From mboxrd@z Thu Jan  1 00:00:00 1970
From: will.deacon@arm.com (Will Deacon)
Date: Tue, 3 Oct 2017 15:22:05 +0100
Subject: [PATCH v5 6/7] drivers/perf: Add support for ARMv8.2 Statistical
 Profiling Extension
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To: linux-arm-kernel@lists.infradead.org
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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