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] x86/sgx: Fix deadlock and race conditions between fork() and EPC reclaim
Date: Thu, 19 Mar 2020 16:15:49 +0200 [thread overview]
Message-ID: <20200319141549.GA3703@linux.intel.com> (raw)
In-Reply-To: <20200318200748.GA26164@linux.intel.com>
On Wed, Mar 18, 2020 at 01:07:48PM -0700, Sean Christopherson wrote:
> On Wed, Mar 18, 2020 at 09:41:32PM +0200, Jarkko Sakkinen wrote:
> > On Wed, Mar 18, 2020 at 09:40:06PM +0200, Jarkko Sakkinen wrote:
> > > On Wed, Mar 18, 2020 at 09:03:16AM -0700, Sean Christopherson wrote:
> > > > How on earth is someone doing to dredge up the above information without a
> > > > comment? Anyone looking at this code without a priori knowledge of the
> > > > development history will assume the missing synchronize_srcu() is a bug.
> > >
> > > By reading the source code of the driver obviously.
> >
> > Secondly, there is no development history. It is in epoch state.
>
> That's exactly my point. Unless someone knows to look through the
> pre-historic threads in the intel_sgx mailing list they'll be clueless as
> to why synchronizing the srcu when attaching a new mm to an enclave is a
> bad idea. And give it a few years and we'll probably be asking ourselves
> why there's no synchronize_sruc()...
>
> The locking rules between SGX and the core MMU are complex enough as it is,
> I don't understand why we'd want to make our lives even more difficult.
A six sentece paragraph is an overkill.
BTW, is smp_wmb() necessary given that the code is strictly x86? x86
does not reorder writes on a core.
/Jarkko
next prev parent reply other threads:[~2020-03-19 14:16 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-17 5:15 [PATCH] x86/sgx: Fix deadlock and race conditions between fork() and EPC reclaim Sean Christopherson
2020-03-18 15:39 ` Jarkko Sakkinen
2020-03-18 15:50 ` Jarkko Sakkinen
2020-03-18 15:51 ` Jarkko Sakkinen
2020-03-18 16:03 ` Sean Christopherson
2020-03-18 19:40 ` Jarkko Sakkinen
2020-03-18 19:41 ` Jarkko Sakkinen
2020-03-18 20:07 ` Sean Christopherson
2020-03-19 14:15 ` Jarkko Sakkinen [this message]
2020-03-18 21:30 ` Jarkko Sakkinen
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