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Re: [Qemu-devel] FPU x86 instructions error
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] FPU x86 instructions error |
Date: |
Fri, 24 May 2013 23:44:21 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6 |
Il 24/05/2013 23:39, Clemens Kolbitsch ha scritto:
> Hi guys,
>
> we recently had an issue with running a program using FPU instructions
> to obtain the current EIP (basically a weird way of "call 0; pop eax")
> that was not working on QEMU (with TCG).
>
> Looking at the problem, we found this patch to be useful/fixing the issue:
>
> https://launchpadlibrarian.net/140457932/patch-qemu-1.5.0-fpip.diff
>
> Looking through the DEVEL archives, I found this patch
>
> http://lists.nongnu.org/archive/html/qemu-devel/2011-06/msg01206.html
>
> that adds the FPU flags to the environment, but is only using them for KVM.
>
> I was wondering - since the above patch is rather old, you have
> probably come across it before - if there was a reason for not
> including it in QEMU (I checked in git:master and it's not applied).
> If there isn't, maybe it'd be worth re-considering :)
For the TCG patch, there is no Signed-off-by and using a helper is not
necessary.
For the KVM patch, it simply fell through the cracks, I believe.
Paolo