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Date:   Mon, 17 Dec 2018 20:23:19 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Sean Christopherson <sean.j.christopherson@intel.com>
Cc:     "Dr. Greg" <greg@enjellic.com>,
        Andy Lutomirski <luto@amacapital.net>,
        Andy Lutomirski <luto@kernel.org>, X86 ML <x86@kernel.org>,
        Platform Driver <platform-driver-x86@vger.kernel.org>,
        linux-sgx@vger.kernel.org, Dave Hansen <dave.hansen@intel.com>,
        nhorman@redhat.com, npmccallum@redhat.com,
        "Ayoun, Serge" <serge.ayoun@intel.com>, shay.katz-zamir@intel.com,
        haitao.huang@linux.intel.com,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Svahn, Kai" <kai.svahn@intel.com>, mark.shanahan@intel.com,
        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>,
        LKML <linux-kernel@vger.kernel.org>, jethro@fortanix.com
Subject: Re: [PATCH v17 18/23] platform/x86: Intel SGX driver
Message-ID: <20181217182319.GA13288@linux.intel.com>
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On Mon, Dec 17, 2018 at 10:09:57AM -0800, Sean Christopherson wrote:
> No, EREMOVE should never fail if the enclave is being released, i.e. all
> references to the enclave are gone.  And failure during sgx_encl_release()
> means we leaked an EPC page, which warrants a WARN.

Right that what I was suspecting as swapper should hold a ref to the
enclave while it is working on it. It is a programming error when this
happens.

Maybe change the boolean parameter to flags parameter have a flag to
use sgx_free_page()?

> That makes sense.

What do you think of Dave's proposal?

/Jarkko