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Re: linux-next: add utrace tree
- From: "Frank Ch. Eigler" <fche at redhat dot com>
- To: Ingo Molnar <mingo at elte dot hu>
- Cc: Linus Torvalds <torvalds at linux-foundation dot org>, Steven Rostedt <rostedt at goodmis dot org>, Fr??d??ric Weisbecker <fweisbec at gmail dot com>, Arnaldo Carvalho de Melo <acme at redhat dot com>, Li Zefan <lizf at cn dot fujitsu dot com>, Tom Zanussi <tzanussi at gmail dot com>, systemtap at sources dot redhat dot com, dle-develop at lists dot sourceforge dot net, Andrew Morton <akpm at linux-foundation dot org>, Stephen Rothwell <sfr at canb dot auug dot org dot au>, Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Peter Zijlstra <a dot p dot zijlstra at chello dot nl>, Peter Zijlstra <peterz at infradead dot org>, LKML <linux-kernel at vger dot kernel dot org>, linux-next at vger dot kernel dot org, "H. Peter Anvin" <hpa at zytor dot com>, utrace-devel at redhat dot com, Thomas Gleixner <tglx at linutronix dot de>
- Date: Sat, 23 Jan 2010 07:03:01 -0500
- Subject: Re: linux-next: add utrace tree
- References: <20100122111747.3c224dfd.sfr@canb.auug.org.au> <20100121163004.8779bd69.akpm@linux-foundation.org> <20100121163145.7e958c3f.akpm@linux-foundation.org> <20100122005147.GD22003@redhat.com> <20100121170541.7425ff10.akpm@linux-foundation.org> <20100122012516.GE22003@redhat.com> <alpine.LFD.2.00.1001211729080.13231@localhost.localdomain> <20100122022255.GF22003@redhat.com> <alpine.LFD.2.00.1001211826060.13231@localhost.localdomain> <20100123060401.GB19399@elte.hu>
Hi -
On Sat, Jan 23, 2010 at 07:04:01AM +0100, Ingo Molnar wrote:
> [...] Also, if any systemtap person is interested in helping us
> create a more generic filter engine out of the current ftrace filter
> engine (which is really a precursor of a safe, sandboxed in-kernel
> script engine), that would be excellent as well. [...]
Thank you for the invitation.
> More could be done - a simple C-like set of function perhaps - some minimal
> per probe local variable state, etc. (perhaps even looping as well, with a
> limit on number of predicament executions per filter invocation.)
Yes, at some point when such bytecode intepreter gets rich enough, one
may not need the translated-to-C means of running scripts.
> ( _Such_ a facility, could then perhaps be used to allow applications access
> to safe syscall sandboxing techniques: i.e. a programmable seccomp concept
> in essence, controlled via ASCII space filter expressions [...]
> IMHO that would be a superior concept for security modules too [...]
>
> [...] specific functionality with an immediately visible upside,
> with no need for opaque hooks.
This OTOH seem like rather a stretch. If one claims that "opaque
hooks" are bad, so instead have hooks that jump not to auditable C
code but an bytecode interpreter? And have the bytecodes be uploaded
from userspace? How is this supposed to produce "transparency" from
the kernel/hook point of view?
- FChE