drivers/char/random.c: remove unused dont_count_entropy

Ever since "random: kill dead extract_state struct" [1], the
dont_count_entropy member of struct timer_rand_state has been
effectively unused. Since it hasn't found a new use in 12 years, it's
probably safe to finally kill it.

[1] Pre-git, https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=c1c48e61c251f57e7a3f1bf11b3c462b2de9dcb5

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 25 insertions, 28 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index ee0c0d18f1eb..e027e7fa1472 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -964,7 +964,6 @@ static ssize_t extract_crng_user(void __user *buf, size_t nbytes)
 struct timer_rand_state {
         cycles_t last_time;
         long last_delta, last_delta2;
-        unsigned dont_count_entropy:1;
 };
 
 #define INIT_TIMER_RAND_STATE { INITIAL_JIFFIES, };
@@ -1030,35 +1029,33 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
          * We take into account the first, second and third-order deltas
          * in order to make our estimate.
          */
+        delta = sample.jiffies - state->last_time;
+        state->last_time = sample.jiffies;
+
+        delta2 = delta - state->last_delta;
+        state->last_delta = delta;
+
+        delta3 = delta2 - state->last_delta2;
+        state->last_delta2 = delta2;
+
+        if (delta < 0)
+                delta = -delta;
+        if (delta2 < 0)
+                delta2 = -delta2;
+        if (delta3 < 0)
+                delta3 = -delta3;
+        if (delta > delta2)
+                delta = delta2;
+        if (delta > delta3)
+                delta = delta3;
 
-        if (!state->dont_count_entropy) {
-                delta = sample.jiffies - state->last_time;
-                state->last_time = sample.jiffies;
-
-                delta2 = delta - state->last_delta;
-                state->last_delta = delta;
-
-                delta3 = delta2 - state->last_delta2;
-                state->last_delta2 = delta2;
-
-                if (delta < 0)
-                        delta = -delta;
-                if (delta2 < 0)
-                        delta2 = -delta2;
-                if (delta3 < 0)
-                        delta3 = -delta3;
-                if (delta > delta2)
-                        delta = delta2;
-                if (delta > delta3)
-                        delta = delta3;
+        /*
+         * delta is now minimum absolute delta.
+         * Round down by 1 bit on general principles,
+         * and limit entropy entimate to 12 bits.
+         */
+        credit_entropy_bits(r, min_t(int, fls(delta>>1), 11));
 
-                /*
-                 * delta is now minimum absolute delta.
-                 * Round down by 1 bit on general principles,
-                 * and limit entropy entimate to 12 bits.
-                 */
-                credit_entropy_bits(r, min_t(int, fls(delta>>1), 11));
-        }
         preempt_enable();
 }