Re: "bad pmd" errors + oops with KPTI on 4.14.11 after loading X.509 certs

[Andy Lutomirski]

> On Jan 3, 2018, at 4:33 PM, Benjamin Gilbert <benjamin.gilbert@xxxxxxxxxx> wrote:
> 
>> On Wed, Jan 03, 2018 at 10:20:16AM +0100, Greg Kroah-Hartman wrote:
>> Ick, not good, any chance you can test 4.15-rc6 to verify that the issue
>> is also there (or not)?
> 
> I haven't been able to reproduce this on 4.15-rc6.

Ah.  Maybe try rebuilding a bad kernel with free_ldt_pgtables() modified to do nothing, and the read /sys/kernel/debug/page_tables/current (or current_kernel, or whatever it's called).  The problem may be obvious.

> 
> --Benjamin Gilbert