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7537bae8b6
The RAPL MSR read path incorrectly validates CPU context when called
from the PMU subsystem:
if (atomic) {
if (unlikely(smp_processor_id() != cpu))
return -EIO;
rdmsrq(ra->reg.msr, ra->value);
}
This check fails for package-scoped MSRs like RAPL energy counters,
which are readable from any CPU within the package.
The perf tool avoids hitting this check by validating against
/sys/bus/event_source/devices/power/cpumask before opening events.
However, turbostat does not perform this validation and may attempt
reads from non-lead CPUs, causing the check to fail and return zero
power values.
Since package-scoped MSRs are architecturally accessible from any CPU
in the package, remove the CPU matching check.
Also rename 'atomic' to 'pmu_ctx' to clarify this indicates PMU context
where rdmsrq() can be used directly instead of rdmsrl_safe_on_cpu().
Fixes:
|
||
|---|---|---|
| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| cxl | ||
| drm | ||
| dt-bindings | ||
| hyperv | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||
| Kbuild | ||