Messages in this thread | | | From | Linus Torvalds <> | Date | Tue, 11 Dec 2012 10:35:57 -0800 | Subject | Re: [PATCH 0/2] ima: policy search speedup |
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On Tue, Dec 11, 2012 at 10:12 AM, Kasatkin, Dmitry <dmitry.kasatkin@intel.com> wrote: > > Actually S_PRIVATE does not work work for normal filesystems which IMA > might want to ignore.
The reading comprehension here is abysmal.
First you claim that you need the new flag for pseudo-filesystems, and now that I point out that we have an *old* flag for pseudo-filesystems you turn around 180 degrees and talk about other filesystems.
And none of that matters for my argument AT ALL.
My argument has not been that we cannot add a new flag.
My argument has been that we already have the logical place for such a flag, and that adding a totally new field seems so stupid.
Seriously. The i_flags place is where we already do pretty much *exactly* what you ask for. The fact that it is faster and more flexible to boot should be a bonus.
Now, there are real reasons to avoid "s_flags", notably the fact that we're running out of bits there (unlike i_flags), and they are exposed as generic fields and are generally meant for mount options etc. So I understand why we might want to avoid that (although the whole mount-option thing could also be seen as an advantage), but I really don't see any argument against i_flags, considering that we already use it for S_IMA and S_PRIVATE, both of which are related to exactly what you seem to want to do.
The one downside of i_flags may be that any update should own the inode semaphore. But within the context of a security model, that should be fine (and normally you'd update it once per lifetime of the inode).
Linus
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