Subject: [PATCH v5 6/7] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension

From: [email-masked] (Will Deacon)
Date: Tue, 3 Oct 2017 15:22:05 +0100

On Mon, Oct 02, 2017 at 06:35:24PM -0500, Kim Phillips wrote:

[trim other stuff]

> Meanwhile, when I build this v5 arm_spe_pmu as a module, load it, do a
> perf list, rmmod it, then re-load it, I get an Oops:
> 
> # insmod arm_spe_pmu.ko
> [ 2018.623646] arm_spe_pmu spe-pmu at 0: probed for CPUs 0-3 [max_record_sz 64, align 1, features 0xf]
> [ 2018.626346] arm_spe_pmu spe-pmu at 1: probed for CPUs 4-7 [max_record_sz 64, align 1, features 0xf]
> # ./perf list
> [ 2021.649688] Unable to handle kernel NULL pointer dereference at virtual address 00000038

[...]

Cheers for the report. Fix here:

https://lkml.org/lkml/2017/10/3/564

Will