Re: [PATCH 0/2] um: improve UML page fault handling

[Richard Weinberger <richard@nod.at>]

----- Ursprüngliche Mail -----
> Von: "Petr Tesarik" <petrtesarik@huaweicloud.com>
> An: "richard" <richard@nod.at>, "anton ivanov" <anton.ivanov@cambridgegreys.com>, "Johannes Berg"
> <johannes@sipsolutions.net>, "linux-um" <linux-um@lists.infradead.org>, "linux-kernel" <linux-kernel@vger.kernel.org>
> CC: "Roberto Sassu" <roberto.sassu@huaweicloud.com>, petr@tesarici.cz, "Petr Tesarik"
> <petr.tesarik1@huawei-partners.com>
> Gesendet: Freitag, 15. Dezember 2023 13:14:29
> Betreff: [PATCH 0/2] um: improve UML page fault handling

> From: Petr Tesarik <petr.tesarik1@huawei-partners.com>
> 
> Improve UML handling of segmentation faults in kernel mode. Although
> such page faults are generally caused by a kernel bug, it is annoying
> if they cause an infinite loop, or panic the kernel. More importantly,
> a robust implementation allows to write KUnit tests for various guard
> pages, preventing potential kernel self-protection regressions.
> 
> Petr Tesarik (2):
>  um: do not panic on kernel mode faults
>  um: oops on accessing an non-present page in the vmalloc area

I think this is a good thing to have.
For the implementation side, this needs to use the oops_* helpers
from kernel/panic.c and taint the kernel, etc...
See arch/x86/kernel/dumpstack.c die() and friends.

Thanks,
//richard