An issue was discovered in the Linux kernel before 5.2 on the powerpc platform. arch/powerpc/kernel/idle_book3s.S does not have save/restore functionality for PNV_POWERSAVE_AMR, PNV_POWERSAVE_UAMOR, and PNV_POWERSAVE_AMOR, aka CID-53a712bae5dd.
https://usn.ubuntu.com/4368-1/
https://usn.ubuntu.com/4363-1/
https://security.netapp.com/advisory/ntap-20200430-0001/
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/208663.html
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/208661.html
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/208660.html
https://github.com/torvalds/linux/commit/53a712bae5dd919521a58d7bad773b949358add0
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.2
https://access.redhat.com/errata/RHSA-2019:3517
http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00035.html