Re: mm: use down_read_killable for locking mmap_sem in access_remote_vm

From: Matthew Wilcox
Date: Wed May 15 2019 - 07:51:47 EST

On Wed, May 15, 2019 at 10:38:26AM +0200, Michal Koutný wrote:
> Hi,
> making this holder of mmap_sem killable was for the reasons of /proc/...
> diagnostics was an idea I was pondeering too. However, I think the
> approach of pretending we read 0 bytes is not correct. The API would IMO
> need to be extended to allow pass a result such as EINTR to the end
> caller.
> Why do you think it's safe to return just 0?

_killable_, not _interruptible_.

The return value will never be seen by userspace because it's dead.