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

include/linux/random.h

@@ -36,6 +36,7 @@ extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;
 
 extern void get_random_bytes(void *buf, int nbytes);
 extern int wait_for_random_bytes(void);
+extern int __init rand_initialize(void);
 extern bool rng_is_initialized(void);
 extern int add_random_ready_callback(struct random_ready_callback *rdy);
 extern void del_random_ready_callback(struct random_ready_callback *rdy);

include/trace/events/random.h

@@ -62,15 +62,14 @@ DEFINE_EVENT(random__mix_pool_bytes, mix_pool_bytes_nolock,
 
 TRACE_EVENT(credit_entropy_bits,
 	TP_PROTO(const char *pool_name, int bits, int entropy_count,
-		 int entropy_total, unsigned long IP),
+		 unsigned long IP),
 
-	TP_ARGS(pool_name, bits, entropy_count, entropy_total, IP),
+	TP_ARGS(pool_name, bits, entropy_count, IP),
 
 	TP_STRUCT__entry(
 		__field( const char *,	pool_name		)
 		__field(	  int,	bits			)
 		__field(	  int,	entropy_count		)
-		__field(	  int,	entropy_total		)
 		__field(unsigned long,	IP			)
 	),
 
@@ -78,14 +77,12 @@ TRACE_EVENT(credit_entropy_bits,
 		__entry->pool_name	= pool_name;
 		__entry->bits		= bits;
 		__entry->entropy_count	= entropy_count;
-		__entry->entropy_total	= entropy_total;
 		__entry->IP		= IP;
 	),
 
-	TP_printk("%s pool: bits %d entropy_count %d entropy_total %d "
-		  "caller %pS", __entry->pool_name, __entry->bits,
-		  __entry->entropy_count, __entry->entropy_total,
-		  (void *)__entry->IP)
+	TP_printk("%s pool: bits %d entropy_count %d caller %pS",
+		  __entry->pool_name, __entry->bits,
+		  __entry->entropy_count, (void *)__entry->IP)
 );
 
 TRACE_EVENT(push_to_pool,

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();