Paul Gofman : ntdll: Preserve untouched parts of xstate in NtSetContextThread().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: a10da8a42a25c6b72d863767461b85e1f3f0ea12
URL:    https://gitlab.winehq.org/wine/wine/-/commit/a10da8a42a25c6b72d863767461b85e...

Author: Paul Gofman 
Date:   Thu Feb  8 14:09:12 2024 -0600

ntdll: Preserve untouched parts of xstate in NtSetContextThread().

---

dlls/ntdll/unix/signal_i386.c   | 2 ++
 dlls/ntdll/unix/signal_x86_64.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/dlls/ntdll/unix/signal_i386.c b/dlls/ntdll/unix/signal_i386.c
index c4d553ba8b8..94799522202 100644
--- a/dlls/ntdll/unix/signal_i386.c
+++ b/dlls/ntdll/unix/signal_i386.c
@@ -1004,9 +1004,11 @@ NTSTATUS WINAPI NtSetContextThread( HANDLE handle, const CONTEXT *context )
     {
         CONTEXT_EX *context_ex = (CONTEXT_EX *)(context + 1);
         XSAVE_AREA_HEADER *xs = (XSAVE_AREA_HEADER *)((char *)context_ex + context_ex->XState.Offset);
+        UINT64 mask = frame->xstate.Mask;

if (xstate_compaction_enabled) frame->xstate.CompactionMask |= xstate_extended_features();
         copy_xstate( &frame->xstate, xs, xs->Mask );
+        if (xs->CompactionMask) frame->xstate.Mask |= mask & ~xs->CompactionMask;
     }

frame->restore_flags |= flags & ~CONTEXT_INTEGER;
diff --git a/dlls/ntdll/unix/signal_x86_64.c b/dlls/ntdll/unix/signal_x86_64.c
index 8fdcc37f078..f4a6fcce8ca 100644
--- a/dlls/ntdll/unix/signal_x86_64.c
+++ b/dlls/ntdll/unix/signal_x86_64.c
@@ -1050,9 +1050,11 @@ NTSTATUS WINAPI NtSetContextThread( HANDLE handle, const CONTEXT *context )
     {
         CONTEXT_EX *context_ex = (CONTEXT_EX *)(context + 1);
         XSAVE_AREA_HEADER *xs = (XSAVE_AREA_HEADER *)((char *)context_ex + context_ex->XState.Offset);
+        UINT64 mask = frame->xstate.Mask;

if (xstate_compaction_enabled) frame->xstate.CompactionMask |= xstate_extended_features();
         copy_xstate( &frame->xstate, xs, xs->Mask );
+        if (xs->CompactionMask) frame->xstate.Mask |= mask & ~xs->CompactionMask;
     }

frame->restore_flags |= flags & ~CONTEXT_INTEGER;