Re: [PATCH] target/i386: Eip error in x86_64-softmmu

[Michael Tokarev]

15.01.2024 05:08, guoguangyao wrote:
> When closing PCREL, qemu-system-x86_64 run into error.
> Eip modification here leads to the result. Using s->pc
> in func gen_update_eip_next() solves the problem.
>
> Fixes: b5e0d5d22fbf("target/i386: Fix 32-bit wrapping of pc/eip computation")

It looks like the situation with PCREL is a bit more complex,
see https://gitlab.com/qemu-project/qemu/-/issues/2092
I'm assuming this particular change does not actually fix the problem
(which is still unfixed on master).

Thanks,

/mjt

> Signed-off-by: guoguangyao <guoguangyao18@mails.ucas.ac.cn>
>
>         modified:   target/i386/tcg/translate.c
> ---
>   target/i386/tcg/translate.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
> index e1eb82a5c6..6f57d5a8a5 100644
> --- a/target/i386/tcg/translate.c
> +++ b/target/i386/tcg/translate.c
> @@ -567,9 +567,9 @@ static void gen_update_eip_next(DisasContext *s)
>       if (tb_cflags(s->base.tb) & CF_PCREL) {
>           tcg_gen_addi_tl(cpu_eip, cpu_eip, s->pc - s->pc_save);
>       } else if (CODE64(s)) {
> -        tcg_gen_movi_tl(cpu_eip, s->base.pc_next);
> +        tcg_gen_movi_tl(cpu_eip, s->pc);
>       } else {
> -        tcg_gen_movi_tl(cpu_eip, (uint32_t)(s->base.pc_next - s->cs_base));
> +        tcg_gen_movi_tl(cpu_eip, (uint32_t)(s->pc - s->cs_base));
>       }
>       s->pc_save = s->pc;
>   }