ntdll: Don't rely on get_thread_context() updating the context flags.

dlls/ntdll/unix/signal_arm.c

@@ -405,19 +405,16 @@ NTSTATUS WINAPI NtSetContextThread( HANDLE handle, const CONTEXT *context )
  */
 NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
 {
-    NTSTATUS ret;
     struct syscall_frame *frame = arm_thread_data()->syscall_frame;
     DWORD needed_flags = context->ContextFlags & ~CONTEXT_ARM;
     BOOL self = (handle == GetCurrentThread());
 
     if (!self)
     {
-        if ((ret = get_thread_context( handle, &context, &self, IMAGE_FILE_MACHINE_ARMNT ))) return ret;
-        needed_flags &= ~context->ContextFlags;
+        NTSTATUS ret = get_thread_context( handle, &context, &self, IMAGE_FILE_MACHINE_ARMNT );
+        if (ret || !self) return ret;
     }
 
-    if (self)
-    {
     if (needed_flags & CONTEXT_INTEGER)
     {
         context->R0  = frame->r0;
@@ -449,7 +446,6 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
         memcpy( context->u.D, frame->d, sizeof(frame->d) );
         context->ContextFlags |= CONTEXT_FLOATING_POINT;
     }
-    }
     return STATUS_SUCCESS;
 }
 

dlls/ntdll/unix/signal_arm64.c

@@ -493,19 +493,16 @@ NTSTATUS WINAPI NtSetContextThread( HANDLE handle, const CONTEXT *context )
  */
 NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
 {
-    NTSTATUS ret;
     struct syscall_frame *frame = arm64_thread_data()->syscall_frame;
     DWORD needed_flags = context->ContextFlags & ~CONTEXT_ARM64;
     BOOL self = (handle == GetCurrentThread());
 
     if (!self)
     {
-        if ((ret = get_thread_context( handle, context, &self, IMAGE_FILE_MACHINE_ARM64 ))) return ret;
-        needed_flags &= ~context->ContextFlags;
+        NTSTATUS ret = get_thread_context( handle, context, &self, IMAGE_FILE_MACHINE_ARM64 );
+        if (ret || !self) return ret;
     }
 
-    if (self)
-    {
     if (needed_flags & CONTEXT_INTEGER)
     {
         memcpy( context->u.X, frame->x, sizeof(context->u.X[0]) * 29 );
@@ -528,7 +525,6 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
         context->ContextFlags |= CONTEXT_FLOATING_POINT;
     }
     if (needed_flags & CONTEXT_DEBUG_REGISTERS) FIXME( "debug registers not supported\n" );
-    }
     return STATUS_SUCCESS;
 }
 

dlls/ntdll/unix/signal_i386.c

@@ -1024,7 +1024,6 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
     if (!self)
     {
         if ((ret = get_thread_context( handle, context, &self, IMAGE_FILE_MACHINE_I386 ))) return ret;
-        needed_flags &= ~context->ContextFlags;
     }
 
     if (self)
@@ -1129,7 +1128,7 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
             }
         }
         /* update the cached version of the debug registers */
-        if (context->ContextFlags & (CONTEXT_DEBUG_REGISTERS & ~CONTEXT_i386))
+        if (needed_flags & CONTEXT_DEBUG_REGISTERS)
         {
             x86_thread_data()->dr0 = context->Dr0;
             x86_thread_data()->dr1 = context->Dr1;

dlls/ntdll/unix/signal_x86_64.c

@@ -1725,26 +1725,19 @@ NTSTATUS WINAPI NtSetContextThread( HANDLE handle, const CONTEXT *context )
  */
 NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
 {
-    NTSTATUS ret;
-    DWORD needed_flags;
     struct syscall_frame *frame = amd64_thread_data()->syscall_frame;
+    DWORD needed_flags = context->ContextFlags & ~CONTEXT_AMD64;
     BOOL self = (handle == GetCurrentThread());
 
-    if (!context) return STATUS_INVALID_PARAMETER;
-
-    needed_flags = context->ContextFlags & ~CONTEXT_AMD64;
-
     /* debug registers require a server call */
-    if (context->ContextFlags & (CONTEXT_DEBUG_REGISTERS & ~CONTEXT_AMD64)) self = FALSE;
+    if (needed_flags & CONTEXT_DEBUG_REGISTERS) self = FALSE;
 
     if (!self)
     {
-        if ((ret = get_thread_context( handle, context, &self, IMAGE_FILE_MACHINE_AMD64 ))) return ret;
-        needed_flags &= ~context->ContextFlags;
+        NTSTATUS ret = get_thread_context( handle, context, &self, IMAGE_FILE_MACHINE_AMD64 );
+        if (ret || !self) return ret;
     }
 
-    if (self)
-    {
     if (needed_flags & CONTEXT_INTEGER)
     {
         context->Rax = frame->rax;
@@ -1837,7 +1830,7 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
         }
     }
     /* update the cached version of the debug registers */
-        if (context->ContextFlags & (CONTEXT_DEBUG_REGISTERS & ~CONTEXT_AMD64))
+    if (needed_flags & CONTEXT_DEBUG_REGISTERS)
     {
         amd64_thread_data()->dr0 = context->Dr0;
         amd64_thread_data()->dr1 = context->Dr1;
@@ -1846,8 +1839,6 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context )
         amd64_thread_data()->dr6 = context->Dr6;
         amd64_thread_data()->dr7 = context->Dr7;
     }
-    }
-
     return STATUS_SUCCESS;
 }