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 <guoguangya...@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;
  }