On 28 July 2022 12:22:20 CEST, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
>From: Jason A. Donenfeld <Jason@xxxxxxxxx>
>
>There are two deadlock scenarios that need addressing, which cause
>problems when the computer goes to sleep, the interface is set down, and
>hwrng_unregister() is called. When the deadlock is hit, sleep is delayed
>for tens of seconds, causing it to fail. These scenarios are:
>
>1) The hwrng kthread can't be stopped while it's sleeping, because it
> uses msleep_interruptible() which does not react to kthread_stop.
>
>2) A normal user thread can't be interrupted by hwrng_unregister() while
> it's sleeping, because hwrng_unregister() is called from elsewhere.
>
>We solve both issues by add a completion object called dying that
>fulfils waiters once we have started the process in hwrng_unregister.
>
>At the same time, we should cleanup a common and useless dmesg splat
>in the same area.
>
>Cc: <stable@xxxxxxxxxxxxxxx>
>Reported-by: Gregory Erwin <gregerwin256@xxxxxxxxx>
>Fixes: fcd09c90c3c5 ("ath9k: use hw_random API instead of directly dumping into random.c")
>Link: https://lore.kernel.org/all/CAO+Okf6ZJC5-nTE_EJUGQtd8JiCkiEHytGgDsFGTEjs0c00giw@xxxxxxxxxxxxxx/
>Link: https://lore.kernel.org/lkml/CAO+Okf5k+C+SE6pMVfPf-d8MfVPVq4PO7EY8Hys_DVXtent3HA@xxxxxxxxxxxxxx/
>Link: https://bugs.archlinux.org/task/75138
>Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
>Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxx>
