Linux Fixes Spectre V1 SWAPGS Mitigation After Being Partially Borked Since Last Year

This week's set of "x86/urgent" changes for the Linux 5.16-rc4 kernel due out later today has some Spectre V1 fixes after kernel commits last year ended up partially messing things up around its SWAPGS handling. These fixes in turn will also likely be back-ported to relevant stable kernel series...