Re: [PATCH] mm/gup: might_lock_read(mmap_sem) in get_user_pages_fast()

[Matthew Wilcox]

On Thu, May 21, 2020 at 06:04:43PM -0700, John Hubbard wrote:
> Instead of scattering these assertions across the drivers,
> do this assertion inside the core of get_user_pages_fast*()
> functions. That also includes pin_user_pages_fast*()
> routines.
> 
> Add a might_lock_read(mmap_sem) call to internal_get_user_pages_fast().
> 
> Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>

Yup, this is exactly what I meant.  Feel free to transform this into
an Acked-by: or Reviewed-by: if that's the appropriate tag.

Thanks, John!