OpenBSD Errata: July 31st, 2018 (amdlfence)
30 July, 2018 by email@example.com | openbsd
Errata patches for the kernel have been released for OpenBSD 6.3 and 6.2. On AMD CPUs, set a chicken bit which turns LFENCE into a serialization instruction against speculation. Binary updates for the amd64 and i386 platforms are available via the syspatch utility. Source code patches can be found on the respective errata pages: https://www.openbsd.org/errata62.html https://www.openbsd.org/errata63.html As these affect the kernel, a reboot will be needed after patching.