There are no code changes here; this is just a reordering of functions,
so that in subsequent commits, the timer entropy functions can call into
the interrupt ones.
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
drivers/char/random.c | 206 +++++++++++++++++++++---------------------
1 file changed, 103 insertions(+), 103 deletions(-)
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 893b8f15fcfe..d15f2133e804 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1011,109 +1011,6 @@ void add_device_randomness(const void *buf, size_t size)
}
EXPORT_SYMBOL(add_device_randomness);
-/* There is one of these per entropy source */
-struct timer_rand_state {
- unsigned long last_time;
- long last_delta, last_delta2;
-};
-
-/*
- * This function adds entropy to the entropy "pool" by using timing
- * delays. It uses the timer_rand_state structure to make an estimate
- * of how many bits of entropy this call has added to the pool.
- *
- * The number "num" is also added to the pool - it should somehow describe
- * the type of event which just happened. This is currently 0-255 for
- * keyboard scan codes, and 256 upwards for interrupts.
- */
-static void add_timer_randomness(struct timer_rand_state *state, unsigned int num)
-{
- unsigned long entropy = random_get_entropy(), now = jiffies, flags;
- long delta, delta2, delta3;
-
- spin_lock_irqsave(&input_pool.lock, flags);
- _mix_pool_bytes(&entropy, sizeof(entropy));
- _mix_pool_bytes(&num, sizeof(num));
- spin_unlock_irqrestore(&input_pool.lock, flags);
-
- if (crng_ready())
- return;
-
- /*
- * Calculate number of bits of randomness we probably added.
- * We take into account the first, second and third-order deltas
- * in order to make our estimate.
- */
- delta = now - READ_ONCE(state->last_time);
- WRITE_ONCE(state->last_time, now);
-
- delta2 = delta - READ_ONCE(state->last_delta);
- WRITE_ONCE(state->last_delta, delta);
-
- delta3 = delta2 - READ_ONCE(state->last_delta2);
- WRITE_ONCE(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 estimate to 12 bits.
- */
- credit_init_bits(min_t(unsigned int, fls(delta >> 1), 11));
-}
-
-void add_input_randomness(unsigned int type, unsigned int code,
- unsigned int value)
-{
- static unsigned char last_value;
- static struct timer_rand_state input_timer_state = { INITIAL_JIFFIES };
-
- /* Ignore autorepeat and the like. */
- if (value == last_value)
- return;
-
- last_value = value;
- add_timer_randomness(&input_timer_state,
- (type << 4) ^ code ^ (code >> 4) ^ value);
-}
-EXPORT_SYMBOL_GPL(add_input_randomness);
-
-#ifdef CONFIG_BLOCK
-void add_disk_randomness(struct gendisk *disk)
-{
- if (!disk || !disk->random)
- return;
- /* First major is 1, so we get >= 0x200 here. */
- add_timer_randomness(disk->random, 0x100 + disk_devt(disk));
-}
-EXPORT_SYMBOL_GPL(add_disk_randomness);
-
-void rand_initialize_disk(struct gendisk *disk)
-{
- struct timer_rand_state *state;
-
- /*
- * If kzalloc returns null, we just won't use that entropy
- * source.
- */
- state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
- if (state) {
- state->last_time = INITIAL_JIFFIES;
- disk->random = state;
- }
-}
-#endif
-
/*
* Interface for in-kernel drivers of true hardware RNGs.
* Those devices may produce endless random bits and will be throttled
@@ -1310,6 +1207,109 @@ void add_interrupt_randomness(int irq)
}
EXPORT_SYMBOL_GPL(add_interrupt_randomness);
+/* There is one of these per entropy source */
+struct timer_rand_state {
+ unsigned long last_time;
+ long last_delta, last_delta2;
+};
+
+/*
+ * This function adds entropy to the entropy "pool" by using timing
+ * delays. It uses the timer_rand_state structure to make an estimate
+ * of how many bits of entropy this call has added to the pool.
+ *
+ * The number "num" is also added to the pool - it should somehow describe
+ * the type of event which just happened. This is currently 0-255 for
+ * keyboard scan codes, and 256 upwards for interrupts.
+ */
+static void add_timer_randomness(struct timer_rand_state *state, unsigned int num)
+{
+ unsigned long entropy = random_get_entropy(), now = jiffies, flags;
+ long delta, delta2, delta3;
+
+ spin_lock_irqsave(&input_pool.lock, flags);
+ _mix_pool_bytes(&entropy, sizeof(entropy));
+ _mix_pool_bytes(&num, sizeof(num));
+ spin_unlock_irqrestore(&input_pool.lock, flags);
+
+ if (crng_ready())
+ return;
+
+ /*
+ * Calculate number of bits of randomness we probably added.
+ * We take into account the first, second and third-order deltas
+ * in order to make our estimate.
+ */
+ delta = now - READ_ONCE(state->last_time);
+ WRITE_ONCE(state->last_time, now);
+
+ delta2 = delta - READ_ONCE(state->last_delta);
+ WRITE_ONCE(state->last_delta, delta);
+
+ delta3 = delta2 - READ_ONCE(state->last_delta2);
+ WRITE_ONCE(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 estimate to 12 bits.
+ */
+ credit_init_bits(min_t(unsigned int, fls(delta >> 1), 11));
+}
+
+void add_input_randomness(unsigned int type, unsigned int code,
+ unsigned int value)
+{
+ static unsigned char last_value;
+ static struct timer_rand_state input_timer_state = { INITIAL_JIFFIES };
+
+ /* Ignore autorepeat and the like. */
+ if (value == last_value)
+ return;
+
+ last_value = value;
+ add_timer_randomness(&input_timer_state,
+ (type << 4) ^ code ^ (code >> 4) ^ value);
+}
+EXPORT_SYMBOL_GPL(add_input_randomness);
+
+#ifdef CONFIG_BLOCK
+void add_disk_randomness(struct gendisk *disk)
+{
+ if (!disk || !disk->random)
+ return;
+ /* First major is 1, so we get >= 0x200 here. */
+ add_timer_randomness(disk->random, 0x100 + disk_devt(disk));
+}
+EXPORT_SYMBOL_GPL(add_disk_randomness);
+
+void rand_initialize_disk(struct gendisk *disk)
+{
+ struct timer_rand_state *state;
+
+ /*
+ * If kzalloc returns null, we just won't use that entropy
+ * source.
+ */
+ state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
+ if (state) {
+ state->last_time = INITIAL_JIFFIES;
+ disk->random = state;
+ }
+}
+#endif
+
struct entropy_timer_state {
unsigned long entropy;
struct timer_list timer;
--
2.35.1
