/* * 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 availiable. */#define VDSO_SYMBOL(base, name) \({ \ extern const char __vdso_##name[]; \ (void __user *)((unsigned long)(base) + __vdso_##name); \})