Re: [POC][RFC][PATCH 0/2] pstore/mm/x86: Add wildcard memmap to map pstore consistently

Kees Cook
2024-04-09T23:37:11Z

On Tue, Apr 09, 2024 at 10:25:33PM +0000, Luck, Tony wrote:
> >> I forgot to mention that this makes it trivial for any machine that doesn't
> >> clear memory on soft-reboot, to enable console ramoops (to have access to
> >> the last boot dmesg without needing serial).
> >>
> >> I tested this on a couple of my test boxes and on QEMU, and it works rather
> >> well.
> >
> > I've long wanted a "stable for this machine and kernel" memory region
> > like this for pstore. It would make testing much easier.
>
> Which systems does this work on? I'd assume that servers (and anything
> else with ECC memory) would nuke contents while resetting ECC to clean
> state.

Do ECC servers wipe their RAM by default? I know that if you build with
CONFIG_RESET_ATTACK_MITIGATION=y on an EFI system that supports the
MemoryOverwriteRequestControl EFI variable you'll get a RAM wipe...

--
Kees Cook