From: Michal Hocko <mhocko@kernel.org>
To: Christian Kellner <ckellner@redhat.com>,
Christian Brauner <christian.brauner@ubuntu.com>
Cc: linux-kernel@vger.kernel.org,
Christian Kellner <christian@kellner.me>,
Andrew Morton <akpm@linux-foundation.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Elena Reshetova <elena.reshetova@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Roman Gushchin <guro@fb.com>,
Andrea Arcangeli <aarcange@redhat.com>,
"Joel Fernandes (Google)" <joel@joelfernandes.org>,
Al Viro <viro@zeniv.linux.org.uk>,
"Dmitry V. Levin" <ldv@altlinux.org>
Subject: Re: [PATCH] pidfd: show pids for nested pid namespaces in fdinfo
Date: Tue, 8 Oct 2019 16:00:49 +0200 [thread overview]
Message-ID: <20191008140049.GM6681@dhcp22.suse.cz> (raw)
In-Reply-To: <20191008135258.mzc7o2djiq5yydko@wittgenstein>
On Tue 08-10-19 15:52:59, Christian Brauner wrote:
> On Tue, Oct 08, 2019 at 03:36:37PM +0200, Christian Kellner wrote:
> > From: Christian Kellner <christian@kellner.me>
> >
> > The fdinfo file for a process file descriptor already contains the
> > pid of the process in the callers namespaces. Additionally, if pid
> > namespaces are configured, show the process ids of the process in
> > all nested namespaces in the same format as in the procfs status
> > file, i.e. "NSPid:\t%d\%d...". This allows the easy identification
> > of the processes in nested namespaces.
> >
> > Signed-off-by: Christian Kellner <christian@kellner.me>
>
> Yeah, makes sense to me.
> Note that if you send the pidfd to a sibling pid namespace NSpid won't
> show you anything useful. But that's what I'd expect security wise. You
> should only be able to snoop on descendant pid namespaces.
>
> Please add a test for this to verify that this all works correctly and
> then resend. The tests live in tools/testing/selftests/pidfd/ and should
> already have most of the infrastructure there. The fdinfo parsing code
> should be in samples/pidfd/ which
>
> For the patch itself:
>
> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
>
> You can resend with my Reviewed-by retained if you don't change
> anything. Before I see tests I'll hold off on merging this. ;)
This is also forming a new user visible "api" right? So the make sure
that linux-api is on the Cc list.
And one minore note. The ifdefery is just ugly, could you just make it a
separate function with ifdef hidden inside?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-10-08 14:00 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-08 13:36 [PATCH] pidfd: show pids for nested pid namespaces in fdinfo Christian Kellner
2019-10-08 13:52 ` Christian Brauner
2019-10-08 14:00 ` Michal Hocko [this message]
2019-10-09 16:05 ` [PATCH v2 1/2] " Christian Kellner
2019-10-09 16:05 ` [PATCH v2 2/2] pidfd: add tests for NSpid info " Christian Kellner
2019-10-11 15:09 ` Jann Horn
2019-10-11 17:08 ` Christian Brauner
2019-10-09 17:29 ` [PATCH v2 1/2] pidfd: show pids for nested pid namespaces " Christian Brauner
2019-10-11 12:23 ` [PATCH v3 " Christian Kellner
2019-10-11 12:23 ` [PATCH v3 2/2] pidfd: add tests for NSpid info " Christian Kellner
2019-10-11 13:18 ` Christian Brauner
2019-10-11 13:17 ` [PATCH v3 1/2] pidfd: show pids for nested pid namespaces " Christian Brauner
2019-10-11 14:55 ` Jann Horn
2019-10-11 15:17 ` Christian Brauner
2019-10-11 15:30 ` Jann Horn
2019-10-11 16:58 ` Christian Brauner
2019-10-11 18:20 ` Jann Horn
2019-10-12 10:19 ` [PATCH] pidfd: add NSpid entries to fdinfo Christian Brauner
2019-10-12 10:21 ` Christian Brauner
2019-10-14 9:43 ` Christian Kellner
2019-10-14 10:31 ` Christian Brauner
2019-10-14 15:10 ` Jann Horn
2019-10-14 15:20 ` Christian Kellner
2019-10-14 15:09 ` Jann Horn
2019-10-14 17:06 ` Christian Brauner
2019-10-14 16:20 ` [PATCH v4 1/2] " Christian Kellner
2019-10-14 16:20 ` [PATCH v4 2/2] pidfd: add tests for NSpid info in fdinfo Christian Kellner
2019-10-15 10:07 ` Christian Brauner
2019-11-13 11:52 ` Naresh Kamboju
2019-11-13 12:20 ` Christian Brauner
2019-10-15 9:40 ` [PATCH v4 1/2] pidfd: add NSpid entries to fdinfo Christian Brauner
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