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Date:   Thu, 29 Sep 2022 19:50:36 +0100
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     David Laight <David.Laight@aculab.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        "Serge E. Hallyn" <serge@hallyn.com>
Subject: Re: [PATCH 3/4] proc: Point /proc/net at /proc/thread-self/net
 instead of /proc/self/net
Message-ID: <YzXo/DIwq65ypHNH@ZenIV>
References: <dacfc18d6667421d97127451eafe4f29@AcuMS.aculab.com>
 <CAHk-=wgS_XpzEL140ovgLwGv6yXvV7Pu9nKJbCuo5pnRfcEbvg@mail.gmail.com>
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Sender: Al Viro <viro@ftp.linux.org.uk>
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On Thu, Sep 29, 2022 at 11:21:36AM -0700, Linus Torvalds wrote:
> On Thu, Sep 29, 2022 at 8:22 AM David Laight <David.Laight@aculab.com> wrote:
> >
> > This was applied and then reverted by Linus (I can't find anything
> > in the LKML archive) - see git show 155134fef - because of
> > issues with apparmor and dhclient.
> 
> lkml archive link:
> 
>   https://lore.kernel.org/all/CADDKRnDD_W5yJLo2otWXH8oEgmGdMP0N_p7wenBQbh17xKGZJg@mail.gmail.com/
> 
> in case anybody cares.
> 
> I wonder if the fix is to replace the symlink with a hardcoded lookup
> (ie basically make it *act* like a hardlink - we don't really support
> hardlinked directories, but we could basically fake the lookup in
> proc). Since the problem was AppArmor reacting to the name in the
> symlink.
> 
> Al added the participants so that he can say "hell no".

What do you mean?  Lookup on "net" in /proc returning what, exactly?
What would that dentry have for ->d_parent?