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Programming Businesses OS X Operating Systems IT Technology Apple

Apple Crippled Its DTrace Port 476

Posted by kdawson
from the nothing-to-see-here dept.
Linnen writes in to note that one of developers of Sun's open source system tracing tool, DTrace, has discovered that Apple crippled its port of the tool so that software like iTunes could not be traced. From Adam Leventhal's blog: "I let it run for a while, made iTunes do some work, and the result when I stopped the script? Nothing. The expensive DTrace invocation clearly caused iTunes to do a lot more work, but DTrace was giving me no output. Which started me thinking... did they? Surely not. They wouldn't disable DTrace for certain applications. But that's exactly what Apple's done with their DTrace implementation. The notion of true systemic tracing was a bit too egalitarian for their classist sensibilities..."
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Apple Crippled Its DTrace Port

Comments Filter:
  • DRM? (Score:4, Interesting)

    by StevisF (218566) on Tuesday January 22, 2008 @05:29PM (#22145398)
    Could this to help prevent circumvention of DRM?
  • Re:DRM? (Score:2, Interesting)

    by mwsmith824 (638640) on Tuesday January 22, 2008 @05:34PM (#22145452)
    Most likely yes as iTunes is the only app that sets the flag. How quickly will Apple patch around the hack is the interesting question....
  • Luckily... (Score:5, Interesting)

    by cromar (1103585) on Tuesday January 22, 2008 @05:35PM (#22145476)
    From the DTrace source (in an #IFDEF APPLE):
    /*
    * If the thread on which this probe has fired belongs to a process marked P_LNOATTACH
    * then this enabling is not permitted to observe it. Move along, nothing to see here.
    */


    Luckily no malicious programmer will mark their malware's process with this flag!
  • Re:Luckily... (Score:2, Interesting)

    by crunchy_one (1047426) on Tuesday January 22, 2008 @05:52PM (#22145770)
    This reminds me of the bozo bit in the early Macintosh file system. Not much protection, but it did force the attacker to take an action that might be later used to demonstrate intent. Perhaps the P_LNOATTACH serves a similar purpose?
  • it's kdawson day (Score:3, Interesting)

    by Quadraginta (902985) on Tuesday January 22, 2008 @05:56PM (#22145832)
    It's like this every time kdawson takes a turn posting stuff to the front page. Wish he'd join up with his natural comrades at digg.com and take the tired rewarmed leftovers of 19th and 20th century politics away with him.
  • One question: (Score:4, Interesting)

    by MsGeek (162936) on Tuesday January 22, 2008 @06:01PM (#22145916) Homepage Journal
    Isn't this a F/OSS program? Couldn't you just recompile an uncompromised version of the source?
  • by Anonymous Coward on Tuesday January 22, 2008 @06:03PM (#22145942)

    Dislike their choice, sure. But there's no epic struggle for humanity here.

    "Do you want to spend the rest of your life selling sugared water or do you want a chance to change the world?"
  • by msimm (580077) on Tuesday January 22, 2008 @06:11PM (#22146050) Homepage
    Is it just my imagination or is this post a dupe [slashdot.org]? And a positively moderated dupe at that (twice!).

    Not that I mind, but suddenly I feel at least 50% less efficient.
  • Re:Luckily... (Score:3, Interesting)

    by Hamilton Lovecraft (993413) on Tuesday January 22, 2008 @06:31PM (#22146358)
    Google says Results 1 - 10 of about 91,600 for "move along, nothing to see here" -site:slashdot.org.
  • One step back (Score:5, Interesting)

    by bdgregg (744616) on Tuesday January 22, 2008 @06:40PM (#22146492) Homepage

    Yes, it's annoying - every time we examine the system we are now looking at everything except for iTunes (and possibly Spy-WaR3 ;-). But this issue is about more than just that.

    I've introduced DTrace to many companies. While most people love it, some developers of closed source software are concerned about people DTracing their code. DTrace allows customers to gather proof of bugs that are embarrassing, hard to fix, or that the developers have deny existed. I've been asked many times if DTrace can be disabled for an application, usually to avoid negative publicity from the bugs that DTrace will expose. The answer has always been no. It's been great to see developers accept this reality and escelate bug fixing.

    This is expected - DTrace visibility should improve overall code quality in IT. Hopefully it will also encourage employers to hire better programmers - since if customers don't use DTrace to point out embarassing bugs, then competitors may. It also erodes reasons to stay closed source - customers can use DTrace to see the code anyway.

    Giving developers another option, to disable DTrace visibility, is allowing a backwards step from the future.

  • OS-X itself (Score:4, Interesting)

    by Sycraft-fu (314770) on Tuesday January 22, 2008 @06:43PM (#22146530)
    It is DRM'd to only run on Apple hardware. There is nothing technical that prevents it from running on any modern PC since that is indeed what Macs are now. However that won't work, hence there are groups out there that have to hack it to disable that and allow it to run on any hardware.

    You can argue till your blue in the face that they need to do this, doesn't change what they are doing. If it wasn't DRM'd, it'd run fine on any hardware that met its technical requirements.
  • Corporations Ethics (Score:1, Interesting)

    by Anonymous Coward on Tuesday January 22, 2008 @07:33PM (#22147106)
    There are two differences here, how a corporation treats internals, and how it treats externals. As I understand the issue, (bear in mind my computer systems knowledge can by written legibly on a 3"x5" card in crayon), Apple disabled a tool used (among other things) to detect malign software, without publishing the fact.

    You may choose to associate with GE, and yet still have objections the Ford plant next door putting out high quantities of Carbon Monoxide. You may also have objections to freely associating with GE, and discovering after working there for 20 years that they release enough benzene into the environment in your plant to triple your cancer risk.

    Now, is disabling one tool very few people use worth government action to stop it. Perhaps not. Is disabling one tool very few people use a reasonable thing for a private individual responsible for keeping his own company's network secure something he should consider before allowing this vendors products inside his firewall? Different question.
  • Re:Luckily... (Score:3, Interesting)

    by Kjella (173770) on Tuesday January 22, 2008 @07:38PM (#22147182) Homepage

    Google says Results 1 - 10 of about 91,600 for "move along, nothing to see here" -site:slashdot.org.
    Yes, but:
    Google says Results 1 - 10 of about 21,900 for "move along, nothing to see here" -slashdot. That makes it 70,000 hits mentioning slashdot, 22000 that don't.
  • by jeff4747 (256583) on Tuesday January 22, 2008 @07:55PM (#22147402)

    The real problem though is that this feature actually does break DTrace. If DTrace probes while the iTunes application happens to be the application currently running on the CPU, the DTrace probe won't run.

    In what situation is this a problem if you are not probing iTunes? If you're trying to get info from another program, iTunes won't be the application currently runing on the CPU when the event happens.

  • Explain Amazon? (Score:1, Interesting)

    by Anonymous Coward on Tuesday January 22, 2008 @07:57PM (#22147412)
    "Without Apple DRM, iTunes (store) would be impossible due to the idiot record labels."

    Well, they're selling mp3's on amazon with no DRM.

    Or are you going to give the credit to apple for that? Next thing you know, you'll be saying "this isn't so bad" and follow it up with "the record labels have the right to protect their property".

  • Re:OS-X itself (Score:2, Interesting)

    by onefriedrice (1171917) on Tuesday January 22, 2008 @09:25PM (#22148294)
    Mac OS X runs on a Mac. This is the way it has always been. Apple started using Intel chips, but why did you expect that anything would (or should) change? Let me repeat: Mac OS X runs on a Mac!

    You can argue till your blue in the face that they need to do this, doesn't change what they are doing. If it wasn't DRM'd, it'd run fine on any hardware that met its technical requirements.
    Your statement is false. If Mac OS X was allowed to (marketed to, sold to) run on commodity x86 hardware, then you can be sure that _many_ people would do it! I think you agree. You are wrong, however, in saying that it (OS X) would run just fine. It wouldn't, and have you considered how much support costs would sky-rocket with people trying to use OS X on hardware or with hardware that wasn't designed for it? The only reason OS X as we know it is possible is because it must only support a much narrower spectrum of hardware. Therefore Apple can put their resources to better use actually developering their products.

    The trade-off of course, if you want to get on-board you had better get a Mac, because Mac OS X runs on a Mac. You can whine and moan all day long about how that mean Apple doesn't support using OS X on commodity hardware to reduce their support costs. On the other hand, you can realize that OS X doesn't carry enough value itself to justify having to buy extra hardware to use it and go along your merry way with Ubuntu or Windows or whatever tool has justifiable value to you.
  • Re:DRM? (Score:3, Interesting)

    by mikael (484) on Tuesday January 22, 2008 @09:44PM (#22148440)
    It might even help someone write a subversive program that cannot be traced - create a new executable file with these bits set (or have them set during execution, or whatever), execute this process and you have something running that can't be traced.
  • Re:Wow (Score:2, Interesting)

    by Lally Singh (3427) on Tuesday January 22, 2008 @10:12PM (#22148694) Journal
    Melodrama aside, it looks like dtrace needs to be fixed to properly deny access. Access is currently denied, as appropriate, but used more CPU than needed to do so. Not exactly broken (which implies a design failure), but a bug.

    Hardly a bug worthy of saying "Apple crippled its dtrace port."

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