Re: [PATCH v4 1/1] mm: introduce put_user_page*(), placeholder versions

[William Kucharski]

> On Mar 19, 2019, at 10:33 PM, Jerome Glisse <jglisse@xxxxxxxxxx> wrote:
> 
> So i believe best we could do is send a SIGBUS to the process that has
> GUPed a range of a file that is being truncated this would match what
> we do for CPU acces. There is no reason access through GUP should be
> handled any differently.

This should be done lazily, as there's no need to send the SIGBUS unless
the GUPed page is actually accessed post-truncate.