On Tue, Sep 15, 2009 at 7:06 AM, Stefan Bucur <stefan.bucur at epfl.ch> wrote:
> Greetings,
>
> I was trying to run KLEE on the "ls" utility, and in a certain point
> KLEE crashed with an output like:
>
> KLEE: WARNING: unable to write output test case, losing it
> KLEE: WARNING: error opening: test3-000075.time
> 0 ? klee 0x08961b48

Right, this is a current known limitation of KLEE and as other emails
describe upping the max number of files is the current best solution.

I do have a bug for the basic KLEE work needed to extended the POSIX
runtime to not have this bug, though:
http://llvm.org/bugs/show_bug.cgi?id=4896

 - Daniel

> I modified KLEE to give more details regarding the cause of the error,
> and it turned out to be that the errno is EMFILE -
> too many open files. I adapted KLEE to avoid crashing by redirecting
> the output to stderr instead of dereferencing a NULL file object, and
> I ran "lsof" on it, while executing after the first error occured. The
> results:
>
> klee ? ? ?10269 ? ? ubuntu ?155r ? ? ?DIR ? ?8,1 ? ? 4096 589827
> /home/ubuntu
> klee ? ? ?10269 ? ? ubuntu ?156r ? ? ?DIR ? ?8,1 ? ? 4096 589827
> /home/ubuntu
> klee ? ? ?10269 ? ? ubuntu ?157r ? ? ?DIR ? ?8,1 ? ? 4096 589827
> /home/ubuntu
> klee ? ? ?10269 ? ? ubuntu ?158r ? ? ?DIR ? ?8,1 ? ? 4096 589827
> /home/ubuntu
> klee ? ? ?10269 ? ? ubuntu ?159r ? ? ?DIR ? ?8,1 ? ? 4096 589827
> /home/ubuntu
> klee ? ? ?10269 ? ? ubuntu ?160r ? ? ?REG ? ?8,1 ? ? ?729 377494
> /etc/group
> klee ? ? ?10269 ? ? ubuntu ?161r ? ? ?DIR ? ?8,1 ? ? 4096 589827
> /home/ubuntu
> [.... more similar results, with the home directory open many many times ...]
>
> ubuntu at domU-12-31-39-04-26-31:~$ lsof | grep klee | wc -l
> 439
>
> I also noticed that while KLEE does not crash anymore, no subsequent
> test files could be written after the initial failure moment. Do you
> have any idea where should I look in the code to fix the problem?
>
> Thank you very much,
> Stefan
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