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Subject: Re: RFC: userspace exception fixups
To:     Andy Lutomirski <luto@amacapital.net>,
        Sean Christopherson <sean.j.christopherson@intel.com>
Cc:     Andy Lutomirski <luto@kernel.org>, Jann Horn <jannh@google.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Rich Felker <dalias@libc.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Jethro Beekman <jethro@fortanix.com>,
        Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
        Florian Weimer <fweimer@redhat.com>,
        Linux API <linux-api@vger.kernel.org>, X86 ML <x86@kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, nhorman@redhat.com,
        npmccallum@redhat.com, "Ayoun, Serge" <serge.ayoun@intel.com>,
        shay.katz-zamir@intel.com, linux-sgx@vger.kernel.org,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Carlos O'Donell <carlos@redhat.com>,
        adhemerval.zanella@linaro.org
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Message-ID: <3d31d0b9-95bf-953e-1e28-d45c57b9c599@intel.com>
Date:   Tue, 6 Nov 2018 09:03:07 -0800
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On 11/6/18 8:57 AM, Andy Lutomirski wrote:
> I’m assuming it’s way too late for the SGX SDK to be changed to use a
> normal RPC mechanism? I’m a bit disappointed that enclaves can even
> manipulate outside state like this. I assume Intel had some reason
> for making it possible, but still.

Just because it's architecturally possible doesn't mean it has to be a
part of the ABI for running enclaves under Linux.

It's not too late to change the SDK.  Intel does not and can not depend
on any behavior of Linux until code gets merged.