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Code Quality: Open Source vs. Proprietary
just_another_sean sends this followup to yesterday's discussion about the quality of open source code compared to proprietary code. Every year, Coverity scans large quantities of code and evaluates it for defects. They've just released their latest report, and the findings were good news for open source. From the article:
"The report details the analysis of 750 million lines of open source software code through the Coverity Scan service and commercial usage of the Coverity Development Testing Platform, the largest sample size that the report has studied to date. A few key points: Open source code quality surpasses proprietary code quality in C/C++ projects. Linux continues to be a benchmark for open source quality. C/C++ developers fixed more high-impact defects. Analysis found that developers contributing to open source Java projects are not fixing as many high-impact defects as developers contributing to open source C/C++ projects."
Sunlight is the best bleach.
Java project developers participating in the Scan service only fixed 13 percent of the identified resource leaks, whereas participating C/C++ developers fixed 46 percent. This could be caused in part by a false sense of security within the Java programming community, due to protections built into the language, such as garbage collection. However, garbage collection can be unpredictable and cannot address system resources so these projects are at risk.
This is especially amusing in light of all the self-righteous bashing that C was getting over OpenSSL's problems. Seems it's true that using a "safe "language just makes the programmer lazy.
First, we shouldn't confuse Coverity's numerical measurements with actual code quality, which is a much more nuanced property.
Second, this report can't compare open source to proprietary code, even on the narrow measure of Coverity defect counts. In the open source group, the cost of the tool is zero (skewing the sample versus the commercial world) and Coverity reserved the rights to reveal data. Would commercial customers behave differently if they were told Coverity might reveal to the world their Coverity-alleged-defect data?
Again, having good Coverity numbers can't be presumed to be causally related to quality. For example, Coverity failed to detect the "heartbleed" bug, demonstrating that the effect of bugs on quality is very nonlinear. 10 bugs is not always worse than 1 bug; it depends on what that one bug is.
Yeah, I have seen the source code to the Windows 7 OS, CISCO's iOS and LINUX of course.
They all suck equally.
However, that being said, I am currenrlty running a version of the LINUX OS I built and modified for my customers use in a PostGRES server which is quite large.
Open Source wins again because I can correct the suck. :-)
Got Geometrodynamics? Awe, too hard to figure out? Too bad.
Crap code remains crap code.
People have to be able to provide updates... and feel appreciated by doing so. BSD licenses allow companies to "appropriate" code, and then sue the original author for copyright violations...
The report doesn't really go into an important measure.
What is the defect density of the new code that is being added to these projects?
Large projects and old projects in particular will demonstrate good scores in polishing - cleaning out old defects that are present. The new code that is being injected into the project is really where we should be looking... Coverity has the capability to do this, but it doesn't seem to be reported.
Next year it would be very interesting to see the "New code defect density" as a separate metric - currently it is "all code defect density" which may not reflect if Open Source is *producing* better code. The report shows that the collection of *existing* code is getting better each year.
First, we shouldn't confuse Coverity's numerical measurements with actual code quality, which is a much more nuanced property.
Yeah, but good quality might well correspond to some sort of measurable anyway. Provided you've got the right measure. Maybe some sort of measure of the degree of interconnectedness of the code? The more things are isolated from each other, across lots of levels (in a fractal dimension sense, perhaps) the better things are likely to be.
Maybe that would only apply to a larger project, and I'm not sure what effect system libraries (and other externals) would have. Yet the fact that it might be a scale-invariant approach makes me a bit more hopeful, as it wouldn't be so susceptible to the "ravioli code" problem, where the code's nicely packaged up into little pieces, but the pieces interconnect in a horrible mess of higher-level spaghetti code. Worked on a large project? You'll have probably seen it in the wild. (Yeah, I've had people argue to me that their code didn't use goto and so it had no spaghetti code problems, despite the fact that everything was so nastily interconnected that nobody else could understand it. If that's not indicative of a problem, what is?)
"Little does he know, but there is no 'I' in 'Idiot'!"
Most static analysis tools look for bugs and potentially buggy behavior. They must rely on limited pattern matching and data flow analysis. They can't find all bugs. See: The Halting Problem.
But that's written in C and C is the worst programming language ever!! How dare they be so dumb to not write Python in a "memory safe" langauge!
Coverity: Hey you, proprietary software developer with the deep pockets. Yeah, you. We've got this great tool for finding software defects. You should buy it.
Proprietary software developer: get lost.
Coverity: Hey, open source dudes, we've got this great defect scanner. Want to use it? Free of course!
Open source dudes: Meh, why not?
Coverity: Hey proprietary software developer, did we mention those dirty hippie neck beards are beating the stuffing out of you in defect (that we detect)-free code?
PSD: Fine, how much?
This is a useless analogy. Code Quality is a function of both skill and the stewardship of the team supporting the code. Tools help as well but you can write some elegant, high quality code regardless of the language chosen. You can also write some real shit too but ultimately how many defects a piece of software has comes down to the design and testing that goes along with it. Some bodies of work get rigorous testing and it's not like OpenSSL's recent problem wasn't about deficient design it was about a faulty implementation. Faulty implementations in logic happen all the time and there are some bugs that just take awhile to become known. I mean even with test driven development and tools for code analysis probably couldn't have found this particular issue but considering how long it was in the code base without somebody questioning it goes back to not only stewardship by the team but the rest of the world who are using the code. If anything this situation points out that FOSS can have vulnerabilities just like proprietary software however the advantage is that with FOSS you can get it fixed much more quickly and because other people can see the implementation it can become scrutinized by folks outside the team that develops and maintains it.
In the case of Heartbleed the system works. A problem was found, it was fixed it's now just a matter of rolling out the fix and regressions are put into place to help insure that it doesn't happen again. The repercussions of what it means is that another gaping hole in our privacy was closed and that "bad guys" may have stolen data, rollout the fix ASAP. Your guess is as good as mine as to what was stolen is a matter of research and conjecture at this point. I doubt that the bad guys will tell us what they gained by exploiting it. Let's also be sure that until the systems with the bug are patched, they're vulnerable so cleanup on aisle 5.
To be honest it's a bit naive if we all assume that FOSS software that handles security doesn't have potential vulnerabilities. Likewise it's also naive to assume that proprietary code has it licked as well given the revelations of NSA spying for the past year. Given that there are numerous nefarious companies that sell vulnerabilities to anybody who can pay for it, that means unless you're buying them you probably will never know what is exposed until somebody trips over it. What this means for everybody that you can depend on is when those vulnerability-selling companies are out of business can assume that your software is free of the easier to exploit vulnerabilities; governments will always use all their tools to get intelligence including subverting standards and paying off companies who can give them access to what they want.
Harrison's Postulate - "For every action there is an equal and opposite criticism"
I'm not going to yell about the openSSL guys.
I'm going to be honest here, they deserve yelling at, and I'm an open source fan. The error they made is exactly the same mistake that everyone else has made in years past when dealing with SSL: x509 and the SSL protocol demands [lengthofstring][string], "pascal" style. This is how everyone (open and closed source) got hit with that domain validation bug where the certificate said "(26)bank.com\0.blahblahblah.com". Certificate signers looked at the domain on the end of the string "blahblahblah.com" and validated it. Client programs treated it like a C string and thought it was a certificate for "bank.com". Not a single person anywhere said "whoa there, null bytes are not part of a valid hostname!"
The attack asks server to respond with "(65535)Hello" and the server replies with 65535 bytes of data. Falling for this attack is exactly like the guy who points and laughs at the person who just fell off their bike, seconds before falling off their own bike. They should have known better, especially with how high-profile these attacks were in the past.
The bit about writing their own malloc implementation, poorly, was just icing on the cake.
Now all we have to do is get Dice to Open Source their stuff so we can FIX IT!
The more complex the task, the simpler the steps need to be.
The more things are isolated from each other, across lots of levels (in a fractal dimension sense, perhaps) the better things are likely to be.
Language has a lot to do with that.
If your project is written in a managed language, allocated memory is always initialised first, there is no pointers arithmetic and array bounds are always checked, so it's impossible to read random data from memory.
If your project is written in C, all code has access to all memory.
with nearly 2x the LOC.
> People have to be able to provide updates... and feel appreciated by doing so. BSD licenses allow companies to "appropriate" code,
Very true
>and then sue the original author for copyright violations...
Say what!?!?! Source code typically must be published before being appropriated, making it trivial to prove who had the prior claim.
Of course that doesn't stop a lawsuit from being *filed*, but then nothing stops me from filing a lawsuit against you for stealing my pink unicorn either.
Patent violation are of course another thing entirely - but even there the "publish early, publish often" nature of open source will very likely work very strongly in their favor if they are the original inventors.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I would expect both "open source" code to be of approximately equal quality to proprietary code. In each ideology you will get people who care (about quality), and people who don't, in approximately equal proportions, the same with skill, ingenuity and passion for the work.
The difference is that proprietary software is constrained by the number of developers able to view and work on the code. An open source project may have a similar number, or smaller set of core developers, but a much larger pool of developers that can spot problems, suggest alternatives, fix the one bug that is affecting them, etc. Having a more diverse set of developers will increase the chances that the software improves.
You could also make an argument about the motivations of the developers. Open source projects are often a community of people passionate about what they are building and have a strong incentive to make their code readable by others. By the nature of open source a developers reputation is on the line with every bit of code they make public. I've met far more developers scared to make their horrible code public than those worried about getting fired for equivalently horrible code.
Complexity Happens
Java calls C for anything performance-critical, anyway.
Code repositories were compromised by the NSA (or other capable group)
"If any question why we died, Tell them because our fathers lied."
Disclaimer, I work for Coverity. There's a write-up on why Coverity didn't find it out of the box here:
http://security.coverity.com/b...
"My name is Linux Torvalds... and I pronounce him 'Linus'...".
"If your project is written in a managed language, allocated memory is always initialised first, there is no pointers arithmetic and array bounds are always checked, so it's impossible to read random data from memory."
Except when you forgot to remove some reference to an object, so it's still stitting around in a list somewhere because it can't be garbage-collected, and some code then uses whatever objects happen to be in that list.
No language is safe for an unthinking programmer to use.
That would be: ... the fix will be obvious to someone.
Given enough eyeballs, all bugs are shallow
Eric S Raymond
Although ESR called it " Linus' Law", it's ESR's writing, from CATB. Linus has a completely different concept that he calls "Linus' Law". Linus talks about motivations for what we do.
With all the noise about OpenSSL lately, running this Coverity test on it (and other security software like GNUTLS) and sharing the results seems like it would be a good thing...
Your four-sentence comment has five glaring errors that make it obvious that you have absolutely no idea what you're talking about. You very much remind me of the job applicant who told me he has experience in C, C+, and C++.
If you have good quality people, especially a good leader, your code will be good.
Even if the people are relatively inexperienced.
At this point, just about everything in IT/CS is a research project, not innovation.
So it's a matter of diligently doing the work based on past archetypes.
Futurist Traditionalism
Coverity is no the best "yardstick". Too many false negatives and too expensive.
Some open source projects will have better code then closed source projects and vice vesa, you can't just make a clean line.
That's an interesting thought. Had it been typed, it might be a typo. I was thinking of a guy who said that, out loud, face-to-face. That's not the only comment that made it clear he was claiming four times as much as he in fact knew.
Of course, in a interview I give someone leeway - my mind went blank once in an interview when I was asked "what are the four pillars of object oriented programming?". At the time, I could have implemented objects in C using the preprocessor*, but interview stress caused a brainfart. This guy was obviously clueless and trying to BS his way through it, though. Perhaps hoping he'd only be interviewed by a manager who wasn't a programmer.
* thanks to Perl for teaching me objects from the inside out. Understanding Perl's implementation of objects, I could see that language support for objects in 98% syntactic sugar, object.method() is the same thing as function(* object), where "object" is an associative array aka namespace aka lookup table, plus a list of class names it has.
Well over a decade? It's more like well over thirty years. There were virus infections written for MS-DOS 3.X back in the 1980s.
Good, inexpensive web hosting
are you sure about that?
that's valid C#, all you need to do is inject something like that into the codebase and let the JIT compile it (using all the lovely features they added to support dynamic code) and you're good to get all the memory you like.
Now I know the CLR will not let you do this so easily, but there's always a security vulnerability lying around waiting to be discovered that will, or an unpatched system that already has such a bug found in any of the .NET framework, for example this one that exploits... a "buffer allocation vulnerability", and is present in Silverlight.
The moral is ... don't think C programs are somehow insecure and managed languages are perfectly safe.
A managed language would not have protected against Heartbleed, because the program maintained it's own freelist to prevent memory from being unallocated. If it did not do this then being written in a managed language would have prevented Heartbleed - but then again, if it did not do this then the C code wouldn't have been vulnerable either.
Guess which language the JVM is mostly written in? Dumbass.
The only problem with this is, of course, that what they claim to be doing (automatically examining code for defects) is literally impossible.
You have very good programmers write languages like Python in C so that other programmers don't have to write in C. They can use Python instead and thus avoid making a whole bunch of common C mistakes that the very good programmers are less likely to do.
It's like letting someone else make the bricks, shingles, cement, planks, steel beams, while you stick to building stuff out of them, instead of making your own from scratch.
On a related note, perhaps you should let the smart ones do the commenting instead.
...home?
Most people will put more effort into something that will be public (both out of positive motivation and the negative motivation of shaming.)
Open Source will always, in general, be better than closed source. Again - in general. There are people who will engineer things properly irrespective of whether or not someone will be browsing your github account or checking it out of the company's private server... Too bad there's not more of them ;).
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One advantage Open Source has is that there are no deadlines and a good project leader can simply reject sub par code. For commercial code no company is going to pay a programmer big bucks and simply throw away his output because it sucks.
Riiiight.......I definitely feel more elite taking my own garbage out rather than having someone else do it for me.
Yes, so your argument is that you can, with great difficulty cause a possible security issue in C#, but in order to do so, you have to basically say... I'm about to do something possibly bad, please don't check to make sure what I'm doing is bad. Then modify the compiler from default to allow said code to be compiled, then put it into a fully trusted assembly so it bypasses all security checks, and THEN you might have an issue.
and this is comparision to where in C/C++ where you can write an exploit in 2 lines of code by accident, using nothing but defaults.
Another problem with the comparison is that the average closed-source project is four times as big as the average open-source project. I'd expect defect density to go up with size of codebase. (Of course, this may not be an issue with what Coverity detects, but if so that emphasized that Coverity doesn't find all the important defects.)
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
How can software that has any bugs be considered as good quality??? I guess that if guns are legal in your country, then buggy software may be too.
Remember that most programmers are far from half as good as the Linux coders, and thus should avoid writing code as much as possible.
FTFY
Unfetter your ideas. Copyfree your mind.
I don't think you understand copyright at all. That makes zero sense.
Unfetter your ideas. Copyfree your mind.
The (lack of) constraints on who can see the code is not the only difference. There's another difference, that for some reason gets explicitly denied as a difference by the preceding anonymous coward:
I would, in fact, expect that the passion and interest of coders in the open source world is actually far greater on average than in the closed source world, rather than exactly the same as the anonymous coward suggests. I have met many "professional" coders who write closed source software for some part of their typical eight hour workdays, and never think about code outside of that time if they can avoid it. Many of them hate coding, in fact, but do it for the paycheck, then go watch American Idol in the evenings and try to avoid having anything "boring" like computer programming intrude on their off-time.
Open source developers are the people who are interested and passionate enough about what they do to do it on their own time, or even to seek out jobs where they're allowed to contribute to open source projects on company time. That takes more dedication and honest interest in producing something good than just working in a cubicle for eight hours a day where they honestly couldn't give a shit whether what they were doing was writing code or picking their noses, as long as the paycheck keeps coming in.
Thus, I think there are some distinct benefits to open source software above and beyond the mere fact that given enough eyes, all bugs are shallow.
So, yeah . . . your second paragraph, only more so. That's my opinion.
Unfetter your ideas. Copyfree your mind.
This is the same broken metric that Coverity has been mis-using year after year.
"Defect density (defects per 1,000 lines of software code) is a commonly used measurement for software quality, and a defect density of 1.0 is considered the accepted industry standard for good quality software."
In other words, if you double the size of the code base by adding no-op code, you increase your quality score.
Also, if you leave the bugs in, but reduce code size, you are reducing your quality score.
I18N == Intergalacticization