[ELDK] 2.4 signal patch

[Detlev Zundel]

Hi Levend,

> I really thank you for your reply. Yes you are absolutely right about
> signal problems. And I share the same idea with you but I do not have
> chance to change that module.  I did not approved that signal based
> timer mechanism, but that module already developed before my project.

It is of course a plain fact that everybody inherits software with
problems and every good project management should cater for this even
before those problems are discovered.
 
> In fact, timer module knows the originator pid of the process. But the problem
> is such that when the timer
> expires, it is not guarantee that kernel is in the originator process'es
> context. So "current" can be a different
> process with a different uid. Is there a way for timer module to handle this ?

I took a cursory glance at the 2.4.25 kernel but it seems that there is
no send_signal(signal, orignator, destination) function which would be
needed.

So for me it seems like either you add even more hacks to "rescue" the
initial hack or you redesign you solution completely.

> I am really tired nowadays. So I did not think a bad side effect for disabling
> uid check for signal deliveration,
There is always a reason why code has been written - so taking out a
check is never a harmless operation.

> but when you said "any user can kill an application started by the superuser",
> I said aha, that is the reason.

Well if the checks are disabled, then effectively anybody can kill any
process - no matter who owns it.

Cheers
  Detlev

-- 
So maybe I lost track of my point.  But if I left a mark, C-x C-x should be
all I need.
      -- David Kastrup, emacs-devel.gnu.org <87hbj37v4x.fsf at lola.goethe.zz>
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