linux-kernel - Re: [RFC][PATCH 3/4] tracing/kprobes: Fail to unregister if probe event files are open

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 1 Aug 2013 15:49:43 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	linux-kernel@...r.kernel.org,
	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	"zhangwei(Jovi)" <jovi.zhangwei@...wei.com>,
	Jiri Olsa <jolsa@...hat.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Ingo Molnar <mingo@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [RFC][PATCH 3/4] tracing/kprobes: Fail to unregister if probe
	event files are open

On 08/01, Oleg Nesterov wrote:
>
> And just in case. I believe that the patch is fine.
>
> Just one off-topic note,

Forgot to mention,

> > @@ -632,7 +635,9 @@ static int release_all_trace_probes(void)
> >  	/* TODO: Use batch unregistration */
> >  	while (!list_empty(&probe_list)) {
> >  		tp = list_entry(probe_list.next, struct trace_probe, list);
> > -		unregister_trace_probe(tp);
> > +		ret = unregister_trace_probe(tp);
> > +		if (ret)
> > +			goto end;
> >  		free_trace_probe(tp);
> >  	}
>
> This obviously breaks all-or-nothing semantics (I mean, this breaks
> the intent, the current code is buggy).
>
> I think we can't avoid this, and I hope this is fine. But then perhaps
> we should simply remove the "list_for_each_entry" check above?

And, of course, turn this "while (!list_empty())" into list_for_each_safe().

But again, this is almost off-topic and we can do this later.

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/