Re: [PATCH v2 2/2] arm64: enable context tracking

[Larry Bassel]

On 07 May 14 11:17, Will Deacon wrote:
> On Wed, May 07, 2014 at 12:32:29AM +0100, Larry Bassel wrote:
> > Make calls to ct_user_enter when the kernel is exited
> > and ct_user_exit when the kernel is entered (in el0_da,
> > el0_ia, el0_svc, el0_irq).
> 
> Why only these entry points? I can reschedule after any exception from EL0,
> so I'd expect all exceptions from userspace to need annotating, no?
> 
> > These macros expand to function calls which will only work
> > properly if el0_sync and related code has been rearranged
> > (in a previous patch of this series).
> > 
> > In order to avoid saving registers, the slow syscall path
> > is forced (as x86 does).
> 
> ... and if you decide to handle undef exceptions, I think you'll need
> the register saving too, in case the kernel needs to perform emulation.

These are excellent points, I will rework the patch and submit v3.

Thanks for the feedback.

> 
> Will

Larry
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