From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephan =?ISO-8859-1?Q?M=FCller?= Subject: [PATCH 5/8] random: remove variable limit Date: Tue, 27 Dec 2016 23:40:59 +0100 Message-ID: <13861626.tTeaaQ9jhE@positron.chronox.de> References: <3254875.f5A5oHPdxF@positron.chronox.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org To: Ted Tso Return-path: Received: from mail.eperm.de ([89.247.134.16]:55042 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754599AbcL0Wno (ORCPT ); Tue, 27 Dec 2016 17:43:44 -0500 In-Reply-To: <3254875.f5A5oHPdxF@positron.chronox.de> Sender: linux-crypto-owner@vger.kernel.org List-ID: The variable limit was used to identify the nonblocking pool's unlimited random number generation. As the nonblocking pool is a thing of the past, remove the limit variable and any conditions around it (i.e. preserve the branches for limit == 1). Signed-off-by: Stephan Mueller --- drivers/char/random.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 8d4d720..d19108c 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -466,7 +466,6 @@ struct entropy_store { int entropy_count; int entropy_total; unsigned int initialized:1; - unsigned int limit:1; unsigned int last_data_init:1; __u8 last_data[EXTRACT_SIZE]; }; @@ -484,7 +483,6 @@ static __u32 blocking_pool_data[OUTPUT_POOL_WORDS] __latent_entropy; static struct entropy_store input_pool = { .poolinfo = &poolinfo_table[0], .name = "input", - .limit = 1, .lock = __SPIN_LOCK_UNLOCKED(input_pool.lock), .pool = input_pool_data }; @@ -492,7 +490,6 @@ static struct entropy_store input_pool = { static struct entropy_store blocking_pool = { .poolinfo = &poolinfo_table[1], .name = "blocking", - .limit = 1, .pull = &input_pool, .lock = __SPIN_LOCK_UNLOCKED(blocking_pool.lock), .pool = blocking_pool_data, @@ -1212,15 +1209,6 @@ static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes) r->entropy_count > r->poolinfo->poolfracbits) return; - if (r->limit == 0 && random_min_urandom_seed) { - unsigned long now = jiffies; - - if (time_before(now, - r->last_pulled + random_min_urandom_seed * HZ)) - return; - r->last_pulled = now; - } - _xfer_secondary_pool(r, nbytes); } @@ -1228,8 +1216,6 @@ static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes) { __u32 tmp[OUTPUT_POOL_WORDS]; - /* For /dev/random's pool, always leave two wakeups' worth */ - int rsvd_bytes = r->limit ? 0 : random_read_wakeup_bits / 4; int bytes = nbytes; /* pull at least as much as a wakeup */ @@ -1240,7 +1226,7 @@ static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes) trace_xfer_secondary_pool(r->name, bytes * 8, nbytes * 8, ENTROPY_BITS(r), ENTROPY_BITS(r->pull)); bytes = extract_entropy(r->pull, tmp, bytes, - random_read_wakeup_bits / 8, rsvd_bytes); + random_read_wakeup_bits / 8, 0); mix_pool_bytes(r, tmp, bytes); credit_entropy_bits(r, bytes*8); } @@ -1268,7 +1254,7 @@ static void push_to_pool(struct work_struct *work) static size_t account(struct entropy_store *r, size_t nbytes, int min, int reserved) { - int entropy_count, orig; + int entropy_count, orig, have_bytes; size_t ibytes, nfrac; BUG_ON(r->entropy_count > r->poolinfo->poolfracbits); @@ -1277,14 +1263,12 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min, retry: entropy_count = orig = ACCESS_ONCE(r->entropy_count); ibytes = nbytes; - /* If limited, never pull more than available */ - if (r->limit) { - int have_bytes = entropy_count >> (ENTROPY_SHIFT + 3); + /* 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 ((have_bytes -= reserved) < 0) + have_bytes = 0; + ibytes = min_t(size_t, ibytes, have_bytes); if (ibytes < min) ibytes = 0; -- 2.9.3