
|
||
|
mov edx,[esp+16] ; (edx) -> DispatcherContext
|
||
|
mov eax,[ecx+8] ; (eax) -> EstablisherFrame for the
|
||
|
; handler active when we
|
||
|
; nested.
|
||
|
mov [edx],eax ; Set DispatcherContext field.
|
||
|
mov eax,ExceptionNestedException
|
||
|
|
||
|
eh10: stdRET ExceptionHandler
|
||
|
|
||
|
stdENDP ExceptionHandler
|
||
|
|
||
|
page
|
||
|
subttl "Local Unwind Handler"
|
||
|
|
||
|
|
||
|
; EXCEPTION_DISPOSITION
|
||
|
; UnwindHandler (
|
||
|
; IN PEXCEPTION_RECORD ExceptionRecord,
|
||
|
; IN PVOID EstablisherFrame,
|
||
|
; IN OUT PCONTEXT ContextRecord,
|
||
|
; IN OUT PVOID DispatcherContext
|
||
|
; )
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function is called when a collided unwind occurs. Its function
|
||
|
; is to retrieve the establisher frame pointer and handler address from
|
||
|
; its establisher's call frame, store this information in the dispatcher
|
||
|
; context record, and return a disposition value of nested unwind.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; ExceptionRecord (esp+4) - Supplies a pointer to an exception record.
|
||
|
|
||
|
; EstablisherFrame (esp+8) - Supplies the frame pointer of the establisher
|
||
|
; of this exception handler.
|
||
|
|
||
|
; ContextRecord (esp+12) - Supplies a pointer to a context record.
|
||
|
|
||
|
; DispatcherContext (esp+16) - Supplies a pointer to the dispatcher context
|
||
|
; record.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; A disposition value ExceptionCollidedUnwind is returned if an unwind is
|
||
|
; in progress. Otherwise a value of ExceptionContinueSearch is returned.
|
||
|
|
||
|
|
||
|
|
||
|
stdPROC UnwindHandler,4
|
||
|
|
||
|
mov ecx,dword ptr [esp+4] ; (ecx) -> ExceptionRecord
|
||
|
test dword ptr [ecx.ErExceptionFlags],Unwind
|
||
|
mov eax,ExceptionContinueSearch ; Assume NOT unwind
|
||
|
jz uh10 ; not unwind, go return
|
||
|
|
||
|
|
||
|
|
||
|
; Unwind is in progress - return collided unwind disposition.
|
||
|
|
||
|
|
||
|
mov ecx,[esp+8] ; (ecx) -> EstablisherFrame
|
||
|
mov edx,[esp+16] ; (edx) -> DispatcherContext
|
||
|
mov eax,[ecx+8] ; (eax) -> EstablisherFrame for the
|
||
|
; handler active when we
|
||
|
; nested.
|
||
|
mov [edx],eax ; Set DispatcherContext field.
|
||
|
mov eax,ExceptionCollidedUnwind
|
||
|
|
||
|
uh10: stdRET UnwindHandler
|
||
|
|
||
|
stdENDP UnwindHandler
|
||
|
|
||
|
page
|
||
|
subttl "Unlink Exception Registration Record & Handler"
|
||
|
|
||
|
|
||
|
; VOID
|
||
|
; RtlpUnlinkHandler(PEXCEPTION_REGISTRATION_RECORD UnlinkPointer)
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function removes the specified exception registration record
|
||
|
; (and thus the relevent handler) from the exception traversal
|
||
|
; chain.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; UnlinkPointer (esp+4) - Address of registration record to unlink.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; The caller's return address.
|
||
|
|
||
|
|
||
|
|
||
|
cPublicProc _RtlpUnlinkHandler ,1
|
||
|
|
||
|
mov ecx,dword ptr [esp+4]
|
||
|
mov ecx,[ecx.ErrNext]
|
||
|
mov fs:PcExceptionList,ecx
|
||
|
stdRET _RtlpUnlinkHandler
|
||
|
|
||
|
stdENDP _RtlpUnlinkHandler
|
||
|
|
||
|
page
|
||
|
subttl "Capture Context"
|
||
|
|
||
|
|
||
|
; VOID
|
||
|
; RtlCaptureContext (PCONTEXT ContextRecord)
|
||
|
; RtlpCaptureContext (PCONTEXT ContextRecord)
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This fucntion fills in the specified context record with the
|
||
|
; current state of the machine, except that the values of EBP
|
||
|
; and ESP are computed to be those of the caller's caller.
|
||
|
|
||
|
; N.B. This function assumes it is called from a 'C' procedure with
|
||
|
; the old ebp at [ebp], the return address at [ebp+4], and
|
||
|
; old esp = ebp + 8.
|
||
|
|
||
|
; Certain 'C' optimizations may cause this to not be true.
|
||
|
|
||
|
; N.B. This function does NOT adjust ESP to pop the arguments off
|
||
|
; the caller's stack. In other words, it provides a __cdecl ESP,
|
||
|
; NOT a __stdcall ESP. This is mainly because we can't figure
|
||
|
; out how many arguments the caller takes.
|
||
|
|
||
|
; N.B. Floating point state is NOT captured.
|
||
|
|
||
|
; RtlpCaptureContext does not capture volitales.
|
||
|
; RtlCaptureContext captures volitales.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; ContextRecord (esp+4) - Address of context record to fill in.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; The caller's return address.
|
||
|
|
||
|
|
||
|
|
||
|
cPublicProc _RtlCaptureContext ,1
|
||
|
|
||
|
push ebx
|
||
|
mov ebx,[esp+8] ; (ebx) -> ContextRecord
|
||
|
|
||
|
mov dword ptr [ebx.CsEax],eax
|
||
|
mov dword ptr [ebx.CsEcx],ecx
|
||
|
mov dword ptr [ebx.CsEdx],edx
|
||
|
mov eax, [esp]
|
||
|
mov dword ptr [ebx.CsEbx],eax
|
||
|
|
||
|
mov dword ptr [ebx.CsEsi],esi
|
||
|
mov dword ptr [ebx.CsEdi],edi
|
||
|
jmp RtlpCaptureCommon
|
||
|
stdENDP _RtlCaptureContext
|
||
|
|
||
|
cPublicProc _RtlpCaptureContext ,1
|
||
|
|
||
|
push ebx
|
||
|
mov ebx,[esp+8] ; (ebx) -> ContextRecord
|
||
|
|
||
|
mov dword ptr [ebx.CsEax],0
|
||
|
mov dword ptr [ebx.CsEcx],0
|
||
|
mov dword ptr [ebx.CsEdx],0
|
||
|
mov dword ptr [ebx.CsEbx],0
|
||
|
|
||
|
mov dword ptr [ebx.CsEsi],0
|
||
|
mov dword ptr [ebx.CsEdi],0
|
||
|
|
||
|
RtlpCaptureCommon:
|
||
|
mov [ebx.CsSegCs],cs
|
||
|
mov [ebx.CsSegDs],ds
|
||
|
mov [ebx.CsSegEs],es
|
||
|
mov [ebx.CsSegFs],fs
|
||
|
mov [ebx.CsSegGs],gs
|
||
|
mov [ebx.CsSegSs],ss
|
||
|
|
||
|
pushfd
|
||
|
pop [ebx.CsEflags]
|
||
|
|
||
|
mov eax,[ebp+4]
|
||
|
mov [ebx.CsEip],eax
|
||
|
|
||
|
mov eax,[ebp]
|
||
|
mov [ebx.CsEbp],eax
|
||
|
|
||
|
lea eax,[ebp+8]
|
||
|
mov [ebx.CsEsp],eax
|
||
|
|
||
|
pop ebx
|
||
|
stdRET _RtlpCaptureContext
|
||
|
|
||
|
stdENDP _RtlpCaptureContext
|
||
|
|
||
|
page
|
||
|
subttl "Capture Context (private)"
|
||
|
|
||
|
|
||
|
; VOID
|
||
|
; RtlCaptureContext (PCONTEXT ContextRecord)
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function is similiar too RtlpCaptureContext expect that
|
||
|
; volitales are captured as well.
|
||
|
|
||
|
; This fucntion fills in the specified context record with the
|
||
|
; current state of the machine, except that the values of EBP
|
||
|
; and ESP are computed to be those of the caller's caller.
|
||
|
|
||
|
; N.B. This function does NOT adjust ESP to pop the arguments off
|
||
|
; the caller's stack. In other words, it provides a __cdecl ESP,
|
||
|
; NOT a __stdcall ESP. This is mainly because we can't figure
|
||
|
; out how many arguments the caller takes.
|
||
|
|
||
|
; N.B. Floating point state is NOT captured.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; ContextRecord (esp+4) - Address of context record to fill in.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; The caller's return address.
|
||
|
|
||
|
|
||
|
|
||
|
|
||
|
ifndef WX86_i386
|
||
|
page
|
||
|
subttl "Get Stack Limits"
|
||
|
|
||
|
|
||
|
; VOID
|
||
|
; RtlpGetStackLimits (
|
||
|
; OUT PULONG LowLimit,
|
||
|
; OUT PULONG HighLimit
|
||
|
; )
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function returns the current stack limits based on the current
|
||
|
; processor mode.
|
||
|
|
||
|
; On the 386 we always store the stack limits in the PCR, and address
|
||
|
; both PCR and TEB the same way, so this code is mode independent.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; LowLimit (esp+4) - Supplies a pointer to a variable that is to receive
|
||
|
; the low limit of the stack.
|
||
|
|
||
|
; HighLimit (esp+8) - Supplies a pointer to a variable that is to receive
|
||
|
; the high limit of the stack.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; None.
|
||
|
|
||
|
|
||
|
|
||
|
cPublicProc _RtlpGetStackLimits ,2
|
||
|
;cPublicFpo 2,0
|
||
|
|
||
|
mov eax,fs:PcStackLimit
|
||
|
mov ecx,[esp+4]
|
||
|
mov [ecx],eax ; Save low limit
|
||
|
|
||
|
mov eax,fs:PcInitialStack
|
||
|
mov ecx,[esp+8]
|
||
|
mov [ecx],eax ; Save high limit
|
||
|
|
||
|
stdRET _RtlpGetStackLimits
|
||
|
|
||
|
stdENDP _RtlpGetStackLimits
|
||
|
|
||
|
endif
|
||
|
page
|
||
|
subttl "Get Exception Registration List Head"
|
||
|
|
||
|
|
||
|
; PVOID
|
||
|
; RtlpGetRegistrationHead()
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function returns the address of the first Exception
|
||
|
; registration record for the current context.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; None.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; The address of the first registration record.
|
||
|
|
||
|
|
||
|
|
||
|
cPublicProc _RtlpGetRegistrationHead ,0
|
||
|
;cPublicFpo 0,0
|
||
|
|
||
|
mov eax,fs:PcExceptionList
|
||
|
stdRET _RtlpGetRegistrationHead
|
||
|
|
||
|
stdENDP _RtlpGetRegistrationHead
|
||
|
|
||
|
page
|
||
|
subttl "Get Return Address"
|
||
|
|
||
|
|
||
|
; PVOID
|
||
|
; RtlpGetReturnAddress()
|
||
|
|
||
|
; Routine Description:
|
||
|
|
||
|
; This function returns the caller's return address. It assumes
|
||
|
; that a standard 'C' entry sequence has been used, be warned
|
||
|
; that certain optimizations might invalidate that assumption.
|
||
|
|
||
|
; Arguments:
|
||
|
|
||
|
; None.
|
||
|
|
||
|
; Return Value:
|
||
|
|
||
|
; The address of the first registration record.
|
||
|
|
||
|
|
||
|
|
||
|
cPublicProc _RtlpGetReturnAddress ,0
|
||
|
;cPublicFpo 0,0
|
||
|
|
||
|
mov eax,[ebp+4]
|
||
|
stdRET _RtlpGetReturnAddress
|
||
|
|
||
|
stdENDP _RtlpGetReturnAddress
|
||
|
_TEXT$01 ends
|
||
|
end
|