except.c

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/*
 * PROJECT:     ReactOS Run-Time Library
 * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
 * PURPOSE:     User-mode exception support for AMD64
 * COPYRIGHT:   Copyright 2018-2021 Timo Kreuzer <timo.kreuzer@reactos.org>
 */
 
/* INCLUDES *****************************************************************/
 
#include <rtl.h>
#define NDEBUG
#include <debug.h>
 
/* PUBLIC FUNCTIONS **********************************************************/
 
VOID
NTAPI
RtlRaiseException(IN PEXCEPTION_RECORD ExceptionRecord)
{
    CONTEXT Context;
    NTSTATUS Status = STATUS_INVALID_DISPOSITION;
 
    /* Capture the current context */
    RtlCaptureContext(&Context);
 
    /* Fix up Context.Rip for the caller */
    Context.Rip = (ULONG64)_ReturnAddress();
 
    /* Fix up Context.Rsp for the caller */
    Context.Rsp = (ULONG64)_AddressOfReturnAddress() + 8;
 
    /* Save the exception address */
    ExceptionRecord->ExceptionAddress = (PVOID)Context.Rip;
 
    /* Check if user mode debugger is active */
    if (RtlpCheckForActiveDebugger())
    {
        /* Raise an exception immediately */
        Status = ZwRaiseException(ExceptionRecord, &Context, TRUE);
    }
    else
    {
        /* Dispatch the exception and check if we should continue */
        if (!RtlDispatchException(ExceptionRecord, &Context))
        {
            /* Raise the exception */
            Status = ZwRaiseException(ExceptionRecord, &Context, FALSE);
        }
        else
        {
            /* Continue, go back to previous context */
            Status = ZwContinue(&Context, FALSE);
        }
    }
 
    /* If we returned, raise a status */
    RtlRaiseStatus(Status);
}
 
/*
* @unimplemented
*/
PVOID
NTAPI
RtlpGetExceptionAddress(VOID)
{
    UNIMPLEMENTED;
    return NULL;
}
 
BOOLEAN
NTAPI
RtlpUnwindInternal(
    _In_opt_ PVOID TargetFrame,
    _In_opt_ PVOID TargetIp,
    _In_ PEXCEPTION_RECORD ExceptionRecord,
    _In_ PVOID ReturnValue,
    _In_ PCONTEXT ContextRecord,
    _In_opt_ struct _UNWIND_HISTORY_TABLE *HistoryTable,
    _In_ ULONG Flags);
 
/*
 * @unimplemented
 */
BOOLEAN
NTAPI
RtlDispatchException(
    _In_ PEXCEPTION_RECORD ExceptionRecord,
    _In_ PCONTEXT ContextRecord)
{
    BOOLEAN Handled;
 
    /* Perform vectored exception handling for user mode */
    if (RtlCallVectoredExceptionHandlers(ExceptionRecord, ContextRecord))
    {
        /* Exception handled, now call vectored continue handlers */
        RtlCallVectoredContinueHandlers(ExceptionRecord, ContextRecord);
 
        /* Continue execution */
        return TRUE;
    }
 
    /* Call the internal unwind routine */
    Handled = RtlpUnwindInternal(NULL, // TargetFrame
                                 NULL, // TargetIp
                                 ExceptionRecord,
                                 0, // ReturnValue
                                 ContextRecord,
                                 NULL, // HistoryTable
                                 UNW_FLAG_EHANDLER);
 
    /* In user mode, call any registered vectored continue handlers */
    RtlCallVectoredContinueHandlers(ExceptionRecord, ContextRecord);
 
    return Handled;
}