Re: [PATCH v2] target/arm: Fix BTI versus CF_PCREL

[Peter Maydell]

On Fri, 2 Aug 2024 at 01:30, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> With pcrel, we cannot check the guarded page bit at translation
> time, as different mappings of the same physical page may or may
> not have the GP bit set.
>
> Instead, add a couple of helpers to check the page at runtime,
> after all other filters that might obviate the need for the check.
>
> The set_btype_for_br call must be moved after the gen_a64_set_pc
> call to ensure the current pc can still be computed.
>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>
> v2: Enable unwind from guarded_page_br.
>     Since guarded_page_check is called exclusively with btype != 0,
>     it must immediately follow an indirect branch or eret, so cpu
>     state is up-to-date, so unwind is not required.
>



Applied to target-arm.next, thanks.

-- PMM