Messages in this thread | | | Date | Thu, 12 Nov 2009 06:40:04 +0100 | From | Willy Tarreau <> | Subject | Re: i686 quirk for AMD Geode |
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On Wed, Nov 11, 2009 at 09:31:26PM -0800, H. Peter Anvin wrote: > On 11/11/2009 09:27 PM, Willy Tarreau wrote: > > > > Right. However we just noticed that with the KVM emulator, you > > can make it loop for a long time if you feed it with prefixes > > only. For instance, write a function which does zillions of 0x66 > > (data size prefix) then return (0xC3) : 66 66 66 ... 66 C3. > > > > This is typically the sort of things we must be very careful about > > in emulators, because we don't want users to steal large amounts > > of system CPU time doing nothing. > > > > That is a (serious) bug in the KVM interpreter, and indeed the exact > kind of issues interpreters tend to have... which is why I'd like one > piece of code with one set of bugs, and more eyeballs on that one piece > of code so they can be fixed.
Well, I could try to work on a fix (basically the same principle as in mine, with prefix flags), but I simply don't know how to test the code. I've never experimented with KVM yet and learned it embeds an emulator for the first time a few days ago in this thread :-/ If it's easy to make use of it, I'm not opposed to try.
Willy
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