From: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat, 12 Feb 2022 00:26:17 +0000 (+0100)
Subject: random: do not take pool spinlock at boot
X-Git-Tag: v4.19.249~129
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=45fad90a5299589fdc4e8f6f88f6643c0317b47f;p=thirdparty%2Fkernel%2Fstable.git

random: do not take pool spinlock at boot

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@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 10b1504e1e687..de82c820b161a 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -973,10 +973,10 @@ 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;