Re: 32-bit PTI with THP = userspace corruption

From: Meelis Roos
Date: Fri Aug 31 2018 - 03:10:59 EST

> > I am seeing userland corruption and application crashes on multiple
> > 32-bit machines with 4.19-rc1+git. The machines vary: PII, PIII, P4.
> > They are all Intel. AMD Duron/Athlon/AthlonMP have been fine in my tests
> > so far (may be configuration dependent).
> Thanks for the report! I'll try to reproduce the problem tomorrow and
> investigate it. Can you please check if any of the kernel configurations
> that show the bug has CONFIG_X86_PAE set? If not, can you please test
> if enabling this option still triggers the problem?

PAE was not visible itself, but when I changed HIGHMEM_4G to
HIGHMEM_64G, X86_PAE was also selected and the resutling kernel works.

Also, I verified that the olid proliants with 6G RAM already have
HIGHMEM_64G set and they do not exhibit the problem either.

Meelis Roos (mroos@xxxxxxxx)