This patchset fixes a bug where on a big-endian 64-bit host the
guest would crash immediately when it did an ERET. This happens
because when we load the new PC value from CPUARMState::esr_el[2]
we do a 32-bit load even though the struct field is 64 bits.
So on 64-bit BE we use the wrong half of the register.

Patch 1 defines a new macro to load the low 32 bits from a
64-bit field, and uses it in the two places where we got this
wrong. Patch 2 adds some compile-time assertions to the
existing load_cpu_field() and store_cpu_field() macros that
catch inadvertent uses on struct fields of the wrong size.

This fix is necessary to be able to run the avocado tests for
the orangepi on a 64-bit BE system.

thanks
-- PMM

Peter Maydell (2):
  target/arm: Define and use new load_cpu_field_low32()
  target/arm: Add compile time asserts to load/store_cpu_field macros

 target/arm/translate-a32.h | 24 ++++++++++++++++++++----
 target/arm/tcg/translate.c |  4 ++--
 2 files changed, 22 insertions(+), 6 deletions(-)

-- 
2.34.1

On Mon, 24 Apr 2023 at 16:39, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> This patchset fixes a bug where on a big-endian 64-bit host the
> guest would crash immediately when it did an ERET. This happens
> because when we load the new PC value from CPUARMState::esr_el[2]
> we do a 32-bit load even though the struct field is 64 bits.
> So on 64-bit BE we use the wrong half of the register.
>
> Patch 1 defines a new macro to load the low 32 bits from a
> 64-bit field, and uses it in the two places where we got this
> wrong. Patch 2 adds some compile-time assertions to the
> existing load_cpu_field() and store_cpu_field() macros that
> catch inadvertent uses on struct fields of the wrong size.
>
> This fix is necessary to be able to run the avocado tests for
> the orangepi on a 64-bit BE system.

Applied to target-arm.next, adjusted to use sizeof_field().

thanks
-- PMM