Messages in this thread | | | Subject | Re: [RFC][PATCH 11/11] security: AppArmor - Export namespace semaphore | From | Stephen Smalley <> | Date | Thu, 20 Apr 2006 08:58:52 -0400 |
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On Thu, 2006-04-20 at 08:48 -0400, Stephen Smalley wrote: > On Thu, 2006-04-20 at 08:21 -0500, Serge E. Hallyn wrote: > > Tony, do you have any performance measurements? Both for unconfined and > > confined apps? Presumably unconfined processes should have 0 performance > > hit, right? > > Preferably something that exercises open, mkdir, link... and friends > intensively, not just the old WebStone data that I've seen posted > before. > > But you don't really need the benchmarks - just look at the code, and > think about the implications of allocating a page and calling d_path on > every permission(9) call (on every component) plus from the separate > hooks in the vfs_ helpers and further consider the impact of taking the > dcache lock all the time there. And look at the iterators being used in > aa_perm_dentry as well as the truly fun ones in aa_link. All because > they are doing it from LSM hooks that were never intended to be used > this way.
Ah, I have to correct the above - the mask filtering skips directory traversal checking, so not every component I suppose. Which is interesting for another reason. But performance situation still looks fairly bad from a code POV, and the existing hooks still seem to be the wrong place for this kind of processing/checking.
-- Stephen Smalley National Security Agency
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