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: Wed, 18 Mar 2020 17:51:45 +0200 [thread overview]
Message-ID: <20200318155145.GB37726@linux.intel.com> (raw)
In-Reply-To: <20200318155043.GA37726@linux.intel.com>
On Wed, Mar 18, 2020 at 05:50:47PM +0200, Jarkko Sakkinen wrote:
> > > + /*
> > > + * DO NOT call synchronize_srcu()! When this is called via dup_mmap(),
> > > + * mmap_sem is held for write in both the old mm and new mm, and the
> > > + * reclaimer may be holding srcu for read while waiting on down_read()
> > > + * for the old mm's mmap_sem, i.e. synchronizing will deadlock.
> > > + * Incrementing the list version ensures readers that must not race
> > > + * with a mm being added will see the updated list.
> > > + */
>
> For this comment, please completely remove it. We either call something
> or do not call it. We do !call anything.
Was meaning to say that we do not !call anything.
/Jarkko
next prev parent reply other threads:[~2020-03-18 15:51 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 [this message]
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
2020-03-18 21:30 ` Jarkko Sakkinen
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