random: make consistent usage of crng_ready()

Rather than sometimes checking `crng_init < 2`, we should always use the
crng_ready() macro, so that should we change anything later, it's
consistent. Additionally, that macro already has a likely() around it,
which means we don't need to open code our own likely() and unlikely()
annotations.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 50973a074d2d5bbec849d9198da2670288bc88d2..19a602c69f2fcc0e202d540ef19da0f358be07e6 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -122,18 +122,13 @@ static void try_to_generate_entropy(void);
  */
 int wait_for_random_bytes(void)
 {
-       if (likely(crng_ready()))
-               return 0;
-
-       do {
+       while (!crng_ready()) {
                int ret;
                ret = wait_event_interruptible_timeout(crng_init_wait, crng_ready(), HZ);
                if (ret)
                        return ret > 0 ? 0 : ret;
-
                try_to_generate_entropy();
-       } while (!crng_ready());
-
+       }
        return 0;
 }
 EXPORT_SYMBOL(wait_for_random_bytes);
@@ -288,7 +283,7 @@ static void crng_reseed(bool force)
                ++next_gen;
        WRITE_ONCE(base_crng.generation, next_gen);
        WRITE_ONCE(base_crng.birth, jiffies);
-       if (crng_init < 2) {
+       if (!crng_ready()) {
                crng_init = 2;
                finalize_init = true;
        }
@@ -351,7 +346,7 @@ static void crng_make_state(u32 chacha_state[CHACHA_STATE_WORDS],
         * ready, we do fast key erasure with the base_crng directly, because
         * this is what crng_pre_init_inject() mutates during early init.
         */
-       if (unlikely(!crng_ready())) {
+       if (!crng_ready()) {
                bool ready;
 
                spin_lock_irqsave(&base_crng.lock, flags);
@@ -794,7 +789,7 @@ static void credit_entropy_bits(size_t nbits)
                entropy_count = min_t(unsigned int, POOL_BITS, orig + add);
        } while (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig);
 
-       if (crng_init < 2 && entropy_count >= POOL_MIN_BITS)
+       if (!crng_ready() && entropy_count >= POOL_MIN_BITS)
                crng_reseed(false);
 }
 
@@ -956,7 +951,7 @@ int __init rand_initialize(void)
        extract_entropy(base_crng.key, sizeof(base_crng.key));
        ++base_crng.generation;
 
-       if (arch_init && trust_cpu && crng_init < 2) {
+       if (arch_init && trust_cpu && !crng_ready()) {
                crng_init = 2;
                pr_notice("crng init done (trusting CPU's manufacturer)\n");
        }
@@ -1558,7 +1553,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
        case RNDRESEEDCRNG:
                if (!capable(CAP_SYS_ADMIN))
                        return -EPERM;
-               if (crng_init < 2)
+               if (!crng_ready())
                        return -ENODATA;
                crng_reseed(false);
                return 0;