From: Paolo Bonzini <pbonzini@redhat.com>
To: Ziqiao Kong <ziqiaokong@gmail.com>, qemu-devel@nongnu.org
Cc: ehabkost@redhat.com, rth@twiddle.net
Subject: Re: Bug: fstenv is wrongly implemented
Date: Fri, 2 Apr 2021 10:45:26 +0200 [thread overview]
Message-ID: <7c63e938-2482-3150-7cfb-1459c132fda6@redhat.com> (raw)
In-Reply-To: <CAM0BWNCTD_oe3BgKQUqG41fgFqGCXVh1gaiMqJpvXbR4Fh5vHg@mail.gmail.com>
On 02/04/21 10:29, Ziqiao Kong wrote:
>
> According to git blame, this bug is introduced about 13 years ago:
> https://github.com/qemu/qemu/blame/633decd71119a4293e5e53e6059026c517a8bef0/target-i386/fpu_helper.c#L997.
>
> We also had a patch for this bug:
> https://github.com/unicorn-engine/unicorn/commit/59b09a71bfc6fd8b95357944f6be9aa54f424421
> which you may refer to. I can also help draft a patch if necessary.
Hi!
Unfortunately the patch is incorrect, because fpu_update_ip is called
only at translation time and not at run-time. If more than one x87
instruction is present in the same translation block, or if a
translation block has been compiled after the one that is executing,
env->fpip will be incorrect.
Thanks,
Paolo
next prev parent reply other threads:[~2021-04-02 8:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-02 8:29 Bug: fstenv is wrongly implemented Ziqiao Kong
2021-04-02 8:45 ` Paolo Bonzini [this message]
2021-04-02 8:56 ` Ziqiao Kong
2021-04-02 9:01 ` Paolo Bonzini
2021-04-02 10:48 ` Peter Maydell
2021-04-06 13:16 ` Ziqiao Kong
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