Message-ID: <dc1db094f94e2b4db58f5f3dce384f6967dd4168.camel@kernel.org>
Subject: Re: [PATCH 10/25] x86/sgx: Support enclave page permission changes
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Dave Hansen <dave.hansen@intel.com>,
        Reinette Chatre <reinette.chatre@intel.com>
Cc:     dave.hansen@linux.intel.com, tglx@linutronix.de, bp@alien8.de,
        luto@kernel.org, mingo@redhat.com, linux-sgx@vger.kernel.org,
        x86@kernel.org, seanjc@google.com, kai.huang@intel.com,
        cathy.zhang@intel.com, cedric.xing@intel.com,
        haitao.huang@intel.com, mark.shanahan@intel.com, hpa@zytor.com,
        linux-kernel@vger.kernel.org
Date:   Sat, 11 Dec 2021 07:17:13 +0200
In-Reply-To: <925629af-8cb3-c3c7-35ca-52d30beb984d@intel.com>
References: <cover.1638381245.git.reinette.chatre@intel.com>
         <44fe170cfd855760857660b9f56cae8c4747cc15.1638381245.git.reinette.chatre@intel.com>
         <Yav0/3jeJsuT3yEq@iki.fi> <925629af-8cb3-c3c7-35ca-52d30beb984d@intel.com>
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On Mon, 2021-12-06 at 12:19 -0800, Dave Hansen wrote:
> On 12/4/21 3:08 PM, Jarkko Sakkinen wrote:
> > > Enclave page permission changes need to be approached with care and
> > > for this reason this initial support is to allow enclave page
> > > permission changes _only_ if the new permissions are the same or
> > > more restrictive that the permissions originally vetted at the time t=
he
> > > pages were added to the enclave. Support for extending enclave page
> > > permissions beyond what was originally vetted is deferred.
> > This paragraph is out-of-scope for a commit message. You could have
> > this in the cover letter but not here. I would just remove it.
>=20
> This does convey valuable information, though.  It tells the reader that
> this is a sub-optimal implementation.  It also acknowledges that there
> is further work to do.  Maybe saying that it is "deferred" is not quite
> the verbiage I would use, but the concept is fine.

BTW, should we consistently speak about protection bits instead of
permissions?

/Jarkko