mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: linux-kernel@vger.kernel.org
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>,
	Dominik Brodowski <linux@dominikbrodowski.net>
Subject: [PATCH] random: avoid checking crng_ready() twice in random_init()
Date: Tue,  7 Jun 2022 12:53:03 +0200	[thread overview]
Message-ID: <20220607105303.744076-1-Jason@zx2c4.com> (raw)

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


                 reply	other threads:[~2022-06-07 10:57 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220607105303.744076-1-Jason@zx2c4.com \
    --to=jason@zx2c4.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@dominikbrodowski.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®