On Fri, 22 Jan 2021 at 11:53, Peter Maydell <peter.mayd...@linaro.org> wrote: > The kernel's "untagged_addr()" implementation: > https://elixir.bootlin.com/linux/latest/source/arch/arm64/include/asm/memory.h#L203 > slightly confusingly does "untag the addr if it's in the userspace > half, leave the tag bits alone if in the kernel half".
...and a kernel person has just explained to me the rationale: TBI is always enabled for userspace and never for the kernel, so "always clear tag bits for a userspace address, never clear them for a kernel address" is the right behaviour. I think we should have the same logic. -- PMM