Re: [PATCH 3/4] target/arm: Take an exception if PC is misaligned

[Peter Maydell]

On Thu, 19 Aug 2021 at 20:18, Peter Maydell <peter.maydell@linaro.org> wrote:
> Just noticed that section G1.16.7 says that when we report
> PC alignment faults to AArch32 they should be prefetch aborts,
> not UDEF. The fault address and fault status registers also need
> to be set (with slightly varying behaviour for when the fault
> is taken to Hyp mode).
>
> For AArch64 we should also be setting the FAR, which means
> that for consistency it's better to use EXCP_PREFETCH_ABORT
> and set exception.vaddress in the translate-a64.c code
> (you get better logging in the exception-entry code)
> even though these different EXCP_* all boil down to the
> same synchronous-exception vector.

Also, looking at kernel code while reviewing your alignment-checking
patchset, I realized that we should also catch this case of
a prefetch abort in linux-user/ and turn it into a
SIGBUS/BUS_ADRALN with the address being whatever the value
in the FAR is (for both arm and aarch64).

-- PMM