[PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag

[Christoph Hellwig]

On Sun, Sep 20, 2020 at 12:14:49PM -0700, Andy Lutomirski wrote:
> I wonder if this is really quite cast in stone.  We could also have
> FMODE_SHITTY_COMPAT and set that when a file like this is *opened* in
> compat mode.  Then that particular struct file would be read and
> written using the compat data format.  The change would be
> user-visible, but the user that would see it would be very strange
> indeed.
> 
> I don't have a strong opinion as to whether that is better or worse
> than denying io_uring access to these things, but at least it moves
> the special case out of io_uring.

open could have happened through an io_uring thread a well, so I don't
see how this would do anything but move the problem to a different
place.

> 
> --Andy
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