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From:   Mauricio Faria de Oliveira <mfo@canonical.com>
Date:   Wed, 10 Jun 2020 11:28:24 -0300
Message-ID: <CAO9xwp2VryJi46+3UPhbQz3npCaZBziOTWEp+Kiqd90rMhkJXQ@mail.gmail.com>
Subject: Re: [v2 PATCH] crypto: af_alg - fix use-after-free in af_alg_accept()
 due to bh_lock_sock()
To:     Herbert Xu <herbert@gondor.apana.org.au>
Cc:     "David S. Miller" <davem@davemloft.net>,
        linux-crypto@vger.kernel.org
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On Tue, Jun 9, 2020 at 9:21 PM Herbert Xu <herbert@gondor.apana.org.au> wrote:
>
> On Tue, Jun 09, 2020 at 12:17:32PM -0300, Mauricio Faria de Oliveira wrote:
> >
> > Per your knowledge/experience with the crypto subsystem, the changed code
> > paths are not hot enough to suffer from such implications?
>
> I don't think replacing a spin-lock with a pair of atomic ops is
> going to be too much of an issue.  We can always look at this again
> if someone comes up with real numbers of course.

Right; I meant the other places as well, where atomic ops were added
(in addition to the existing spinlocks.)

But indeed, real numbers would be great and tell whether or not
there's performance differences.

We're working on that -- Brian (bug reporter) has access to detailed
metrics/stats from the workload, and kindly agreed to set up two
identical instances to compare the numbers.  I'll keep you posted.

Thank you,
Mauricio


>
> Cheers,
> --
> Email: Herbert Xu <herbert@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt


-- 
Mauricio Faria de Oliveira