[PATCH] random: avoid checking crng_ready() twice in random_init()

From: Jason A. Donenfeld
Date: Tue Jun 07 2022 - 06:57:51 EST


The current flow expands to:

if (crng_ready())
...
else if (...)
if (!crng_ready())
...

The second crng_ready() call is redundant, but can't so easily be
optimized out by the compiler.

This commit simplifies that to:

if (crng_ready()
...
else if (...)
...

Fixes: 560181c27b58 ("random: move initialization functions out of hot pages")
Cc: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
drivers/char/random.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index b691b9d59503..4862d4d3ec49 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -801,7 +801,7 @@ int __init random_init(const char *command_line)
if (crng_ready())
crng_reseed();
else if (trust_cpu)
- credit_init_bits(arch_bytes * 8);
+ _credit_init_bits(arch_bytes * 8);
used_arch_random = arch_bytes * 8 >= POOL_READY_BITS;

WARN_ON(register_pm_notifier(&pm_notifier));
--
2.35.1