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Message-ID: <1570210902.3563.19.camel@HansenPartnership.com>
Subject: Re: [PATCH v3 2/2] tpm: Detach page allocation from tpm_buf
From:   James Bottomley <James.Bottomley@HansenPartnership.com>
To:     Mimi Zohar <zohar@linux.ibm.com>,
        Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
        linux-integrity@vger.kernel.org
Cc:     Jerry Snitselaar <jsnitsel@redhat.com>,
        Sumit Garg <sumit.garg@linaro.org>,
        Stefan Berger <stefanb@linux.vnet.ibm.com>,
        Peter Huewe <peterhuewe@gmx.de>,
        Jason Gunthorpe <jgg@ziepe.ca>, Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        open list <linux-kernel@vger.kernel.org>
Date:   Fri, 04 Oct 2019 10:41:42 -0700
In-Reply-To: <1570210647.5046.78.camel@linux.ibm.com>
References: <20191003185103.26347-1-jarkko.sakkinen@linux.intel.com>
         <20191003185103.26347-3-jarkko.sakkinen@linux.intel.com>
         <1570207062.3563.17.camel@HansenPartnership.com>
         <1570210647.5046.78.camel@linux.ibm.com>
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On Fri, 2019-10-04 at 13:37 -0400, Mimi Zohar wrote:
> On Fri, 2019-10-04 at 09:37 -0700, James Bottomley wrote:
> > On Thu, 2019-10-03 at 21:51 +0300, Jarkko Sakkinen wrote:
> > > As has been seen recently, binding the buffer allocation and
> > > tpm_buf
> > > together is sometimes far from optimal.
> > 
> > Can you elaborate on this a bit more?  I must have missed the
> > discussion.
> 
> Refer to e13cd21ffd50 ("tpm: Wrap the buffer from the caller to
> tpm_buf in tpm_send()") for the details.

Yes, I get that, but to my mind that calls for moving the
tpm_init/destroy_buf into the callers of tpm_send (which, for the most
part, already exist), which means there's no need to separate the buf
and data lifetimes.

James