Re: [PATCH] target/hppa: Generate illegal instruction exception for 64-bit instructions

[Richard Henderson]

On 9/24/22 15:13, Helge Deller wrote:
> Qemu currently emulates a 32-bit CPU only, and crashes with this error
> when it faces a 64-bit load (e.g.  "ldd 0(r26),r0") or 64-bit store
> (e.g. "std r26,0(r26)") instruction in the guest:
>
> ERROR:../qemu/tcg/tcg-op.c:2822:tcg_canonicalize_memop: code should not be 
> reached
>
> Fix this by adding checks for 64-bit sizes and generate an illegal
> instruction exception if necessary.
>
> Signed-off-by: Helge Deller <deller@gmx.de>
>
> diff --git a/target/hppa/translate.c b/target/hppa/translate.c
> index b8dbfee5e9..287cc410cd 100644
> --- a/target/hppa/translate.c
> +++ b/target/hppa/translate.c
> @@ -1568,7 +1568,12 @@ static bool do_load(DisasContext *ctx, unsigned rt, 
> unsigned rb,
>           /* Make sure if RT == RB, we see the result of the load.  */
>           dest = get_temp(ctx);
>       }
> -    do_load_reg(ctx, dest, rb, rx, scale, disp, sp, modify, mop);
> +    if (unlikely(TARGET_REGISTER_BITS == 32 && (mop & MO_SIZE) > MO_32)) {
> +        gen_illegal(ctx);
> +        dest = tcg_constant_reg(0);
> +    } else {
> +        do_load_reg(ctx, dest, rb, rx, scale, disp, sp, modify, mop);
> +    }

This should be done in trans_ld,

> @@ -1631,7 +1636,11 @@ static bool do_store(DisasContext *ctx, unsigned rt, 
> unsigned rb,
>                        int modify, MemOp mop)
>   {
>       nullify_over(ctx);
> -    do_store_reg(ctx, load_gpr(ctx, rt), rb, 0, 0, disp, sp, modify, mop);
> +    if (unlikely(TARGET_REGISTER_BITS == 32 && (mop & MO_SIZE) > MO_32)) {
> +        gen_illegal(ctx);
> +    } else {
> +        do_store_reg(ctx, load_gpr(ctx, rt), rb, 0, 0, disp, sp, modify, mop);
> +    }

and this in trans_st.


r~