Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull randomness updates from Ted Ts'o:
 "Cleanups and bug fixes to /dev/random, add a new getrandom(2) system
  call, which is a superset of OpenBSD's getentropy(2) call, for use
  with userspace crypto libraries such as LibreSSL.

  Also add the ability to have a kernel thread to pull entropy from
  hardware rng devices into /dev/random"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  hwrng: Pass entropy to add_hwgenerator_randomness() in bits, not bytes
  random: limit the contribution of the hw rng to at most half
  random: introduce getrandom(2) system call
  hw_random: fix sparse warning (NULL vs 0 for pointer)
  random: use registers from interrupted code for CPU's w/o a cycle counter
  hwrng: add per-device entropy derating
  hwrng: create filler thread
  random: add_hwgenerator_randomness() for feeding entropy from devices
  random: use an improved fast_mix() function
  random: clean up interrupt entropy accounting for archs w/o cycle counters
  random: only update the last_pulled time if we actually transferred entropy
  random: remove unneeded hash of a portion of the entropy pool
  random: always update the entropy pool under the spinlock

arch/x86/syscalls/syscall_32.tbl

@@ -361,3 +361,4 @@
 352	i386	sched_getattr		sys_sched_getattr
 353	i386	renameat2		sys_renameat2
 354	i386	seccomp			sys_seccomp
+355	i386	getrandom		sys_getrandom

arch/x86/syscalls/syscall_64.tbl

@@ -324,6 +324,7 @@
 315	common	sched_getattr		sys_sched_getattr
 316	common	renameat2		sys_renameat2
 317	common	seccomp			sys_seccomp
+318	common	getrandom		sys_getrandom
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact