Re: [PATCH v8 00/14] kasan: x86: arm64: KASAN tag-based mode for x86

From: Andrew Morton

Date: Mon Jan 12 2026 - 15:53:51 EST


On Mon, 12 Jan 2026 20:08:23 +0000 Maciej Wieczór-Retman <m.wieczorretman@xxxxx> wrote:

> >OK, known issues and they are understandable. With this patchset is
> >there any way in which our testers can encounter these things? If so
> >can we make changes to protect them from hitting known issues?
>
> The gcc documentation states that the -fsanitize=kernel-hwaddress is
> similar to -fsanitize=hwaddress, which only works on AArch64. So that
> hints that it shouldn't work.
>
> But while with KASAN sw_tags enabled the kernel compiles fine with gcc,
> at least in my patched qemu it doesn't run. I remember Ada Couprie Diaz
> mention that passing -march=arrowlake might help since the tag support
> seems to be based on arch.
>
> I'll check if there's a non-hacky way to have gcc work too, but perhaps
> to minimize hitting known issue, for now HAVE_ARCH_KASAN_SW_TAGS should
> be locked behind both ADDRESS_MASKING and CC_IS_CLANG in the Kconfig?

Yes please - my main concern is that we avoid causing any disruption to
testers/buildbots/fuzzers/etc.