Clamav-90_2 Lockup with freebsd 6.2

[Martin Blapp]

Hi all,

After adding some debug stuff to clamd running with freebsd
libpthread.so I found that:

looking at the output value of 'ps -auxH | grep clamd | grep -v grep | wc -l'
is always staying at 6 threads, but the number of threadpool->thr_alive is
going higher and higher. So threadpool->thr_alive isn't decreased and
is completly incorrect.

In my tests the number of threads with libpthread.so is never going higher than 
6 threads. That explains, why a higher load is going to delay all scan 
operations more and more.

With libthr.so the value of threadpool->thr_alive is equal with the 
output of the ps. It can go very high, but always goes back if no more
work is there to do.

After the maxthreads limit is reached, clamd becomes completly unresponsive
with libpthreads.so.

SIGKILL and SIGSTOP don't work because some (unexisting) worker threads block 
on pthread_cond_timedwait(). Only kill -9 helps. Of course, the counter 
threadpool->thr_alive is wrong and may cause this problem.

Maybe someone with more threads knowledge can help here. I'll now add some debug
stuff to see where threadpool->thr_alive is going to be increased and where it
is decreased. The strange thing is that this works fine with libthr.so.

Martin