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

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

Posted by Mark Cave-Ayland 2 years, 3 months ago

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);
-- 
2.20.1

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

Posted by Laurent Vivier 2 years, 3 months ago

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>