From mboxrd@z Thu Jan  1 00:00:00 1970
From: anfei.zhou@gmail.com (anfei)
Date: Wed, 21 Apr 2010 20:43:17 +0800
Subject: kernel virtual memory access (from app) does not generatesegfault
In-Reply-To: <000001cae144$4281a9a0$4044010a@Emea.Arm.com>
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>
	<000001cae144$4281a9a0$4044010a@Emea.Arm.com>
Message-ID: <20100421124317.GA9408@desktop>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Wed, Apr 21, 2010 at 12:17:41PM +0100, Dave P. Martin wrote:
>  
> 
> > -----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?
> 
You said your kernel is .28, so it seems too old and this commit may fix
it: 
commit d25ef8b86e6a58f5476bf6e4a8da730b335f68fa
	ARM: 5728/1: Proper prefetch abort handling on ARMv6 and ARMv7

Cheers,
Anfei.

> Cheers
> ---Dave
> 
> 
>