Re: [PATCH] procfs: make /proc style symlinks behave like "normal"symlinks

From: Pavel Machek
Date: Thu Nov 19 2009 - 16:39:50 EST


> > Adding all of the short comings to followlink that readlink has is a problem,
> > especially as followlink does much better now.
> >
> > At a practical level I think your changes are much easier to exploit than
> > Pavels contrived example.
> >
> > I really don't have any problems with your first patch to proc to add the
> > missing revalidate.
> >
>
> Thanks, that makes sense. The raciness was evident once you pointed it
> out, so I think you're correct that we can't take this approach.
>
> Adding the missing revalidations is fine, but I don't believe that
> helps to fix Pavel's issue. I'll go back and take a more careful look
> at the suggestion that Miklos made and see whether it makes sense to
> implement a new FS_* flag for this, and see what it'll take to fix
> Pavel's issue.

One posibility would be to make open(/proc/XX/fd/XX) behave like
dup(). That should solve the NFS problems, too, no?
Pavel
--
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