------- Comment on attachment From kamale...@in.ibm.com 2018-01-09 01:39 EDT-------
Livepatch re-uses module loader function apply_relocate_add() to write relocations, instead of managing them by arch-dependent klp_write_module_reloc() function. apply_relocate_add() doesn't understand livepatch symbols (marked with SHN_LIVEPATCH symbol section index) and assumes them to be local symbols by default for R_PPC64_REL24 relocation type. It fails with an error, when trying to calculate offset with local_entry_offset(): module_64: kpatch_meminfo: REL24 -1152921504897399800 out of range! Whereas livepatch symbols are essentially SHN_UNDEF, should be called via stub used for global calls. This issue can be fixed by teaching apply_relocate_add() to handle both SHN_UNDEF/SHN_LIVEPATCH symbols via the same stub. This patch extends SHN_UNDEF code to handle livepatch symbols too. ** Attachment added: "[1/3] powerpc/modules: Add REL24 relocation support of livepatch symbols" https://bugs.launchpad.net/bugs/1741992/+attachment/5033167/+files/0001-powerpc-modules-Add-REL24-relocation-support-of-live.patch -- 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/1741992 Title: kpatch - Add livepatch hook support for ppc64le Status in The Ubuntu-power-systems project: Triaged Status in linux package in Ubuntu: New Bug description: kpatch is a Linux dynamic kernel patching infrastructure which allows you to patch a running kernel without rebooting or restarting any processes. It enables sysadmins to apply critical security patches to the kernel immediately, without having to wait for long-running tasks to complete, for users to log off, or for scheduled reboot windows. It gives more control over uptime without sacrificing security or stability. kpatch is upstream hosted at https://github.com/dynup/kpatch https://github.com/dynup/kpatch/releases Add support for livepatch infrastructure on ppc64le https://github.com/dynup/kpatch/pull/650 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1741992/+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
