Revert "random: use static branch for crng_ready()"

This reverts upstream commit f5bda35fba615ace70a656d4700423fa6c9bebee
from stable. It's not essential and will take some time during 5.19 to
work out properly.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

diff --git a/drivers/char/random.c b/drivers/char/random.c
index e2f1fce..4ed2dc2 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -79,8 +79,7 @@ static enum {
        CRNG_EARLY = 1, /* At least POOL_EARLY_BITS collected */
        CRNG_READY = 2  /* Fully initialized with POOL_READY_BITS collected */
 } crng_init __read_mostly = CRNG_EMPTY;
-static DEFINE_STATIC_KEY_FALSE(crng_is_ready);
-#define crng_ready() (static_branch_likely(&crng_is_ready) || crng_init >= CRNG_READY)
+#define crng_ready() (likely(crng_init >= CRNG_READY))
 /* Various types of waiters for crng_init->CRNG_READY transition. */
 static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);
 static struct fasync_struct *fasync;
@@ -110,11 +109,6 @@ bool rng_is_initialized(void)
 }
 EXPORT_SYMBOL(rng_is_initialized);
 
-static void __cold crng_set_ready(struct work_struct *work)
-{
-       static_branch_enable(&crng_is_ready);
-}
-
 /* Used by wait_for_random_bytes(), and considered an entropy collector, below. */
 static void try_to_generate_entropy(void);
 
@@ -268,7 +262,7 @@ static void crng_reseed(void)
                ++next_gen;
        WRITE_ONCE(base_crng.generation, next_gen);
        WRITE_ONCE(base_crng.birth, jiffies);
-       if (!static_branch_likely(&crng_is_ready))
+       if (!crng_ready())
                crng_init = CRNG_READY;
        spin_unlock_irqrestore(&base_crng.lock, flags);
        memzero_explicit(key, sizeof(key));
@@ -711,7 +705,6 @@ static void extract_entropy(void *buf, size_t len)
 
 static void __cold _credit_init_bits(size_t bits)
 {
-       static struct execute_work set_ready;
        unsigned int new, orig, add;
        unsigned long flags;
 
@@ -727,7 +720,6 @@ static void __cold _credit_init_bits(size_t bits)
 
        if (orig < POOL_READY_BITS && new >= POOL_READY_BITS) {
                crng_reseed(); /* Sets crng_init to CRNG_READY under base_crng.lock. */
-               execute_in_process_context(crng_set_ready, &set_ready);
                process_random_ready_list();
                wake_up_interruptible(&crng_init_wait);
                kill_fasync(&fasync, SIGIO, POLL_IN);