Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <CAO+Okf6ZJC5-nTE_EJUGQtd8JiCkiEHytGgDsFGTEjs0c00giw@mail.gmail.com>
 <YrRZLPQHK0QbLTjr@zx2c4.com> <YrRZoGBMBa3lFkwx@zx2c4.com>
In-Reply-To: <YrRZoGBMBa3lFkwx@zx2c4.com>
From:   Gregory Erwin <gregerwin256@gmail.com>
Date:   Thu, 23 Jun 2022 16:36:34 -0700
Message-ID: <CAO+Okf5JbZ7vUeXWMOZU9Fz=igoVBOZZAiWn7w7SxW5t+dO0Ag@mail.gmail.com>
Subject: Re: ath9k: hwrng blocks for several minutes when phy is un-associated
To:     "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc:     Rui Salvaterra <rsalvaterra@gmail.com>,
        linux-crypto@vger.kernel.org, linux-wireless@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

No luck.

The first patch caused a warning and oops with ath9k_rng_read() at the
top of the call stack when reading from /dev/hwrng:
  WARNING: CPU: 1 PID: 454 at kernel/kthread.c:75 kthread_should_stop+0x2a/0x30
  BUG: kernel NULL pointer dereference, address: 0000000000000000

The second didn't have a noticeable effect, for better or worse.


On Thu, Jun 23, 2022 at 5:16 AM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
>
> Or perhaps more simply:
>
> diff --git a/drivers/net/wireless/ath/ath9k/rng.c b/drivers/net/wireless/ath/ath9k/rng.c
> index cb5414265a9b..5b44cd918c2b 100644
> --- a/drivers/net/wireless/ath/ath9k/rng.c
> +++ b/drivers/net/wireless/ath/ath9k/rng.c
> @@ -83,7 +83,8 @@ static int ath9k_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
>                 if (!wait || !max || likely(bytes_read) || fail_stats > 110)
>                         break;
>
> -               msleep_interruptible(ath9k_rng_delay_get(++fail_stats));
> +               if (msleep_interruptible(ath9k_rng_delay_get(++fail_stats)))
> +                       break;
>         }
>
>         if (wait && !bytes_read && max)
>