Comment 4 for bug 633668

(In reply to comment #1)
> Rpm is blocking the signals for a reason here: safe access - even read-only -
> in a concurrent setup such as the rpmdb requires locking. Bad things happening
> when you kill -9 a process while its blocking signals to protect critical
> sections is not a bug.

That's why POSIX provides fcntl locks that are cleaned up automatically when the process is killed. So, use them.