[16:39] <ChmEarl> running xen in noble 24.04 with kernel-6.5, I see UBSAN kernel errors in xen-blkback and xen-netback drivers when domU launch
[16:39] <ChmEarl> but everything works
[16:40] <ChmEarl> in dmesg: UBSAN: array-index-out-of-bounds in /build/linux-D15vQj/linux-6.5.0/drivers/block/xen-blkback/blkback.c:1227:4
[16:44] <lotuspsychje> ChmEarl: since noble development is still early and i dont see xen related bugs on your case, might be worth a new bug?
[16:44] <lotuspsychje> unless some of our server testers can try to reproduce that first
[16:45] <ChmEarl> lotuspsychje, ty, I was trying to see if there are any reproduce cases yet
[16:45] <ChmEarl> my CPU is ancient, CORE2quad
[16:47] <lotuspsychje> ChmEarl: there are some other bugs with your ubsan error around though
[16:47] <lotuspsychje> bug #2002842 would be one
[16:47] -ubottu:#ubuntu-next- Bug 2008157 in linux (Ubuntu) "[SRU][Ubuntu 22.04.1]: Observed 'Array Index out of bounds' Call Trace multiple times on Ubuntu 22.04.1 OS during boot" [Medium, In Progress] [duplicate: 2002842] https://launchpad.net/bugs/2008157
[16:47] <ChmEarl> I might try to run it on ivy-bridge soon
[16:47] <lotuspsychje> so, not sure its noble specific?
[16:54] <lotuspsychje> ChmEarl: an idea arising could be booting a previous kernel, to see if this is kernel related
[16:56] <ChmEarl> lotuspsychje, not sure if I can run a kernel from mantic? or jammy?
[16:56] <ChmEarl> there is only 1 kernel for noble
[16:57] <ChmEarl> I was worried that its related to CPU support for stuff like: avx or aes
[16:58] <lotuspsychje> well its only for a test, if we assume your UBSAN error would only arise from kernel 6.5 for example
[16:58] <ChmEarl> yes, thinking its specific to very recent kernel
[16:59] <lotuspsychje> im also thinking so
[17:00] <lotuspsychje> im seeing those UBSAN kernel errors in different bugs all over, not only xen
[17:19] <ChmEarl> trying with 4 files from lunar: 6.2.0.20.20
[17:20] <ChmEarl> noble made no complaint
[17:23] <lotuspsychje> ok tnx for the test ChmEarl 
[17:29] <lotuspsychje> so now to findout its really a useful warning to xen; or just an UBSAN default warning since a kernel version
[17:44] <ChmEarl> lotuspsychje, the install of the lunar  6.2.0-20 packages worked, but xen/kernel-6.2 won't boot
[17:44] <ChmEarl> at least I didn't waste hardly any time trying
[17:45] <lotuspsychje> what you can do is messing with later mainline kernels too
[17:46] <lotuspsychje> i didnt test xen myself so cant help there
[17:49] <ChmEarl> the XEN & UBSAN configs are the same for the 2 kernels
[22:15] <ChmEarl> requesting a kernel-6.5 build with  # CONFIG_UBSAN is not set
[22:15] <ChmEarl> or turn-off array bound checks
[22:16] <ChmEarl>  xen domU is flooded with ubsan errors