[reactos] 30/30: [NTOS:EX] HACK: on livecd, disable security features in NtSystemDebugControl

[Hervé Poussineau]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=b9852e83d294f7f047943…
commit b9852e83d294f7f047943ca5eaa89e9aa24462d8
Author:     Hervé Poussineau <hpoussin(a)reactos.org>
AuthorDate: Sun Sep 22 21:43:25 2024 +0200
Commit:     Hermès Bélusca-Maïto <hermes.belusca-maito(a)reactos.org>
CommitDate: Tue Jan 28 22:00:56 2025 +0100
    [NTOS:EX] HACK: on livecd, disable security features in NtSystemDebugControl
    WinDBG can do some local debugging using 'windbg -kl'. In that case,
    WinDBG tries to directly use NtSystemDebugControl. If this function
    returns an error, WinDBG extracts a driver from its resources.
    WinDBG will send IOCTLs to this driver, and this driver will call
    KdSystemDebugControl.
    However, on livecd (where %SYSTEMROOT% is read-only), WinDBG is unable
    to extract the driver from its resources, and can't use the driver to
    call KdSystemDebugControl.
    As a work-around, allow all control classes in NtSystemDebugControl
    in case of livecd.
    WinDBG local debugging now also works on livecd (windbg -kl).
---
 ntoskrnl/ex/dbgctrl.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/ntoskrnl/ex/dbgctrl.c b/ntoskrnl/ex/dbgctrl.c
index a62345ee692..5ed32619fee 100644
--- a/ntoskrnl/ex/dbgctrl.c
+++ b/ntoskrnl/ex/dbgctrl.c
@@ -267,7 +267,17 @@ NtSystemDebugControl(
             case SysDbgWriteBusData:
             case SysDbgCheckLowMemory:
                 /* Those are implemented in KdSystemDebugControl */
-                Status = STATUS_NOT_IMPLEMENTED;
+                if (InitIsWinPEMode)
+                {
+                    Status = KdSystemDebugControl(Command,
+                                                  InputBuffer, InputBufferLength,
+                                                  OutputBuffer, OutputBufferLength,
+                                                  &Length, PreviousMode);
+                }
+                else
+                {
+                    Status = STATUS_NOT_IMPLEMENTED;
+                }
                 break;
             case SysDbgBreakPoint: