Re: [PATCH] target/m68k: don't word align SP in stack frame if M68K_FEATURE_UNALIGNED_DATA feature enabled

[Laurent Vivier]

Le 08/01/2022 à 19:04, Mark Cave-Ayland a écrit :
> Commit a9431a03f7 ("target/m68k: add M68K_FEATURE_UNALIGNED_DATA feature") added
> a new feature for processors from the 68020 onwards which do not require data
> accesses to be word aligned.
>
> Unfortunately the original commit missed an additional case whereby the SP is
> still word aligned when setting up an additional format 1 stack frame so add the
> necessary M68K_FEATURE_UNALIGNED_DATA feature guard.
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> Fixes: a9431a03f7 ("target/m68k: add M68K_FEATURE_UNALIGNED_DATA feature")
> ---
>   target/m68k/op_helper.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/target/m68k/op_helper.c b/target/m68k/op_helper.c
> index ab6b559fd3..59d8d5a09e 100644
> --- a/target/m68k/op_helper.c
> +++ b/target/m68k/op_helper.c
> @@ -429,7 +429,10 @@ static void m68k_interrupt_all(CPUM68KState *env, int 
> is_hw)
>           oldsr = sr;
>           env->aregs[7] = sp;
>           cpu_m68k_set_sr(env, sr &= ~SR_M);
> -        sp = env->aregs[7] & ~1;
> +        sp = env->aregs[7];
> +        if (!m68k_feature(env, M68K_FEATURE_UNALIGNED_DATA)) {
> +            sp &= ~1;
> +        }
>           do_stack_frame(env, &sp, 1, oldsr, 0, retaddr);
>       } else {
>           do_stack_frame(env, &sp, 0, oldsr, 0, retaddr);

Reviewed-by: Laurent Vivier <laurent@vivier.eu>