From: "Stephan Müller" <smueller@chronox.de>
To: Ted Tso <tytso@mit.edu>
Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org
Subject: [PATCH 5/8] random: remove variable limit
Date: Tue, 27 Dec 2016 23:40:59 +0100 [thread overview]
Message-ID: <13861626.tTeaaQ9jhE@positron.chronox.de> (raw)
In-Reply-To: <3254875.f5A5oHPdxF@positron.chronox.de>
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 <smueller@chronox.de>
---
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
next prev parent reply other threads:[~2016-12-27 22:44 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-27 22:38 [PATCH 0/8] random: cleanup of code after removal of nonblocking pool Stephan Müller
2016-12-27 22:39 ` [PATCH 1/8] random: remove stale maybe_reseed_primary_crng Stephan Müller
2016-12-27 22:39 ` [PATCH 2/8] random: remove stale urandom_init_wait Stephan Müller
2016-12-27 22:39 ` [PATCH 3/8] random: trigger random_ready callback upon crng_init == 1 Stephan Müller
2017-01-18 4:12 ` Theodore Ts'o
2017-01-18 17:09 ` Stephan Müller
2016-12-27 22:40 ` [PATCH 4/8] random: remove unused branch in hot code path Stephan Müller
2017-01-18 4:35 ` Theodore Ts'o
2017-04-27 11:23 ` Geert Uytterhoeven
2016-12-27 22:40 ` Stephan Müller [this message]
2016-12-27 22:41 ` [PATCH 6/8] random: fix comment for unused random_min_urandom_seed Stephan Müller
2016-12-27 22:41 ` [PATCH 7/8] random: remove noop function call to xfer_secondary_pool Stephan Müller
2017-01-18 16:10 ` Theodore Ts'o
2016-12-27 22:42 ` [PATCH 8/8] random: move FIPS continuous test to output functions Stephan Müller
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