Messages in this thread | | | Date | Wed, 28 Dec 2011 09:01:16 -0800 | From | Tejun Heo <> | Subject | Re: [patch 1/4] Add routine for generating an ID for kernel pointer |
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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.
> 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.
Thanks.
-- tejun
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