Alex Henrie : ntoskrnl: Add ExGetPreviousMode and test.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: b9627b996f0a9680c95c6d705449a5925334d9f5
URL:    https://gitlab.winehq.org/wine/wine/-/commit/b9627b996f0a9680c95c6d705449a59...

Author: Alex Henrie 
Date:   Fri Jan 27 21:17:42 2023 -0700

ntoskrnl: Add ExGetPreviousMode and test.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54378

---

dlls/ntoskrnl.exe/ntoskrnl.c        | 6 ++++++
 dlls/ntoskrnl.exe/ntoskrnl.exe.spec | 2 +-
 dlls/ntoskrnl.exe/tests/driver.c    | 1 +
 include/ddk/wdm.h                   | 1 +
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/dlls/ntoskrnl.exe/ntoskrnl.c b/dlls/ntoskrnl.exe/ntoskrnl.c
index cc30750a160..2d506402036 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.c
+++ b/dlls/ntoskrnl.exe/ntoskrnl.c
@@ -4566,6 +4566,12 @@ NTSTATUS WINAPI KdEnableDebugger(void)
     return STATUS_DEBUGGER_INACTIVE;
 }

+KPROCESSOR_MODE WINAPI ExGetPreviousMode(void)
+{
+    TRACE("\n");
+    return PsIsSystemThread((PETHREAD)KeGetCurrentThread()) ? KernelMode : UserMode;
+}
+
 #ifdef __x86_64__

void WINAPI KfRaiseIrql(KIRQL new, KIRQL *old)
diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
index 2447d01458d..0b694b08de0 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
+++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
@@ -154,7 +154,7 @@
 @ stub ExGetCurrentProcessorCounts
 @ stub ExGetCurrentProcessorCpuUsage
 @ stdcall ExGetExclusiveWaiterCount(ptr)
-@ stub ExGetPreviousMode
+@ stdcall ExGetPreviousMode()
 @ stdcall ExGetSharedWaiterCount(ptr)
 @ stdcall ExInitializeNPagedLookasideList(ptr ptr ptr long long long long)
 @ stdcall ExInitializePagedLookasideList(ptr ptr ptr long long long long)
diff --git a/dlls/ntoskrnl.exe/tests/driver.c b/dlls/ntoskrnl.exe/tests/driver.c
index d293889c823..d55ad846ef7 100644
--- a/dlls/ntoskrnl.exe/tests/driver.c
+++ b/dlls/ntoskrnl.exe/tests/driver.c
@@ -454,6 +454,7 @@ static void test_current_thread(BOOL is_system)

ok(PsGetThreadId((PETHREAD)KeGetCurrentThread()) == PsGetCurrentThreadId(), "thread IDs don't match\n");
     ok(PsIsSystemThread((PETHREAD)KeGetCurrentThread()) == is_system, "unexpected system thread\n");
+    ok(ExGetPreviousMode() == is_system ? KernelMode : UserMode, "previous mode is not correct\n");
     if (!is_system)
     {
         ok(create_caller_thread == KeGetCurrentThread(), "thread is not create caller thread\n");
diff --git a/include/ddk/wdm.h b/include/ddk/wdm.h
index 321b07b84fa..bf240f4fe53 100644
--- a/include/ddk/wdm.h
+++ b/include/ddk/wdm.h
@@ -1683,6 +1683,7 @@ void      WINAPI ExDeleteNPagedLookasideList(PNPAGED_LOOKASIDE_LIST);
 void      WINAPI ExDeletePagedLookasideList(PPAGED_LOOKASIDE_LIST);
 NTSTATUS  WINAPI ExDeleteResourceLite(ERESOURCE*);
 ULONG     WINAPI ExGetExclusiveWaiterCount(ERESOURCE*);
+KPROCESSOR_MODE WINAPI ExGetPreviousMode(void);
 ULONG     WINAPI ExGetSharedWaiterCount(ERESOURCE*);
 void      WINAPI ExInitializeNPagedLookasideList(PNPAGED_LOOKASIDE_LIST,PALLOCATE_FUNCTION,PFREE_FUNCTION,ULONG,SIZE_T,ULONG,USHORT);
 void      WINAPI ExInitializePagedLookasideList(PPAGED_LOOKASIDE_LIST,PALLOCATE_FUNCTION,PFREE_FUNCTION,ULONG,SIZE_T,ULONG,USHORT);