Messages in this thread | | | Date | Wed, 28 Dec 2011 21:14:19 +0400 | From | Cyrill Gorcunov <> | Subject | Re: [patch 1/4] Add routine for generating an ID for kernel pointer |
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On Wed, Dec 28, 2011 at 09:01:16AM -0800, Tejun Heo wrote: > Hello, > > On Wed, Dec 28, 2011 at 08:53:36PM +0400, Cyrill Gorcunov wrote: > > Well, it is not deciding but it should be taken into account. One could > > be reading this IDs again and again and again affecting performance of > > the whole system, > > I can't see how it would affect performance of the whole system. > Calculating hash doesn't involve any further locking or use of scarce > global resource. It would add small amount memory and processing > overhead for the task reading the hash. It sure is something to be > considered but I really don't think this should be a major factor > here. >
Yeah, indeed.
> > which means I really would prefer to limit access to such > > features (ie root-only). If (as I said) for other cases there is simply no way to > > _not_ use crypto, our case might be the one where using crypto is redundant. > > Limiting it to root and just exporting printer (or maybe XOR with a > randomish value) may be good enough. I don't know. However, we no > longer consider exporting pointers to unpriviliedged userland safe and > this can be useful in many circumstances, so if it's not too > difficult, I think trying to use proper hash would be nide.
OK, Tejun, I'll try, but no promises :) Thanks!
Cyrill
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