Alexandre Julliard : ntdll: Implement KiUserCallbackDispatcher for ARM64EC.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 9e0f2e3b92666fec9e6efa6e3f19c3887b6ac8c9
URL:    https://gitlab.winehq.org/wine/wine/-/commit/9e0f2e3b92666fec9e6efa6e3f19c38...

Author: Alexandre Julliard <julliard(a)winehq.org>
Date:   Thu Dec  7 14:44:32 2023 +0100

ntdll: Implement KiUserCallbackDispatcher for ARM64EC.

---

 dlls/ntdll/signal_arm64ec.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/dlls/ntdll/signal_arm64ec.c b/dlls/ntdll/signal_arm64ec.c
index fc92a453b56..75b4c71bc9c 100644
--- a/dlls/ntdll/signal_arm64ec.c
+++ b/dlls/ntdll/signal_arm64ec.c
@@ -1694,10 +1694,35 @@ void WINAPI KiUserApcDispatcher( CONTEXT *context, ULONG_PTR arg1, ULONG_PTR arg
 /*******************************************************************
  *		KiUserCallbackDispatcher (NTDLL.@)
  */
-void WINAPI KiUserCallbackDispatcher( ULONG id, void *args, ULONG len )
+void WINAPI dispatch_callback( void *args, ULONG len, ULONG id )
 {
-    FIXME( "not implemented\n" );
-}
+    NTSTATUS status;
+
+    __TRY
+    {
+        NTSTATUS (WINAPI *func)(void *, ULONG) = ((void **)NtCurrentTeb()->Peb->KernelCallbackTable)[id];
+        status = NtCallbackReturn( NULL, 0, func( args, len ));
+    }
+    __EXCEPT_ALL
+    {
+        ERR_(seh)( "ignoring exception\n" );
+        status = NtCallbackReturn( 0, 0, 0 );
+    }
+    __ENDTRY
+
+    RtlRaiseStatus( status );
+}
+__ASM_GLOBAL_FUNC( "#KiUserCallbackDispatcher",
+                   __ASM_SEH(".seh_pushframe\n\t")
+                   "nop\n\t"
+                   __ASM_SEH(".seh_stackalloc 0x20\n\t")
+                   "nop\n\t"
+                   __ASM_SEH(".seh_save_reg lr, 0x18\n\t")
+                   __ASM_SEH(".seh_endprologue\n\t")
+                   "ldr x0, [sp]\n\t"             /* args */
+                   "ldp w1, w2, [sp, #0x08]\n\t"  /* len, id */
+                   "bl " __ASM_NAME("dispatch_callback") "\n\t"
+                   "brk #1" )
 
 
 /**************************************************************************