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Commit c59974ae authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

random: optimize the entropy_store structure 



Use smaller types to slightly shrink the size of the entropy store
structure.

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 3ef4cb2d

drivers/char/random.c

+8 −8
Original line number Diff line number Diff line
@@ -436,16 +436,16 @@ 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];

};
@@ -513,7 +513,7 @@ 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 */
@@ -533,7 +533,7 @@ 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;
@@ -1049,7 +1049,7 @@ 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,

					      ENTROPY_BITS(r), _RET_IP_);
@@ -1189,7 +1189,7 @@ 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))