From: ebiederm@xmission.com (Eric W. Biederman)
To: Steve French <smfrench@gmail.com>
Cc: linux-fsdevel@vger.kernel.org,
Linux Containers <containers@lists.linux-foundation.org>,
linux-kernel@vger.kernel.org,
"Serge E. Hallyn" <serge@hallyn.com>,
Steve French <sfrench@samba.org>
Subject: Re: [PATCH RFC 04/12] userns: Convert cifs to use kuid/kgid where appropriate
Date: Tue, 20 Nov 2012 09:22:42 -0800 [thread overview]
Message-ID: <87lidwqjdp.fsf@xmission.com> (raw)
In-Reply-To: <CAH2r5mt91Av7w6GQUPNu2A9EGRNbPGGAhMO=EobOMi5Cn8gh5g@mail.gmail.com> (Steve French's message of "Tue, 20 Nov 2012 10:56:40 -0600")
Steve French <smfrench@gmail.com> writes:
> Do you have a pointer to the background on kuid/kgid
You might try this lwn article
https://lwn.net/Articles/491310/
In a nutshell each user namespace has it's own view of uid_t and gid_t
values. Those values are mapped into kernel internal kuid_t and kgid_t
values. Then user space interfaces convert from kuid_t and kgid_t when
read from userspace.
The initial user namespace as a 1-1 identity mapping between kuid_t and
uid_t values.
kuid_t and kgid_t are not assignment compatible with uid_t and gid_t so
that if the conversions are left out a compile error results.
My strategy is to push kuid_t and kgid_t values as deeply into the
kernel data structures as possible so that there is a high propbability
that when we get it wrong a compile error will happen.
Eric
next prev parent reply other threads:[~2012-11-20 17:22 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-20 12:42 [PATCH RFC 0/12] Final userns conversions Eric W. Biederman
2012-11-20 12:42 ` Eric W. Biederman
2012-11-20 12:42 ` Eric W. Biederman
[not found] ` <87pq38wimv.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-11-20 12:43 ` [PATCH RFC 01/12] userns: Support 9p interacting with multiple user namespaces Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
[not found] ` <1353415420-5457-1-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-11-20 12:43 ` [PATCH RFC 02/12] userns: Convert afs to use kuid/kgid where appropriate Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` [PATCH RFC 03/12] userns: Convert ceph " Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
[not found] ` <1353415420-5457-3-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-11-20 16:48 ` Sage Weil
2012-11-20 16:48 ` Sage Weil
[not found] ` <alpine.DEB.2.00.1211200847110.7369-vIokxiIdD2AQNTJnQDzGJqxOck334EZe@public.gmane.org>
2012-11-20 17:15 ` Eric W. Biederman
2012-11-20 17:15 ` Eric W. Biederman
2012-11-20 12:43 ` [PATCH RFC 04/12] userns: Convert cifs " Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
[not found] ` <1353415420-5457-4-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-11-20 16:56 ` Steve French
2012-11-20 17:22 ` Eric W. Biederman [this message]
[not found] ` <CAH2r5mt91Av7w6GQUPNu2A9EGRNbPGGAhMO=EobOMi5Cn8gh5g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-11-20 17:22 ` Eric W. Biederman
2012-11-25 12:47 ` Jeff Layton
2012-11-25 12:47 ` Jeff Layton
2012-11-20 12:43 ` [PATCH RFC 05/12] userns: Convert coda's " Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` [PATCH RFC 06/12] userns: Convert gfs2 " Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-22 9:47 ` [Cluster-devel] " Steven Whitehouse
2012-11-22 9:47 ` Steven Whitehouse
2012-11-22 9:47 ` Steven Whitehouse
2012-11-20 12:43 ` [PATCH RFC 07/12] userns: Convert ncpfs to use kuid and kgid " Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` [PATCH RFC 08/12] userns: Convert nfs and nfsd to use kuid/kgid " Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` [PATCH RFC 09/12] userns: Convert ocfs2 to use kuid and kgid " Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-21 19:51 ` Joel Becker
2013-02-13 17:12 ` Eric W. Biederman
2013-02-13 17:12 ` Eric W. Biederman
[not found] ` <1353415420-5457-9-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-11-21 19:51 ` Joel Becker
2012-11-21 19:59 ` Joel Becker
2012-11-21 19:59 ` Joel Becker
2013-02-13 17:41 ` Eric W. Biederman
2012-11-20 12:43 ` [PATCH RFC 10/12] userns: Convert xfs to use kuid/kgid/kprojid " Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 23:55 ` Dave Chinner
2012-11-21 19:52 ` Joel Becker
2012-11-21 19:52 ` Joel Becker
2013-02-13 18:13 ` Eric W. Biederman
2013-02-13 18:13 ` Eric W. Biederman
[not found] ` <87obfoxetf.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2013-02-14 2:19 ` Dave Chinner
2013-02-14 2:19 ` Dave Chinner
2013-02-18 1:25 ` Eric W. Biederman
2013-02-18 1:25 ` Eric W. Biederman
[not found] ` <87621qpg4o.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2013-02-19 3:30 ` Dave Chinner
2013-02-19 3:30 ` Dave Chinner
[not found] ` <1353415420-5457-10-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-11-20 23:55 ` Dave Chinner
2012-11-20 12:43 ` [PATCH RFC 11/12] userns: Now that everything has been converted remove the unnecessary infrastructure Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` [PATCH RFC 12/12] userns: Remove the EXPERMINTAL kconfig tag Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-20 12:43 ` Eric W. Biederman
2012-11-21 0:09 ` [PATCH RFC 0/12] Final userns conversions Dave Chinner
2012-11-21 0:09 ` Dave Chinner
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