From: "Theodore Ts'o" <tytso@mit.edu>
To: Linux Kernel Developers List <linux-kernel@vger.kernel.org>
Cc: hpa@zytor.com, joern@logfs.org, macro@linux-mips.org,
ralf@linux-mips.org, dave.taht@gmail.com, blogic@openwrt.org,
andrewmcgr@gmail.com, smueller@chronox.de, geert@linux-m68k.org,
tg@mirbsd.de, "Theodore Ts'o" <tytso@mit.edu>
Subject: [PATCH, RFC 09/12] random: optimize the entropy_store structure
Date: Sun, 22 Sep 2013 16:38:55 -0400 [thread overview]
Message-ID: <1379882338-7209-10-git-send-email-tytso@mit.edu> (raw)
In-Reply-To: <1379882338-7209-1-git-send-email-tytso@mit.edu>
Use smaller types to slightly shrink the size of the entropy store
structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
drivers/char/random.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 6d5e8e6..292e717 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -435,16 +435,16 @@ struct entropy_store {
__u32 *pool;
const char *name;
struct entropy_store *pull;
- int limit;
/* read-write data: */
spinlock_t lock;
- unsigned add_ptr;
- unsigned input_rotate;
+ unsigned short add_ptr;
+ unsigned short input_rotate;
int entropy_count;
int entropy_total;
unsigned int initialized:1;
- bool last_data_init;
+ unsigned int limit:1;
+ unsigned int last_data_init:1;
__u8 last_data[EXTRACT_SIZE];
};
@@ -512,7 +512,7 @@ static void _mix_pool_bytes(struct entropy_store *r, const void *in,
/* mix one byte at a time to simplify size handling and churn faster */
while (nbytes--) {
- w = rol32(*bytes++, input_rotate & 31);
+ w = rol32(*bytes++, input_rotate);
i = (i - 1) & wordmask;
/* XOR in the various taps */
@@ -532,7 +532,7 @@ static void _mix_pool_bytes(struct entropy_store *r, const void *in,
* rotation, so that successive passes spread the
* input bits across the pool evenly.
*/
- input_rotate += i ? 7 : 14;
+ input_rotate = (input_rotate + (i ? 7 : 14)) & 31;
}
ACCESS_ONCE(r->input_rotate) = input_rotate;
@@ -1047,7 +1047,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
if (fips_enabled) {
spin_lock_irqsave(&r->lock, flags);
if (!r->last_data_init) {
- r->last_data_init = true;
+ r->last_data_init = 1;
spin_unlock_irqrestore(&r->lock, flags);
trace_extract_entropy(r->name, EXTRACT_SIZE,
r->entropy_count, _RET_IP_);
@@ -1187,7 +1187,7 @@ static void init_std_data(struct entropy_store *r)
r->entropy_count = 0;
r->entropy_total = 0;
- r->last_data_init = false;
+ r->last_data_init = 0;
mix_pool_bytes(r, &now, sizeof(now), NULL);
for (i = r->poolinfo->poolbytes; i > 0; i -= sizeof(rv)) {
if (!arch_get_random_long(&rv))
--
1.7.12.rc0.22.gcdd159b
next prev parent reply other threads:[~2013-09-22 20:39 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-22 20:38 [PATCH, RFC 00/12] random driver changes Theodore Ts'o
2013-09-22 20:38 ` [PATCH, RFC 01/12] random: run random_int_secret_init() run after all late_initcalls Theodore Ts'o
2013-09-22 20:38 ` [PATCH, RFC 02/12] random: Statically compute poolbitshift, poolbytes, poolbits Theodore Ts'o
2013-09-22 20:38 ` [PATCH, RFC 03/12] random: Allow fractional bits to be tracked Theodore Ts'o
2013-09-23 4:01 ` Theodore Ts'o
2013-09-23 4:03 ` H. Peter Anvin
2013-09-22 20:38 ` [PATCH, RFC 04/12] random: Account for entropy loss due to overwrites Theodore Ts'o
2013-09-22 20:38 ` [PATCH, RFC 05/12] random: fix the tracepoint for get_random_bytes(_arch) Theodore Ts'o
2013-09-22 20:38 ` [PATCH, RFC 06/12] random: optimize spinlock use in add_device_randomness() Theodore Ts'o
2013-09-22 20:38 ` [PATCH, RFC 07/12] random: allow architectures to optionally define random_get_entropy() Theodore Ts'o
2013-09-23 10:38 ` Stephan Mueller
2013-09-23 11:05 ` Theodore Ts'o
2013-09-22 20:38 ` [PATCH, RFC 08/12] random: mix in architectural randomness earlier in extract_buf() Theodore Ts'o
2013-09-23 4:11 ` H. Peter Anvin
2013-09-23 4:33 ` Theodore Ts'o
2013-09-22 20:38 ` Theodore Ts'o [this message]
2013-09-22 20:38 ` [PATCH, RFC 10/12] random: cap the rate which the /dev/urandom pool gets reseeded Theodore Ts'o
2013-09-22 21:21 ` H. Peter Anvin
2013-09-22 21:40 ` Theodore Ts'o
2013-09-22 22:45 ` H. Peter Anvin
2013-09-22 23:23 ` Theodore Ts'o
2013-09-23 0:26 ` H. Peter Anvin
2013-09-22 20:38 ` [PATCH, RFC 11/12] random: speed up the fast_mix function by a factor of four Theodore Ts'o
2013-09-22 20:38 ` [PATCH, RFC 12/12] random: adjust the generator polynomials in the mixing function slightly Theodore Ts'o
2013-09-25 10:51 ` Jörg-Volker Peetz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1379882338-7209-10-git-send-email-tytso@mit.edu \
--to=tytso@mit.edu \
--cc=andrewmcgr@gmail.com \
--cc=blogic@openwrt.org \
--cc=dave.taht@gmail.com \
--cc=geert@linux-m68k.org \
--cc=hpa@zytor.com \
--cc=joern@logfs.org \
--cc=linux-kernel@vger.kernel.org \
--cc=macro@linux-mips.org \
--cc=ralf@linux-mips.org \
--cc=smueller@chronox.de \
--cc=tg@mirbsd.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®