Messages in this thread | | | From | Toke Høiland-Jørgensen <> | Subject | Re: [PATCH v8] ath9k: let sleep be interrupted when unregistering hwrng | Date | Tue, 05 Jul 2022 00:04:46 +0200 |
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"Jason A. Donenfeld" <Jason@zx2c4.com> writes:
> 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() instead of schedule_timeout_interruptible(). > The fix is a simple moving to the correct function. At the same time, > we should cleanup a common and useless dmesg splat in the same area. > > 2) A normal user thread can't be interrupted by hwrng_unregister() while > it's sleeping, because hwrng_unregister() is called from elsewhere. > The solution here is to keep track of which thread is currently > reading, and asleep, and signal that thread when it's time to > unregister. There's a bit of book keeping required to prevent > lifetime issues on current. > > Reported-by: Gregory Erwin <gregerwin256@gmail.com> > Cc: Toke Høiland-Jørgensen <toke@redhat.com> > Cc: Kalle Valo <kvalo@kernel.org> > Cc: Rui Salvaterra <rsalvaterra@gmail.com> > Cc: Herbert Xu <herbert@gondor.apana.org.au> > Cc: stable@vger.kernel.org > Fixes: fcd09c90c3c5 ("ath9k: use hw_random API instead of directly dumping into random.c") > Link: https://lore.kernel.org/all/CAO+Okf6ZJC5-nTE_EJUGQtd8JiCkiEHytGgDsFGTEjs0c00giw@mail.gmail.com/ > Link: https://lore.kernel.org/lkml/CAO+Okf5k+C+SE6pMVfPf-d8MfVPVq4PO7EY8Hys_DVXtent3HA@mail.gmail.com/ > Link: https://bugs.archlinux.org/task/75138 > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
With the change to EXPORT_SYMBOL_GPL() for wake_up_state that Kalle has kindly agreed to fix up while applying:
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
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