From: David Vrabel <david.vrabel@citrix.com>
To: Frediano Ziglio <frediano.ziglio@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: xen: Fix possible page fault in fifo events
Date: Mon, 28 Jul 2014 13:55:04 +0100 [thread overview]
Message-ID: <53D64828.6020209@citrix.com> (raw)
In-Reply-To: <1405432129.1749.5.camel@hamster.uk.xensource.com>
On 15/07/14 14:48, Frediano Ziglio wrote:
> sync_test_bit function require a long* read access to pointer.
> This is a problem if the you are using last entry in the page causing
> an access to next page. If this page is not readable you get a memory
> access failure (page fault).
> All other x64 bit functions access memory using 32 bit operations.
> For processors different than x64 long aligned operations are used.
I think we should implement a set of 32-bit bit ops. We fudged around
it for the arm64 problem but this second problem shows we need a better
solution.
David
prev parent reply other threads:[~2014-07-28 12:55 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-15 13:48 xen: Fix possible page fault in fifo events Frediano Ziglio
2014-07-15 14:32 ` [Xen-devel] " Andrew Cooper
2014-07-15 15:27 ` Konrad Rzeszutek Wilk
2014-07-15 15:54 ` Frediano Ziglio
2014-07-28 12:55 ` David Vrabel [this message]
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