We should, but this is also part of why we want the early ucode capability.
On September 18, 2014 12:53:28 PM PDT, Chuck Ebbert <cebbert.l...@gmail.com> wrote: >On Thu, 18 Sep 2014 12:14:59 -0700 >Andy Lutomirski <l...@amacapital.net> wrote: > >> On 09/18/2014 06:52 AM, Henrique de Moraes Holschuh wrote: >> > The new Haswell microcode update[1] removes the "hle" (hardware >lock >> > elision) processor capability. And it is not cosmetic, either: >Intel TSX >> > opcodes will cause an illegal opcode trap after the microcode >update[2]. >> > >> > This means cpu_info()->x86_capability becomes stale after the >microcode >> > update. >> > >> > We could add logic to compute the new x86_capability after a >microcode >> > update run, and OOPS the kernel if something too important (i.e. >anything >> > the kernel uses) went away. Otherwise, refresh >cpu_info()->x86_capability. >> > >> > Is that doable? >> > >> > >> > [1] sig 0x000306f2, pf mask 0x6f, 2014-09-03, rev 0x0029, size >28672 >> > sig 0x000306c3, pf mask 0x32, 2014-07-03, rev 0x001c, size >21504 >> > sig 0x00040651, pf mask 0x72, 2014-07-03, rev 0x001c, size >20480 >> > sig 0x00040661, pf mask 0x32, 2014-07-03, rev 0x0012, size >23552 >> >> This is HSD136, right? Do you have a link to where that ucode comes >> from? Does it have release notes? >> > >https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=24290&lang=eng > >I can't find any release notes. > >Haswell-EP is also affected, it appears: > >http://techreport.com/news/26911/errata-prompts-intel-to-disable-tsx-in-haswell-early-broadwell-cpus > >> > >> > [2] instantly segfaulting every running process using >libpthread-2.19, >> > as well as any other users of Intel TSX. >> > https://bugs.launchpad.net/intel/+bug/1370352 >> > >> > And yes, this means we will kill support for microcode updates >> > outside of the initramfs/early-initramfs, at least in Debian, >> > and likely in Ubuntu. >> > >> >> Given that there is exactly one microcode update like this (at least >of >> the sort that blows up userspace), I think that we should seriously >> consider blacklisting just this particular microcode update once >> userspace is running. >> > >All future updates for these CPUs will have this problem. -- Sent from my mobile phone. Please pardon brevity and lack of formatting. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/