[powerpc/merge] System crash during cpu offline/online operation

[Sachin Sant]

> On 11-Dec-2020, at 3:47 PM, Sachin Sant <sachinp at linux.vnet.ibm.com> wrote:
> 
> I am observing system crash during a cpu offline/online operation
> with latest merge branch code running in a PowerVM LPAR (P8 onwards)
> 
> # uname -r
> 5.10.0-rc7-01792-g244569c777ca
> # ppc64_cpu --smt=1
> [  244.205194] cpu 1 (hwid 1) Ready to die…
> ………
> ……...
> [  247.015113] cpu 30 (hwid 30) Ready to die...
> [  247.104973] cpu 31 (hwid 31) Ready to die…
> # ppc64_cpu --smt=8
> 
> At this point the LPAR reboots instantly without any trace message.

Git bisect leads me to the following commit:

3b47b7549ead0719e94022c6742199333c7c8d9f is the first bad commit
commit 3b47b7549ead0719e94022c6742199333c7c8d9f
Author: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
Date:   Fri Nov 27 10:14:07 2020 +0530

    powerpc/book3s64/kuap: Move KUAP related function outside radix

Here is the bisect log:

# git bisect log
git bisect start
# bad: [244569c777ca638b08c75db88fe035bdec52ef80] Automatic merge of 'next' into merge (2020-12-10 00:34)
git bisect bad 244569c777ca638b08c75db88fe035bdec52ef80
# good: [9acd775e4579bde0a6d937d72f9669e418aa87ad] Automatic merge of 'master' into merge (2020-12-05 22:54)
git bisect good 9acd775e4579bde0a6d937d72f9669e418aa87ad
# good: [ab91292cb3e9f43d9c6839d7572d17b35bc21710] Merge tag 'char-misc-5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
git bisect good ab91292cb3e9f43d9c6839d7572d17b35bc21710
# bad: [19b311ca51e108b6d8d679496af8635fdc1984a8] ocxl: Initiate a TLB invalidate command
git bisect bad 19b311ca51e108b6d8d679496af8635fdc1984a8
# bad: [d94b827e89dc3f92cd871d10f4992a6bd3c861e5] powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation
git bisect bad d94b827e89dc3f92cd871d10f4992a6bd3c861e5
# good: [1d15ffdfc94127d75e04a88344ee1ce8c79f05fd] KVM: PPC: Book3S HV: Ratelimit machine check messages coming from guests
git bisect good 1d15ffdfc94127d75e04a88344ee1ce8c79f05fd
# good: [9f378b9f007cc94beadea40df83cc62a76975c6f] KVM: PPC: BOOK3S: PR: Ignore UAMOR SPR
git bisect good 9f378b9f007cc94beadea40df83cc62a76975c6f
# bad: [3b47b7549ead0719e94022c6742199333c7c8d9f] powerpc/book3s64/kuap: Move KUAP related function outside radix
git bisect bad 3b47b7549ead0719e94022c6742199333c7c8d9f
# good: [39df17bc20059c84ddc6f91831fce2e2cc79a6f3] powerpc/book3s64/kuap/kuep: Move uamor setup to pkey init
git bisect good 39df17bc20059c84ddc6f91831fce2e2cc79a6f3
# first bad commit: [3b47b7549ead0719e94022c6742199333c7c8d9f] powerpc/book3s64/kuap: Move KUAP related function outside radix

Thanks
-Sachin