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Commit ec134003 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Greg Kroah-Hartman
Browse files

random: delete code to pull data into pools 



commit 84df7cdfbb215a34657b39f4257dab739efa2df9 upstream.

There is no pool that pulls, so it was just dead code.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/4a05fe0c7a5c831389ef4aea51d24528ac8682c7.1577088521.git.luto@kernel.org


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a9564e14

drivers/char/random.c

+0 −40
Original line number Diff line number Diff line
@@ -529,10 +529,8 @@ struct entropy_store { 
	const struct poolinfo *poolinfo;

	__u32 *pool;

	const char *name;

	struct entropy_store *pull;



	/* read-write data: */

	unsigned long last_pulled;

	spinlock_t lock;

	unsigned short add_ptr;

	unsigned short input_rotate;
@@ -1367,41 +1365,6 @@ EXPORT_SYMBOL_GPL(add_disk_randomness); 
 *

 *********************************************************************/



/*

 * This utility inline function is responsible for transferring entropy

 * from the primary pool to the secondary extraction pool. We make

 * sure we pull enough for a 'catastrophic reseed'.

 */

static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes);

static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes)

{

	if (!r->pull ||

	    r->entropy_count >= (nbytes << (ENTROPY_SHIFT + 3)) ||

	    r->entropy_count > r->poolinfo->poolfracbits)

		return;



	_xfer_secondary_pool(r, nbytes);

}



static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes)

{

	__u32	tmp[OUTPUT_POOL_WORDS];



	int bytes = nbytes;



	/* pull at least as much as a wakeup */

	bytes = max_t(int, bytes, random_read_wakeup_bits / 8);

	/* but never more than the buffer size */

	bytes = min_t(int, bytes, sizeof(tmp));



	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, 0);

	mix_pool_bytes(r, tmp, bytes);

	credit_entropy_bits(r, bytes*8);

}



/*

 * This function decides how many bytes to actually take from the

 * given pool, and also debits the entropy count accordingly.
@@ -1565,7 +1528,6 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf, 
			spin_unlock_irqrestore(&r->lock, flags);

			trace_extract_entropy(r->name, EXTRACT_SIZE,

					      ENTROPY_BITS(r), _RET_IP_);

			xfer_secondary_pool(r, EXTRACT_SIZE);

			extract_buf(r, tmp);

			spin_lock_irqsave(&r->lock, flags);

			memcpy(r->last_data, tmp, EXTRACT_SIZE);
@@ -1574,7 +1536,6 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf, 
	}



	trace_extract_entropy(r->name, nbytes, ENTROPY_BITS(r), _RET_IP_);

	xfer_secondary_pool(r, nbytes);

	nbytes = account(r, nbytes, min, reserved);



	return _extract_entropy(r, buf, nbytes, fips_enabled);
@@ -1846,7 +1807,6 @@ static void __init init_std_data(struct entropy_store *r) 
	ktime_t now = ktime_get_real();

	unsigned long rv;



	r->last_pulled = jiffies;

	mix_pool_bytes(r, &now, sizeof(now));

	for (i = r->poolinfo->poolbytes; i > 0; i -= sizeof(rv)) {

		if (!arch_get_random_seed_long(&rv) &&