Date: Tue, 13 Aug 2013 13:06:18 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Dave Jones <davej@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
        Oleg Nesterov <oleg@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [GIT PULL] tracing: final fixes for events and some
Message-ID: <20130813110618.GA3300@gmail.com>
References: <1375712355.22073.45.camel@gandalf.local.home>
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 <20130812181325.GA19405@gmail.com>
 <20130813023922.GA1042@redhat.com>
 <20130812231443.52563398@gandalf.local.home>
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* Steven Rostedt <rostedt@goodmis.org> wrote:

> On Mon, 12 Aug 2013 22:39:22 -0400
> Dave Jones <davej@redhat.com> wrote:
> 
> 
> > I'm not sure why I got cc'd on this, but for my part, the perf/tracing 
> > related bugs I've found recently may have been there for ages, but 
> > they were triggerable as non-root users.
> 
> Which bug was able to trigger with non-root? The hash one that you 
> reported? That is something with the function tracer. Are you able to 
> enable function tracing as non-root?
> 
> Or is it because you gave more permissions for non-root to use extra 
> perf commands. Because no one but root should be able to enable function 
> tracing, as that can add a large overhead to the system.

Hm, also, tracepoints should in general only be accessible to root - all 
sorts of random privileged info leaks through tracepoints, a thorough 
review and sanitizing is needed to expose that to users. (and that does 
not consider the complication caused by exposing timing info.)

Thanks,

	Ingo
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