Subject: Re: psignal() and COMPAT_MACH exceptions
To: Christos Zoulas <>
From: Emmanuel Dreyfus <>
List: tech-kern
Date: 12/01/2003 13:15:43
Emmanuel Dreyfus <> wrote:

> 2) softsignals will be handled in darwin_sendsig. This solves the
> special case of SIGTRAP in sys_execve without the need for modifying MI
> code.

Um, I spoke too fast. This won't work, as softsignals are not raised for
masked signals, but they should be raised for unmasked but uncatched
signals (ie: unmasked signal with no signal handler installed). And we
only go in darwin_sendsig if the signal is catched by a signal handler.

Raising the exception could be achieved through kqueue, but I don't see
how I'll be able to prevent the signal emission. I'm back to the
emulation hook in kpsignal2 to inhibit signal sending.

Except of course if there are other suggestions...

Emmanuel Dreyfus
Il y a 10 sortes de personnes dans le monde: ceux qui comprennent 
le binaire et ceux qui ne le comprennent pas.