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