Zack's Kernel News
Zack's Kernel News

In kernel news: Vulnerabilities using a 32-Bit Kernel on a 64-Bit CPU; Working Around Hardware Security Vulnerabilities; and When It's OK to Panic.
Vulnerabilities using a 32-Bit Kernel on a 64-Bit CPU
Naresh Kamboju of Linaro reported that the kernel was giving some serious Spectre and Retbleed security warnings on the Linaro test farm. He said they were using the i386 kernel on the 64-bit Intel Skylake CPU. Or at least, he posted some debugging output that identified the specific CPU.
Greg Kroah-Hartman remarked that this particular combination – a 32-bit kernel running on a 64-bit architecture – was sort of pathological. People should really use a faster and more efficient 64-bit kernel if their architecture supports it. Greg said this particular environment might not be something the kernel developers needed to care about. He suggested that Pawan Gupta from Intel might be the person to ask.
Meanwhile, Peter Zijlstra remarked, "Yeah, so far nobody cared to fix 32bit. If someone *realllllly* cares and wants to put the effort in I suppose I'll review the patches, but seriously, you shouldn't be running 32bit kernels on Skylake / Zen based systems, that's just silly."
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