Re: [PATCH 0/2] ima: policy search speedup

From: Eric Paris
Date: Tue Dec 11 2012 - 15:07:53 EST


S_PRIVATE is totally unacceptable as it has a meaning across all LSMs,
not just IMA.

S_NOSEC means 'this is not setuid or setgid and we don't need to do
those checks on modify'

You are going to need to use a S_NOIMA.

Of Dmitry's 90,000 fewer policy lookups using the per sb flag, how
many of them are the same inode over and over again which would be
circumvented using S_NOIMA per inode flag?



On Tue, Dec 11, 2012 at 2:48 PM, Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> wrote:
> On Tue, 2012-12-11 at 11:10 -0800, Linus Torvalds wrote:
>
>> Anyway, the whole "you can do it at file granularity" isn't the bulk
>> of my argument (the "we already have the field that makes sense" is).
>> But my point is that per-inode is not only the logically more
>> straightforward place to do it, it's also the much more flexible place
>> to do it. Because it *allows* for things like that.
>
> Ok. To summarize, S_IMA indicates that there is a rule and that the iint
> was allocated. To differentiate between 'haven't looked/don't know' and
> 'definitely not', we need another bit. For this, you're suggesting
> using IS_PRIVATE()? Hopefully, I misunderstood.
>
> thanks,
>
> Mimi
>
>
>
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