------- Comment From kamale...@in.ibm.com 2018-06-15 04:33 EDT------- The proposed Bionic kernel enables the 'Implement reliable stack tracing for the consistency model' patch.
In brief: ------------ After upgrading the system by enabling bionic-proposed to sources.list: deb http://archive.ubuntu.com/ubuntu/ bionic-proposed restricted main multiverse universe system booted into kernel version 4.15.0-24-generic, using 4.15.0-24-generic sources (apt source linux) to build livepatch modules: # insmod ./livepatch-0001-mm-thp-Do-not-make-page-table-dir.ko # dmesg ..... [ 1827.037453] livepatch_0001_mm_thp_Do_not_make_page_table_dir: loading out-of-tree module taints kernel. [ 1827.037458] livepatch_0001_mm_thp_Do_not_make_page_table_dir: tainting kernel with TAINT_LIVEPATCH [ 1827.043106] livepatch_0001_mm_thp_Do_not_make_page_table_dir: module verification failed: signature and/or required key missing - tainting kernel [ 1827.176933] livepatch: enabling patch 'livepatch_0001_mm_thp_Do_not_make_page_table_dir' [ 1827.179784] livepatch: 'livepatch_0001_mm_thp_Do_not_make_page_table_dir': starting patching transition [ 1827.179785] livepatch: 'livepatch_0001_mm_thp_Do_not_make_page_table_dir': patching complete [ 2526.521348] livepatch: 'livepatch_0001_mm_thp_Do_not_make_page_table_dir': starting unpatching transition [ 2526.525554] livepatch: 'livepatch_0001_mm_thp_Do_not_make_page_table_dir': unpatching complete ** Tags removed: verification-needed-bionic ** Tags added: verification-done-bionic -- 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/1771844 Title: powerpc/livepatch: Implement reliable stack tracing for the consistency model Status in The Ubuntu-power-systems project: Fix Committed Status in linux package in Ubuntu: Fix Committed Status in linux source package in Bionic: Fix Committed Status in linux source package in Cosmic: Fix Committed Bug description: == SRU Justification == Livepatch has a consistency model which is a hybrid of kGraft and kpatch: it uses kGraft's per-task consistency and syscall barrier switching combined with kpatch's stack trace switching. The current approach is stack checking of sleeping tasks. If no affected functions are on the stack of a given task, the task is patched. In most cases this will patch most or all of the tasks on the first try. Otherwise, it'll keep trying periodically. This patch implements the reliable stack tracing for consistency model a.k.a HAVE_RELIABLE_STACKTRACE. This will help in switching livepatching implementation to basic per-task consistency model. It is the foundation, which will help us enable security patches changing function or data semantics. This is the biggest remaining piece needed on ppc64le to make livepatch more generally useful. == Fix == df78d3f61480 ("powerpc/livepatch: Implement reliable stack tracing for the consistency model") == Regression Potential == Low. Limited to powerpc. == Test Case == A test kernel was built with this patch and tested by the original bug reporter. The bug reporter states the test kernel resolved the bug. https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id=df78d3f6148092d33a9a24c7a9cfac To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1771844/+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
