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Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/random.c38
1 files changed, 19 insertions, 19 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index c1763bcbcaed..0bb3d7cf33e5 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -71,16 +71,16 @@
*********************************************************************/
/*
- * crng_init = 0 --> Uninitialized
- * 1 --> Initialized
- * 2 --> Initialized from input_pool
- *
* crng_init is protected by base_crng->lock, and only increases
- * its value (from 0->1->2).
+ * its value (from empty->early->ready).
*/
-static int crng_init = 0;
-#define crng_ready() (likely(crng_init > 1))
-/* Various types of waiters for crng_init->2 transition. */
+static enum {
+ CRNG_EMPTY = 0, /* Little to no entropy collected */
+ CRNG_EARLY = 1, /* At least POOL_EARLY_BITS collected */
+ CRNG_READY = 2 /* Fully initialized with POOL_READY_BITS collected */
+} crng_init = CRNG_EMPTY;
+#define crng_ready() (likely(crng_init >= CRNG_READY))
+/* Various types of waiters for crng_init->CRNG_READY transition. */
static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);
static struct fasync_struct *fasync;
static DEFINE_SPINLOCK(random_ready_chain_lock);
@@ -283,7 +283,7 @@ static void crng_reseed(void)
WRITE_ONCE(base_crng.generation, next_gen);
WRITE_ONCE(base_crng.birth, jiffies);
if (!crng_ready()) {
- crng_init = 2;
+ crng_init = CRNG_READY;
finalize_init = true;
}
spin_unlock_irqrestore(&base_crng.lock, flags);
@@ -377,7 +377,7 @@ static void crng_make_state(u32 chacha_state[CHACHA_STATE_WORDS],
* For the fast path, we check whether we're ready, unlocked first, and
* then re-check once locked later. In the case where we're really not
* ready, we do fast key erasure with the base_crng directly, extracting
- * when crng_init==0.
+ * when crng_init is CRNG_EMPTY.
*/
if (!crng_ready()) {
bool ready;
@@ -385,7 +385,7 @@ static void crng_make_state(u32 chacha_state[CHACHA_STATE_WORDS],
spin_lock_irqsave(&base_crng.lock, flags);
ready = crng_ready();
if (!ready) {
- if (crng_init == 0)
+ if (crng_init == CRNG_EMPTY)
extract_entropy(base_crng.key, sizeof(base_crng.key));
crng_fast_key_erasure(base_crng.key, chacha_state,
random_data, random_data_len);
@@ -739,8 +739,8 @@ EXPORT_SYMBOL(get_random_bytes_arch);
enum {
POOL_BITS = BLAKE2S_HASH_SIZE * 8,
- POOL_INIT_BITS = POOL_BITS, /* No point in settling for less. */
- POOL_FAST_INIT_BITS = POOL_INIT_BITS / 2
+ POOL_READY_BITS = POOL_BITS, /* When crng_init->CRNG_READY */
+ POOL_EARLY_BITS = POOL_READY_BITS / 2 /* When crng_init->CRNG_EARLY */
};
static struct {
@@ -835,13 +835,13 @@ static void credit_init_bits(size_t nbits)
init_bits = min_t(unsigned int, POOL_BITS, orig + add);
} while (cmpxchg(&input_pool.init_bits, orig, init_bits) != orig);
- if (!crng_ready() && init_bits >= POOL_INIT_BITS)
+ if (!crng_ready() && init_bits >= POOL_READY_BITS)
crng_reseed();
- else if (unlikely(crng_init == 0 && init_bits >= POOL_FAST_INIT_BITS)) {
+ else if (unlikely(crng_init == CRNG_EMPTY && init_bits >= POOL_EARLY_BITS)) {
spin_lock_irqsave(&base_crng.lock, flags);
- if (crng_init == 0) {
+ if (crng_init == CRNG_EMPTY) {
extract_entropy(base_crng.key, sizeof(base_crng.key));
- crng_init = 1;
+ crng_init = CRNG_EARLY;
}
spin_unlock_irqrestore(&base_crng.lock, flags);
}
@@ -1610,7 +1610,7 @@ const struct file_operations urandom_fops = {
*
* - write_wakeup_threshold - the amount of entropy in the input pool
* below which write polls to /dev/random will unblock, requesting
- * more entropy, tied to the POOL_INIT_BITS constant. It is writable
+ * more entropy, tied to the POOL_READY_BITS constant. It is writable
* to avoid breaking old userspaces, but writing to it does not
* change any behavior of the RNG.
*
@@ -1625,7 +1625,7 @@ const struct file_operations urandom_fops = {
#include <linux/sysctl.h>
static int sysctl_random_min_urandom_seed = CRNG_RESEED_INTERVAL / HZ;
-static int sysctl_random_write_wakeup_bits = POOL_INIT_BITS;
+static int sysctl_random_write_wakeup_bits = POOL_READY_BITS;
static int sysctl_poolsize = POOL_BITS;
static u8 sysctl_bootid[UUID_SIZE];