From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754418AbdJPPg7 (ORCPT ); Mon, 16 Oct 2017 11:36:59 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:51772 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754391AbdJPPg4 (ORCPT ); Mon, 16 Oct 2017 11:36:56 -0400 X-Google-Smtp-Source: ABhQp+Q5W8/dxu/0B0TfsUY+AmwI9ZYDNPF0MSNFUEWmpD/NnfJy84TqfFccqY4FbM4pC+/oErwLEQ== Date: Mon, 16 Oct 2017 17:36:53 +0200 From: Christian Brauner To: Christian Brauner Cc: linux-kernel@vger.kernel.org, ebiederm@xmission.com, serge@hallyn.com, stgraber@ubuntu.com, tycho@tycho.ws Subject: Re: [PATCH 1/2 v2] user namespace: use union in {g,u}idmap struct Message-ID: <20171016153652.p266xv32wgskm4am@gmail.com> References: <20171016153054.22401-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20171016153054.22401-1-christian.brauner@ubuntu.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Please disregard v2 - It messed up the email addresses for Serge and Eric. v3 with the correct email addresses is already sent out. On Mon, Oct 16, 2017 at 05:30:53PM +0200, Christian Brauner wrote: > This is preparation for bumping the {g,u}idmap limits for usernamespaces. > > Signed-off-by: Christian Brauner > --- > include/linux/user_namespace.h | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > > diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h > index c18e01252346..7c83d7f6289b 100644 > --- a/include/linux/user_namespace.h > +++ b/include/linux/user_namespace.h > @@ -12,13 +12,21 @@ > > #define UID_GID_MAP_MAX_EXTENTS 5 > > +struct uid_gid_extent { > + u32 first; > + u32 lower_first; > + u32 count; > +}; > + > struct uid_gid_map { /* 64 bytes -- 1 cache line */ > u32 nr_extents; > - struct uid_gid_extent { > - u32 first; > - u32 lower_first; > - u32 count; > - } extent[UID_GID_MAP_MAX_EXTENTS]; > + union { > + struct uid_gid_extent extent[UID_GID_MAP_MAX_EXTENTS]; > + struct { > + struct uid_gid_extent *forward; > + struct uid_gid_extent *reverse; > + }; > + }; > }; > > #define USERNS_SETGROUPS_ALLOWED 1UL > -- > 2.14.1 >