Re: [PATCH] mm/secretmem: fix panic when growing a memfd_secret

[Matthew Wilcox]

On Thu, Mar 24, 2022 at 02:09:09PM -0700, Axel Rasmussen wrote:
> This patch avoids the panic by implementing a custom setattr for
> memfd_secret, which detects resizes specifically (setting the size for
> the first time works just fine, since there are no existing pages to try
> to zero), and rejects them as not supported (ENOTSUP).

Isn't ENOTTY the normal return value for this?  Or even ENOSYS?