processes match the given criteria. Since revision 1.60 of malloc.c,
malloc() and friends return an invalid pointer when given a size of 0.
kvm_getprocs() uses sysctl() with a NULL oldp argument to get an
initial size, but does not check whether it's 0 before passing it to
realloc() (via _kvm_realloc()). Before the aforementioned malloc()
change, this resulted in a minimal allocation made and a valid poitner
returned, but now results in an invalid, but non-NULL, pointer being
returned. When this is passed to sysctl(), the latter returns EFAULT
(as it should).