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random: remove variable limit

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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: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Stephan Müller 2016-12-27 23:40:59 +01:00 committed by Theodore Ts'o
parent 2e03c36f25
commit 43d8a72cd9
1 changed files with 7 additions and 23 deletions
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30
drivers/char/random.c
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@ -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 ((have_bytes -= reserved) < 0)
have_bytes = 0;
ibytes = min_t(size_t, ibytes, have_bytes);
if (ibytes < min)
ibytes = 0;