From 0e21c6f3fd2bdf933fd1d98596e04849adf4185b Mon Sep 17 00:00:00 2001
From: Serge Gautherie <32623169+SergeGautherie@users.noreply.github.com>
Date: Tue, 15 Apr 2025 08:04:53 +0200
Subject: [PATCH] [NTOS:KD] Accept some packet types without KDBG (#7892)

When KDBG isn't included in the kernel (Release build), the fall-back
KdSend/ReceivePacket() routines are invoked by KD64. A minimal handling
of the basic packets needs to be done:
PACKET_TYPE_KD_STATE_CHANGE32/64 for KdSendPacket(),
and PACKET_TYPE_KD_POLL_BREAKIN, PACKET_TYPE_KD_STATE_MANIPULATE
for KdReceivePacket().

Addendum to commit 2046a17ef4
CORE-20107
---
 ntoskrnl/kd/kdio.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/ntoskrnl/kd/kdio.c b/ntoskrnl/kd/kdio.c
index cfaa0d46875..36f28d00a73 100644
--- a/ntoskrnl/kd/kdio.c
+++ b/ntoskrnl/kd/kdio.c
@@ -609,6 +609,14 @@ KdSendPacket(
 
     if (PacketType != PACKET_TYPE_KD_DEBUG_IO)
     {
+#ifndef KDBG
+        if (PacketType == PACKET_TYPE_KD_STATE_CHANGE64)
+        {
+            // KdIoPrintf("%s: PacketType %d is ignored without KDBG\n", __FUNCTION__, PacketType);
+            return;
+        }
+#endif
+
         KdIoPrintf("%s: PacketType %d is UNIMPLEMENTED\n", __FUNCTION__, PacketType);
         return;
     }
@@ -652,8 +660,29 @@ KdReceivePacket(
     CHAR MessageBuffer[512];
 #endif
 
+#ifndef KDBG
+    // Polling happens regularly, so check it first.
+    if (PacketType == PACKET_TYPE_KD_POLL_BREAKIN)
+    {
+        // KdIoPrintf("%s: PacketType %d is refused without KDBG\n", __FUNCTION__, PacketType);
+        return KdPacketTimedOut;
+    }
+#endif
+
     if (PacketType != PACKET_TYPE_KD_DEBUG_IO)
     {
+#ifndef KDBG
+        if (PacketType == PACKET_TYPE_KD_STATE_MANIPULATE)
+        {
+            PDBGKD_MANIPULATE_STATE64 ManipulateState = (PDBGKD_MANIPULATE_STATE64)MessageHeader->Buffer;
+
+            // KdIoPrintf("%s: PacketType %d is ignored without KDBG\n", __FUNCTION__, PacketType);
+            ManipulateState->ApiNumber = DbgKdContinueApi;
+            ManipulateState->u.Continue.ContinueStatus = STATUS_SUCCESS;
+            return KdPacketReceived;
+        }
+#endif
+
         KdIoPrintf("%s: PacketType %d is UNIMPLEMENTED\n", __FUNCTION__, PacketType);
         return KdPacketTimedOut;
     }