** Tags added: petest-450 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2003374
Title: Undefined Behavior Sanitizer (UBSAN) causes failure to match symbols Status in dh-kpatches: Unknown Status in Ubuntu on IBM z Systems: Fix Committed Status in kpatch package in Ubuntu: In Progress Status in linux package in Ubuntu: Fix Released Status in kpatch source package in Jammy: In Progress Status in linux source package in Jammy: Fix Released Status in kpatch source package in Kinetic: Won't Fix Bug description: [ Impact ] * When UBSAN is enabled in an s390x kernel configuration, kpatch- build can fail to find matching symbols in the vmlinux symbol table (see attached example_livepatch.patch). This was discovered in both Jammy 5.15 and Kinetic 5.19 kernels, where UBSAN was first enabled (releases up to Focal did not enable UBSAN). See attached kpatch-build console output (output.log) and kpatch-build log (build.log). * Disabling UBSAN in s390x kernel configurations resolved the issue for both Jammy 5.15 and Kinetic 5.19. Possibly this could be fixed in kpatch/kpatch-build to continue to enable UBSAN while still allowing Livepatch functionality. [ Test Plan ] * Use kpatch-build testcases to build and load a fs/proc/meminfo.c Livepatch on s390x kernel (see attached example_livepatch.patch). This should be successful. [ Where problems could occur ] * A fix in kpatch/kpatch-build to properly handle UBSAN objects shouldn't yield any regressions. If UBSAN is disabled to ultimately get past this issue, it could lead to undefined behavior not being caught. To manage notifications about this bug go to: https://bugs.launchpad.net/dh-kpatches/+bug/2003374/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
