** Description changed: [ 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 UBAAN in s390x kernel configurations resolved the issue for + * 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.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2003374 Title: Undefined Behavior Sanitizer (UBSAN) causes failure to match symbols To manage notifications about this bug go to: https://bugs.launchpad.net/dh-kpatches/+bug/2003374/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
