On 08/05/18 15:55, Ben Caradoc-Davies wrote:
If something calls getrandom without GRND_NONBLOCK while crng_init==1
(during early boot)
I now have conclusive evidence that this is the cause of the hang. If I
add a printk:
diff --git a/drivers/char/random.c b/drivers/char/random.c
index cd888d4ee605..b7358cc32f42 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -2021,6 +2021,9 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf,
size_t, count,
if (!crng_ready()) {
if (flags & GRND_NONBLOCK)
return -EAGAIN;
+ printk(KERN_NOTICE "random: %s: getrandom without "
+ "GRND_NONBLOCK while crng not ready\n",
+ current->comm);
ret = wait_for_random_bytes();
if (unlikely(ret))
return ret;
I get these at the console just before the hang:
random: plymouthd: uninitialized urandom read (8 bytes read)
random: plymouthd: uninitialized urandom read (8 bytes read)
random: plymouthd: getrandom without GRND_NONBLOCK while crng not ready
Kind regards,
--
Ben Caradoc-Davies <b...@transient.nz>
Director
Transient Software Limited <https://transient.nz/>
New Zealand
