Ben Woodard wrote: Got the dump, thanks, Ben. Not sure how to fix this one yet. Given the live-kernel /proc/version mismatch, it's looking at the /boot/System.map of the actual (booted) kernel for the address of the system utsname structure. And it that matches OK, it will use that System.map file for symbol values, and automatically do the bait-and-switch operation for you. (i.e. the "please wait... (patching ### gdb minimal_symbol values)" operation, as if you had manually entered the System.map file on the command line) But, as it's trying to do a kernel vtop operation on the system utsname structure address -- which is no longer a simple mask operation on x86_64 because of the potentially varying physical base address -- it's crapping out in x86_64_VTOP() using an uninitialized machdep structure. May have to disallow that feature on x86_64 (and ia64 as well I think...) Dave