[$] Another try for getrandom() in the vDSO

Random numbers, it seems, can never be random enough, and they cannot be
generated quickly enough. The kernel's getrandom()
system call might, after years of discussion, be seen as sufficiently
secure by most users, but it is still a system call. Linux system calls
are relatively fast, but they are necessarily slower than calling a
function directly. In an attempt to speed the provision of secure random
data to user space, Jason Donenfeld has put together an
implementation of getrandom() that lives in the virtual dynamic
shared object (vDSO) area.