From: "George Spelvin" <linux@horizon.com>
To: davem@davemloft.net, dborkman@redhat.com, linux@horizon.com,
shemminger@osdl.org, tytso@mit.edu
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 6/7] lib/random32.c: Randomize timeout to the millisecond, not the second
Date: 7 Jun 2014 04:28:59 -0400 [thread overview]
Message-ID: <20140607082859.10162.qmail@ns.horizon.com> (raw)
In-Reply-To: <20140607081828.9294.qmail@ns.horizon.com>
If you're going to bother randomizing it, do it right.
And use prandom_u32_max(), which is designed for the job, rather
than "% 40".
Signed-off-by: George Spelvin <linux@horizon.com>
---
lib/random32.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/lib/random32.c b/lib/random32.c
index eee60100..9cc410dd 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -208,14 +208,14 @@ static DEFINE_TIMER(seed_timer, __prandom_timer, 0, 0);
static void __prandom_timer(unsigned long dontcare)
{
u32 entropy;
- unsigned long expires;
+ unsigned int expires;
get_random_bytes(&entropy, sizeof(entropy));
prandom_seed(entropy);
/* reseed every ~60 seconds, in [40 .. 80) interval with slack */
- expires = 40 + (prandom_u32() % 40);
- seed_timer.expires = jiffies + msecs_to_jiffies(expires * MSEC_PER_SEC);
+ expires = 40000 + prandom_u32_max(40000);
+ seed_timer.expires = jiffies + msecs_to_jiffies(expires);
add_timer(&seed_timer);
}
--
2.0.0
next prev parent reply other threads:[~2014-06-07 8:29 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-07 8:18 [PATCH 0/7] random32: Various minor cleanups George Spelvin
2014-06-07 8:19 ` [PATCH 1/7] lib/random32.c: Mark self-test data as __initconst George Spelvin
2014-06-08 12:06 ` Daniel Borkmann
2014-06-07 8:20 ` [PATCH 2/7] lib/random32.c: Remove excess calls to prandom_u32_state in initialization George Spelvin
2014-06-08 12:11 ` Daniel Borkmann
2014-06-08 12:19 ` George Spelvin
2014-06-07 8:22 ` [PATCH 3/7] lib/random32.c: Replace an #ifdef with a stub prandom_state_selftest() George Spelvin
2014-06-08 12:16 ` Daniel Borkmann
2014-06-08 12:27 ` George Spelvin
2014-06-07 8:25 ` [PATCH 4/7] lib/random32.c: Use <asm/unaligned.h> instead of hand-rolling it George Spelvin
2014-06-08 12:25 ` Daniel Borkmann
2014-06-08 12:40 ` George Spelvin
2014-06-08 20:26 ` Hannes Frederic Sowa
2014-06-10 15:13 ` Daniel Borkmann
2014-06-07 8:28 ` [PATCH 5/7] lib/random32.c: Make prandom_u32_max efficient for powers of 2 George Spelvin
2014-06-08 12:03 ` Daniel Borkmann
2014-06-08 17:34 ` Hannes Frederic Sowa
2014-06-08 20:02 ` Daniel Borkmann
2014-06-09 0:28 ` George Spelvin
2014-06-08 20:48 ` George Spelvin
2014-06-09 10:30 ` Hannes Frederic Sowa
2014-06-07 8:28 ` George Spelvin [this message]
2014-06-08 10:43 ` [PATCH 6/7] lib/random32.c: Randomize timeout to the millisecond, not the second Daniel Borkmann
2014-06-08 11:30 ` George Spelvin
2014-06-08 12:28 ` Daniel Borkmann
2014-06-08 12:42 ` George Spelvin
2014-06-08 20:01 ` Daniel Borkmann
2014-06-07 8:31 ` [PATCH 7/7] lib/random32.c: Remove redundant U suffixes on integers George Spelvin
2014-06-08 10:36 ` Daniel Borkmann
2014-06-08 11:14 ` George Spelvin
2014-06-08 12:05 ` Daniel Borkmann
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