random: optimize the entropy_store structure

Use smaller types to slightly shrink the size of the entropy store
structure.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 89eb5a8dec82..b8809d4ae186 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -436,16 +436,16 @@ struct entropy_store {
         __u32 *pool;
         const char *name;
         struct entropy_store *pull;
-        int limit;
 
         /* read-write data: */
         spinlock_t lock;
-        unsigned add_ptr;
-        unsigned input_rotate;
+        unsigned short add_ptr;
+        unsigned short input_rotate;
         int entropy_count;
         int entropy_total;
         unsigned int initialized:1;
-        bool last_data_init;
+        unsigned int limit:1;
+        unsigned int last_data_init:1;
         __u8 last_data[EXTRACT_SIZE];
 };
 
@@ -513,7 +513,7 @@ static void _mix_pool_bytes(struct entropy_store *r, const void *in,
 
         /* mix one byte at a time to simplify size handling and churn faster */
         while (nbytes--) {
-                w = rol32(*bytes++, input_rotate & 31);
+                w = rol32(*bytes++, input_rotate);
                 i = (i - 1) & wordmask;
 
                 /* XOR in the various taps */
@@ -533,7 +533,7 @@ static void _mix_pool_bytes(struct entropy_store *r, const void *in,
                  * rotation, so that successive passes spread the
                  * input bits across the pool evenly.
                  */
-                input_rotate += i ? 7 : 14;
+                input_rotate = (input_rotate + (i ? 7 : 14)) & 31;
         }
 
         ACCESS_ONCE(r->input_rotate) = input_rotate;
@@ -1049,7 +1049,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
         if (fips_enabled) {
                 spin_lock_irqsave(&r->lock, flags);
                 if (!r->last_data_init) {
-                        r->last_data_init = true;
+                        r->last_data_init = 1;
                         spin_unlock_irqrestore(&r->lock, flags);
                         trace_extract_entropy(r->name, EXTRACT_SIZE,
                                               ENTROPY_BITS(r), _RET_IP_);
@@ -1189,7 +1189,7 @@ static void init_std_data(struct entropy_store *r)
 
         r->entropy_count = 0;
         r->entropy_total = 0;
-        r->last_data_init = false;
+        r->last_data_init = 0;
         mix_pool_bytes(r, &now, sizeof(now), NULL);
         for (i = r->poolinfo->poolbytes; i > 0; i -= sizeof(rv)) {
                 if (!arch_get_random_long(&rv))