From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Nicolas Pitre <nico@fluxnic.net>
Cc: Tony Lindgren <tony@atomide.com>,
linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: Please help with the OMAP static mapping mess
Date: Tue, 4 Oct 2011 23:54:24 +0100 [thread overview]
Message-ID: <20111004225424.GA32102@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <alpine.LFD.2.02.1110041528050.9106@xanadu.home>
On Tue, Oct 04, 2011 at 05:10:36PM -0400, Nicolas Pitre wrote:
> Which makes me think... with all those architectures intercepting
> ioremap calls in order to provide an equivalent static mapping address,
> they already get an unexpected domain given that static mappings are
> mostly DOMAIN_IO and not DOMAIN_KERNEL as would result from an non
> intercepted ioremap call.
That's a necessary evil - otherwise we have to separate out the
ioremap from vmalloc.
Incidentally, how are you dealing with the problem of a static mapping
setting up a L1 page table entry for DOMAIN_IO, and then a vmalloc
request coming in, overlapping that L1 page table?
If this memory then gets accessed with get_user() with set_fs(get_ds()),
the kernel will oops as we don't switch DOMAIN_IO memory on set_fs().
(I don't know if this happens in practice, but there's nothing to say
that it's illegal to do this.)
next prev parent reply other threads:[~2011-10-04 22:54 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-03 18:59 Please help with the OMAP static mapping mess Nicolas Pitre
2011-10-03 20:56 ` Tony Lindgren
2011-10-03 22:09 ` Nicolas Pitre
2011-10-03 22:38 ` Tony Lindgren
2011-10-04 7:04 ` Santosh Shilimkar
2011-10-04 21:21 ` Nicolas Pitre
2011-10-05 2:09 ` Rob Herring
2011-10-05 2:39 ` Nicolas Pitre
2011-10-05 6:16 ` Santosh Shilimkar
2011-10-03 22:39 ` Nicolas Pitre
2011-10-03 22:59 ` Tony Lindgren
2011-10-04 6:18 ` Shilimkar, Santosh
2011-10-04 17:50 ` Tony Lindgren
2011-10-03 22:44 ` Russell King - ARM Linux
2011-10-04 21:10 ` Nicolas Pitre
2011-10-04 22:54 ` Russell King - ARM Linux [this message]
2011-10-04 23:20 ` Nicolas Pitre
2011-10-05 0:42 ` Tony Lindgren
2011-10-05 0:57 ` Nicolas Pitre
2011-10-05 1:35 ` Tony Lindgren
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