Hi folks, sorry if messed something up, this email has never been in my inbox.
Disable the TSC Deadline timer in lapic_timer_shutdown() by writing to MSR_IA32_TSC_DEADLINE when in TSC-deadline mode. Also avoid writing to the initial-count register (APIC_TMICT) which is ignored in TSC-deadline mode.
So this commit hit stable and we now see section mismatch errors:
// stripped
WARNING: vmlinux.o(__ex_table+0x447c): Section mismatch in reference from the (unknown reference) (unknown) to the (unknown reference) .irqentry.text:(unknown) The relocation at __ex_table+0x447c references section ".irqentry.text" which is not in the list of authorized sections.
WARNING: vmlinux.o(__ex_table+0x4480): Section mismatch in reference from the (unknown reference) (unknown) to the (unknown reference) .irqentry.text:(unknown) The relocation at __ex_table+0x4480 references section ".irqentry.text" which is not in the list of authorized sections.
FATAL: modpost: Section mismatches detected.
Specifically because of wrmsrl.
I'm aware of the section mismatch errors on linux-5.4 (I know), not aware of any other stable versions (but I haven't checked). Is this something specific to linux-5.4?