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From: Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public•gmane.org>
To: Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public•gmane.org>
Cc: "David Ahern" <dsahern-Re5JQEeQqe8AvxtiuMwx3w@public•gmane.org>,
	"Alexei Starovoitov"
	<alexei.starovoitov-Re5JQEeQqe8AvxtiuMwx3w@public•gmane.org>,
	"Andy Lutomirski" <luto-DgEjT+Ai2ygdnm+yROfE0A@public•gmane.org>,
	"Daniel Mack" <daniel-cYrQPVfZoowdnm+yROfE0A@public•gmane.org>,
	"Mickaël Salaün" <mic-WFhQfpSGs3bR7s880joybQ@public•gmane.org>,
	"Kees Cook" <keescook-F7+t8E8rja9g9hUCZPvPmw@public•gmane.org>,
	"Jann Horn" <jann-XZ1E9jl8jIdeoWH0uzbU5w@public•gmane.org>,
	"Tejun Heo" <tj-DgEjT+Ai2ygdnm+yROfE0A@public•gmane.org>,
	"David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public•gmane.org>,
	"Thomas Graf" <tgraf-G/eBtMaohhA@public•gmane.org>,
	"Michael Kerrisk"
	<mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public•gmane.org>,
	"Linux API" <linux-api-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>,
	"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public•gmane.org"
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>,
	"Network Development"
	<netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>
Subject: Re: Potential issues (security and otherwise) with the current cgroup-bpf API
Date: Tue, 20 Dec 2016 10:11:50 +0100	[thread overview]
Message-ID: <20161220091150.GJ3124@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <CALCETrUW2jEYmjSsOrPj+MAjkDGGUCw_rdxQh+5Er0r4ReGLnA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

On Mon, Dec 19, 2016 at 05:56:24PM -0800, Andy Lutomirski wrote:
> >> Huh?  My example in the original email attaches a program in a
> >> sub-hierarchy.  Are you saying that 4.11 could make that example stop
> >> working?
> >
> > Are you suggesting sub-cgroups should not be allowed to override the filter of a parent cgroup?
> 
> Yes, exactly.  I think there are two sensible behaviors:
> 
> a) sub-cgroups cannot have a filter at all of the parent has a filter.
> (This is the "punt" approach -- it lets different semantics be
> assigned later without breaking userspace.)
> 
> b) sub-cgroups can have a filter if a parent does, too.  The semantics
> are that the sub-cgroup filter runs first and all side-effects occur.
> If that filter says "reject" then ancestor filters are skipped.  If
> that filter says "accept", then the ancestor filter is run and its
> side-effects happen as well.  (And so on, all the way up to the root.)

So from what I understand the proposed cgroup is not in fact
hierarchical at all.

@TJ, I thought you were enforcing all new cgroups to be properly
hierarchical, that would very much include this one.

  parent reply	other threads:[~2016-12-20  9:11 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-17 18:18 Potential issues (security and otherwise) with the current cgroup-bpf API Andy Lutomirski
2016-12-17 19:26 ` Mickaël Salaün
2016-12-17 20:02   ` Andy Lutomirski
2016-12-19 20:56 ` Alexei Starovoitov
2016-12-19 21:23   ` Andy Lutomirski
2016-12-20  0:02     ` Alexei Starovoitov
     [not found]       ` <20161220000254.GA58895-+o4/htvd0TDFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2016-12-20  0:25         ` Andy Lutomirski
2016-12-20  1:43           ` Andy Lutomirski
     [not found]           ` <CALCETrU1_bDVLfokQ7zasHVmeq7S-R+603GEw59V_wuj4eE1hw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-12-20  1:44             ` David Ahern
     [not found]               ` <2dbec775-6304-e44c-19c5-fbf07877e7b1-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-12-20  1:56                 ` Andy Lutomirski
     [not found]                   ` <CALCETrUW2jEYmjSsOrPj+MAjkDGGUCw_rdxQh+5Er0r4ReGLnA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-12-20  2:52                     ` David Ahern
2016-12-20  3:12                       ` Andy Lutomirski
2016-12-20  4:44                         ` Alexei Starovoitov
     [not found]                           ` <20161220044440.GB86803-+o4/htvd0TDFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2016-12-20  5:27                             ` Andy Lutomirski
     [not found]                               ` <CALCETrVxkdZA3SsRv0KKhBz9YvNMsnmHSjS8HN1GHrgWRYNM1g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-12-20  5:32                                 ` Alexei Starovoitov
2016-12-20  9:11                     ` Peter Zijlstra [this message]
     [not found]                       ` <20161220091150.GJ3124-ndre7Fmf5hadTX5a5knrm8zTDFooKrT+cvkQGrU6aU0@public.gmane.org>
2017-01-03 10:25                         ` Michal Hocko
     [not found]                           ` <20170103102559.GA30129-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2017-01-16  1:19                             ` Tejun Heo
2017-01-17 13:03                               ` Michal Hocko
2017-01-17 13:32                                 ` Peter Zijlstra
2017-01-17 13:58                                   ` Michal Hocko
     [not found]                                     ` <20170117135830.GO19699-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2017-01-17 20:23                                       ` Andy Lutomirski
2017-01-18 22:18                                     ` Tejun Heo
2017-01-19  9:00                                       ` Michal Hocko
2016-12-20  3:18             ` Alexei Starovoitov
     [not found]               ` <20161220031802.GA77838-+o4/htvd0TDFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2016-12-20  3:50                 ` Andy Lutomirski
2016-12-20  4:41                   ` Alexei Starovoitov
     [not found]                   ` <CALCETrXymvAo-9zhQe=amToz_fs9XGniK2KLZv5Fxc66qcUx6A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-12-20 10:21                     ` Daniel Mack
2016-12-20 17:23                       ` Andy Lutomirski
     [not found]                         ` <CALCETrXyp2ddf4HRsEoN=qEwTBaezOUX2XWj6nxPcbc4t13svw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-12-20 18:36                           ` Daniel Mack
2016-12-20 18:49                             ` Andy Lutomirski
2016-12-21  4:01                               ` Alexei Starovoitov
2016-12-20  1:34         ` David Miller
     [not found]           ` <20161219.203422.500916400463091702.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2016-12-20  1:40             ` Andy Lutomirski
2016-12-20  4:51               ` Alexei Starovoitov
2016-12-20  5:26                 ` Andy Lutomirski
  -- strict thread matches above, loose matches on Subject: below --
2017-01-17  5:18 (unknown), Andy Lutomirski
     [not found] ` <CALCETrW+ZQ1xMEfdEOzx6RK9ZoCvQiqQSnOyhDJ=-FZMwUbucg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-01-18 22:41   ` Potential issues (security and otherwise) with the current cgroup-bpf API Tejun Heo
     [not found]     ` <20170118224120.GG9171-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
2017-01-19  0:18       ` Andy Lutomirski
     [not found]         ` <CALCETrXv3k+=C=9D5YGypzPk8_f4yo8ShQ3tM2fOo++gJFBM4A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-01-19  0:59           ` Tejun Heo
2017-01-19  2:29             ` Andy Lutomirski
     [not found]               ` <CALCETrVrEnL4cvkdDu2LUhxmeOZ+SMEmF=yKKsm9OYoW2y1Kpg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-01-20  2:39                 ` Alexei Starovoitov
2017-01-20  4:04                   ` Andy Lutomirski
2017-01-23  4:31                     ` Alexei Starovoitov
     [not found]                       ` <20170123043154.GA93519-+o4/htvd0TDFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2017-01-23 20:20                         ` Andy Lutomirski
     [not found]                           ` <CALCETrXK65itdDqYTdhB-Td8d-Hzj00dcDScUOUh9psCZN_cLA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-02-03 21:07                             ` Andy Lutomirski
2017-02-03 23:21                               ` Alexei Starovoitov
     [not found]                                 ` <20170203232154.GA30114-+o4/htvd0TDFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2017-02-04 17:10                                   ` Andy Lutomirski
2017-01-19  1:01           ` Mickaël Salaün

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