Re: [PATCH 03/14] mm/hmm: HMM should have a callback before MM is destroyed v2

On Fri, 16 Mar 2018 15:14:08 -0400 jglisse@redhat.com wrote:

The hmm_mirror_register() function registers a callback for when the CPU pagetable is modified. Normally, the device driver will call hmm_mirror_unregister() when the process using the device is finished. However, if the process exits uncleanly, the struct_mm can be destroyed with no warning to the device driver.

Again, what are the user-visible effects of the bug? Such info is needed when others review our request for a -stable backport. And the many people who review -stable patches for integration into their own kernel trees will want to understand the benefit of the patch to their users.