In the Linux kernel, the following vulnerability has been resolved: i40e: Fix preempt count leak in napi poll tracepoint Using getcpu() in the tracepoint assignment causes an obvious preempt count leak because nothing invokes putcpu() to undo it: softirq: huh, entered softirq 3 NETRX with preemptcount 00000100, exited with 00000101? This clearly has seen a lot of testing in the last 3+ years... Use smpprocessorid() instead.