[PATCH 4/4] ntdll: Support THREAD_CREATE_FLAGS_SKIP_LOADER_INIT flag.

[Billy Laws]

From: Billy Laws

I confirmed that ARM64EC BT thread creation callbacks aren't called through
some logging in FEX.
---
 dlls/ntdll/loader.c       |  2 ++
 dlls/ntdll/tests/thread.c |  4 ++--
 dlls/ntdll/unix/thread.c  | 10 ++++++++--
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/dlls/ntdll/loader.c b/dlls/ntdll/loader.c
index 5859d1e5a74..8df76c6cc26 100644
--- a/dlls/ntdll/loader.c
+++ b/dlls/ntdll/loader.c
@@ -4401,6 +4401,8 @@ void loader_init( CONTEXT *context, void **entry )

if (process_detaching) NtTerminateThread( GetCurrentThread(), 0 );

+    if (NtCurrentTeb()->SkipLoaderInit) return;
+
     RtlEnterCriticalSection( &loader_section );

if (!imports_fixup_done)
diff --git a/dlls/ntdll/tests/thread.c b/dlls/ntdll/tests/thread.c
index 6192104b9dc..b892ca04f6c 100644
--- a/dlls/ntdll/tests/thread.c
+++ b/dlls/ntdll/tests/thread.c
@@ -505,11 +505,11 @@ static void test_arm64_skip_loader_init(void)
     status = pNtCreateThreadEx( &thread, THREAD_ALL_ACCESS, NULL, GetCurrentProcess(), (PRTL_THREAD_START_ROUTINE)code_mem,
                                 &args, THREAD_CREATE_FLAGS_SKIP_THREAD_ATTACH | THREAD_CREATE_FLAGS_SKIP_LOADER_INIT, 0, 0, 0, NULL );

-    todo_wine ok( status == STATUS_SUCCESS, "Got unexpected status %#lx.\n", status );
+    ok( status == STATUS_SUCCESS, "Got unexpected status %#lx.\n", status );

WaitForSingleObject( thread, INFINITE );

-    todo_wine ok( (args.teb_same_teb_flags & 0x4008) == 0x4008, "wrong value %x\n", args.teb_same_teb_flags );
+    ok( (args.teb_same_teb_flags & 0x4008) == 0x4008, "wrong value %x\n", args.teb_same_teb_flags );

CloseHandle( thread );
 }
diff --git a/dlls/ntdll/unix/thread.c b/dlls/ntdll/unix/thread.c
index 65e7fbcb6bf..8f3fb701a38 100644
--- a/dlls/ntdll/unix/thread.c
+++ b/dlls/ntdll/unix/thread.c
@@ -1316,7 +1316,8 @@ NTSTATUS WINAPI NtCreateThreadEx( HANDLE *handle, ACCESS_MASK access, OBJECT_ATT
                                   SIZE_T stack_reserve, PS_ATTRIBUTE_LIST *attr_list )
 {
     static const ULONG supported_flags = THREAD_CREATE_FLAGS_CREATE_SUSPENDED | THREAD_CREATE_FLAGS_SKIP_THREAD_ATTACH |
-                                         THREAD_CREATE_FLAGS_HIDE_FROM_DEBUGGER | THREAD_CREATE_FLAGS_BYPASS_PROCESS_FREEZE;
+                                         THREAD_CREATE_FLAGS_HIDE_FROM_DEBUGGER | THREAD_CREATE_FLAGS_SKIP_LOADER_INIT |
+                                         THREAD_CREATE_FLAGS_BYPASS_PROCESS_FREEZE;
     sigset_t sigset;
     pthread_t pthread_id;
     pthread_attr_t pthread_attr;
@@ -1413,8 +1414,13 @@ NTSTATUS WINAPI NtCreateThreadEx( HANDLE *handle, ACCESS_MASK access, OBJECT_ATT
     set_thread_id( teb, GetCurrentProcessId(), tid );

teb->SkipThreadAttach = !!(flags & THREAD_CREATE_FLAGS_SKIP_THREAD_ATTACH);
+    teb->SkipLoaderInit = !!(flags & THREAD_CREATE_FLAGS_SKIP_LOADER_INIT);
     wow_teb = get_wow_teb( teb );
-    if (wow_teb) wow_teb->SkipThreadAttach = teb->SkipThreadAttach;
+    if (wow_teb)
+    {
+        wow_teb->SkipThreadAttach = teb->SkipThreadAttach;
+        wow_teb->SkipLoaderInit = teb->SkipLoaderInit;
+    }

thread_data = (struct ntdll_thread_data *)&teb->GdiTebBatch;
     thread_data->request_fd  = request_pipe[1];