On Thu, 4 Jan 2018 08:14:11 -0600 John McKown <[email protected]> wrote:
:>On Thu, Jan 4, 2018 at 7:36 AM, Guest, Darren <[email protected]> :>wrote: :>> Not sure if people have seen that attached article or heard of the 'intel' :>> chip issues from elsewhere: :>> https://www.theregister.co.uk/2018/01/02/intel_cpu_design_flaw/ :>> The 'fix' for meltdown (at least) is apparently to change the Linux kernel :>> which will potentially affect performance. I'm pretty sure that zSeries :>> isn't affected by the issue (is it?), but if the Linux Kernel is changed, :>> are we likely to see a performance hit on Linux running on zSeries as well :>> (even though we don't need the fix)? :>> Best case scenario, can I tell my management that these won't affect Linux :>> on z? :>?I am not any kind of Linux internals wizzard. But this exploit takes :>advantage of a _HARDWARD_ flaw in the Intel CPU. Linux on z does not run on :>an _Intel_ chip. The story, that I've read at least, specifically mentions :>that? most AMD chips are not affected; nor are ARM chips. So why would the :>z chip? Of course, management usually being composed of hardware illiterate :>"liberal arts" majors, perhaps it would be a good idea for IBM to :>explicitly announce to the work that this flaw does not affect the IBMZ :>machines. I am having difficulty understanding the flaw. As the look-ahead instructions are not posted, they didn't do anything. Is it that the cache lines are exposed to the unprivileged process and it can figure out which cache lines has had some data? -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
