Linus has released 6.4-rc1 and closed the
merge window for this development cycle.

The one feature that didn’t make it was the x86 shadow stack code.
That side was probably a bit unlucky, in that it came in as I was
looking at x86 issues anyway, and so I looked at it quite a bit,
and had enough reservations that I asked for a couple of fairly big
re-organizations.

This is just one more back in the long-running shadow-stack story; see this article for some background.

In the end, 13,044 non-merge changesets were pulled during this merge window.

Source: LWN.net – Kernel prepatch 6.4-rc1