[PATCH 1/3] random: Further dead code elimination

From: George Spelvin
Date: Tue Mar 31 2020 - 04:57:11 EST


Earlier commits left some dead code behind in credit_entropy_bits().

In particular, has_initialized was always zero.

Fixes: 90ea1c6436d2 ("random: remove the blocking pool")
Signed-off-by: George Spelvin <lkml@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
---
Just some odds & ends I noticed.

drivers/char/random.c | 23 +++++------------------
1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index c7f9584de2c8..273dcbb4a790 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -660,7 +660,7 @@ static void process_random_ready_list(void)
*/
static void credit_entropy_bits(struct entropy_store *r, int nbits)
{
- int entropy_count, orig, has_initialized = 0;
+ int entropy_count, orig;
const int pool_size = r->poolinfo->poolfracbits;
int nfrac = nbits << ENTROPY_SHIFT;

@@ -717,24 +717,11 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
goto retry;

- if (has_initialized) {
- r->initialized = 1;
- kill_fasync(&fasync, SIGIO, POLL_IN);
- }
+ entropy_count >>= ENTROPY_SHIFT; /* Convert to bits */
+ trace_credit_entropy_bits(r->name, nbits, entropy_count, _RET_IP_);

- trace_credit_entropy_bits(r->name, nbits,
- entropy_count >> ENTROPY_SHIFT, _RET_IP_);
-
- if (r == &input_pool) {
- int entropy_bits = entropy_count >> ENTROPY_SHIFT;
-
- if (crng_init < 2) {
- if (entropy_bits < 128)
- return;
- crng_reseed(&primary_crng, r);
- entropy_bits = ENTROPY_BITS(r);
- }
- }
+ if (r == &input_pool && crng_init < 2 && entropy_count >= 128)
+ crng_reseed(&primary_crng, r);
}

static int credit_entropy_bits_safe(struct entropy_store *r, int nbits)
--
2.26.0