Linux-Sgx Archive on lore.kernel.org
 help / color / Atom feed
From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: linux-sgx@vger.kernel.org
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: <20191104223019.GB3606@linux.intel.com> (raw)
In-Reply-To: <20191104205401.GB5960@linux.intel.com>

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
change.

/Jarkko

  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

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191104223019.GB3606@linux.intel.com \
    --to=jarkko.sakkinen@linux.intel.com \
    --cc=linux-sgx@vger.kernel.org \
    --cc=sean.j.christopherson@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Sgx Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-sgx/0 linux-sgx/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-sgx linux-sgx/ https://lore.kernel.org/linux-sgx \
		linux-sgx@vger.kernel.org
	public-inbox-index linux-sgx

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-sgx


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git