diff -uNr go/src/runtime/cgo/gcc_linux_arm64.c go.mod/src/runtime/cgo/gcc_linux_arm64.c
--- go/src/runtime/cgo/gcc_linux_arm64.c	2020-12-03 19:32:44.000000000 +0200
+++ go.mod/src/runtime/cgo/gcc_linux_arm64.c	2020-12-29 00:12:33.341670237 +0200
@@ -12,7 +12,7 @@
 
 static void *threadentry(void*);
 
-void (*x_cgo_inittls)(void **tlsg, void **tlsbase);
+extern void (*x_cgo_inittls)(void **tlsg, void **tlsbase);
 static void (*setg_gcc)(void*);
 
 void