RE: [PATCH] crypto: virtio-crypto: call finalize with bh disabled

["Gonglei (Arei)" <arei.gonglei@huawei.com>]

Ping Herbert.  

Thanks.

> -----Original Message-----
> From: Gonglei (Arei)
> Sent: Wednesday, September 27, 2023 5:18 PM
> To: 'Halil Pasic' <pasic@linux.ibm.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>; linux-crypto@vger.kernel.org;
> Marc Hartmayer <mhartmay@linux.ibm.com>; Michael S. Tsirkin
> <mst@redhat.com>; Jason Wang <jasowang@redhat.com>;
> virtualization@lists.linux-foundation.org; linux-kernel@vger.kernel.org;
> pizhenwei@bytedance.com; Cornelia Huck <cohuck@redhat.com>
> Subject: RE: [PATCH] crypto: virtio-crypto: call finalize with bh disabled
> 
> 
> 
> > -----Original Message-----
> > From: Halil Pasic [mailto:pasic@linux.ibm.com]
> > Sent: Wednesday, September 27, 2023 12:42 AM
> > To: Gonglei (Arei) <arei.gonglei@huawei.com>
> > Cc: Herbert Xu <herbert@gondor.apana.org.au>;
> > linux-crypto@vger.kernel.org; Marc Hartmayer <mhartmay@linux.ibm.com>;
> > Michael S. Tsirkin <mst@redhat.com>; Jason Wang
> <jasowang@redhat.com>;
> > virtualization@lists.linux-foundation.org;
> > linux-kernel@vger.kernel.org; pizhenwei@bytedance.com; Halil Pasic
> > <pasic@linux.ibm.com>; Cornelia Huck <cohuck@redhat.com>
> > Subject: Re: [PATCH] crypto: virtio-crypto: call finalize with bh
> > disabled
> >
> > [..]
> > > --- a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
> > > +++ b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
> > > @@ -61,8 +61,9 @@ static void virtio_crypto_akcipher_finalize_req(
> > >  	vc_akcipher_req->src_buf = NULL;
> > >  	vc_akcipher_req->dst_buf = NULL;
> > >  	virtcrypto_clear_request(&vc_akcipher_req->base);
> > > -
> > > +	local_bh_disable();
> > >
> > > crypto_finalize_akcipher_request(vc_akcipher_req->base.dataq->engine
> > > ,
> > > req, err);
> > > +	local_bh_enable();
> >
> > Thanks Gonglei!
> >
> > I did this a quick spin, and it does not seem to be sufficient on s390x.
> > Which does not come as a surprise to me, because
> >
> > #define lockdep_assert_in_softirq()
> > \
> > do
> > {
> >      \
> >         WARN_ON_ONCE(__lockdep_enabled                  &&
> > \
> >                      (!in_softirq() || in_irq() || in_nmi()));          \
> > } while (0)
> >
> > will still warn because  in_irq() still evaluates to true (your patch
> > addresses the !in_softirq() part).
> >
> You are right.
> 
> So I think the core of this question is: Can we call crypto_finalize_request() in
> the upper half of the interrupt?
> If so, maybe we should introduce a new function, such as
> lockdep_assert_in_interrupt().
> 
> #define lockdep_assert_in_interrupt()                               \
> do {                                                           \
>        WARN_ON_ONCE(__lockdep_enabled && !in_interrupt());        \
> } while (0)
> 
> If not, why?
> 
> Herbert, do you have any suggestions? Thanks.
> 
> 
> Regards,
> -Gonglei
>