- r->entropy_count < r->poolinfo->poolfracbits) {
- /* If we're limited, always leave two wakeup worth's BITS */
- int rsvd = r->limit ? 0 : random_read_wakeup_thresh/4;
- int bytes = nbytes;
-
- /* pull at least as many as BYTES as wakeup BITS */
- bytes = max_t(int, bytes, random_read_wakeup_thresh / 8);
- /* but never more than the buffer size */
- bytes = min_t(int, bytes, sizeof(tmp));
-
- DEBUG_ENT("going to reseed %s with %d bits "
- "(%zu of %d requested)\n",
- r->name, bytes * 8, nbytes * 8,
- r->entropy_count >> ENTROPY_SHIFT);
-
- bytes = extract_entropy(r->pull, tmp, bytes,
- random_read_wakeup_thresh / 8, rsvd);
- mix_pool_bytes(r, tmp, bytes, NULL);
- credit_entropy_bits(r, bytes*8);
- }
+ r->entropy_count < r->poolinfo->poolfracbits)
+ _xfer_secondary_pool(r, nbytes);
+}
+
+static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
+{
+ __u32 tmp[OUTPUT_POOL_WORDS];
+
+ /* For /dev/random's pool, always leave two wakeup worth's BITS */
+ int rsvd = r->limit ? 0 : random_read_wakeup_thresh/4;
+ int bytes = nbytes;
+
+ /* pull at least as many as BYTES as wakeup BITS */
+ bytes = max_t(int, bytes, random_read_wakeup_thresh / 8);
+ /* but never more than the buffer size */
+ bytes = min_t(int, bytes, sizeof(tmp));
+
+ DEBUG_ENT("going to reseed %s with %d bits (%zu of %d requested)\n",
+ r->name, bytes * 8, nbytes * 8,
+ r->entropy_count >> ENTROPY_SHIFT);
+
+ bytes = extract_entropy(r->pull, tmp, bytes,
+ random_read_wakeup_thresh / 8, rsvd);
+ mix_pool_bytes(r, tmp, bytes, NULL);
+ credit_entropy_bits(r, bytes*8);
+}
+
+/*
+ * Used as a workqueue function so that when the input pool is getting
+ * full, we can "spill over" some entropy to the output pools. That
+ * way the output pools can store some of the excess entropy instead
+ * of letting it go to waste.
+ */
+static void push_to_pool(struct work_struct *work)
+{
+ struct entropy_store *r = container_of(work, struct entropy_store,
+ push_work);
+ BUG_ON(!r);
+ _xfer_secondary_pool(r, random_read_wakeup_thresh/8);
+ trace_push_to_pool(r->name, r->entropy_count >> ENTROPY_SHIFT,
+ r->pull->entropy_count >> ENTROPY_SHIFT);