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Webservice Debugs Linux Binaries While-U-Wait
null-und-eins writes "A new webservice offers automatic
debugging of Linux binaries. It takes a (with "-g" compiled) binary and two invocations where one fails and the other doesn't. The service repeatedly runs the two programs and tries to find the smallest difference between the two that causes the failure. Nice google-like interface with statistics about its own performance."
...these guys allow me to upload any linux executable, which they will then execute in a gdb context?
Alfred, prepare the rootkit!
All's true that is mistrusted
Now we've got it debugging the code, we only need to get it started writing the code, and we're sorted :-)
Simon
Physicists get Hadrons!
Why ask Igor when you can ask slashdot? :-)
One thing I've learned from working on and encouraging students to use GPL programs is that they are largely much higher in quality than other standard programming code deliverables.
Therefore, I challenge the author of this article to state why Linux code would need to be debugged.
I mean, honestly -- have YOU ever seen a function or class or subroutine in Linux that WASN'T damn near perfectly coded?
Reply or e-mail; don't vaguely moderate. Ex-O'Reilly/MIT employee, now a full-time Google employee.
...When I was trying to figure out what the hell was making my program crash! I figured it out, and got it fixed, but it took me 6 hours to pin point it! Something like this can (hopefully) be very useful next time I have a program that unexpectedly seg faults! =)
This space for rent, inquire within.
I site's admin configured the site to forward visitors to the google cache of the site, but if you actually try to debug something, you get back to the real site, poor admin, he thought he could get away from /.ing!
The IT section color scheme sucks.
If you have a working version, why do you need the debugger?
Your program may fail if invoked one way and work if you invoke it some other way.
Hence this.
--
the strongest word is still the word "free"
I think this is a neat idea, but I wonder why it isn't a standalone program you can run yourself as well as/instead of a web interface.
This is because I wonder why he wants to run the risk of running foreign binaries (sandbox or not) when he could have just not done that. There doesn't seem to be any advertising on the page, so that isn't it.
Oh well, maybe he just thinks it's cooler this way, actually it kinda is, so long as it's safe for him I guess.
The program I'm trying to run that is causing my computer to fail is "rm -rf". What's wrong?
-R
Find out what's wrong with that crap.
Life in Orange County
You must be joking. While some of the more "mature" projects are definately solidly coded, some of the others are nightmares. Try mixing several different coding styles, nights coding on only caffeine, starting, stopping, and losing your place...leaving debug to-fix-later code in by accident...
Open source suffers the same problems as closed. In some projects moreso, as the variance of different coding styles/standards-adherance can lead to very interesting things happening. Even some mature projects have this problem, I've heard of some common ones where a rewrite was considered, because as the code evolved and was added to, the author(s) learned much better coding as it progressed but left the core a bit flaky.
Please read the article.
The tool executes your program multiple times, and examines the internal state of the program (variable values and memory contents) at various stages in the execution.
It then automatically isolates the root cause of the failure. This is pretty cool stuff, and ought to save a lot of time tracking down complex bugs.
-Mark
I presume igor had some bugs when you were writing it. Was it able to find it's own problems? :)
Smart kids. Redirecting to their google cache.
I wonder what happens on google's next cache update, if you're doing something like that. Do you get a google cache within a google cache? Or does google just forget about you?
There are no trails. There are no trees out here.
We're redirecting only if you come from /.
That's very clever! Smart cookies.
It certainly mitigates the awesome server-melting power of the slashdot effect
Actually the characters name was Ygor, a role made famous by Bela Lugosi in Son of Frankenstein and The Ghost of Frankenstein, late 30's early 40's. Hope this helps.
I notice that Fedora Linux is full of bugs, however this site won't let me upload the entire first cd.
This fields has decades of history. A good starting point, should you like to explore it, is here.
Arg, I thought us Euro's didn't have to worry about software patents anymore. Then again, isn't it a bit weird to have AskIgor licensed under the GPL and filing patents on it at the same time? IANAL, but is this possible? You file a patent to make cash from it by licensing it to others (or using the technique yourself), or you make it opensource and give it away freely. They say that "Delta Debugging" isn't patented, but when it's applied to program states it is (will be).
Gotta love IP...
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Some bugs, though, are hard to reproduce, which means that you should set up appropriate isolation and monitoring layers in your program. The recent issue of Communications of the ACM, for instance, has a nice article on record/replay of program executions, which solves all problems of reproducing runs - in principle, that is, because such tools are not readily available yet.
Now there's some bugs that are hard to understand, especially those where there's a long delay between the defect being executed and the experienced failure. Think about a compiler that generates bad code. This is not an issue of reproduction; nor can the problem be solved by examining the stack trace. You have to work your way backwards all through the execution to understand the cause-effect chain. This is where AskIgor can really help you.
And, yeah, I got 12 years of C/C++ programming and debugging experience, too :-)
www.askigor.org - automated debugging service
Nice google-like interface...
What, you mean like a textbox?
-3Suns
~~~~
The Revolution will be Slashdotted
I totally agree with your observation. But the program doesn't have to crash for Igor to work. If the program simply outputs, say, "fail" instead of "pass" (as in the working run), AskIgor will narrow down the cause-effect chain that leads to the "fail".
www.askigor.org - automated debugging service
I remember reading a rant about a year ago. Someone wrote a replay tool for program executions for under linux, I think 2.0 or 2.2. They dropped it because nobody cared about it (probably because nobody knew about it), and they got sick of updating it constantly for new IOCTL's as the kernel constantly changed.
I think it was Carmack lamenting its loss.
Good old SIGSEGV. That's what happens when you deference null pointers, write to memory that's not yours, etc. It's the most common crash-n-burn error an application will experience. Windows calls these "Program Errors" or something now in XP. I forget. It use to call them "Access Violations". IIRC only Windows ME->98->95 had the "feature" that you could destroy other program's memory if you didn't follow all the rules.
Fuck Beta. Fuck Dice
multithreaded programs? Does it catch race conditions and such?
Igor FAQ:
...
"The Eclipse plug-ins are licensed under the GNU public license."
"The basic Delta Debugging technique (narrowing down relevant circumstances by experiments) is not covered by any patent (as far as we know); in fact, we have released Delta Debugging plug-ins for Eclipse under a GNU license.
However, Passau University has filed international patents for the automatic isolation of cause-effect chains from computer programs--that is, Delta Debugging applied to program states. This is the core technology of AskIgor. This means that if you want to make money out of AskIgor technologies, you'll have to license the patent. (That's how Passau University attempts to get some revenue from its research.) Patent licenses are handled by the Fraunhofer Society in the BayernPatent initiative. "
GPL:
"For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program."
WTF?
Maybe there is some difference between what the Eclipse plugins do and what AskIgor does, but it's not very clear from the FAQ if that is the case.
Cthulhu loves you.
Read some Terry Pratchett Discworld books.
Yeth Mathter.
eBooks available on eMule, but Hardcopy are worth the currency.
Do not meddle in the affairs of geeks for they are subtle and quick to anger
This program (which needs updating to more recent kernels) allows one to replay a binary execution.
http://old.lwn.net/1999/0121/kernel.php3
http://lwn.net/1999/0121/a/mec.html
Apparently its been out for *8* years, and has had exactly 3 people download it. Horrible -- its a feature I'd kill to have, and a feature linux should have.
I'm sorry for the inconvenience, and have made sure this problem won't happen again. But remember that this is a research project, and we can't sit besides the machine 24/7.
www.askigor.org - automated debugging service
In January, Jamie Zawinski made a post about the possibility of running a debugger backwards...