linux-kernel - [PATCH 5.17 039/111] random: do not take pool spinlock at boot

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 27 May 2022 10:49:11 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Eric Biggers <ebiggers@...gle.com>,
        Dominik Brodowski <linux@...inikbrodowski.net>,
        "Jason A. Donenfeld" <Jason@...c4.com>
Subject: [PATCH 5.17 039/111] random: do not take pool spinlock at boot

From: "Jason A. Donenfeld" <Jason@...c4.com>

commit afba0b80b977b2a8f16234f2acd982f82710ba33 upstream.

Since rand_initialize() is run while interrupts are still off and
nothing else is running, we don't need to repeatedly take and release
the pool spinlock, especially in the RDSEED loop.

Reviewed-by: Eric Biggers <ebiggers@...gle.com>
Reviewed-by: Dominik Brodowski <linux@...inikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@...c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/char/random.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -978,10 +978,10 @@ int __init rand_initialize(void)
 			rv = random_get_entropy();
 			arch_init = false;
 		}
-		mix_pool_bytes(&rv, sizeof(rv));
+		_mix_pool_bytes(&rv, sizeof(rv));
 	}
-	mix_pool_bytes(&now, sizeof(now));
-	mix_pool_bytes(utsname(), sizeof(*(utsname())));
+	_mix_pool_bytes(&now, sizeof(now));
+	_mix_pool_bytes(utsname(), sizeof(*(utsname())));
 
 	extract_entropy(base_crng.key, sizeof(base_crng.key));
 	++base_crng.generation;