* Mark Rutland <mark.rutland@xxxxxxx> wrote: > It still seems wrong to make up data, though. So what we have here is a hardware quirk: we asked for user-space samples, but didn't get them and we cannot expose the kernel-internal address. The question is, how do we handle the hardware quirk. Since we cannot fix the hardware on existing systems there's really just two choices: - Lose the sample (and signal it as a lost sample) - Keep the sample but change the sensitive kernel-internal address to something that is not sensitive: 0 or -1 works, but we could perhaps also return a well-known user-space address such as the vDSO syscall trampoline or such? there's no other option really. I'd lean towards Vince's take: losing samples is more surprising than getting the occasional sample with some sanitized data in it. If we make the artificial data still a meaningful user-space address, related to kernel entries, then it might even be a bonus, as users would learn to recognize it as: 'oh, skid artifact, I know about that'. Thanks, Ingo