Meltdown, Spectre, *BSD


#1

Latest BSDNow has some good info:

http://www.jupiterbroadcasting.com/121362/the-spectre-of-meltdown-bsd-now-228/

Matt Dillon of DragonflyBSD has some performance measurements:
http://lists.dragonflybsd.org/pipermail/users/2018-January/335643.html


#2

https://lists.freebsd.org/pipermail/freebsd-security/2018-January/009719.html


#3

Looks like some meltdown/spectre work may be starting to hit 12Current.
Fun read if you’re a software geek ; the solution shows the complexity of the problem and this is a very good example of how a commit message should be written.

https://docs.freebsd.org/cgi/getmsg.cgi?fetch=1311178+0+current/svn-src-head


#4

OK, but how will the new kernel work with the new processor chips? In the next years machines will be with new processors and will be with the “old” wrong processors. Will the new kernel “support” the new and old processor chips also?


#5

back to the 8080 era :wink:

just guessing here

unless we all move to arm64(?), intel/amd will keep some of their current architecture. and that could take some time to be delivered


#6

@Zoltan that is a good question. The kernel developers can only work with the published information, they write the code to conform. Newer CPUs typically add newer features or new ways of doing something, but they will support the old ways. If you do dmesg and look for “features” that tells you what your cpu can do.

So today’s kernel will run on tomorrow’s CPU, but won’t enable the features it doesn’t know about. As the developers find out and figure out how to use them, detection code gets added to enable them.