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From: Jarkko Sakkinen <>
To: Sean Christopherson <>
Subject: Re: [PATCH for v24 2/3] x86/sgx: Destroy enclave if EADD fails
Date: Tue, 5 Nov 2019 00:31:25 +0200
Message-ID: <> (raw)
In-Reply-To: <>

On Mon, Nov 04, 2019 at 12:54:01PM -0800, Sean Christopherson wrote:
> On Mon, Nov 04, 2019 at 10:01:40PM +0200, Jarkko Sakkinen wrote:
> > __sgx_encl_add_page() can only fail in the case of EPCM conflict at least
> > in non-artificial situations.
> Huh?  EADD can fail for a variety of reasons.  I can't think of a use case
> where userspace _won't_ kill the enclave in response to failure, but that
> doesn't justify killing the enclave, e.g. we don't kill the enclave in any
> other error path that is just as indicative of a userspace bug.

I think it does because it is the only sane metrics to take and it
also makes the semantics more sound and coherent.

> > Also, it consistent semantics in rollback is something to pursue for.
> I don't follow this at all.  How is it inconsistent to state that errors
> are handled gracefully unless they're unrecoverable?

Always when the user space gets -EIO it will know that enclave ceased
to exist. That is very consistent.

> > Thus, destroy enclave when the EADD fails as we do when EEXTEND fails
> > already.
> > 
> > In the cases it is sane to return -EIO. From this the caller can deduce
> > the failure and knows that the enclave was destroyed. The previous
> > -EFAULT could happen in numerous situations.
> This should be a separate patch.

No it shouldn't because it is so closely connected to the semantics


  reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-04 20:01 [PATCH for v24 1/3] x86/sgx: Use GFP_KERNEL for allocations Jarkko Sakkinen
2019-11-04 20:01 ` [PATCH for v24 2/3] x86/sgx: Destroy enclave if EADD fails Jarkko Sakkinen
2019-11-04 20:54   ` Sean Christopherson
2019-11-04 22:31     ` Jarkko Sakkinen [this message]
2019-11-04 20:01 ` [PATCH for v24 3/3] x86/sgx: Remove a subordinate clause Jarkko Sakkinen
2019-11-04 21:21   ` Sean Christopherson
2019-11-04 22:36     ` Jarkko Sakkinen
2019-11-04 22:37       ` Jarkko Sakkinen
2019-11-04 20:46 ` [PATCH for v24 1/3] x86/sgx: Use GFP_KERNEL for allocations Sean Christopherson
2019-11-04 22:26   ` Jarkko Sakkinen
2019-11-05  2:17     ` Sean Christopherson
2019-11-06 21:54       ` Jarkko Sakkinen
2019-11-06 21:59         ` Jarkko Sakkinen
2019-11-06 22:02           ` Jarkko Sakkinen

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