Re: [PATCH v4 1/2] livepatch: send a fake signal to all blocking tasks

[Michael Ellerman]

Jiri Kosina <jikos@xxxxxxxxxx> writes:
> On Wed, 15 Nov 2017, Miroslav Benes wrote:
>> Live patching consistency model is of LEAVE_PATCHED_SET and
>> SWITCH_THREAD. This means that all tasks in the system have to be marked
>> one by one as safe to call a new patched function. Safe means when a
>> task is not (sleeping) in a set of patched functions. That is, no
>> patched function is on the task's stack. Another clearly safe place is
>> the boundary between kernel and userspace. The patching waits for all
>> tasks to get outside of the patched set or to cross the boundary. The
>> transition is completed afterwards.
...
>> 
>> Signed-off-by: Miroslav Benes <mbenes@xxxxxxx>
>> Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
>> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
>> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
>> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
>> Cc: Andy Lutomirski <luto@xxxxxxxxxx>
>> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
>> Cc: x86@xxxxxxxxxx
>> ---
>>  Documentation/ABI/testing/sysfs-kernel-livepatch | 12 +++++++
>>  Documentation/livepatch/livepatch.txt            | 11 +++++--
>>  arch/powerpc/kernel/signal.c                     |  6 ++--
>>  arch/x86/entry/common.c                          |  6 ++--
>>  kernel/livepatch/core.c                          | 30 +++++++++++++++++
>>  kernel/livepatch/transition.c                    | 41 ++++++++++++++++++++++++
>>  kernel/livepatch/transition.h                    |  1 +
>>  kernel/signal.c                                  |  4 ++-
>
> I'd like to be queuing this patchset for the next merge window, so if 
> there are any objections for the out-of-kernel/livepatch/* changes, please 
> speak up now.

The powerpc changes look innocuous and in-line with the change log, no
objection from me. Have an ack if you like:

Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc)

cheers