Re: Domain faults when CONFIG_CPU_SW_DOMAIN_PAN is enabled

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Thu, Dec 03, 2015 at 11:38:20AM +0000, Peter Rosin wrote:
> Russell King wrote:
> > On Thu, Dec 03, 2015 at 08:33:13AM +0000, Peter Rosin wrote:
> > > I wrote:
> > > > If I enable CONFIG_CPU_SW_DOMAIN_PAN, I sometimes (but not always) get the
> > > > following (or very similar) on boot.
> > > 
> > > I should have said "if I don't disable", as the option is "default y".
> > > 
> > > Also, if it survives on boot, below is an example of later trouble (after
> > > 30+ minutes on this occasion).
> > 
> > Please apply this patch so we (might) get a slightly better oops dump,
> > and then try to reproduce.
> 
> Sure thing, but it's still "DAC: 00000051"...

Thanks, that confirms that something in the uaccess-with-memcpy code
is clearing the DACR back to 0x51.

This has come up several times before, and I really can't spot the
problem in this code, so I've always said to disable the
uaccess-with-memcpy code.  Personally, I'd like to see the back
of that code...

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