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

Pull randomness updates from Ted Ts'o:

 - initialize the random driver earler

 - fix CRNG initialization when we trust the CPU's RNG on NUMA systems

 - other miscellaneous cleanups and fixes.

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: add a spinlock_t to struct batched_entropy
  random: document get_random_int() family
  random: fix CRNG initialization when random.trust_cpu=1
  random: move rand_initialize() earlier
  random: only read from /dev/random after its pool has received 128 bits
  drivers/char/random.c: make primary_crng static
  drivers/char/random.c: remove unused stuct poolinfo::poolbits
  drivers/char/random.c: constify poolinfo_table

1 files changed, 14 insertions, 7 deletions

diff --git a/init/main.c b/init/main.c
index efe6d62e3846..33c87e91dc37 100644
--- a/init/main.c
+++ b/init/main.c
@@ -569,13 +569,6 @@ asmlinkage __visible void __init start_kernel(void)
         page_address_init();
         pr_notice("%s", linux_banner);
         setup_arch(&command_line);
-        /*
-         * Set up the the initial canary and entropy after arch
-         * and after adding latent and command line entropy.
-         */
-        add_latent_entropy();
-        add_device_randomness(command_line, strlen(command_line));
-        boot_init_stack_canary();
         mm_init_cpumask(&init_mm);
         setup_command_line(command_line);
         setup_nr_cpu_ids();
@@ -660,6 +653,20 @@ asmlinkage __visible void __init start_kernel(void)
         hrtimers_init();
         softirq_init();
         timekeeping_init();
+
+        /*
+         * For best initial stack canary entropy, prepare it after:
+         * - setup_arch() for any UEFI RNG entropy and boot cmdline access
+         * - timekeeping_init() for ktime entropy used in rand_initialize()
+         * - rand_initialize() to get any arch-specific entropy like RDRAND
+         * - add_latent_entropy() to get any latent entropy
+         * - adding command line entropy
+         */
+        rand_initialize();
+        add_latent_entropy();
+        add_device_randomness(command_line, strlen(command_line));
+        boot_init_stack_canary();
+
         time_init();
         printk_safe_init();
         perf_event_init();