On Mon, May 02, 2022 at 08:50:04PM +0200, Heiko Carstens wrote: > On Mon, May 02, 2022 at 01:31:00PM +0000, Liam Howlett wrote: > > * Heiko Carstens <hca@xxxxxxxxxxxxx> [220502 06:18]: > > > On Sun, May 01, 2022 at 05:24:12PM -0700, Andrew Morton wrote: > > > > (cc S390 maintainers) > > > > (cc stable & Greg) ... > > > > > booting. The last thing I see is: > > > > > > > > > > "[ 4.668916] Spectre V2 mitigation: execute trampolines" > > > > > > > > > > I've bisected back to commit e553f62f10d9 (mm, page_alloc: fix > > > > > build_zonerefs_node()) > > > > > > > > > > With the this commit, I am unable to boot one out of three times. When > > > > > using the previous commit I was not able to get it to hang after trying > > > > > 10+ times. This is a qemu s390 install with KASAN on and I see no error > > > > > messages. I think it's likely it is this patch, but no guaranteed. ... > > > Liam, could you share your kernel config? > > > > Sure thing. See attached. > > So, I can reproduce the hanging system now. However this looks like a > qemu problem on s390, since I can reproduce this only with Qemu+TCG. > Qemu with kvm works without any problems (same if I use z/VM as > hypervisor). > > Janosch, Claudio, can you have a look at this please? So, at least for me this problem also exists with plain v5.17. Switching off KASAN, or alternatively switching to KASAN_INLINE "fixes" it for me with Qemu+TCG. Liam, could you please also try to disable KASAN in your config? With that I think we can be almost sure this could be some bug in Qemu.
