If it wasn't clear the last time he tore into Intel over the company's patches for the Meltdown and Spectre vulnerabilities, the father of Linux is at it again, referring to the patches as 'garbage' and claiming they do 'insane things'.
The comments come in the latest communique from Torvalds on the Linux kernel mailing list where he discusses Intel's approach to patching the severe vulnerabilities affecting all modern processors, not only from Intel but also AMD and ARM. He suggested Intel may not be looking out for the best interests of the user, remarking,
"The speculation control cpuid stuff shows that Intel actually seems to plan on doing the right thing for meltdown (the main question being _when_). Which is not a huge surprise, since it should be easy to fix, and it's a really honking big hole to drive through. Not doing the right thing for meltdown would be completely unacceptable. So the IBRS garbage implies that Intel is _not_ planning on doing the right thing for the indirect branch speculation.
The whole IBRS_ALL feature to me very clearly says "Intel is not serious about this, we'll have a ugly hack that will be so expensive that we don't want to enable it by default, because that would look bad in benchmarks".
They do literally insane things. They do things that do not make sense. That makes all your arguments questionable and suspicious. The patches do things that are not sane."
Elsewhere, he states, "As it is, the patches are COMPLETE AND UTTER GARBAGE." Torvalds also took issue with Intel's philosophy, suggesting its decision to not adopt Google's Retpoline approach - which claims to have a minimal performance impact in solving one variant of the vulnerability - is bizarre.
Of course, while Torvald's critiques may be largely technical in nature, users are already experiencing real-world problems because of the patches, with Intel itself admitting a bug in them can "introduce a higher than expected number of reboots". The company has already started asking all its customers to delay installing the patches until it pushes out a fix to correct the problem.
Meltdown and Spectre are also actively causing trouble for Linux development, as Torvalds this week again delayed the release of Linux 4.15, instead opting to release a ninth release candidate, something that last happened in 2011.