From: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Tue, 7 Jun 2022 07:44:07 +0000 (+0200)
Subject: random: avoid checking crng_ready() twice in random_init()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9b29b6b20376ab64e1b043df6301d8a92378e631;p=linux.git

random: avoid checking crng_ready() twice in random_init()

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: stable@vger.kernel.org
Cc: 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 b691b9d595033..4862d4d3ec49c 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));