From: Mike Rapoport <rppt@linux.ibm.com>
To: Daniel Colascione <dancol@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
Andy Lutomirski <luto@kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jann Horn <jannh@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Lokesh Gidra <lokeshgidra@google.com>,
Nick Kralevich <nnk@google.com>, Nosh Minwalla <nosh@google.com>,
Pavel Emelyanov <ovzxemul@gmail.com>,
Tim Murray <timmurray@google.com>,
Linux API <linux-api@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>
Subject: Re: [PATCH 1/1] userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK
Date: Thu, 7 Nov 2019 10:39:03 +0200 [thread overview]
Message-ID: <20191107083902.GB3247@linux.ibm.com> (raw)
In-Reply-To: <CAKOZuet=g++G+biSP5bU-Rppu6fykU1TVUDj20NapqAYQY4r9A@mail.gmail.com>
Hi Daniel,
On Tue, Nov 05, 2019 at 08:41:18AM -0800, Daniel Colascione wrote:
> On Tue, Nov 5, 2019 at 8:24 AM Andrea Arcangeli <aarcange@redhat.com> wrote:
> > The long term plan is to introduce UFFD_FEATURE_EVENT_FORK2 feature
> > flag that uses the ioctl to receive the child uffd, it'll consume more
> > CPU, but it wouldn't require the PTRACE privilege anymore.
>
> Why not just have callers retrieve FDs using recvmsg? This way, you
> retrieve the message packet and the file descriptor at the same time
> and you don't need any appreciable extra CPU use.
I don't follow you here. Can you elaborate on how recvmsg would be used in
this case?
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2019-11-07 8:39 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-05 15:29 [PATCH 0/1] userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK Mike Rapoport
2019-11-05 15:29 ` [PATCH 1/1] " Mike Rapoport
2019-11-05 15:37 ` Andrea Arcangeli
2019-11-05 15:55 ` Daniel Colascione
2019-11-05 16:00 ` Andy Lutomirski
2019-11-05 16:06 ` Daniel Colascione
2019-11-05 16:33 ` Andrea Arcangeli
2019-11-05 16:39 ` Daniel Colascione
2019-11-05 16:55 ` Andrea Arcangeli
2019-11-05 17:02 ` Daniel Colascione
2019-11-05 17:30 ` Andrea Arcangeli
2019-11-05 22:01 ` Andy Lutomirski
2019-11-05 22:10 ` Daniel Colascione
2019-11-05 16:24 ` Andrea Arcangeli
2019-11-05 16:41 ` Daniel Colascione
2019-11-07 8:39 ` Mike Rapoport [this message]
2019-11-07 8:54 ` Daniel Colascione
2019-11-07 15:38 ` Andrea Arcangeli
2019-11-07 16:15 ` Daniel Colascione
2019-11-07 18:22 ` Andrea Arcangeli
2019-11-07 18:50 ` Daniel Colascione
2019-11-07 19:27 ` Andrea Arcangeli
2019-11-10 17:02 ` Andy Lutomirski
2019-11-05 15:59 ` Aleksa Sarai
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