Re: [PATCH 03/26] signal: Do not perform permission checks when sending pdeath_signal

Eric,

On Tue, Jun 6, 2017 at 9:03 PM, Eric W. Biederman [off-list ref] wrote:

This fixes and old old regression.  When Roland switched from
sending pdeath_signal with send_sig() to send_group_sig_info
it gained a permission check, and started taking the tasklist
lock.  Roland earlier fixed the double taking of the tasklist
lock in 3f2a0d1df938 ("[PATCH] fix pdeath_signal SMP locking")
but pdeath_signal still performs an unnecessary permission
check.

Ordinarily I would be hesitant at fixing an ancient regression but
a permission check for our parent sending to us is almost never
likely to fail (so it is unlikely anyone has noticed), and it
is stupid.  It makes absolutely no sense to see if our
parent has permission to send us a signal we requested be
sent to us.

Another side effect of this change is that audit_signal_info() is no longer
being called. AFAICT this is a user space visible change.

-- 
Thanks,
//richard