From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
To:     linux-kernel@vger.kernel.org, tytso@mit.edu
Cc:     "Jason A. Donenfeld" <Jason@zx2c4.com>
Subject: [PATCH 4/7] random: remove unused reserved argument
Date:   Thu, 13 Jan 2022 16:44:10 +0100
Message-Id: <20220113154413.29513-5-Jason@zx2c4.com>
In-Reply-To: <20220113154413.29513-1-Jason@zx2c4.com>
References: <20220113154413.29513-1-Jason@zx2c4.com>
MIME-Version: 1.0
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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.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 drivers/char/random.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 7a4d858ac731..5bef9565b251 100644
--- 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_state *crng, struct entropy_store *r)
 	} 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 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
 	/* 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 entropy_store *r, void *buf,
  * 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);
 }
 
-- 
2.34.1