Bug 917670 – sys-kernel/gentoo-kernel: modprobe: FATAL: Module msr not found

• Status: RESOLVED WONTFIX
• Product: Gentoo Linux

[Description Agostino Sarubbo 2023-11-21 11:50:26 UTC]

I'm running gentoo-kernel-6.1.60 and while I'm trying to use cpupower (from sys-power/cpupower) I get:

modprobe: FATAL: Module msr not found in directory /lib/modules/6.1.60-gentoo-dist-hardened

Would be great if you can enable CONFIG_X86_MSR

[Comment 1 Nowa Ammerlaan 2023-11-21 12:34:45 UTC]

This is currently explicitly disabled by the hardend-*.config[1]. From what I'm reading[2] the rational for this is because this option allows the root user to modify the kernel at runtime.

[1] https://github.com/projg2/gentoo-kernel-config/blob/master/hardened-amd64.config
[2] https://www.kicksecure.com/wiki/Hardened-kernel

[Comment 2 genBTC 2023-11-21 13:11:03 UTC]

MSR is disabled on purpose for hardened configs, its a security hole because it can send secret commands deep into the CPU. You can re-enable it if you want CPU telemetry.

The cpupower .ebuild should probably be patched to include a CONFIG_CHECK item for needing X86_MSR as a warning.

[Comment 3 Agostino Sarubbo 2023-11-21 13:28:57 UTC]

That's enough to auto-close, thanks.