Here's v5 of the consistency model, targeted for 4.12. Only a few minor changes this time. I would very much appreciate reviews/acks from the following: - Michael Ellerman for the powerpc changes in patch 5. - Heiko Carstens for the s390 changes in patches 6 & 7. - Peter Zijlstra/Ingo Molnar for the use of task_rq_lock() and the modification of do_idle() in patch 13. Thanks! Based on linux-next/master (20170213). v5: - return -EINVAL in __save_stack_trace_reliable() - only call show_stack() once - add save_stack_trace_tsk_reliable() define for !CONFIG_STACKTRACE - update kernel version and date in ABI doc - make suggested improvements to livepatch.txt - update barrier comments - remove klp_try_complete_transition() call from klp_start_transition() - move end of klp_try_complete_transition() into klp_complete_transition() - fix __klp_enable_patch() error path - check for transition in klp_module_going() v4: - add warnings for "impossible" scenarios in __save_stack_trace_reliable() - sort _TIF_ALLWORK_MASK flags - move klp_transition_work to transition.c. This resulted in the following related changes: - klp_mutex is now visible to transition.c - klp_start_transition() now calls klp_try_complete_transition() - klp_try_complete_transition() now sets up the work - rearrange code in transition.c accordingly - klp_reverse_transition(): clear TIF flags and call synchronize_rcu() - klp_try_complete_transition(): do synchronize_rcu() only when unpatching - klp_start_transition(): only set TIF flags when necessary - klp_complete_transition(): add synchronize_rcu() when patching - klp_ftrace_handler(): put WARN_ON_ONCE back in and add comment - use for_each_possible_cpu() to patch offline idle tasks - add warnings to sample module when setting patch.immediate - don't use pr_debug() with the task rq lock - add documentation about porting consistency model to other arches - move klp_patch_pending() to patch 13 - improve several comments and commit messages v3: - rebase on new x86 unwinder - force !HAVE_RELIABLE_STACKTRACE arches to use patch->immediate for now, because we don't have a way to transition kthreads otherwise - rebase s390 TIF_PATCH_PENDING patch onto latest entry code - update barrier comments and move barrier from the end of klp_init_transition() to its callers - "klp_work" -> "klp_transition_work" - "klp_patch_task()" -> "klp_update_patch_state()" - explicit _TIF_ALLWORK_MASK - change klp_reverse_transition() to not try to complete transition. instead modify the work queue delay to zero. - get rid of klp_schedule_work() in favor of calling schedule_delayed_work() directly with a KLP_TRANSITION_DELAY - initialize klp_target_state to KLP_UNDEFINED - move klp_target_state assignment to before patch->immediate check in klp_init_transition() - rcu_read_lock() in klp_update_patch_state(), test the thread flag in patch task, synchronize_rcu() in klp_complete_transition() - use kstrtobool() in enabled_store() - change task_rq_lock() argument type to struct rq_flags - add several WARN_ON_ONCE assertions for klp_target_state and task->patch_state v2: - "universe" -> "patch state" - rename klp_update_task_universe() -> klp_patch_task() - add preempt IRQ tracking (TF_PREEMPT_IRQ) - fix print_context_stack_reliable() bug - improve print_context_stack_reliable() comments - klp_ftrace_handler comment fixes - add "patch_state" proc file to tid_base_stuff - schedule work even for !RELIABLE_STACKTRACE - forked child inherits patch state from parent - add detailed comment to livepatch.h klp_func definition about the klp_func patched/transition state transitions - update exit_to_usermode_loop() comment - clear all TIF_KLP_NEED_UPDATE flags in klp_complete_transition() - remove unnecessary function externs - add livepatch documentation, sysfs documentation, /proc documentation - /proc/pid/patch_state: -1 means no patch is currently being applied/reverted - "TIF_KLP_NEED_UPDATE" -> "TIF_PATCH_PENDING" - support for s390 and powerpc-le - don't assume stacks with dynamic ftrace trampolines are reliable - add _TIF_ALLWORK_MASK info to commit log v1.9: - revive from the dead and rebased - reliable stacks! - add support for immediate consistency model - add a ton of comments - fix up memory barriers - remove "allow patch modules to be removed" patch for now, it still needs more discussion and thought - it can be done with something - "proc/pid/universe" -> "proc/pid/patch_status" - remove WARN_ON_ONCE from !func condition in ftrace handler -- can happen because of RCU - keep klp_mutex private by putting the work_fn in core.c - convert states from int to boolean - remove obsolete '@state' comments - several header file and include improvements suggested by Jiri S - change kallsyms_lookup_size_offset() errors from EINVAL -> ENOENT - change proc file permissions S_IRUGO -> USR - use klp_for_each_object/func helpers Jiri Slaby (1): livepatch/s390: reorganize TIF thread flag bits Josh Poimboeuf (12): stacktrace/x86: add function for detecting reliable stack traces x86/entry: define _TIF_ALLWORK_MASK flags explicitly livepatch: create temporary klp_update_patch_state() stub livepatch/x86: add TIF_PATCH_PENDING thread flag livepatch/powerpc: add TIF_PATCH_PENDING thread flag livepatch: separate enabled and patched states livepatch: remove unnecessary object loaded check livepatch: move patching functions into patch.c livepatch: use kstrtobool() in enabled_store() livepatch: store function sizes livepatch: change to a per-task consistency model livepatch: add /proc/<pid>/patch_state Miroslav Benes (2): livepatch/s390: add TIF_PATCH_PENDING thread flag livepatch: allow removal of a disabled patch Documentation/ABI/testing/sysfs-kernel-livepatch | 8 + Documentation/filesystems/proc.txt | 18 + Documentation/livepatch/livepatch.txt | 214 +++++++-- arch/Kconfig | 6 + arch/powerpc/include/asm/thread_info.h | 4 +- arch/powerpc/kernel/signal.c | 4 + arch/s390/include/asm/thread_info.h | 24 +- arch/s390/kernel/entry.S | 31 +- arch/x86/Kconfig | 1 + arch/x86/entry/common.c | 9 +- arch/x86/include/asm/thread_info.h | 13 +- arch/x86/include/asm/unwind.h | 6 + arch/x86/kernel/stacktrace.c | 96 +++- arch/x86/kernel/unwind_frame.c | 2 + fs/proc/base.c | 15 + include/linux/init_task.h | 9 + include/linux/livepatch.h | 68 ++- include/linux/sched.h | 3 + include/linux/stacktrace.h | 9 +- kernel/fork.c | 3 + kernel/livepatch/Makefile | 2 +- kernel/livepatch/core.c | 436 +++++++----------- kernel/livepatch/patch.c | 272 +++++++++++ kernel/livepatch/patch.h | 33 ++ kernel/livepatch/transition.c | 551 +++++++++++++++++++++++ kernel/livepatch/transition.h | 14 + kernel/sched/idle.c | 4 + kernel/stacktrace.c | 12 +- samples/livepatch/livepatch-sample.c | 18 +- 29 files changed, 1531 insertions(+), 354 deletions(-) create mode 100644 kernel/livepatch/patch.c create mode 100644 kernel/livepatch/patch.h create mode 100644 kernel/livepatch/transition.c create mode 100644 kernel/livepatch/transition.h -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
