Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull /dev/random fix from Ted Ts'o:
"Fix a soft lockup regression when reading from /dev/random in early
boot"
* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: fix soft lockup when trying to read from an uninitialized blocking pool
diff --git a/drivers/char/random.c b/drivers/char/random.c
index a42b3d7..5d5ea4c 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -772,8 +772,11 @@
if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
goto retry;
- if (has_initialized)
+ if (has_initialized) {
r->initialized = 1;
+ wake_up_interruptible(&random_read_wait);
+ kill_fasync(&fasync, SIGIO, POLL_IN);
+ }
trace_credit_entropy_bits(r->name, nbits,
entropy_count >> ENTROPY_SHIFT, _RET_IP_);
@@ -789,6 +792,13 @@
entropy_bits = r->entropy_count >> ENTROPY_SHIFT;
}
+ /* initialize the blocking pool if necessary */
+ if (entropy_bits >= random_read_wakeup_bits &&
+ !other->initialized) {
+ schedule_work(&other->push_work);
+ return;
+ }
+
/* should we wake readers? */
if (entropy_bits >= random_read_wakeup_bits &&
wq_has_sleeper(&random_read_wait)) {
@@ -1936,8 +1946,8 @@
return -EAGAIN;
wait_event_interruptible(random_read_wait,
- ENTROPY_BITS(&input_pool) >=
- random_read_wakeup_bits);
+ blocking_pool.initialized &&
+ (ENTROPY_BITS(&input_pool) >= random_read_wakeup_bits));
if (signal_pending(current))
return -ERESTARTSYS;
}
