Re: [PATCH 1/8] keyhandler: don't pass cpu_user_regs around

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 11/01/2024 3:49 pm, Jan Beulich wrote:
> On 11.01.2024 16:24, Andrew Cooper wrote:
>> On 11/01/2024 12:11 pm, Jan Beulich wrote:
>> It does occur to me that we're trying to accommodate for two behaviours
>> here.
>>
>> For a real keypress, we want to dump from the the point the interrupt
>> hit because that's the interesting bit of stack to see.  For a SYSCTL,
>> there's nothing, and we're using BUGFRAME_run_fn to generate one.
> There's three forms of handle_keypress() invocations really, and hence
> why (after having dropped the regs parameter already) I re-instated it.

Ok.  As you've done this analysis work, can you list these 3 forms?

I've clearly missed one in my analysis.

>
> As an aside - no, sysctl handling does not generate an exception frame.
> Is uses guest_cpu_user_regs() (and imo validly so).
>
>> So actually we just simply want "regs = get_irq_regs();" here and retain
>> prior NULL check, don't we?
> As per above, after I had it that way first, I backed off to accommodate
> all present use forms of handle_keypress(). But dealing with that (in
> whichever way we may end up deeming workable) can be separate anyway,
> afaict.

When complexity is involved, I always prefer to make changes in smaller
chunks.

~Andrew