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Date:   Mon, 17 Dec 2018 21:37:58 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Dave Hansen <dave.hansen@intel.com>
Cc:     Sean Christopherson <sean.j.christopherson@intel.com>,
        x86@kernel.org, platform-driver-x86@vger.kernel.org,
        linux-sgx@vger.kernel.org, nhorman@redhat.com,
        npmccallum@redhat.com, serge.ayoun@intel.com,
        shay.katz-zamir@intel.com, haitao.huang@linux.intel.com,
        andriy.shevchenko@linux.intel.com, tglx@linutronix.de,
        kai.svahn@intel.com, mark.shanahan@intel.com, luto@amacapital.net,
        Suresh Siddha <suresh.b.siddha@intel.com>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Darren Hart <dvhart@infradead.org>,
        Andy Shevchenko <andy@infradead.org>,
        "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" 
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v17 18/23] platform/x86: Intel SGX driver
Message-ID: <20181217193758.GC29785@linux.intel.com>
References: <20181116010412.23967-1-jarkko.sakkinen@linux.intel.com>
 <20181116010412.23967-19-jarkko.sakkinen@linux.intel.com>
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 <20181217180102.GA12560@linux.intel.com>
 <20181217183613.GD12491@linux.intel.com>
 <20181217184333.GA26920@linux.intel.com>
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On Mon, Dec 17, 2018 at 11:09:33AM -0800, Dave Hansen wrote:
> On 12/17/18 10:48 AM, Sean Christopherson wrote:
> > We can't set mm to NULL as we need it to unregister the notifier, and
> > I'm fairly certain attempting to unregister in the release callback
> > will deadlock.
> 
> Suggestion:
> 
> It looks like you only expect one VMA per enclave.  Things go bonkers if
> this is not true.  So, instead of storing encl->mm, don't.  You can get
> the mm from vma->vm_mm and you could just store encl->vma instead.

The code actually supports having multiple VMAs per enclave.

/Jarkko