On Fri, Jun 12, 2020 at 09:34:06AM -0700, Sean Christopherson wrote:
> The kernel should be tainted if the WRMSR is attempted, regardless of
> whether it succeeds, and it should happen before the WRMSR. E.g. pointing
> MSR_IA32_DS_AREA at a bad address will likely cause an OOPS on the #PF
If the MSR write fails, MSR_IA32_DS_AREA won't have the bad address. If
the writes fail, nothing has been changed.
> This can be 0600, or maybe 0644, i.e. allow the user to enable/disable
> writes after the module has been loaded.
What for?
crw------- 1 root root 202, 0 Jun 10 19:54 /dev/cpu/0/msr
You need root to write to the chrdev.
Also, the intent is *not* to open it more but to close it so that the
incentive to design proper interfaces is there.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
