+
+ .section ".rwshared",""
+
+ // Userspace must set this to an appropriate entry point
+ // prior to registering objects with the kernel. It should
+ // not be modified while an object is registered (the kernel
+ // won't mind, but there's no mechanism to wait until no more
+ // upcalls to the old entry point are in progress).
+ .global x86_upcall_entry
+x86_upcall_entry:
+ .long 0