From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dave.Martin@arm.com (Dave P. Martin)
Date: Wed, 21 Apr 2010 12:17:41 +0100
Subject: kernel virtual memory access (from app) does not generatesegfault
In-Reply-To: <20100420224108.GA1432@n2100.arm.linux.org.uk>
References: <4BCD7076.9030802@browserseal.com>
	<20100420093441.GD6684@trinity.fluff.org>
	<000001cae074$1b564ff0$4044010a@Emea.Arm.com>
	<20100420142047.GA7398@desktop>
	<20100420170944.GE2234@trinity.fluff.org>
	<20100420192813.GA29831@n2100.arm.linux.org.uk>
	<20100420223106.GQ11723@shareable.org>
	<20100420224108.GA1432@n2100.arm.linux.org.uk>
Message-ID: <000001cae144$4281a9a0$4044010a@Emea.Arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

 

> -----Original Message-----
> From: Russell King - ARM Linux [mailto:linux at arm.linux.org.uk] 
> Sent: 20 April 2010 23:41
> To: Jamie Lokier
> Cc: Ben Dooks; anfei; Dave P Martin; 
> linux-arm-kernel at lists.infradead.org
> Subject: Re: kernel virtual memory access (from app) does not 
> generatesegfault

[...]

> The difference between instruction faults and data faults is 
> that we always interpret instruction faults on pre-ARMv6 CPUs 
> as a 'translation fault' rather than a permission fault since 
> they can't tell us what the problem was.

Note that my observations were on an armv7 kernel.  Should we still hit the
same bit of code in this case, or have I misdiagnosed the problem?

Cheers
---Dave