[Devel] Re: [PATCH 11/13] Changes to show virtual ids to user

[Pavel Emelianov]

Pavel Emelianov wrote:
> Cedric Le Goater wrote:
>> Hello !
>>
>>>>> The worst case I can see with pid == 0.  Is that it would be a bug
>>>>> that we can fix later.  For other cases it would seem to be a user
>>>>> space API thing that we get stuck with for all time.
>>>> We cannot trust userspace application to expect some pid other than
>>>> positive. All that we can is either use some always-absent pid or
>>>> send the signal as SI_KERNEL.
>>>>
>>>> Our experience show that making decisions like above causes random
>> <>> applications failures that are hard (or even impossible) to debug.
>>
>>> Ok.  So I guess I see what you are proposing is picking an arbitrary
>>> pid, say pid == 2, and reserving that in all pid namespaces and using
>>> it when we have a pid that does not map to a specific namespace. I'm
>>> fine with that.
>>>
>>> All I care about is that we have a solution, preferably simple,
>>> to the non-mapped pid problem.
>> Pavel, are you against using pid == 0 and setting si_code to SI_KERNEL ? 
> 
> I think I am. A quick grep through the code revealed one place where

Sorry. I have misprinted. I meant "I think I am *NOT*". My bad :(

> this can happen, so I believe application are (have to be) somehow
> prepared to this.
> 
>> C.
>>
> 
>