From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 2E452440460 for ; Thu, 9 Nov 2017 02:44:50 -0500 (EST) Received: by mail-wm0-f69.google.com with SMTP id b189so3358493wmd.9 for ; Wed, 08 Nov 2017 23:44:50 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id v10sor3812080edf.47.2017.11.08.23.44.48 for (Google Transport Security); Wed, 08 Nov 2017 23:44:49 -0800 (PST) Subject: Re: [PATCH] userfaultfd.2: document spurious UFFD_EVENT_FORK References: <1510124048-7991-1-git-send-email-rppt@linux.vnet.ibm.com> From: "Michael Kerrisk (man-pages)" Message-ID: <1b812837-b368-5e6e-ff9d-7d570354437a@gmail.com> Date: Thu, 9 Nov 2017 08:44:47 +0100 MIME-Version: 1.0 In-Reply-To: <1510124048-7991-1-git-send-email-rppt@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mike Rapoport Cc: mtk.manpages@gmail.com, Andrea Arcangeli , linux-man@vger.kernel.org, linux-mm On 11/08/2017 07:54 AM, Mike Rapoport wrote: > Signed-off-by: Mike Rapoport Thanks, Mike. Applied. Cheers, Michael > --- > man2/userfaultfd.2 | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/man2/userfaultfd.2 b/man2/userfaultfd.2 > index 1c9e64b..08c41e1 100644 > --- a/man2/userfaultfd.2 > +++ b/man2/userfaultfd.2 > @@ -465,6 +465,16 @@ for checkpoint/restore mechanisms, > as well as post-copy migration to allow (nearly) uninterrupted execution > when transferring virtual machines and Linux containers > from one host to another. > +.SH BUGS > +If the > +.B UFFD_FEATURE_EVENT_FORK > +is enabled and a system call from the > +.BR fork (2) > +family is interrupted by a signal or failed,q a stale userfaultfd descriptor > +might be created. > +In this case a spurious > +.B UFFD_EVENT_FORK > +will be delivered to the userfaultfd monitor. > .SH EXAMPLE > The program below demonstrates the use of the userfaultfd mechanism. > The program creates two threads, one of which acts as the > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org