local-blacklist-for-Intel-TSX

local-blacklist-for-Intel-TSX

Intel TSX is broken on Haswell based processors (erratum HSD136/HSW136)
and a microcode update is available to simply disable the corresponding
instructions.

A live microcode update will disable the TSX instructions causing
already started binaries to segfault. This patch simply disable Intel
TSX (HLE and RTM) on processors which might receive a microcode update,
so that it doesn't happen.  We might expect newer steppings to fix the
issue (e.g. as Haswell-EX did).

Intel TSX-NI is also broken on Broadwell systems, and documented as
being unavailable in their specification updates errata list.  However,
some end-user systems were shipped with old microcode that left Intel
TSX-NI still enabled in CPUID on these processors.  We must not allow
RTM to be used by glibc on these systems, due to runtime system
misbehavior and live-update of microcode hazards.

Author: Henrique de Moraes Holschuh <hmh@debian.org>

Gbp-Pq: Topic amd64
Gbp-Pq: Name local-blacklist-for-Intel-TSX.diff