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From: Nicolai Stange <nstange@suse.de>
To: "Theodore Y. Ts'o" <tytso@mit.edu>
Cc: linux-crypto@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	"Alexander E. Patrakov" <patrakov@gmail.com>,
	"Ahmed S. Darwish" <darwish.07@gmail.com>,
	"Willy Tarreau" <w@1wt.eu>,
	"Matthew Garrett" <mjg59@srcf.ucam.org>,
	"Vito Caputo" <vcaputo@pengaru.com>,
	"Andreas Dilger" <adilger.kernel@dilger.ca>,
	"Jan Kara" <jack@suse.cz>, "Ray Strode" <rstrode@redhat.com>,
	"William Jon McCann" <mccann@jhu.edu>,
	zhangjs <zachary@baishancloud.com>,
	"Andy Lutomirski" <luto@kernel.org>,
	"Florian Weimer" <fweimer@redhat.com>,
	"Lennart Poettering" <mzxreary@0pointer.de>,
	"Peter Matthias" <matthias.peter@bsi.bund.de>,
	"Marcelo Henrique Cerri" <marcelo.cerri@canonical.com>,
	"Roman Drahtmueller" <draht@schaltsekun.de>,
	"Neil Horman" <nhorman@redhat.com>,
	"Randy Dunlap" <rdunlap@infradead.org>,
	"Julia Lawall" <julia.lawall@inria.fr>,
	"Dan Carpenter" <dan.carpenter@oracle.com>,
	"Andy Lavr" <andy.lavr@gmail.com>,
	"Eric Biggers" <ebiggers@kernel.org>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>,
	"Stephan Müller" <smueller@chronox.de>,
	"Torsten Duwe" <duwe@suse.de>, "Petr Tesarik" <ptesarik@suse.cz>,
	"Nicolai Stange" <nstange@suse.de>
Subject: [RFC PATCH 03/41] random: prune dead assignment to entropy_bits in credit_entropy_bits()
Date: Mon, 21 Sep 2020 09:58:19 +0200	[thread overview]
Message-ID: <20200921075857.4424-4-nstange@suse.de> (raw)
In-Reply-To: <20200921075857.4424-1-nstange@suse.de>

Since commit 90ea1c6436d2 ("random: remove the blocking pool"), the
last assignment to 'entropy_bits' is dead. Remove it.

While at it, move the declaration of 'entropy_bits' one scope down and make
it const: it's not used anywhere outside and never updated after
initialization.

Signed-off-by: Nicolai Stange <nstange@suse.de>
---
 drivers/char/random.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index c4b7bdbd460e..14c39608cc17 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -716,13 +716,12 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
 				  entropy_count >> ENTROPY_SHIFT, _RET_IP_);
 
 	if (r == &input_pool) {
-		int entropy_bits = entropy_count >> ENTROPY_SHIFT;
-
 		if (crng_init < 2) {
+			const int entropy_bits = entropy_count >> ENTROPY_SHIFT;
+
 			if (entropy_bits < 128)
 				return;
 			crng_reseed(&primary_crng, r);
-			entropy_bits = ENTROPY_BITS(r);
 		}
 	}
 }
-- 
2.26.2


  parent reply	other threads:[~2020-09-21  8:01 UTC|newest]

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-21  7:58 [DISCUSSION PATCH 00/41] random: possible ways towards NIST SP800-90B compliance Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 01/41] random: remove dead code in credit_entropy_bits() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 02/41] random: remove dead code for nbits < 0 " Nicolai Stange
2020-09-21  7:58 ` Nicolai Stange [this message]
2020-09-21  7:58 ` [RFC PATCH 04/41] random: drop 'reserved' parameter from extract_entropy() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 05/41] random: don't reset entropy to zero on overflow Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 06/41] random: factor the exponential approximation in credit_entropy_bits() out Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 07/41] random: let pool_entropy_delta() take nbits in units of 2^-ENTROPY_SHIFT Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 08/41] random: introduce __credit_entropy_bits_fast() for hot paths Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 09/41] random: protect ->entropy_count with the pool spinlock Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 10/41] random: implement support for delayed entropy dispatching Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 11/41] random: convert add_timer_randomness() to queued_entropy API Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 12/41] random: convert add_interrupt_randomness() " Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 13/41] random: convert try_to_generate_entropy() " Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 14/41] random: drop __credit_entropy_bits_fast() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 15/41] random: convert add_hwgenerator_randomness() to queued_entropy API Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 16/41] random: convert random_ioctl() " Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 17/41] random: drop credit_entropy_bits() and credit_entropy_bits_safe() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 18/41] random: move arch_get_random_seed() calls in crng_reseed() into own loop Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 19/41] random: reintroduce arch_has_random() + arch_has_random_seed() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 20/41] random: provide min_crng_reseed_pool_entropy() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 21/41] random: don't invoke arch_get_random_long() from add_interrupt_randomness() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 22/41] random: introduce arch_has_sp800_90b_random_seed() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 23/41] random: don't award entropy to non-SP800-90B arch RNGs in FIPS mode Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 24/41] init: call time_init() before rand_initialize() Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 25/41] random: probe cycle counter resolution at initialization Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 26/41] random: implement support for evaluating larger fast_pool entropies Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 27/41] random: increase per-IRQ event entropy estimate if in FIPS mode Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 28/41] random: don't award entropy to disk + input events " Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 29/41] random: move definition of struct queued_entropy and related API upwards Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 30/41] random: add a queued_entropy instance to struct fast_pool Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 31/41] random: introduce struct health_test + health_test_reset() placeholders Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 32/41] random: introduce health test stub and wire it up Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 33/41] random: make health_test_process() maintain the get_cycles() delta Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 34/41] random: implement the "Adaptive Proportion" NIST SP800-90B health test Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 35/41] random: improve the APT's statistical power Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 36/41] random: optimize the APT's presearch Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 37/41] random: implement the "Repetition Count" NIST SP800-90B health test Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 38/41] random: enable NIST SP800-90B startup tests Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 39/41] random: make the startup tests include muliple APT invocations Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 40/41] random: trigger startup health test on any failure of the health tests Nicolai Stange
2020-09-21  7:58 ` [RFC PATCH 41/41] random: lower per-IRQ entropy estimate upon health test failure Nicolai Stange
2020-09-21  8:09 ` [DISCUSSION PATCH 00/41] random: possible ways towards NIST SP800-90B compliance Jason A. Donenfeld
2020-09-21  8:40 ` Stephan Mueller
2020-09-22 13:23   ` Torsten Duwe
2020-09-22 16:21     ` Greg Kroah-Hartman
2020-09-22 17:48       ` Torsten Duwe
2020-10-02 12:38 ` Torsten Duwe
2020-10-02 13:15   ` Willy Tarreau
2020-10-02 13:33     ` Greg Kroah-Hartman
2020-10-02 14:05       ` Torsten Duwe
2020-10-02 13:56     ` Stephan Mueller
2020-10-16 17:26       ` Torsten Duwe
2020-10-19 19:28         ` [PATCH v36 00/13] /dev/random - a new approach Stephan Müller
2020-10-19 19:30           ` [PATCH v36 01/13] Linux Random Number Generator Stephan Müller
2020-10-19 19:31           ` [PATCH v36 02/13] LRNG - allocate one DRNG instance per NUMA node Stephan Müller
2020-10-19 19:32           ` [PATCH v36 03/13] LRNG - sysctls and /proc interface Stephan Müller
2020-10-19 19:32           ` [PATCH v36 04/13] LRNG - add switchable DRNG support Stephan Müller
2020-10-19 19:33           ` [PATCH v36 05/13] LRNG - add common generic hash support Stephan Müller
2020-10-19 19:34           ` [PATCH v36 06/13] crypto: DRBG - externalize DRBG functions for LRNG Stephan Müller
2020-10-19 19:34           ` [PATCH v36 07/13] LRNG - add SP800-90A DRBG extension Stephan Müller
2020-10-19 19:35           ` [PATCH v36 08/13] LRNG - add kernel crypto API PRNG extension Stephan Müller
2020-10-19 19:35           ` [PATCH v36 09/13] crypto: provide access to a static Jitter RNG state Stephan Müller
2020-10-19 19:36           ` [PATCH v36 10/13] LRNG - add Jitter RNG fast noise source Stephan Müller
2020-10-19 19:37           ` [PATCH v36 11/13] LRNG - add SP800-90B compliant health tests Stephan Müller
2020-10-19 19:37           ` [PATCH v36 12/13] LRNG - add interface for gathering of raw entropy Stephan Müller
2020-10-19 19:38           ` [PATCH v36 13/13] LRNG - add power-on and runtime self-tests Stephan Müller
2020-10-28 17:51           ` [PATCH v36 00/13] /dev/random - a new approach Torsten Duwe
2020-10-28 18:07             ` Greg Kroah-Hartman
2020-11-02 13:44               ` Torsten Duwe
2020-11-04 14:26                 ` Marcelo Henrique Cerri
2020-11-17 14:01                 ` Torsten Duwe
2020-11-10 10:22           ` Stephan Mueller
2020-10-02 13:35   ` [DISCUSSION PATCH 00/41] random: possible ways towards NIST SP800-90B compliance Van Leeuwen, Pascal
2020-10-02 14:04     ` Greg Kroah-Hartman
2020-10-02 14:34       ` Van Leeuwen, Pascal
2020-10-02 15:13         ` Greg Kroah-Hartman
2020-10-02 15:39           ` Van Leeuwen, Pascal
2020-10-02 16:30             ` Randy Dunlap
2020-10-02 18:14             ` Theodore Y. Ts'o
2020-10-02 19:09               ` Van Leeuwen, Pascal
2020-10-07  4:24   ` Eric Biggers
2020-10-07  5:52     ` Stephan Mueller
2020-10-07 10:38     ` Nicolai Stange

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