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Date: Thu, 22 Jan 2015 10:16:35 +0300
From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Calvin Owens <calvinowens@fb.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexey Dobriyan <adobriyan@gmail.com>, Oleg Nesterov <oleg@redhat.com>,
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        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Peter Feiner <pfeiner@google.com>,
        Grant Likely <grant.likely@secretlab.ca>,
        Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>,
        linux-kernel@vger.kernel.org, kernel-team@fb.com,
        Pavel Emelyanov <xemul@openvz.org>
Subject: Re: [RFC][PATCH] procfs: Always expose /proc/<pid>/map_files/ and
 make it readable
Message-ID: <20150122071635.GM3676@moon>
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On Wed, Jan 21, 2015 at 06:45:54PM -0800, Calvin Owens wrote:
> Currently, /proc/<pid>/map_files/ is restricted to CAP_SYS_ADMIN, and
> is only exposed if CONFIG_CHECKPOINT_RESTORE is set. This interface
> is very useful for enumerating the files mapped into a process when
> the more verbose information in /proc/<pid>/maps is not needed.
> 
> This patch moves the folder out from behind CHECKPOINT_RESTORE, and
> removes the CAP_SYS_ADMIN restrictions. To avoid exposing files to
> processes for whom they may not be visible, a follow_link() stub is
> added to the inode_operations struct attached to the symlinks that
> prevent them from being followed without CAP_SYS_ADMIN.
> 
> Signed-off-by: Calvin Owens <calvinowens@fb.com>

Looks good to me, thanks.