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From: Matt Mackall <mpm@selenic.com>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 7/22] /dev/random: simplify reseed logic
Date: Thu, 25 Mar 2004 17:57:43 -0600	[thread overview]
Message-ID: <8.524465763@selenic.com> (raw)
In-Reply-To: <7.524465763@selenic.com>


/dev/random  simplify reseed logic

Automatically reseed from input pool when pulling from output pools.


 tiny-mpm/drivers/char/random.c |   20 ++++++--------------
 1 files changed, 6 insertions(+), 14 deletions(-)

diff -puN drivers/char/random.c~kill-extract-secondary drivers/char/random.c
--- tiny/drivers/char/random.c~kill-extract-secondary	2004-03-20 13:38:20.000000000 -0600
+++ tiny-mpm/drivers/char/random.c	2004-03-20 13:38:20.000000000 -0600
@@ -1259,8 +1259,7 @@ static void MD5Transform(__u32 buf[HASH_
  *********************************************************************/
 
 #define EXTRACT_ENTROPY_USER		1
-#define EXTRACT_ENTROPY_SECONDARY	2
-#define EXTRACT_ENTROPY_LIMIT		4
+#define EXTRACT_ENTROPY_LIMIT		2
 #define TMP_BUF_SIZE			(HASH_BUFFER_SIZE + HASH_EXTRA_SIZE)
 #define SEC_XFER_SIZE			(TMP_BUF_SIZE*4)
 
@@ -1298,10 +1297,6 @@ static inline void xfer_secondary_pool(s
  * number of bytes that are actually obtained.  If the EXTRACT_ENTROPY_USER
  * flag is given, then the buf pointer is assumed to be in user space.
  *
- * If the EXTRACT_ENTROPY_SECONDARY flag is given, then we are actually
- * extracting entropy from the secondary pool, and can refill from the
- * primary pool if needed.
- *
  * Note: extract_entropy() assumes that .poolwords is a multiple of 16 words.
  */
 static ssize_t extract_entropy(struct entropy_store *r, void * buf,
@@ -1317,7 +1312,7 @@ static ssize_t extract_entropy(struct en
 	if (r->entropy_count > r->poolinfo->POOLBITS)
 		r->entropy_count = r->poolinfo->POOLBITS;
 
-	if (flags & EXTRACT_ENTROPY_SECONDARY)
+	if (r != input_pool)
 		xfer_secondary_pool(r, nbytes, tmp);
 
 	/* Hold lock while accounting */
@@ -1418,10 +1413,9 @@ static ssize_t extract_entropy(struct en
 void get_random_bytes(void *buf, int nbytes)
 {
 	if (blocking_pool)
-		extract_entropy(blocking_pool, (char *) buf, nbytes,
-				EXTRACT_ENTROPY_SECONDARY);
+		extract_entropy(blocking_pool, buf, nbytes, 0);
 	else if (input_pool)
-		extract_entropy(input_pool, (char *) buf, nbytes, 0);
+		extract_entropy(input_pool, buf, nbytes, 0);
 	else
 		printk(KERN_NOTICE "get_random_bytes called before "
 				   "random driver initialization\n");
@@ -1541,8 +1535,7 @@ random_read(struct file * file, char * b
 
 		n = extract_entropy(blocking_pool, buf, n,
 				    EXTRACT_ENTROPY_USER |
-				    EXTRACT_ENTROPY_LIMIT |
-				    EXTRACT_ENTROPY_SECONDARY);
+				    EXTRACT_ENTROPY_LIMIT);
 
 		DEBUG_ENT("read got %d bits (%d still needed)\n",
 			  n*8, (nbytes-n)*8);
@@ -1594,8 +1587,7 @@ urandom_read(struct file * file, char * 
 		      size_t nbytes, loff_t *ppos)
 {
 	return extract_entropy(blocking_pool, buf, nbytes,
-			       EXTRACT_ENTROPY_USER |
-			       EXTRACT_ENTROPY_SECONDARY);
+			       EXTRACT_ENTROPY_USER);
 }
 
 static unsigned int

_

  reply	other threads:[~2004-03-26  1:24 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-03-25 23:57 [PATCH 0/22] /dev/random: Assorted fixes and cleanups Matt Mackall
2004-03-25 23:57 ` [PATCH 1/22] /dev/random: Simplify entropy debugging Matt Mackall
2004-03-25 23:57   ` [PATCH 2/22] /dev/random: Cleanup sleep logic Matt Mackall
2004-03-25 23:57     ` [PATCH 3/22] /dev/random: remove broken resizing sysctl Matt Mackall
2004-03-25 23:57       ` [PATCH 4/22] /dev/random: remove outdated RNDGETPOOL ioctl Matt Mackall
2004-03-25 23:57         ` [PATCH 5/22] /dev/random: pool struct cleanup and rename Matt Mackall
2004-03-25 23:57           ` [PATCH 6/22] /dev/random: simplify pool initialization Matt Mackall
2004-03-25 23:57             ` Matt Mackall [this message]
2004-03-25 23:57               ` [PATCH 8/22] /dev/random: BUG on premature random users Matt Mackall
2004-03-25 23:57                 ` [PATCH 9/22] /dev/random: more robust catastrophic reseed logic Matt Mackall
2004-03-25 23:57                   ` [PATCH 10/22] /dev/random: entropy reserve logic for starvation preve Matt Mackall
2004-03-25 23:57                     ` [PATCH 11/22] /dev/random: flag pools that need entropy reserve Matt Mackall
2004-03-25 23:57                       ` [PATCH 12/22] /dev/random: add pool for /dev/urandom to prevent starv Matt Mackall
2004-03-25 23:57                         ` [PATCH 13/22] /dev/random: kill extract_timer_state Matt Mackall
2004-03-25 23:57                           ` [PATCH 14/22] /dev/random: kill unused md5 copy Matt Mackall
2004-03-25 23:57                             ` [PATCH 15/22] /dev/random: kill unrolled SHA code Matt Mackall
2004-03-25 23:57                               ` [PATCH 16/22] /dev/random: kill 2.2 cruft Matt Mackall
2004-03-25 23:57                                 ` [PATCH 17/22] /dev/random: minor shrinkage Matt Mackall
2004-03-25 23:57                                   ` [PATCH 18/22] /dev/random: bitop cleanup Matt Mackall
2004-03-25 23:57                                     ` [PATCH 19/22] /dev/random: use sched_clock for timing data Matt Mackall
2004-03-25 23:57                                       ` [PATCH 20/22] /dev/random: cleanup rol bitop Matt Mackall
2004-03-25 23:57                                         ` [PATCH 21/22] /dev/random: kill batching of entropy mixing Matt Mackall
2004-03-25 23:57                                           ` [PATCH 22/22] /dev/random: update credits Matt Mackall
2004-03-27 13:52                                           ` [PATCH 21/22] /dev/random: kill batching of entropy mixing Jamie Lokier
2004-03-27 15:17                                             ` Matt Mackall
2004-03-26  1:43                               ` [PATCH 15/22] /dev/random: kill unrolled SHA code Jeff Garzik
2004-03-26  3:59                                 ` Matt Mackall
2004-03-27 13:49                                   ` Jamie Lokier
2004-03-26  0:15         ` [PATCH 4/22] /dev/random: remove outdated RNDGETPOOL ioctl Andrew Morton
2004-03-26  0:15       ` [PATCH 3/22] /dev/random: remove broken resizing sysctl Andrew Morton
2004-03-26  3:53         ` Matt Mackall
2004-03-26  0:14     ` [PATCH 2/22] /dev/random: Cleanup sleep logic Andrew Morton
2004-03-26  3:49       ` Matt Mackall

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