Is zero a valid value for the pid member of the AUDIT_SIGNAL_INFO message?

[Eric Paris]

On Tue, 2014-03-11 at 18:15 -0400, Richard Guy Briggs wrote:
> Steve,
> 
> Subject says it all...
> 
> Is zero a valid value for the pid member of the AUDIT_SIGNAL_INFO message?

No...

Given that userspace requests AUDIT_SIGNAL_INFO after it gets a signal,
and that audit_sig_{uid,pid,...} get filled in when some task sent
auditd that signal, the idea that the pid would be 0 doesn't make
sense...  (unless auditd requests AUDIT_SIGNAL_INFO without getting a
signal, but that's just dumb)