[PATCH -next 0/3] replace open coded VA->PA calculation

[Linus Walleij]

On Tue, Dec 21, 2021 at 10:16 AM Arnd Bergmann <arnd at arndb.de> wrote:

> I think for CPUs that can use LPAE, we want to eventually move to the 4G:4G
> memory model, which in turn depends on having the kernel in vmalloc space, as
> implemented by Linus Walleij in
> https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git/log/?h=kernel-in-vmalloc-v5.14-rc1

Yeah I'm still working on this series. The 4/4 split works pretty well,
but it breaks KASan and I was in the process of fixing that when I left
for parental leave.

The reason it breaks would be related to KASan not expecting
executable code in the vmalloc area, and since the shadowing
algorithm is a simple pointer offset, and since we go to lengths
to chisel shadow memory out of lowmem at a fixed offset from
TEXT_OFFSET, we have a problem.

The patch "KASAN horror" shows what I am trying to do to fix it,
it's "just" some hard work missing.

Yours,
Linus Walleij