Re: Problem with io_uring splice and KTLS

Jens Axboe
2023-10-13T13:46:06Z

On 10/12/23 11:47 PM, Sascha Hauer wrote:
> On Thu, Oct 12, 2023 at 07:45:07PM -0600, Jens Axboe wrote:
>> On 10/12/23 7:34 AM, Sascha Hauer wrote:
>>> In case you don't have encryption hardware you can create an
>>> asynchronous encryption module using cryptd. Compile a kernel with
>>> CONFIG_CRYPTO_USER_API_AEAD and CONFIG_CRYPTO_CRYPTD and start the
>>> webserver with the '-c' option. /proc/crypto should then contain an
>>> entry with:
>>>
>>> name : gcm(aes)
>>> driver : cryptd(gcm_base(ctr(aes-generic),ghash-generic))
>>> module : kernel
>>> priority : 150
>>
>> I did a bit of prep work to ensure I had everything working for when
>> there's time to dive into it, but starting it with -c doesn't register
>> this entry. Turns out the bind() in there returns -1/ENOENT.
>
> Yes, that happens here as well, that's why I don't check for the error
> in the bind call. Nevertheless it has the desired effect that the new
> algorithm is registered and used from there on. BTW you only need to
> start the webserver once with -c. If you start it repeatedly with -c a
> new gcm(aes) instance is registered each time.

Gotcha - I wasn't able to trigger the condition, which is why I thought
perhaps I was missing something.

Can you try the below patch and see if that makes a difference? I'm not
quite sure why it would since you said it triggers with DEFER_TASKRUN as
well, and for that kind of notification, you should never hit the paths
you have detailed in the debug patch.

diff --git a/net/core/stream.c b/net/core/stream.c
index f5c4e47df165..a9a196587254 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -67,7 +67,7 @@ int sk_stream_wait_connect(struct sock *sk, long *timeo_p)
return -EPIPE;
if (!*timeo_p)
return -EAGAIN;
- if (signal_pending(tsk))
+ if (task_sigpending(tsk))
return sock_intr_errno(*timeo_p);

add_wait_queue(sk_sleep(sk), &wait);
@@ -103,7 +103,7 @@ void sk_stream_wait_close(struct sock *sk, long timeout)
do {
if (sk_wait_event(sk, &timeout, !sk_stream_closing(sk), &wait))
break;
- } while (!signal_pending(current) && timeout);
+ } while (!task_sigpending(current) && timeout);

remove_wait_queue(sk_sleep(sk), &wait);
}
@@ -134,7 +134,7 @@ int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
goto do_error;
if (!*timeo_p)
goto do_eagain;
- if (signal_pending(current))
+ if (task_sigpending(current))
goto do_interrupted;
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
if (sk_stream_memory_free(sk) && !vm_wait)

--
Jens Axboe