[PATCH 5.4 053/240] random: remove unused extract_entropy() reserved argument

Greg Kroah-Hartman
2022-06-20T13:34:46Z

commit 8b2d953b91e7f60200c24067ab17b77cc7bfd0d4 upstream.

This argument is always set to zero, as a result of us not caring about
keeping a certain amount reserved in the pool these days. So just remove
it and cleanup the function signatures.

Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/char/random.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -519,7 +519,7 @@ struct entropy_store {
};

static ssize_t extract_entropy(struct entropy_store *r, void *buf,
- size_t nbytes, int min, int rsvd);
+ size_t nbytes, int min);
static ssize_t _extract_entropy(struct entropy_store *r, void *buf,
size_t nbytes);

@@ -989,7 +989,7 @@ static void crng_reseed(struct crng_stat
} buf;

if (r) {
- num = extract_entropy(r, &buf, 32, 16, 0);
+ num = extract_entropy(r, &buf, 32, 16);
if (num == 0)
return;
} else {
@@ -1327,8 +1327,7 @@ EXPORT_SYMBOL_GPL(add_disk_randomness);
* This function decides how many bytes to actually take from the
* given pool, and also debits the entropy count accordingly.
*/
-static size_t account(struct entropy_store *r, size_t nbytes, int min,
- int reserved)
+static size_t account(struct entropy_store *r, size_t nbytes, int min)
{
int entropy_count, orig, have_bytes;
size_t ibytes, nfrac;
@@ -1342,7 +1341,7 @@ retry:
/* never pull more than available */
have_bytes = entropy_count >> (ENTROPY_SHIFT + 3);

- if ((have_bytes -= reserved) < 0)
+ if (have_bytes < 0)
have_bytes = 0;
ibytes = min_t(size_t, ibytes, have_bytes);
if (ibytes < min)
@@ -1448,15 +1447,13 @@ static ssize_t _extract_entropy(struct e
* returns it in a buffer.
*
* The min parameter specifies the minimum amount we can pull before
- * failing to avoid races that defeat catastrophic reseeding while the
- * reserved parameter indicates how much entropy we must leave in the
- * pool after each pull to avoid starving other readers.
+ * failing to avoid races that defeat catastrophic reseeding.
*/
static ssize_t extract_entropy(struct entropy_store *r, void *buf,
- size_t nbytes, int min, int reserved)
+ size_t nbytes, int min)
{
trace_extract_entropy(r->name, nbytes, ENTROPY_BITS(r), _RET_IP_);
- nbytes = account(r, nbytes, min, reserved);
+ nbytes = account(r, nbytes, min);
return _extract_entropy(r, buf, nbytes);
}