[PATCH 6/22] /dev/random: simplify pool initialization

From: Matt Mackall
Date: Thu Mar 25 2004 - 20:24:39 EST

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/dev/random simplify pool initialization

tiny-mpm/drivers/char/random.c | 86 ++++++++++++++++-------------------------
1 files changed, 35 insertions(+), 51 deletions(-)

diff -puN drivers/char/random.c~pool-init drivers/char/random.c
--- tiny/drivers/char/random.c~pool-init 2004-03-20 13:38:19.000000000 -0600
+++ tiny-mpm/drivers/char/random.c 2004-03-20 13:38:19.000000000 -0600
@@ -497,19 +497,12 @@ struct entropy_store {
unsigned add_ptr;
int entropy_count;
int input_rotate;
- struct poolinfo poolinfo;
- __u32 *pool;
+ struct poolinfo *poolinfo;
spinlock_t lock;
+ __u32 pool[0];
};

-/*
- * Initialize the entropy store. The input argument is the size of
- * the random pool.
- *
- * Returns an negative error if there is a problem.
- */
-static int create_entropy_store(int size, const char *name,
- struct entropy_store **ret_bucket)
+static struct entropy_store *create_entropy_store(int size, const char *name)
{
struct entropy_store *r;
struct poolinfo *p;
@@ -524,25 +517,18 @@ static int create_entropy_store(int size
break;
}
if (p->poolwords == 0)
- return -EINVAL;
+ return 0;

- r = kmalloc(sizeof(struct entropy_store), GFP_KERNEL);
+ r = kmalloc(sizeof(struct entropy_store)+POOLBYTES, GFP_KERNEL);
if (!r)
- return -ENOMEM;
+ return 0;

- memset (r, 0, sizeof(struct entropy_store));
- r->poolinfo = *p;
+ memset(r, 0, sizeof(struct entropy_store));
+ r->poolinfo = p;
r->name = name;
-
- r->pool = kmalloc(POOLBYTES, GFP_KERNEL);
- if (!r->pool) {
- kfree(r);
- return -ENOMEM;
- }
- memset(r->pool, 0, POOLBYTES);
r->lock = SPIN_LOCK_UNLOCKED;
- *ret_bucket = r;
- return 0;
+
+ return r;
}

/* Clear the entropy pool and associated counters. */
@@ -551,11 +537,11 @@ static void clear_entropy_store(struct e
r->add_ptr = 0;
r->entropy_count = 0;
r->input_rotate = 0;
- memset(r->pool, 0, r->poolinfo.POOLBYTES);
+ memset(r->pool, 0, r->poolinfo->POOLBYTES);
}

/*
- * This function adds a byte into the entropy "pool". It does not
+ * This function adds words into the entropy "pool". It does not
* update the entropy estimate. The caller should call
* credit_entropy_store if this is appropriate.
*
@@ -572,7 +558,7 @@ static void add_entropy_words(struct ent
0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
unsigned i;
int new_rotate;
- int wordmask = r->poolinfo.poolwords - 1;
+ int wordmask = r->poolinfo->poolwords - 1;
__u32 w;
unsigned long flags;

@@ -593,11 +579,11 @@ static void add_entropy_words(struct ent
r->input_rotate = new_rotate & 31;

/* XOR in the various taps */
- w ^= r->pool[(i + r->poolinfo.tap1) & wordmask];
- w ^= r->pool[(i + r->poolinfo.tap2) & wordmask];
- w ^= r->pool[(i + r->poolinfo.tap3) & wordmask];
- w ^= r->pool[(i + r->poolinfo.tap4) & wordmask];
- w ^= r->pool[(i + r->poolinfo.tap5) & wordmask];
+ w ^= r->pool[(i + r->poolinfo->tap1) & wordmask];
+ w ^= r->pool[(i + r->poolinfo->tap2) & wordmask];
+ w ^= r->pool[(i + r->poolinfo->tap3) & wordmask];
+ w ^= r->pool[(i + r->poolinfo->tap4) & wordmask];
+ w ^= r->pool[(i + r->poolinfo->tap5) & wordmask];
w ^= r->pool[i];
r->pool[i] = (w >> 3) ^ twist_table[w & 7];
}
@@ -618,8 +604,8 @@ static void credit_entropy_store(struct
DEBUG_ENT("negative entropy/overflow (%d+%d)\n",
r->entropy_count, nbits);
r->entropy_count = 0;
- } else if (r->entropy_count + nbits > r->poolinfo.POOLBITS) {
- r->entropy_count = r->poolinfo.POOLBITS;
+ } else if (r->entropy_count + nbits > r->poolinfo->POOLBITS) {
+ r->entropy_count = r->poolinfo->POOLBITS;
} else {
r->entropy_count += nbits;
if (nbits)
@@ -714,7 +700,7 @@ EXPORT_SYMBOL(batch_entropy_store);
static void batch_entropy_process(void *private_)
{
struct entropy_store *r = (struct entropy_store *) private_, *p;
- int max_entropy = r->poolinfo.POOLBITS;
+ int max_entropy = r->poolinfo->POOLBITS;
unsigned head, tail;

/* Mixing into the pool is expensive, so copy over the batch
@@ -738,7 +724,7 @@ static void batch_entropy_process(void *
if (r->entropy_count >= max_entropy) {
r = (r == blocking_pool) ? input_pool :
blocking_pool;
- max_entropy = r->poolinfo.POOLBITS;
+ max_entropy = r->poolinfo->POOLBITS;
}
add_entropy_words(r, batch_entropy_copy[tail].data, 2);
credit_entropy_store(r, batch_entropy_copy[tail].credit);
@@ -1290,7 +1276,7 @@ static inline void xfer_secondary_pool(s
size_t nbytes, __u32 *tmp)
{
if (r->entropy_count < nbytes * 8 &&
- r->entropy_count < r->poolinfo.POOLBITS) {
+ r->entropy_count < r->poolinfo->POOLBITS) {
int bytes = max_t(int, random_read_wakeup_thresh / 8,
min_t(int, nbytes, TMP_BUF_SIZE));

@@ -1328,8 +1314,8 @@ static ssize_t extract_entropy(struct en

/* Redundant, but just in case... */
- if (r->entropy_count > r->poolinfo.POOLBITS)
- r->entropy_count = r->poolinfo.POOLBITS;
+ if (r->entropy_count > r->poolinfo->POOLBITS)
+ r->entropy_count = r->poolinfo->POOLBITS;

if (flags & EXTRACT_ENTROPY_SECONDARY)
xfer_secondary_pool(r, nbytes, tmp);
@@ -1386,7 +1372,7 @@ static ssize_t extract_entropy(struct en
* attempts to find previous ouputs), unless the hash
* function can be inverted.
*/
- for (i = 0, x = 0; i < r->poolinfo.poolwords; i += 16, x+=2) {
+ for (i = 0, x = 0; i < r->poolinfo->poolwords; i += 16, x+=2) {
HASH_TRANSFORM(tmp, r->pool+i);
add_entropy_words(r, &tmp[x%HASH_BUFFER_SIZE], 1);
}
@@ -1482,15 +1468,15 @@ static int __init rand_initialize(void)
{
int i;

- if (create_entropy_store(INPUT_POOL_SIZE, "input", &input_pool))
- goto err;
+ input_pool = create_entropy_store(INPUT_POOL_SIZE, "input");
+ blocking_pool = create_entropy_store(BLOCKING_POOL_SIZE, "blocking");
+
+ if (!(input_pool && blocking_pool))
+ return -1;
+
if (batch_entropy_init(BATCH_ENTROPY_SIZE, input_pool))
- goto err;
- if (create_entropy_store(BLOCKING_POOL_SIZE, "blocking",
- &blocking_pool))
- goto err;
- clear_entropy_store(input_pool);
- clear_entropy_store(blocking_pool);
+ return -1;
+
init_std_data(input_pool);
#ifdef CONFIG_SYSCTL
sysctl_init_random(input_pool);
@@ -1502,8 +1488,6 @@ static int __init rand_initialize(void)
memset(&extract_timer_state, 0, sizeof(struct timer_rand_state));
extract_timer_state.dont_count_entropy = 1;
return 0;
-err:
- return -1;
}
module_init(rand_initialize);

@@ -1893,7 +1877,7 @@ static void sysctl_init_random(struct en
{
min_read_thresh = 8;
min_write_thresh = 0;
- max_read_thresh = max_write_thresh = pool->poolinfo.POOLBITS;
+ max_read_thresh = max_write_thresh = pool->poolinfo->POOLBITS;
random_table[0].data = &pool->entropy_count;
}
#endif /* CONFIG_SYSCTL */

_
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Next message: Matt Mackall: "[PATCH 7/22] /dev/random: simplify reseed logic"
Previous message: Matt Mackall: "[PATCH 0/22] /dev/random: Assorted fixes and cleanups"
In reply to: Matt Mackall: "[PATCH 5/22] /dev/random: pool struct cleanup and rename"
Next in thread: Matt Mackall: "[PATCH 7/22] /dev/random: simplify reseed logic"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]