Re: [RFC][PATCH 09/11] tty_io: Use do_send_sig_info in __do_SACK to forcibly kill tasks

[Eric W. Biederman]

Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:

> On Mon, Jul 16, 2018 at 12:17 PM Eric W. Biederman
> <ebiederm@xxxxxxxxxxxx> wrote:
>>
>> I should have said it doesn't matter because init does not open ttys and
>> become a member of session groups.  Or at least it never has in my
>> experience.  The only way I know to get that behavior is to boot with
>> init=/bin/bash.
>
> That's hopefully true, yes.
>
> Presumably init does open the console, but hopefull doesn't do setsid.
>
> (We *do* do "setsid()" for the linuxrc running, but that's not done by
> the init thread itself).
>
>> With the force_sig already in do_SAK today my change is not a
>> regression.  As force_sig in a completely different way forces the
>> signal to init.
>
> Ok. A couple of notes in the commit description on this might be good.

Definitely.

>> So I think we want the patch below to clean that up.  Then we don't have
>> to worry about the wrong things sending signals to init by accident, and
>> SEND_SIG_FORCED becomes just SEND_SIG_PRIV that skips the unnecesary
>> allocation of a siginfo struct.
>>
>> Thoughts?
>
> I think the end result is fine, but then I look at that patch of yours
> and it does many other things and that makes me nervous.
>
> Can you separate out the different things it does into separate
> patches to make it easier to read?

I will take a look.

Eric