From: Andrew Morton <akpm@linux-foundation.org>
To: Andrey Wagin <avagin@gmail.com>
Cc: linux-kernel@vger.kernel.org, Oleg Nesterov <oleg@redhat.com>,
Cyrill Gorcunov <gorcunov@openvz.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Pavel Emelyanov <xemul@parallels.com>
Subject: Re: [PATCH] pidns: limit the nesting depth of pid namespaces
Date: Wed, 24 Oct 2012 12:46:07 -0700 [thread overview]
Message-ID: <20121024124607.43f599e8.akpm@linux-foundation.org> (raw)
In-Reply-To: <CANaxB-xVVmQaCze=4+SaLbwkbJYxBwjbzF0hWX+Js94veWxj3w@mail.gmail.com>
On Wed, 24 Oct 2012 09:38:57 +0400
Andrey Wagin <avagin@gmail.com> wrote:
> >
> > I think that returning -ENOMEM in response to an excessive nesting
> > attempt is misleading - the system *didn't* run out of memory. EINVAL
> > is better?
>
> I chose ENOMEM by analogy with max_pid. When a new PID can not be
> allocated, ENOMEM is returned too.
I don't know what this means - please be carefully specific when
identifying kernel code.
If you're referring to kernel/pid.c:alloc_pid() then -ENOMEM is
appropriate there, because a failure *is* caused by memory allocation
failure.
But ENOMEM isn't appropriate for nesting-depth-exceeded - we shouldn't
tell the user "you ran out of memory" when he didn't! -EINVAL isn't
really appropriate either ("Invalid argument") but it has become a
general you-screwed-up catchall and seems to me to be the most
appropriate errno we have available.
next prev parent reply other threads:[~2012-10-24 19:46 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-12 12:30 [PATCH] pidns: limit the nesting depth of pid namespaces Andrew Vagin
2012-10-19 14:25 ` Andrey Wagin
2012-10-20 15:21 ` Oleg Nesterov
2012-10-23 23:56 ` Andrew Morton
2012-10-24 5:38 ` Andrey Wagin
2012-10-24 19:46 ` Andrew Morton [this message]
2012-10-25 15:02 ` Andrey Wagin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121024124607.43f599e8.akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=avagin@gmail.com \
--cc=ebiederm@xmission.com \
--cc=gorcunov@openvz.org \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@redhat.com \
--cc=xemul@parallels.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).