Linus Torvalds wants to know "WHAT THE F*CK IS GOING ON?," to quote a part of a public email exchange he had with an Amazon engineer in the UK. His ire is not with Amazon, however, but with Intel and how it is approaching Meltdown and Spectre.
As it stands, Torvalds says Intel's patches are "COMPLETE AND UTTER GARBAGE," and declares them as such in all caps because he's really, really angry.
"The patches do things like add the garbage MSR writes to the kernel entry/exit points. That's insane. That says 'we're trying to protect the kernel'. We already have retpoline there, with less overhead," Torvalds added.
Torvalds, who is no stranger to tirades, is highly critical of Intel's approach to Spectre specifically. In the email chain, he points out that Intel "seems to plan on doing the right thing for Meltdown," which he says "should be easy to fix." But as The Register points out, Intel is not treating one of the Spectre vulnerabilities as a bug that needs to be fixed, and instead plans to roll out protections as a feature in future processor releases.
More specifically, Torvalds would like to see Intel attack the problem head on by implementing a flag or version number that would let the kernel know if a processor is not susceptible to Spectre. Instead, Intel is going with an opt-in approach—future processors will be able to reveal to the kernel that Spectre protections are present but disabled by default, and need to be enabled by the operating system.
"All of this is pure garbage. Is Intel really planning on making this shit architectural?," Torvalds asked. "Has anybody talked to them and told them they are f*cking insane? Please, any Intel engineers here— talk to your managers."
Intel is aware of Torvalds' criticism and apparently has a dialogue going with him, along with others in the Linux community.
"We take the feedback of industry partners serious," an Intel spokesperson told The Register. "We are actively engaging with the Linux community, including Linus, as we seek to work together on solutions."
The feedback Intel is receiving, at least from Torvalds, is that the company's patches do "insane things" and are "much worse" than a "nasty hack."