Re: disabling group leader perf_event

[Pavel Machek <pavel@ucw.cz>]

Hi!

> > >>Is this a roundabout way of saying "jit"?
> > >Partly. I'm not sure we want to actually upload programs in bytecode
> > >form. ASCII is just fine - just like a .gz Javascript is fine for web
> > >apps. (and in most cases compresses down better than the bytecode
> > >equivalent)
> > >
> > >So a clear language (the simpler initially the better) plus an in-kernel
> > >compiler.
> > >
> > >This could be used for far more than just instrumentation: IMO security
> > >policies could be expressed in such a way. (Simplified, they are quite
> > >similar to filters installed on syscall entry/exit, with the ability of
> > >the filter to influence whether the syscall is performed.)
> > 
> > For me the requirements are:
> > - turing complete (more than just filters)
> 
> Yep. Filters are obviously just basically expressions.
> 
> Conditions and variables can be added. Maybe loops too in simpler forms 
> - as long as we can prove halting - or maybe with a runtime abort 
> mechanism.
> 
> > - easy interface to kernel APIs (like hrtimers)
> > - safe to use by untrusted users
> 
> Yep.
> 
> > The actual language doesn't really matter.
> 
> There are 3 basic categories:
> 
>  1- Most (least abstract) specific code: a block of bytecode in the form 
>     of a simplified, executable, kernel-checked x86 machine code block - 
>     this is also the fastest form. [yes, this is actually possible.]

Well... if we want to be a bit x86-entric.... can we just reuse ACPI
interpretter?

Plus, TOMOYO actually has a language inside... AppArmor actually has
something, too, but iirc it is only as powerful as regexps.
									Pavel

-- 
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