From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4DDCEEEB.9050500@domain.hid> Date: Wed, 25 May 2011 13:58:35 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <4DDA66CF.2010307@domain.hid> <4DDB349B.5030209@domain.hid> <4DDB76C6.2090008@domain.hid> <4DDB7B3D.2030607@domain.hid> <4DDB7C2C.4030206@domain.hid> <4DDB8136.10506@domain.hid> <4DDB8A1D.4050704@domain.hid> <4DDB8B5F.9070906@domain.hid> <4DDBA341.6060009@domain.hid> <4DDBA4D6.5070106@domain.hid> <4DDBB82D.6040803@domain.hid> <4DDBBAAF.2090008@domain.hid> <4DDCE5EA.5020900@domain.hid> In-Reply-To: <4DDCE5EA.5020900@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-core] [PULL] native: Fix msendq fastlock leakage List-Id: Xenomai life and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Xenomai core On 05/25/2011 01:20 PM, Jan Kiszka wrote: > On 2011-05-24 16:03, Gilles Chanteperdrix wrote: >> On 05/24/2011 03:52 PM, Jan Kiszka wrote: >>> On 2011-05-24 14:30, Gilles Chanteperdrix wrote: >>>>>>>>> Do you already have an idea how to get that info to the delete hook >>>>>>>>> function? >>>>>>>> >>>>>>>> Yes. We start by not applying the list reversal patch, then the sys_ppd >>>>>>>> is the first in the list. So, we can, in the function ppd_remove_mm, >>>>>>>> start by removing all the others ppd, then remove the sys ppd (that is >>>>>>>> the first), last. This changes a few signatures in the core code, a lot >>>>>>>> of things in the skin code, but that would be for the better... >>>>>>> >>>>>>> I still don't see how this affects the order we use in >>>>>>> do_taskexit_event, the one that prevents xnsys_get_ppd usage even when >>>>>>> the mm is still present. >>>>>> >>>>>> The idea is to change the cleanup routines not to call xnsys_get_ppd. >>>>> >>>>> ...and use what instead? Sorry, I'm slow today. >>>> >>>> The sys_ppd passed as other argument to the cleanup function. >>> >>> That would affect all thread hooks, not only the one for deletion. And >>> it would pull in more shadow-specific bits into the pod. >>> >>> Moreover, I think we would still be in troubles as mm, thus ppd, >>> deletion takes place before last task deletion, thus taskexit hook >>> invocation. That's due to the cleanup ordering in the kernel's do_exit. >>> >>> However, if you have a patch, I'd be happy to test and rework my leakage >>> fix. >> >> I will work on this ASAP. > > Sorry for pushing, but I need to decide if we should role out my > imperfect fix or if there is chance to use some upstream version > directly. Were you able to look into this, or will this likely take a > bit more time? I intended to try and do this next week-end. If it is more urgent than that, I can try in one or two days. In any case, I do not think we should try and workaround the current code, it is way to fragile. -- Gilles.