From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Thu, 09 Dec 2004 23:08:35 +0000 Subject: Re: [patch 2.6.10-rc3] Add TIF_SIGDELAYED processing Message-Id: <16824.56051.207249.1262@napali.hpl.hp.com> List-Id: References: <15449.1102482344@kao1.melbourne.sgi.com> In-Reply-To: <15449.1102482344@kao1.melbourne.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On Thu, 09 Dec 2004 12:41:33 +1100, Keith Owens said: >> It seems rather dangerous to stash away PIDs and deliver signals >> to them later on. It's just an invitation for races, IMHO. Keith> The pid is checked to see if it is still valid, see Keith> do_sigdelayed(). Yes, there is a very small race where the Keith> pid could be reused, but to hit that race we have to - I just think stashing away pids in the kernel is a slippery slope we do not want to get onto. Can't you stash away a reference to the task-structure and bump the reference count? I suspect that might get you into trouble when a task exits with first unmapping all MMIO-memory, but that's might not be so hard to deal with (when task exits, check whether it has any MMIO mappings and if so, kill those, or at least the associated registrations first). --david