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Commit 43d8a72c authored by Stephan Müller's avatar Stephan Müller Committed by Theodore Ts'o
Browse files

random: remove variable limit 



The variable limit was used to identify the nonblocking pool's unlimited
random number generation. As the nonblocking pool is a thing of the
past, remove the limit variable and any conditions around it (i.e.
preserve the branches for limit == 1).

Signed-off-by: default avatarStephan Mueller <smueller@chronox.de>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 2e03c36f

drivers/char/random.c

+7 −23
Original line number Diff line number Diff line
@@ -466,7 +466,6 @@ struct entropy_store { 
	int entropy_count;

	int entropy_total;

	unsigned int initialized:1;

	unsigned int limit:1;

	unsigned int last_data_init:1;

	__u8 last_data[EXTRACT_SIZE];

};
@@ -484,7 +483,6 @@ static __u32 blocking_pool_data[OUTPUT_POOL_WORDS] __latent_entropy; 
static struct entropy_store input_pool = {

	.poolinfo = &poolinfo_table[0],

	.name = "input",

	.limit = 1,

	.lock = __SPIN_LOCK_UNLOCKED(input_pool.lock),

	.pool = input_pool_data

};
@@ -492,7 +490,6 @@ static struct entropy_store input_pool = { 
static struct entropy_store blocking_pool = {

	.poolinfo = &poolinfo_table[1],

	.name = "blocking",

	.limit = 1,

	.pull = &input_pool,

	.lock = __SPIN_LOCK_UNLOCKED(blocking_pool.lock),

	.pool = blocking_pool_data,
@@ -1212,15 +1209,6 @@ static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes) 
	    r->entropy_count > r->poolinfo->poolfracbits)

		return;



	if (r->limit == 0 && random_min_urandom_seed) {

		unsigned long now = jiffies;



		if (time_before(now,

				r->last_pulled + random_min_urandom_seed * HZ))

			return;

		r->last_pulled = now;

	}



	_xfer_secondary_pool(r, nbytes);

}
@@ -1228,8 +1216,6 @@ static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes) 
{

	__u32	tmp[OUTPUT_POOL_WORDS];



	/* For /dev/random's pool, always leave two wakeups' worth */

	int rsvd_bytes = r->limit ? 0 : random_read_wakeup_bits / 4;

	int bytes = nbytes;



	/* pull at least as much as a wakeup */
@@ -1240,7 +1226,7 @@ static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes) 
	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, rsvd_bytes);

				random_read_wakeup_bits / 8, 0);

	mix_pool_bytes(r, tmp, bytes);

	credit_entropy_bits(r, bytes*8);

}
@@ -1268,7 +1254,7 @@ static void push_to_pool(struct work_struct *work) 
static size_t account(struct entropy_store *r, size_t nbytes, int min,

		      int reserved)

{

	int entropy_count, orig;

	int entropy_count, orig, have_bytes;

	size_t ibytes, nfrac;



	BUG_ON(r->entropy_count > r->poolinfo->poolfracbits);
@@ -1277,14 +1263,12 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min, 
retry:

	entropy_count = orig = ACCESS_ONCE(r->entropy_count);

	ibytes = nbytes;

	/* If limited, never pull more than available */

	if (r->limit) {

		int have_bytes = entropy_count >> (ENTROPY_SHIFT + 3);

	/* never pull more than available */

	have_bytes = entropy_count >> (ENTROPY_SHIFT + 3);



	if ((have_bytes -= reserved) < 0)

		have_bytes = 0;

	ibytes = min_t(size_t, ibytes, have_bytes);

	}

	if (ibytes < min)

		ibytes = 0;