Messages in this thread | | | Subject | Re: [S390] cio: kernel stack overflow. | From | Martin Schwidefsky <> | Date | Thu, 31 Aug 2006 11:06:07 +0200 |
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On Wed, 2006-08-30 at 21:19 +0200, Heiko Carstens wrote: > > >- cdev->id = (struct ccw_device_id) { > > >- .cu_type = cdev->private->senseid.cu_type, > > >- .cu_model = cdev->private->senseid.cu_model, > > >- .dev_type = cdev->private->senseid.dev_type, > > >- .dev_model = cdev->private->senseid.dev_model, > > >- }; > > >+ cdev->id.cu_type = cdev->private->senseid.cu_type; > > >+ cdev->id.cu_model = cdev->private->senseid.cu_model; > > >+ cdev->id.dev_type = cdev->private->senseid.dev_type; > > >+ cdev->id.dev_model = cdev->private->senseid.dev_model; > > > > I don't see any obvious place that zeroes out cdev->id. > > In particular, it looks like cdev->id.match_flags and .driver_info > > are never cleared (i.e., they retain whatever old garbage they had > > before). More importantly, if anyone ever adds any more fields to > > struct ccw_device_id, then they will also be retain old garbage values, > > which is a maintenance pitfall. Is this right, or did I miss something > > again? > > You're right. Thanks for pointing this out! I will take care of it.
The ccw_device_id structure contains two more fields in addition to the field that are set up in ccw_device_recog_done, namely match_flags and driver_info. driver_info is set later in ccw_bus_match, so that is fine. match_flags of the device is never used, only the match_flags of the drivers version of the ccw_device_id is used. So the code is correct even without the memset. But your point about the maintenance pitfall is valid, we will add a memset after 2.6.18. I don't want to push yet another patch.
-- blue skies, Martin.
Martin Schwidefsky Linux for zSeries Development & Services IBM Deutschland Entwicklung GmbH
"Reality continues to ruin my life." - Calvin.
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