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Skype 5-way Calling Limit Cracked

CmdrTaco posted more than 8 years ago | from the well-isn't-that-unsurprising dept.

427

BobPaul writes "It turns out when Skype limited 10 way calling to Intel Processors only it really was arbitrary! Maxxus has a patched version of Skype that allows 10-way calling regardless of the processor installed. There's also info about the patch: "The patch is the result of two phases: code analysis and design of the patch. The code analysis, or reverse engineering, reveals the relevant code block, which overrides Skype's limitation for Intel's dual-core CPUs. The patch design isolates the minimal set of instructions that need to be modified to cancel this limitation." Windows only so far."

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Joy! (-1)

Anonymous Coward | more than 8 years ago | (#14850032)

Great, yet more marchitecture!

Re:Joy! (0)

I_Heat_Sexylaid (675028) | more than 8 years ago | (#14850268)

marchitecture
Cool, but not as chilling as "Eurabia"

Yay!??? (-1, Troll)

OxygenPenguin (785248) | more than 8 years ago | (#14850034)

I'm not really sure that this a feature that most people will ever use. Sucks that they felt the need to install a block. Strange that Intel has a block against it somewhere, rather than AMD.

Watch out! (-1, Flamebait)

BoomerSooner (308737) | more than 8 years ago | (#14850112)

In our republican nation you may get a visit courtesy DMCA/Patriot Act.

Land of the free no more.

Re:Watch out! (1, Insightful)

amliebsch (724858) | more than 8 years ago | (#14850125)

This has nothing to do with the DMCA or Patriot Act.

Re:Watch out! (1)

drgonzo59 (747139) | more than 8 years ago | (#14850161)

A lot of companies have a clause in the EUA that the user may not reverse compile or reverse engineer the binaries. I wonder if Skype will now add one of those then install a new block in a different section of the code, and close watch the IRC/Usenet/Bittorent/P2P nets etc. to catch those who claim they made patch, and slap them with a lawsuit.

Re:Watch out! (0)

Anonymous Coward | more than 8 years ago | (#14850314)

Dude...it's not only a federal crime to mention the Patriot Act, you're also not supporting our troops and encouraging the enemy. Why do you hate our freedom?

Re:Watch out! (1)

Orgazmus (761208) | more than 8 years ago | (#14850376)

Dude, its freedoms
Always make it clear that USA has a lot of those ;)

Re:Watch out! (0)

Anonymous Coward | more than 8 years ago | (#14850388)

Dude...it's not only a federal crime to mention the Patriot Act, you're also not supporting our troops and encouraging the enemy. Why do you hate our freedom?

If your statement were not so true a reflection of the sad state of things, it would be hilarious. It is tragic that vile seething hatemongers (the asses of evil) have Pavlov's people so perfectly trained.

Re:Watch out! (0)

Distinguished Hero (618385) | more than 8 years ago | (#14850218)

In our republican nation you may get a visit courtesy DMCA/Patriot Act.

Do you even know what (lower case r) republican means?

Re:Yay!??? (5, Insightful)

bitt3n (941736) | more than 8 years ago | (#14850237)

utility is not the point. the point is to stick it to the unctuous twits who crippled their product and lied about the reason.

Lawsuit (4, Insightful)

mtenhagen (450608) | more than 8 years ago | (#14850043)

I think this shows this was done on purpose to lock out amd users. A lawsuit by amd should be succesfull.

Re:Lawsuit (-1, Redundant)

MyLongNickName (822545) | more than 8 years ago | (#14850181)

How is this redundant? Maybe if you've read the other five "not quite dupe" stories... but this is not redundat to this article.

shut the hell up (-1, Offtopic)

Anonymous Coward | more than 8 years ago | (#14850044)

the soup's waiting

fp

MOD PARENT UP (-1, Offtopic)

Anonymous Coward | more than 8 years ago | (#14850066)

why does soup taste good using skype?

OH AND I GOT FPSBISH

Aaaah Maxxuss (5, Funny)

Anonymous Coward | more than 8 years ago | (#14850050)

Ah, Maxxuss. Is there anything you can't do? First you crack OS X, now Skype. You and DVD Jon should team up and become some sort of cracking superheros.

Re:Aaaah Maxxuss (1)

Ethan Allison (904983) | more than 8 years ago | (#14850402)

You're implying that they're not already?

should teach intel a lesson (1)

thelost (808451) | more than 8 years ago | (#14850059)

people really don't want to pay money to have less features in a product you dimwits [intel]. I hope AMD sues ya ass to kingdom come for anti-competative practices. where are maxxas based, somewhere where they can't be served with a DMCA order?

Re:should teach intel a lesson (1)

oliverthered (187439) | more than 8 years ago | (#14850107)

I don't think they can be servered a valid DMCA order wherever they are, DMCA is for copy protection this hack doesn't break any form of copy protection.

It could be that the Intel only locking is a bit like the IE locking on many websites, not dictated by Intel but implemented by some idiot who didn't know any better.

Re:should teach intel a lesson (0)

Anonymous Coward | more than 8 years ago | (#14850421)

Did you miss all the news stories about this a couple of weeks ago? Intel actually paid Skype to disable this feature on AMD processors.

Re:should teach intel a lesson (0)

Millenniumman (924859) | more than 8 years ago | (#14850276)

If Skype or Intel wants to limit features on certain CPUs with their product, they have every right to do so. Freedom.

Re:should teach intel a lesson (0)

Anonymous Coward | more than 8 years ago | (#14850369)

Yeah, the freedom to deprive YOU the costumer the right to a feature that you have paid for, because you didn't choose your CPU 'wisely'...

Re:should teach intel a lesson (1)

KDR_11k (778916) | more than 8 years ago | (#14850370)

Except Intel is currently under investigation whether it is a monopoly and violating antitrust laws. This is evidence for that investigation.

"Arbitrary"? (4, Interesting)

v1 (525388) | more than 8 years ago | (#14850065)

Since this limit was "arbitrary", that means the only deciding factor was not technology, but money. I wonder how much the block cost Intel?

And now that it's in the open, (like that was going to take very long?) I wonder if they'll remove the block?

Re:"Arbitrary"? (1)

bj8rn (583532) | more than 8 years ago | (#14850072)

I wonder if they'll sue the cracker?

Re:"Arbitrary"? (4, Interesting)

BVis (267028) | more than 8 years ago | (#14850207)

It'd be an interesting test case for the DMCA, wouldn't it? In this case it's not specifically copy or content protection software that's being circumvented, but a feature designed to maintain (potentially) a marketing agreement, if in fact that's what this turns out to be.

Re:"Arbitrary"? (0)

Anonymous Coward | more than 8 years ago | (#14850127)

Was there ever even the possibility that it wasn't arbitrary? It sounded like powersauce from the beginning.

"Homer Simpson, defying all medical advice, has switched to Powersauce's archrival, 'The Vitapeach Health Lock'. Doctors say he might not have the meganutrients necessary to stave off death."
 
This is like the claims that Intel processors were superior to competitors for browsing the web.

Re:"Arbitrary", but they already admitted it (5, Informative)

djtack (545324) | more than 8 years ago | (#14850333)

In the first article [com.com] on this deal that slashdot linked, Intel admitted the limit was arbitrary, and the result of a marketing deal:
But there are no specific instructions in Intel's current Pentium D or Core Duo chips that enhance the performance of VoIP applications, an Intel representative said. Skype is using an operation called "Get CPU ID" to identify the type of processor running on the PC. The Skype software has been preset to only accept Intel's chips as having the performance necessary to host conference calls of more than five people, the representative said.

Re:"Arbitrary", but they already admitted it (4, Insightful)

SillyNickName4me (760022) | more than 8 years ago | (#14850429)

The Skype software has been preset to only accept Intel's chips as having the performance necessary to host conference calls of more than five people, the representative said.

If that was said by a representative from Intel then that statement quite qualifies as misrepresenting a competing product. Comparison is perfectly fine, misrepresentation is definitely not and Intel should be forced to compensate for it.

Now all that's missing (2, Insightful)

Anonymous Coward | more than 8 years ago | (#14850067)

..is someone demonstrating that the X2 can in fact handle 9+1 persons at once, which I have no doubt it can. Then it's time for Intel to open up the wallet and give AMD some nice $$$ and some even nicer PR. Stand by to bend over!

Re:Now all that's missing (0)

Anonymous Coward | more than 8 years ago | (#14850120)

time for Intel to open up the wallet and give AMD some nice $$$

So, why is it that Intel should pay AMD for software that Skype wrote? I'm not seeing the connection here.

Re:Now all that's missing (1)

geoff lane (93738) | more than 8 years ago | (#14850182)

Well AMD could justifiably ask why there are no checks for multi-core AMD CPUs.

If the only reason why the limit exists is that on less powerful systems the performance of > 5 members is poor, then surely a better set of checks would allow a better service on a wider number of platforms.

Victory for AMD? Not so fast! (2, Funny)

DingerX (847589) | more than 8 years ago | (#14850075)

I know what you all are thinking. Great! He hacked it with three bytes, and showed his work. Now all AMD needs to do is get a 10-way conference call going on an X2 and they'll have another strike in their lawsuit against intel.

But wait -- there is a way out. See the code is written to identify CPUs, and to run on dual core CPUs, but it doesn't make that distinction for AMD. So all the defense needs to do is set up an XP box running an AMD 1.4 GhZ "Firebird", next to some oily rags, get a 10-way conference call going, and simulate a CPU heatsink failure. Clearly they were blocking AMD 10-way calls out of product liability concerns.

Parent is a loser. (-1, Flamebait)

Anonymous Coward | more than 8 years ago | (#14850100)

Parent is a loser. Mod down.

Re:Parent is a loser. (0)

Anonymous Coward | more than 8 years ago | (#14850121)

parent doesnt understand sarcasm and needs to get a life

Re:Parent is a loser. (-1, Flamebait)

Anonymous Coward | more than 8 years ago | (#14850309)

Parent doesn't understand how to execute sarcasm and should be executed himself.

Re:Parent is a loser. (0)

Anonymous Coward | more than 8 years ago | (#14850428)

parent engaged in a silly argument, and should be executed too

Optimization is where? (5, Interesting)

augustz (18082) | more than 8 years ago | (#14850077)

Skype made a lot of noise in their press release saying that the 10-way feature was "optimized" for Intel chips. This was picked up by the media of course as well as evidence of AMD's poor performance.

I'm having trouble understanding what this optimization that used the special features of Intel chips (presumably their high power) was. It looks from the patch that they just check who the manufacturer is, and if it is not AMD, they pretend your computer doesn't have the power to host 10 participants.

What's also interesting is that folks likely signed up for SkypeOut and other paid products not realizing that they would be treated differently depending on what chipsets they happen to use, especially as that choice matters almost no where else. They should give more warning about this to paid users.

This focus on locking software into specific vendor chips seems a dangerous one. No longer will it be the best chip that will win, but the focus goes to competing on locking up software applications. The proprietary unix'es went down that path, and it would be sad if Intel managed to get that to happen here.

Re:Optimization is where? (4, Interesting)

dubl-u (51156) | more than 8 years ago | (#14850108)

I'm having trouble understanding what this optimization that used the special features of Intel chips (presumably their high power) was. It looks from the patch that they just check who the manufacturer is, and if it is not AMD, they pretend your computer doesn't have the power to host 10 participants.

My guess, like yours, is that this is blatant marketing crap. But it would be nice to see some tests of how many people can be usefully conferenced on different hardware. Skype is a CPU pig, and it's possible that they really have optimized it for some Intel-specific feature.

Re:Optimization is where? (5, Insightful)

Anonymous Coward | more than 8 years ago | (#14850156)

To anyone doing such testing, make sure the code running is the same that would run on a dual-core Pentium. I didn't follow the patch in detail, but you'd have to make sure that any flags changed after CPU detection (like for instance the one at 0xB8E6DC) is the same for both cases. Else you might find yourself in the situation that, yes, the limit is removed, but you're still running a different ("unoptimized") path. In the (very interesting case) that the code crashes on AMD (due to use of Intel-only prefetch instructions or whatever, I don't even know if such still exists?), such crash can be used to land smack boom right in the relevant code to analyze.

A good reverse-engineer could then fix the code if needed (substituting or even noping the faulting ops) -- the theory being that the major optimizations are in fact portable.

In fact, demonstrating that there truly really is only one code-path would be pretty damning too; that's evidence this is just pure PR with no grounding in tech at all. So either case makes for an interesting evening in front of IDA.

Re:Optimization is where? (5, Informative)

LLuthor (909583) | more than 8 years ago | (#14850199)

due to use of Intel-only prefetch instructions or whatever

The AMD instruction set is a strict superset of the Intel instruction set. There are no Intel-only instructions anymore. There are however many AMD-only instructions (3dnow, 3dnow+, etc.), so if the situation were reversed, there might have been a legitimate claim, but since the AMD CPUs were locked out, it is clearly a bribe^Wmarketing descision.

Re:Optimization is where? (2, Funny)

Breakfast Pants (323698) | more than 8 years ago | (#14850312)

"There are no Intel-only instructions anymore." Ah, but you see, the "CPUID" instruction works differently on intel than than it does on AMD. On AMD it actually reports that the user is using an AMD processor! Intel's chips therefore have a huge advantage--marketing.

Re:Optimization is where? (0)

Anonymous Coward | more than 8 years ago | (#14850332)

Sure? IIRC there being cache synchronization instruction on the P4 that aren't in the AMD IA. But if you say so... either way it wouldn't be anything "revolutionary". i.e, it wouldn't account for any significant increase in efficiency that couldn't be properly coded to work on both types of CPUs.

Re:Optimization is where? (0)

Anonymous Coward | more than 8 years ago | (#14850381)

The EMT64 instruction set, by virtue of coming out after the AMD64, removes a couple of obscure addressing limitations in 64-bit mode that are present in the AMD64 instructions (x86-64 in general is replete with weird addressing limitations). It's technically possible to run into the use of these instructions and not have them work on an AMD64 then. Not too likely to happen in real world scenarios. Certainly not Skype.

The details are in the intel manuals somewhere.

Re:Optimization is where? (1)

netsharc (195805) | more than 8 years ago | (#14850188)

Yeah, the hacker should've done more code comparisons to see if CUPID checks are done in other parts of the programs. Having said that, a clever programmer working for Skype would've done the CPU check just once and store the result somewhere, so he could read it when he wants to do CPU-specific optimization. Considering this check was done only during the "Add Users to this Conference" segment of the program, it seems to confirm the suspicion that the only thing the CPUID is used for is to determine how many users can conference simultaneously, i.e. purely for marketing.

Re:Optimization is where? (2, Interesting)

zerocool^ (112121) | more than 8 years ago | (#14850299)


What I'd like to see is benchmarks, on Intel and Amd, with 10 clients attached. That way, we can see if the code is indeed optimized for Intel, or if it's just crap. I suspect it's crap.

If anything, I'd suspect we'd see Intel being, what, 10% or 15% less load. Which would be something, but not something which justifies a 50% crippling of AMD hardware. And it'd be funny if AMD actually performed better.

Yeah, someone should benchmark:
Origional Executable, 5 clients, Intel
Origional Executable, 5 clients, AMD
Origional Executable, 10 clients, Intel (for reference against modifications)
Modified Executable, 10 clients, Intel
Modified Executable, 10 clients, AMD

and let us know what the real beef is.

~Will

Re:Optimization is where? (0)

Anonymous Coward | more than 8 years ago | (#14850303)

How long before Microsoft pays Intel to lock out Linux?

Wait... same guy? (-1, Redundant)

Anonymous Coward | more than 8 years ago | (#14850089)

Is this the same guy that did this? OSX Crack Link [slashdot.org]

Skype Patch... from Russia with Trojan?? (5, Funny)

Anonymous Coward | more than 8 years ago | (#14850090)

Yeah right.. I'm gonna' d/l this patch and app from www.silo.ru (in Russia!!!), they even say on their aite that that "There is no virus or backdoor added!". You've got to be kidding me!

Poor programmer at Skype (4, Insightful)

tlk nnr (449342) | more than 8 years ago | (#14850098)

Will we see transcripts from depositions done by AMD?
I'd bet that they will be as funny as some of the SCO transcripts.

I'd bet that they will depose the programmer who wrote the code encryption and the GenuineIntel check, and then continue with his supervisors.

Who authorized to add code encryption?
Who approved it?
How were the limits to 5 or 10 concurrent connections determined?

Re:Poor programmer at Skype (1, Interesting)

Anonymous Coward | more than 8 years ago | (#14850144)

It's not even illegal, is it? I get a free Disney toy with my Happy Meal, so I can get 5 free extra conference callers with my Intel chip.
Skype are acting like utter jackasses, and this is a nice big point for OSS in the open-vs-closed software wars, but it's really just marketing bullshit - Skype can do what they want with their software and caveat emptor... if it was something serious like Ford removing your car's side impact guards if you own a Hitachi garage door opener then maaaybe there would be a lawsuit there...

Negative. (2, Informative)

Anonymous Coward | more than 8 years ago | (#14850217)

>I get a free Disney toy with my Happy Meal

The difference is that Skype is getting paid to make sure their software does NOT work fully with a competitor to Intel. That's a whole different ball game as far as the law is concerned. If this was 'Buy Skype and get a X% off of your next Intel Purchase' no one would give it a second thought. They're not making it BETTER on Intel, they're making it WORSE on AMD. This is very different.

(if this post is redundant it might be because I have to wait no less than 15 minutes in order to post it -- I wish this system could take into account the moderation of my earlier anonymous posts. But maybe that's patented? :-\)

Re:Negative. (0)

Anonymous Coward | more than 8 years ago | (#14850408)

The posting limit is only for anonymous posts, get an account and you can post every 2 minutes.

The system can't take your anonymous posts ino account because it doesn't know that they are your anonymous posts.

DMCA/TOS/EULA (-1, Redundant)

nurb432 (527695) | more than 8 years ago | (#14850101)

This would be considered a violation of the law, and make any complainer a hyprocrit. So how is this good?

Re:DMCA/TOS/EULA (1)

amliebsch (724858) | more than 8 years ago | (#14850136)

How is this a violation of the law? Reverse-engineering things not a violation of the DMCA if done for interoperability.

Re:DMCA/TOS/EULA (1)

nurb432 (527695) | more than 8 years ago | (#14850283)

Tell that to the judge.

Re:DMCA/TOS/EULA (1)

TheGhostOfDerrida (953992) | more than 8 years ago | (#14850398)

Traditionally, judges (at least in the American legal system) are supposed to, in theory, make decisions based not on what's right or wrong, but on what's legal or illegal, according to precedents set in previous similar cases, existing laws, etc. The whole point of paying 8 million billion dollars for a team of lawyers is so that they can find and present as much evidence to convince the judge that something is legal or illegal based on those same standards. Lawyers have to know a lot of very uninteresting things, be good people-persons, and argue at least on par with (if not better than) Cicero. Tell the judge nothing. You'll only make it that much harder on your lawyer when he has to translate tech-to-law to convince a judge that you're in the right.

Re:DMCA/TOS/EULA (0)

Anonymous Coward | more than 8 years ago | (#14850367)

fuck off

DMCA anyone? (0)

Anonymous Coward | more than 8 years ago | (#14850109)

Just had to mention that.

An encrypted binary? (3, Insightful)

dubl-u (51156) | more than 8 years ago | (#14850116)

Anybody know anything about their encrypted binary? I can't figure out what they were trying to achieve with that. Some sort of misguided anti-hax0r protection? Or perhaps they're trying to conceal something...

Re:An encrypted binary? (0)

Anonymous Coward | more than 8 years ago | (#14850176)


Goverment/Corporate back door ? i wouldnt past the USA

Re:An encrypted binary? (2, Informative)

quantum bit (225091) | more than 8 years ago | (#14850336)

No black helicopters here -- just greed. This is the same company that created Kazaa and bundled a bunch of spyware with it. So enterprising hackers modified it to remove the spyware, as well as the built-in advertising banners, and released Kazaa Lite.

The Skype binary is encrypted to try to prevent a similar thing from happening (removal of ads, addition of features that are technically possible but they might want to limit for marketing reasons). Up until now Skype hasn't done any sufficiently annoying advertising to drive anyone to publicly break the encryption. However, as I predicted [slashdot.org] , it didn't take long for someone to bypass once there was a reason to.

Re:An encrypted binary? (1)

killmenow (184444) | more than 8 years ago | (#14850354)

I didn't RTFA so I'm gonna make some assumptions and a SWAG. First, the assumptions:
  1. The binary you're referencing is Skype's
  2. They released it "encrypted"
  3. The reverse engineering effort succesfully circumvented the encryption
Now, the SWAG: many companies release packed and/or encrypted binaries to befuddle reverse engineering techniques. It is genuinely useless, because people who are good at reverse engineering know the counter-measures to render it useless. Perhaps people who are a little less skilled at reverse engineering executables would by stymied, but I've yet to hear of a case where encrypting a binary actually prevented it from being cracked. For every 1000 people the tactic keeps from being able to do it, there are another 10 or more for whom it's no more than a speed bump.

Re:An encrypted binary? (1)

slavemowgli (585321) | more than 8 years ago | (#14850405)

I think it's more of an effort to thwart reverse-engineering and the creation of compatible third-party clients than anything else. Encrypting the binary is just one thing; they also try to pull some other tricks, such as refusing to run when SoftICE is installed on your system, and so on.

Limit (4, Interesting)

Eightyford (893696) | more than 8 years ago | (#14850119)

So what is now limiting the conference calls to 10 people now? Is that a phone company limit, or another arbitrary limit?

Probably a limit due to bandwidth or latency... (5, Insightful)

Svartalf (2997) | more than 8 years ago | (#14850239)

Unless Skype's playing reflector for the whole conference, each peer's connectivity limits what you can/can't do.

At 128kbps (the average upstream speed on broadband these days in the US...), you can typically host a four to six way voice conference or a 2-3 way video conference. This is because you have to provide the outbound traffic for each of the peers and control traffic. With a reflector system, you can host larger conferences, limited only by the inbound bandwidth because the reflector is flipping the traffic from your mic (and possibly camera...) to all the participants. However, that's REALLY bandwidth intensive, so to keep it economical, you'd probably limit it to 10 participants or so to limit hogging of that limited resource.

Now, this is all due to everything being unicast UDP. If we had IPv6 and Multicast support for the same available, one could handle at least up to the 10 without needing a reflector as the router infrastructure would handle it right along with the video on demand, etc. streams. However, since this is not likely to happen in our or several generations' lifetimes at the rates things are going, waiting or wishing for that is a waste of time. :-)

Emulation would have worked too? (1)

winphreak (915766) | more than 8 years ago | (#14850138)

Going by CPU is useless. It's just a marketing scheme so that they make a few extra bucks. And, as proven shortly after the release, it is easily broken. However, on 2000/XP, did anyone ever consider editing the system settings to say it had a GenuineIntel brand? I can pose my 64-bit as a 32-bit sempron if i simply change it, and I'm sure that it could just as easily be branded Intel. At least that wouldn't involve decompiling and breaking various laws.

Re:Emulation would have worked too? (4, Insightful)

thebes (663586) | more than 8 years ago | (#14850187)

The software doesn't make a call to the registry or other software settings. The software makes a call to the hard coded cpuid. To get around that, need to a) hack the processor; or b) hack the software making the call.

Re:Emulation would have worked too? (1)

Dimensio (311070) | more than 8 years ago | (#14850206)

The software doesn't make a call to the registry or other software settings. The software makes a call to the hard coded cpuid. To get around that, need to a) hack the processor; or b) hack the software making the call.

Would there be a way to run the software through an emulation layer that catches such calls and sends back false information, or would such a call always go directly through the hardware?

Re:Emulation would have worked too? (1)

evilviper (135110) | more than 8 years ago | (#14850320)

Would there be a way to run the software through an emulation layer that catches such calls and sends back false information,

Possibly, but it would definately require quite a bit of overhead.

Re:Emulation would have worked too? (1)

quantum bit (225091) | more than 8 years ago | (#14850347)

You could always do full emulation in software, but that would be slow enough that the 10-party conference probably wouldn't work anyway.

I don't think there's any way to catch CPUID through processor virtualization (a la VMWare), since it's not a privledged instruction and doesn't touch any memory pages.

Re:Emulation would have worked too? (0)

Anonymous Coward | more than 8 years ago | (#14850342)

And that's exactly what he did.

Replace

CPUID

by

MOV EAX, 0x???????? (whatever P4 reports to EDX:EAX)
MOV EDX, 0x????????

and everything is fine. No way to tell WHO actually filled EAX with those bits. Now if Skype actually has a different codepath for P4 (which is not sure), and actually uses instructions that AMD CPUs don't know (which also is not sure), AMD CPUs should throw unknown opcode exceptions.

The throw locations immediately point you to the specialized P4 codepath area.
Now it'll be a bit of work to patch the codepath so it works with AMD. If it's only PREFETCH stuff, that's easy.

Re:Emulation would have worked too? (1)

Mr Z (6791) | more than 8 years ago | (#14850422)

Well, you have to be a bit more careful than that, since CPUID's a lot shorter, opcode wise, than what you're replacing it with. The key here is to hack something in-place. (CPUID is only 2 bytes long.)

Re:Emulation would have worked too? (5, Informative)

yuriismaster (776296) | more than 8 years ago | (#14850191)

The drop from 64 bit to 32 bit is one thing, however, in this case, the Skype code specifically queried the hardware for the GenuineIntel. If I remember this correctly from another /. post (not mine)

The opcode used in Skype, when activated on the processor, sets 3 4-byte registers on the processor as an identifier. This is burned into the silicon, basically.

For Intel Chips, the registers become
Genu, ineI, ntel - Genuine Intel

For AMD:
Auth, enti, cAMD - Authentic AMD

Like I said, since it's burned into the chip, there's no real way of 'masking' those registers as something else. This crack skips the verification, basically telling Skype that 'any processor is cool to run 10way' as opposed 'only GeniuneIntel chips can run 10way'

Maxxuss (1, Redundant)

LiNKz (257629) | more than 8 years ago | (#14850163)

Maxxuss is definitely making a name for himself (if it really is only one person). He is already heavily involved with removing Apple's restrictions on Mac OS X for Intel too.

The feature was also locked on certain Intel chips (0, Offtopic)

Browzer (17971) | more than 8 years ago | (#14850164)

So when the patched version runs even on your 486DX2, but runs like a special olympian don't forget not to bitch.

BitTorrent Mirror (3, Informative)

Anonymous Coward | more than 8 years ago | (#14850193)

BitTorrent Mirror here [mininova.org]

Re:BitTorrent Mirror (0)

Anonymous Coward | more than 8 years ago | (#14850241)

If Mininova is acting slow: Skype 10-User Conferencing Limitation Patch [nyud.net]

Don't Believe the Skype (3, Interesting)

Mignon (34109) | more than 8 years ago | (#14850219)

The code seems to be calling the cpuid instruction, so as far as the "Windows-only" patch, could anyone comment on patching the Linux kernel to essentially lie to the Skype client?

Or, so as not to break other programs that use cpuid (to determine which instructions they can run, for example) perhaps this could be done in a user-space way.

I'm thinking of artsdp as a model, so you would just launch your Skype client with something like "cpufake --cpuid='Genuine Intel Dual Core We Like Skype' skype.bin" (or whatever it's called.)

I've got no idea how such a program would work, but the article did say the code was encrypted so I wonder if that would be an issue.

Re:Don't Believe the Skype (1)

frieko (855745) | more than 8 years ago | (#14850296)

CPUID is a CPU opcode that runs directly on the processor. It's not even trappable, so the OS doesn't really have any way of spoofing it.

Indeed... (4, Insightful)

Svartalf (2997) | more than 8 years ago | (#14850297)

Considering that SIPPhone already HAS voice conference calls of at least 10 or more, works with ANY SIP enabled device that's not crippled to a single provider (Vonage devices come immediately to mind...), and costs nothing for VoIP calls- I'd say, skip Skype all together, especially after this little stunt.

Re:Indeed... (4, Interesting)

bobcat7677 (561727) | more than 8 years ago | (#14850415)

Svartalf, you are indeed insightful today. Personally I use Asterisk meetme conferences for all my conferencing needs. Only limited to my server horsepower and available bandwidth. Can have almost an unlimited number of people call into it through SIP, IAX2 or an IAX2 trunked PTSN #.

I tried skype a couple times (mostly because some girl talked me into it), but she wasn't worth it. The lack on interoperability totally killed it. The last thing I need is yet another app running on my main console all the time. Asterisk runs happilly on my server in the corner and rings my normal home phones all over the house if someone is trying to reach me. I might even pay for a skype IAX2 or SIP access account. But being a closed system they are too much trouble to deal with.

Re:Don't Believe the Skype (1)

serialdogma (883470) | more than 8 years ago | (#14850313)

Changing Qemu sounds like the better way to do this, the cpuid thing is an unprivileged instruction. Linux does not really care that they are called and has not part in changing the data the programme gets. But as qemu is a fast cpu emulator you could molest all the cpuid data you would ever want to with little slow down.

Need Open Standards (5, Informative)

fastdecade (179638) | more than 8 years ago | (#14850231)

Just goes to show why we need open protocols and open code for the future of VOIP. It's too important to leave to a single company, which is why I prefer SIP and clients like Google Talk and Gizmo [gizmoproject.com] where possible.

don't forget openwengo (3, Interesting)

patcito (932676) | more than 8 years ago | (#14850330)

openwengo [openwengo.org] not only uses open standard protocol but is also fully GPL.

heh heh (0, Troll)

bi_boy (630968) | more than 8 years ago | (#14850249)

Pwnt.

Hackers/Crackers... The last revolutionaries? (0)

Jackie_Chan_Fan (730745) | more than 8 years ago | (#14850290)

You gotta love their efforts. Keep it up.

so what (1)

cg0def (845906) | more than 8 years ago | (#14850315)

well what can I say ... Intel is about to take one more for the team ... a law suit for unfare competition that is ... Other than that I really could care less about skype and their limit of 5 people on a conference call. The only cituation that you would use a conference call with more than 5 users is a corporate environment and I have yet to hear about one that uses Skype.

No shit (4, Insightful)

grasshoppa (657393) | more than 8 years ago | (#14850316)

It was a made-up limit? No kidding.

Remember folks; Asterisk. Skype isn't open source, and the company behind it has it's own motives. Asterisk is open source, has a good community behind it, and can do *anything* you want it to. Regardless of the hardware behind it.

Optimizing for AMD (2, Interesting)

JFMulder (59706) | more than 8 years ago | (#14850335)

Being in a company who worked exclusively on Intel and nVidia chips until recently, it is possible to have horrible performance when switching to AMD and ATI. In our case, we didn't use any nVidia specific GL calls. As for SS2, it is supported on both platform so in theory it shouldn't be an issue. The reality is, unless you are making a game and using what I'd call "game-oriented opengl calls", the performance is going to vary a LOT between ATI and nVidia. Don't believe the hype of these companies when they say that they support full OpenGL. Some either have very bad hardware for 2d ops with OpenGL or literally do software "decelleration". Benchmarks have shown speed dropping as much as 200% in some areas. As for AMD and Intel, after patching the executable, the performance was different, sometimes in favor of Intel, sometimes on AMD.

With that being said, no platform specific instructions or features were used. I suspect the Skype guys may have simply used Intel machines for so long and never bothered using AMD machines for development and then were too lazy to simply rewrite some of the code so that it runs normally on AMD. This happens especially when you write tight assembly loops by taking into account instruction latencies for one processor and then realize the performance sucks on another platform. You then have the choice, rewrite it so that the performance is similar, or slap a OPTIMIZED FOR INTEL on the box.

Thankfully we rewrote.

Why would they do this? (1)

andybarrett (958890) | more than 8 years ago | (#14850346)

This whole issue has the icky stickiness of marketing all over it. Just think how much play the Skype name will get with this, especially if it goes to the old school media houses as a story. When my Grandma calls me after she hears about it on ABC nightly news, I'll know the truth.

Interoperability? (0)

Anonymous Coward | more than 8 years ago | (#14850350)

Didn't Nintendo get in trouble a long time ago for making the GameBoy not boot unless the cartridge contained the Nintendo logo, in an attempt to force everybody to pay fees? If Intel was in fact behind this Skype thing, could you argue that AMD should be able to legitimately report GenuineIntel to applications if they want to?

10, or more? (3, Interesting)

sam0737 (648914) | more than 8 years ago | (#14850379)

Of interest here is also the code marked with (*). It reveals that the string is somehow used if a certain memory location has the value 4. Theory is, this 4 means "4 additional conference members";

Is that possible that by modifying some variables...we can have unlimited number of user in the conference?

A patch can fix? (0)

Anonymous Coward | more than 8 years ago | (#14850387)

I thought Skype said that only Intel made cpus that could handle a 10 way call. Surely that's something a patch cannot fix? ;)

Intel compiler? (3, Interesting)

kryptx (894550) | more than 8 years ago | (#14850390)

This sounds an awful lot like the type of code built by Intel's compilers, for which they're being sued by AMD. Is it possible Skype is using that very compiler, and just couldn't figure out how to make it work on AMD machines (presumably pre-lawsuit)?

DMCA for IP protection or Trade protection? (2, Insightful)

aisnota (98420) | more than 8 years ago | (#14850395)

This is a case of DMCA IP Protection being abused for trade protection rights Intel bought and paid for and AMD did not.

Sherman Anti-trust aside (which this may be a real material breach) it looks like DMCA could either get abridged or affirmed for trade control purposes. For instance, does this mean someone with an Oracle license has the right to use some delta patches to open it wider open on their AMD Opteron for better threading than Intel?

Hmmm... you see how the lines get to be less than black and white.

Two phases, huh? (2, Insightful)

Just Some Guy (3352) | more than 8 years ago | (#14850414)

The patch is the result of two phases: code analysis and design of the patch.

In other words, he found the problem then fixed it. Forgive my ignorance, but how else would you possibly go about it? Apply random patches until one kind of works?

kids these days... (5, Funny)

flynt (248848) | more than 8 years ago | (#14850425)

Spoiled kids. When I was young, an occasional 3-way was enough.
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