Re: [PATCH 3/4] proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net

From: Al Viro
Date: Thu Sep 29 2022 - 14:50:52 EST


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@xxxxxxxxxx> 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@xxxxxxxxxxxxxx/
>
> 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?