From patchwork Mon Sep 21 07:58:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolai Stange X-Patchwork-Id: 11788737 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F17A4618 for ; Mon, 21 Sep 2020 08:01:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1AAC20874 for ; Mon, 21 Sep 2020 08:01:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726497AbgIUIBw (ORCPT ); Mon, 21 Sep 2020 04:01:52 -0400 Received: from mx2.suse.de ([195.135.220.15]:56606 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726402AbgIUH7S (ORCPT ); Mon, 21 Sep 2020 03:59:18 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6CE26B500; Mon, 21 Sep 2020 07:59:51 +0000 (UTC) From: Nicolai Stange To: "Theodore Y. Ts'o" Cc: linux-crypto@vger.kernel.org, LKML , Arnd Bergmann , Greg Kroah-Hartman , "Eric W. Biederman" , "Alexander E. Patrakov" , "Ahmed S. Darwish" , Willy Tarreau , Matthew Garrett , Vito Caputo , Andreas Dilger , Jan Kara , Ray Strode , William Jon McCann , zhangjs , Andy Lutomirski , Florian Weimer , Lennart Poettering , Peter Matthias , Marcelo Henrique Cerri , Roman Drahtmueller , Neil Horman , Randy Dunlap , Julia Lawall , Dan Carpenter , Andy Lavr , Eric Biggers , "Jason A. Donenfeld" , =?utf-8?q?Stephan_M=C3=BCller?= , Torsten Duwe , Petr Tesarik , Nicolai Stange Subject: [RFC PATCH 04/41] random: drop 'reserved' parameter from extract_entropy() Date: Mon, 21 Sep 2020 09:58:20 +0200 Message-Id: <20200921075857.4424-5-nstange@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200921075857.4424-1-nstange@suse.de> References: <20200921075857.4424-1-nstange@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Since commit 43d8a72cd985 ("random: remove variable limit") all call sites of extract_entropy() pass in zero for the 'reserved' argument and the corresponding code in account() is effectively dead. Remove it and the drop the now unused 'reserved' argument from extract_entropy() as well as from account() called therefrom. Signed-off-by: Nicolai Stange --- drivers/char/random.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 14c39608cc17..35e381be20fe 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -506,7 +506,7 @@ struct entropy_store { }; static ssize_t extract_entropy(struct entropy_store *r, void *buf, - size_t nbytes, int min, int rsvd); + size_t nbytes, int min); static ssize_t _extract_entropy(struct entropy_store *r, void *buf, size_t nbytes, int fips); @@ -944,7 +944,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) } buf; if (r) { - num = extract_entropy(r, &buf, 32, 16, 0); + num = extract_entropy(r, &buf, 32, 16); if (num == 0) return; } else { @@ -1330,8 +1330,7 @@ EXPORT_SYMBOL_GPL(add_disk_randomness); * This function decides how many bytes to actually take from the * given pool, and also debits the entropy count accordingly. */ -static size_t account(struct entropy_store *r, size_t nbytes, int min, - int reserved) +static size_t account(struct entropy_store *r, size_t nbytes, int min) { int entropy_count, orig, have_bytes; size_t ibytes, nfrac; @@ -1345,8 +1344,6 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min, /* never pull more than available */ have_bytes = entropy_count >> (ENTROPY_SHIFT + 3); - if ((have_bytes -= reserved) < 0) - have_bytes = 0; ibytes = min_t(size_t, ibytes, have_bytes); if (ibytes < min) ibytes = 0; @@ -1469,12 +1466,10 @@ static ssize_t _extract_entropy(struct entropy_store *r, void *buf, * returns it in a buffer. * * The min parameter specifies the minimum amount we can pull before - * failing to avoid races that defeat catastrophic reseeding while the - * reserved parameter indicates how much entropy we must leave in the - * pool after each pull to avoid starving other readers. + * failing to avoid races that defeat catastrophic reseeding. */ static ssize_t extract_entropy(struct entropy_store *r, void *buf, - size_t nbytes, int min, int reserved) + size_t nbytes, int min) { __u8 tmp[EXTRACT_SIZE]; unsigned long flags; @@ -1495,7 +1490,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf, } trace_extract_entropy(r->name, nbytes, ENTROPY_BITS(r), _RET_IP_); - nbytes = account(r, nbytes, min, reserved); + nbytes = account(r, nbytes, min); return _extract_entropy(r, buf, nbytes, fips_enabled); }