From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4BC86E70.1010707@domain.hid> Date: Fri, 16 Apr 2010 16:04:32 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <4BC855E6.106@domain.hid> <4BC85899.90700@domain.hid> <1271423429.2365.719.camel@domain.hid> In-Reply-To: <1271423429.2365.719.camel@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-core] [Xenomai-git] Wolfgang Mauerer : RTDM: Fix potential NULL pointer dereference List-Id: Xenomai life and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum Cc: xenomai-core Philippe Gerum wrote: > On Fri, 2010-04-16 at 14:31 +0200, Jan Kiszka wrote: >> Gilles Chanteperdrix wrote: >>> GIT version control wrote: >>>> Module: xenomai-jki >>>> Branch: for-upstream >>>> Commit: 55ebde80258b5b6c3d29d37b5f30a3199faf0881 >>>> URL: http://git.xenomai.org/?p=xenomai-jki.git;a=commit;h=55ebde80258b5b6c3d29d37b5f30a3199faf0881 >>>> >>>> Author: Wolfgang Mauerer >>>> Date: Tue Mar 30 11:13:33 2010 +0200 >>>> >>>> RTDM: Fix potential NULL pointer dereference >>>> >>>> The rework in 95278926edc559d4 misses the case that context can be NULL, >>>> which can (and has) triggered a kernel oops. Take care of this case. >>>> >>>> Signed-off-by: Wolfgang Mauerer >>>> Signed-off-by: Jan Kiszka >>> I still think that fix is a useles waste of time. Let us merge >>> Philippe's patches instead. >> Please accept that Philippe's patch is orthogonal to this bug. >> >> And it didn't work as-is. I'll post a rework which has the same benefit >> (avoiding to poll on pending context references) - once it is tested. > > You mean that your current implementation, does poll, right? Because > mine does not, that was the point of it, also to solve races in > cross-context management IIRC. Polling is part of the RTDM API: If a driver requests it via EAGAIN, we have to provide it. We may deprecate this feature long-term, but for now there are no drop-in replacements available and we have drivers in the field that make use of it. > That patch dates back to the 2.5 -rc > cycle, when I needed it to have a decent behavior while working on the > RTIPC stuff. It should not be that difficult to forward port it to > -head, I guess. Let me know if I can help. Thanks. The patch is done, it just waits for the final tests as I wrote. I would be happy if you could test it as well if you have something that nicely stresses e.g. RTIPC in this domain. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux