From: Peter Xu <peterx@redhat.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: linux-kernel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Hugh Dickins <hughd@google.com>,
Luis Chamberlain <mcgrof@kernel.org>,
Maxime Coquelin <maxime.coquelin@redhat.com>,
kvm@vger.kernel.org, Jerome Glisse <jglisse@redhat.com>,
Pavel Emelyanov <xemul@virtuozzo.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Martin Cracauer <cracauer@cons.org>,
Denis Plotnikov <dplotnikov@virtuozzo.com>,
linux-mm@kvack.org, Marty McFadden <mcfadden8@llnl.gov>,
Maya Gokhale <gokhale2@llnl.gov>,
Mike Kravetz <mike.kravetz@oracle.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Kees Cook <keescook@chromium.org>, Mel Gorman <mgorman@suse.de>,
linux-fsdevel@vger.kernel.org,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-api@vger.kernel.org
Subject: Re: [PATCH 0/3] userfaultfd: allow to forbid unprivileged users
Date: Tue, 12 Mar 2019 20:43:02 +0800 [thread overview]
Message-ID: <20190312124302.GA2433@xz-x1> (raw)
In-Reply-To: <20190312074951.i2md3npcjcceywqj@kshutemo-mobl1>
Hi, Kirill,
On Tue, Mar 12, 2019 at 10:49:51AM +0300, Kirill A. Shutemov wrote:
> On Mon, Mar 11, 2019 at 05:36:58PM +0800, Peter Xu wrote:
> > Hi,
> >
> > (The idea comes from Andrea, and following discussions with Mike and
> > other people)
> >
> > This patchset introduces a new sysctl flag to allow the admin to
> > forbid users from using userfaultfd:
> >
> > $ cat /proc/sys/vm/unprivileged_userfaultfd
> > [disabled] enabled kvm
>
> CC linux-api@
>
> This is unusual way to return current value for sysctl. Does it work fine
> with sysctl tool?
It can work, though it displays the same as "cat":
$ sysctl vm.unprivileged_userfaultfd
vm.unprivileged_userfaultfd = disabled enabled [kvm]
>
> Have you considered to place the switch into /sys/kernel/mm instead?
> I doubt it's the last tunable for userfaultfd. Maybe we should have an
> directory for it under /sys/kernel/mm?
I haven't thought about sysfs, if that's preferred I can consider to
switch to that. And yes I think creating a directory should be a good
idea.
Thanks,
--
Peter Xu
next prev parent reply other threads:[~2019-03-12 12:43 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-11 9:36 [PATCH 0/3] userfaultfd: allow to forbid unprivileged users Peter Xu
2019-03-11 9:36 ` [PATCH 1/3] userfaultfd/sysctl: introduce unprivileged_userfaultfd Peter Xu
2019-03-12 6:58 ` Mike Rapoport
2019-03-12 12:26 ` Peter Xu
2019-03-12 13:53 ` Mike Rapoport
2019-03-11 9:37 ` [PATCH 2/3] kvm/mm: introduce MMF_USERFAULTFD_ALLOW flag Peter Xu
2019-03-11 9:37 ` [PATCH 3/3] userfaultfd: apply unprivileged_userfaultfd check Peter Xu
2019-03-11 9:58 ` Peter Xu
2019-03-12 7:01 ` [PATCH 0/3] userfaultfd: allow to forbid unprivileged users Mike Rapoport
2019-03-12 12:29 ` Peter Xu
2019-03-12 7:49 ` Kirill A. Shutemov
2019-03-12 12:43 ` Peter Xu [this message]
2019-03-12 19:59 ` Mike Kravetz
2019-03-13 6:00 ` Peter Xu
2019-03-13 8:22 ` Paolo Bonzini
2019-03-13 18:52 ` Andrea Arcangeli
2019-03-13 19:12 ` Paolo Bonzini
2019-03-13 23:44 ` Andrea Arcangeli
2019-03-14 10:58 ` Paolo Bonzini
2019-03-14 15:23 ` Alexei Starovoitov
2019-03-14 16:00 ` Paolo Bonzini
2019-03-14 16:16 ` Andrea Arcangeli
2019-03-15 16:09 ` Kees Cook
2019-03-13 20:01 ` Mike Kravetz
2019-03-13 23:55 ` Andrea Arcangeli
2019-03-14 3:32 ` Mike Kravetz
2019-03-13 17:50 ` Mike Kravetz
2019-03-15 8:26 ` Peter Xu
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