udlist.c

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/*
 * Copyright (c) 2020 Bitdefender
 * SPDX-License-Identifier: Apache-2.0
 */
#include "udlist.h"
#include "guests.h"


LIST_HEAD gListPendingUD = LIST_HEAD_INIT(gListPendingUD);


INTSTATUS
IntUDAddToPendingList(
    _In_ const QWORD Cr3,
    _In_ const QWORD Rip,
    _In_ const QWORD Thread,
    _Out_ INFO_UD_PENDING **CurrentPendingUD
    )
{
    INFO_UD_PENDING *infoUD;

    if (0 == Cr3)
    {
        return INT_STATUS_INVALID_PARAMETER_1;
    }

    if (0 == Rip)
    {
        return INT_STATUS_INVALID_PARAMETER_2;
    }

    if (0 == Thread)
    {
        return INT_STATUS_INVALID_PARAMETER_3;
    }

    if (NULL == CurrentPendingUD)
    {
        return INT_STATUS_INVALID_PARAMETER_4;
    }

    infoUD = HpAllocWithTag(sizeof(*infoUD), IC_TAG_UDCX);
    if (NULL == infoUD)
    {
        return INT_STATUS_INSUFFICIENT_RESOURCES;
    }

    infoUD->Cr3 = Cr3;
    infoUD->Rip = Rip;
    infoUD->Thread = Thread;

    // Add the entry to the list of pending UDs
    InsertTailList(&gListPendingUD, &infoUD->Link);

    // After #UD is injected (IntHandleEventInjection), we will remove the entry from the list and for that,
    // we need to keep this info
    *CurrentPendingUD = infoUD;

    return INT_STATUS_SUCCESS;
}


void
IntUDRemoveEntry(
    _Inout_ INFO_UD_PENDING **InfoUD
    )
{
    if (NULL != InfoUD && NULL != *InfoUD)
    {
        RemoveEntryList(&(*InfoUD)->Link);
        HpFreeAndNullWithTag(InfoUD, IC_TAG_UDCX);
    }
}


void
IntUDRemoveAllEntriesForCr3(
    _In_ const QWORD Cr3
    )
{
    list_for_each(gListPendingUD, INFO_UD_PENDING, pInfoUD)
    {
        if (Cr3 == pInfoUD->Cr3)
        {
            WARNING("[WARNING] There are still pending UDs in the list when process terminates (will remove them) "
                    "CR3: 0x%016llx RIP: 0x%016llx THREAD: 0x%016llx\n",
                    pInfoUD->Cr3, pInfoUD->Rip, pInfoUD->Thread);

            for (DWORD index = 0; index < gGuest.CpuCount; index++)
            {
                if (pInfoUD == gGuest.VcpuArray[index].CurrentUD)
                {
                    gGuest.VcpuArray[index].CurrentUD = NULL;
                }
            }

            IntUDRemoveEntry(&pInfoUD);
        }
    }
}


INFO_UD_PENDING *
IntUDGetEntry(
    _In_ const QWORD Cr3,
    _In_ const QWORD Rip,
    _In_ const QWORD Thread
    )
{
    list_for_each(gListPendingUD, INFO_UD_PENDING, pInfoUD)
    {
        if (Cr3 == pInfoUD->Cr3 && Rip == pInfoUD->Rip && Thread == pInfoUD->Thread)
        {
            TRACE("[INFO] Already an UD pending for CR3: 0x%016llx RIP: 0x%016llx THREAD: 0x%016llx\n",
                  pInfoUD->Cr3, pInfoUD->Rip, pInfoUD->Thread);

            return pInfoUD;
        }
    }

    return NULL;
}