1 files changed, 22 insertions, 0 deletions
diff --git a/arch/csky/include/asm/vdso.h b/arch/csky/include/asm/vdso.h
new file mode 100644
index 000000000000..181a15edafe8
--- /dev/null
+++ b/arch/csky/include/asm/vdso.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_VDSO_H
+#define __ASM_CSKY_VDSO_H
+
+#include <linux/types.h>
+
+/*
+ * The VDSO symbols are mapped into Linux so we can just use regular symbol
+ * addressing to get their offsets in userspace.  The symbols are mapped at an
+ * offset of 0, but since the linker must support setting weak undefined
+ * symbols to the absolute address 0 it also happens to support other low
+ * addresses even when the code model suggests those low addresses would not
+ * otherwise be available.
+ */
+#define VDSO_SYMBOL(base, name)							\
+({										\
+	extern const char __vdso_##name[];					\
+	(void __user *)((unsigned long)(base) + __vdso_##name);			\
+})
+
+#endif /* __ASM_CSKY_VDSO_H */