[PATCH v7 0/1] MR1282: ntoskrnl.exe: Implement ExInterlockedInsertTailList.

[Etaash Mathamsetty (＠etaash.mathamsetty)]

I'm not exactly sure what is calling this function, but it's probably that anti virus I installed to test the KeInitializeGuardedMutex implementation.  
edit: TkCtrl2k64.sys calls it

--
  v7: ntoskrnl.exe: Implement ExInterlockedInsertTailList.

https://gitlab.winehq.org/wine/wine/-/merge_requests/1282

[PATCH v7 1/1] ntoskrnl.exe: Implement ExInterlockedInsertTailList.

[Etaash Mathamsetty]

From: Etaash Mathamsetty

---
 dlls/ntoskrnl.exe/ntoskrnl.exe.spec |  2 +-
 dlls/ntoskrnl.exe/sync.c            | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
index 0a484829ca3..23770e54367 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
+++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
@@ -167,7 +167,7 @@
 @ stub ExInterlockedExtendZone
 @ stub ExInterlockedIncrementLong
 @ stub ExInterlockedInsertHeadList
-@ stub ExInterlockedInsertTailList
+@ stdcall ExInterlockedInsertTailList(ptr ptr ptr)
 @ stub ExInterlockedPopEntryList
 @ stub ExInterlockedPushEntryList
 @ stdcall ExInterlockedRemoveHeadList(ptr ptr)
diff --git a/dlls/ntoskrnl.exe/sync.c b/dlls/ntoskrnl.exe/sync.c
index d9b5726b920..3ad255b1211 100644
--- a/dlls/ntoskrnl.exe/sync.c
+++ b/dlls/ntoskrnl.exe/sync.c
@@ -778,6 +778,34 @@ LIST_ENTRY * WINAPI ExInterlockedRemoveHeadList( LIST_ENTRY *list, KSPIN_LOCK *l
     return ret;
 }

+/***********************************************************************
+ *           ExInterlockedInsertTailList   (NTOSKRNL.EXE.@)
+ */
+PLIST_ENTRY WINAPI ExInterlockedInsertTailList( PLIST_ENTRY head, PLIST_ENTRY entry, PKSPIN_LOCK lock )
+{
+    PLIST_ENTRY ret;
+    KIRQL irql;
+
+    TRACE( "(%p %p %p)\n", head, entry, lock );
+
+    if ( !head || !entry || !lock )
+        return NULL;
+
+    KeAcquireSpinLock( lock, &irql );
+
+    if ( IsListEmpty(head) )
+    {
+        KeReleaseSpinLock( lock, irql );
+        return NULL;
+    }
+
+    ret = head->Blink;
+    InsertTailList( head, entry );
+
+    KeReleaseSpinLock( lock, irql );
+
+    return ret;
+}

/***********************************************************************
  *           InterlockedPopEntrySList   (NTOSKRNL.EXE.@)

[Zebediah Figura (＠zfigura)]

Zebediah Figura (@zfigura) commented about dlls/ntoskrnl.exe/sync.c:
> +{
> - PLIST_ENTRY ret;
> - KIRQL irql;
> -
> - TRACE( "(%p %p %p)\n", head, entry, lock );
> -
> - if ( !head || !entry || !lock )
> -
>    return NULL;
> -
> - KeAcquireSpinLock( lock, &irql );
> -
> - if ( IsListEmpty(head) )
> - {
> -
>    KeReleaseSpinLock( lock, irql );
> -
>    return NULL;
> - }

So... if the list was empty we don't insert the item? Are you sure that's right?

[Zebediah Figura (＠zfigura)]

Zebediah Figura (@zfigura) commented about dlls/ntoskrnl.exe/sync.c:
>  return ret;
>
> }
>
> +/***********************************************************************
> -
> -
>       ExInterlockedInsertTailList   (NTOSKRNL.EXE.@)
> - */
>
> +PLIST_ENTRY WINAPI ExInterlockedInsertTailList( PLIST_ENTRY head, PLIST_ENTRY entry, PKSPIN_LOCK lock )
> +{
> - PLIST_ENTRY ret;
> - KIRQL irql;

Please try to avoid P* types in new code.

[Etaash Mathamsetty (＠etaash.mathamsetty)]

On Tue Nov 22 22:56:44 2022 +0000, Zebediah Figura wrote:
> So... if the list was empty we don't insert the item? Are you sure
> that's right?

no that's not right, it was right before when I checked for a null head->blink and head->flink, I think it's probably best to check for that instead