Shouldn't glibc provide an arc4random?
Apparently the new syscall is not for direct use [1], and
you might not want to link with LibreSSL just to get arc4random [2]
[1] http://www.openbsd.org/papers/hackfest2014-arc4random/mgp000... [2] http://www.openbsd.org/papers/hackfest2014-arc4random/mgp000...