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Diffstat (limited to 'drivers/char/hw_random')
-rw-r--r--drivers/char/hw_random/core.c47
1 files changed, 4 insertions, 43 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index c42fb9fdccce..57c51efa5613 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -64,19 +64,6 @@ static size_t rng_buffer_size(void)
return RNG_BUFFER_SIZE;
}
-static void add_early_randomness(struct hwrng *rng)
-{
- int bytes_read;
-
- mutex_lock(&reading_mutex);
- bytes_read = rng_get_data(rng, rng_fillbuf, 32, 0);
- mutex_unlock(&reading_mutex);
- if (bytes_read > 0) {
- size_t entropy = bytes_read * 8 * rng->quality / 1024;
- add_hwgenerator_randomness(rng_fillbuf, bytes_read, entropy, false);
- }
-}
-
static inline void cleanup_rng(struct kref *kref)
{
struct hwrng *rng = container_of(kref, struct hwrng, ref);
@@ -339,13 +326,12 @@ static ssize_t rng_current_store(struct device *dev,
const char *buf, size_t len)
{
int err;
- struct hwrng *rng, *old_rng, *new_rng;
+ struct hwrng *rng, *new_rng;
err = mutex_lock_interruptible(&rng_mutex);
if (err)
return -ERESTARTSYS;
- old_rng = current_rng;
if (sysfs_streq(buf, "")) {
err = enable_best_rng();
} else {
@@ -361,11 +347,8 @@ static ssize_t rng_current_store(struct device *dev,
new_rng = get_current_rng_nolock();
mutex_unlock(&rng_mutex);
- if (new_rng) {
- if (new_rng != old_rng)
- add_early_randomness(new_rng);
+ if (new_rng)
put_rng(new_rng);
- }
return err ? : len;
}
@@ -533,7 +516,6 @@ int hwrng_register(struct hwrng *rng)
{
int err = -EINVAL;
struct hwrng *tmp;
- bool is_new_current = false;
if (!rng->name || (!rng->data_read && !rng->read))
goto out;
@@ -565,25 +547,8 @@ int hwrng_register(struct hwrng *rng)
err = set_current_rng(rng);
if (err)
goto out_unlock;
- /* to use current_rng in add_early_randomness() we need
- * to take a ref
- */
- is_new_current = true;
- kref_get(&rng->ref);
}
mutex_unlock(&rng_mutex);
- if (is_new_current || !rng->init) {
- /*
- * Use a new device's input to add some randomness to
- * the system. If this rng device isn't going to be
- * used right away, its init function hasn't been
- * called yet by set_current_rng(); so only use the
- * randomness from devices that don't need an init callback
- */
- add_early_randomness(rng);
- }
- if (is_new_current)
- put_rng(rng);
return 0;
out_unlock:
mutex_unlock(&rng_mutex);
@@ -594,12 +559,11 @@ EXPORT_SYMBOL_GPL(hwrng_register);
void hwrng_unregister(struct hwrng *rng)
{
- struct hwrng *old_rng, *new_rng;
+ struct hwrng *new_rng;
int err;
mutex_lock(&rng_mutex);
- old_rng = current_rng;
list_del(&rng->list);
complete_all(&rng->dying);
if (current_rng == rng) {
@@ -618,11 +582,8 @@ void hwrng_unregister(struct hwrng *rng)
} else
mutex_unlock(&rng_mutex);
- if (new_rng) {
- if (old_rng != new_rng)
- add_early_randomness(new_rng);
+ if (new_rng)
put_rng(new_rng);
- }
wait_for_completion(&rng->cleanup_done);
}