On Tue, May 30, 2017 at 09:38:36AM -0500, Tom Lendacky wrote: > In this case we're running identity mapped and the "on" constant ends up > as kernel address (0xffffffff81...) which results in a segfault. Would static const char *__on_str = "on"; ... if (!strncmp(buffer, __pa_nodebug(__on_str), 2)) ... work? __phys_addr_nodebug() seems to pay attention to phys_base and PAGE_OFFSET and so on... I'd like to avoid that rip-relative address finding in inline asm which looks fragile to me. Thanks. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.