v4.19.13 snapshot.
diff --git a/arch/x86/um/asm/segment.h b/arch/x86/um/asm/segment.h
new file mode 100644
index 0000000..453db37
--- /dev/null
+++ b/arch/x86/um/asm/segment.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_SEGMENT_H
+#define __UM_SEGMENT_H
+
+extern int host_gdt_entry_tls_min;
+
+#define GDT_ENTRY_TLS_ENTRIES 3
+#define GDT_ENTRY_TLS_MIN host_gdt_entry_tls_min
+#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
+
+typedef struct {
+ unsigned long seg;
+} mm_segment_t;
+
+#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
+#define KERNEL_DS MAKE_MM_SEG(~0UL)
+#define USER_DS MAKE_MM_SEG(TASK_SIZE)
+
+#endif