Re: KASLR causes intermittent boot failures on some systems

[Dan Williams]

On Fri, Apr 7, 2017 at 9:08 PM, Baoquan He <bhe@xxxxxxxxxx> wrote:
> On 04/07/17 at 10:41am, Jeff Moyer wrote:
>> Hi,
>>
>> commit 021182e52fe01 ("x86/mm: Enable KASLR for physical mapping memory
>> regions") causes some of my systems with persistent memory (whether real
>> or emulated) to fail to boot with a couple of different crash
>> signatures.  The first signature is a NMI watchdog lockup of all but 1
>> cpu, which causes much difficulty in extracting useful information from
>> the console.  The second variant is an invalid paging request, listed
>> below.
>>
>> On some systems, I haven't hit this problem at all.  Other systems
>> experience a failed boot maybe 20-30% of the time.  To reproduce it,
>> configure some emulated pmem on your system.  You can find directions
>> for that here: https://nvdimm.wiki.kernel.org/
>
> I got below problem when configure ndctl, didn't find a package named
> libkmod:
>
> ~~~~~~~~~
> configure: error: Package requirements (libkmod) were not met:
>
> No package 'libkmod' found

kmod-devel provides that dependency. Otherwise ndctl is included in
Fedora or you can find EPEL 7 packages here:

https://copr.fedorainfracloud.org/coprs/djbw/ndctl/