Re: [PATCH] Hibernation: Document __save_processor_state() on x86-64

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Sunday, 30 of December 2007, Ingo Molnar wrote:
> 
> * Rafael J. Wysocki <rjw@sisk.pl> wrote:
> 
> > From: Rafael J. Wysocki <rjw@sisk.pl>
> > 
> > Document the fact that __save_processor_state() has to save all CPU 
> > registers referred to by the kernel in case a different kernel is used 
> > to load and restore a hibernation image containing it.
> 
> ok - so i guess i should drop this from x86.git:
> 
>  @@ -53,7 +53,6 @@ void __save_processor_state(struct saved
>          ctxt->cr2 = read_cr2();
>          ctxt->cr3 = read_cr3();
>          ctxt->cr4 = read_cr4();
>  -       ctxt->cr8 = read_cr8();
>   }
> 
> right?

Well, if cr8 is used for anything that matters, then yes.

> But i'm wondering - are we really ever resuming to a different  
> kernel version, for this to be an issue?

The boot kernel may be different from the kernel within the image, if that's
what you're asking for.

Rafael