On Mon, 24 Oct 2022 18:02:32 -0700
Linus Torvalds [off-list ref] wrote:

On Mon, Oct 24, 2022 at 5:21 PM Steven Rostedt [off-list ref] wrote:

quoted

It's all about updating read only pages that are executable with a shadow mm.  

Right. And it doesn't actually need the mm at all, all it wants is the
kernel page tables. Which is why all the "dup_mmap()" stuff seems so
wrong.

I suspect mm_alloc() does everything that VM actually needs.

IOW, it shouldn't have used the fork() helper, it should have used the
execve() helper that actually starts out from a clean slate. Because a
clean slate is exactly what that code wants.

No?

Something to look into. But I'm guessing that's best for the next merge
window, and not for the -rc releases?

-- Steve