Re: livepatching selftests failure on current master branch

[Joe Lawrence]

On 5/17/19 10:17 AM, Miroslav Benes wrote:
> Hi,
>
> I noticed that livepatching selftests fail on our master branch
> (https://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching.git/).
>
> ...
> TEST: busy target module ... not ok
>
> --- expected
> +++ result
> @@ -7,16 +7,24 @@ livepatch: 'test_klp_callbacks_demo': in
>   test_klp_callbacks_demo: pre_patch_callback: vmlinux
>   test_klp_callbacks_demo: pre_patch_callback: test_klp_callbacks_busy -> [MODULE_STATE_LIVE] Normal state
>   livepatch: 'test_klp_callbacks_demo': starting patching transition
> +livepatch: 'test_klp_callbacks_demo': completing patching transition
> +test_klp_callbacks_demo: post_patch_callback: vmlinux
> +test_klp_callbacks_demo: post_patch_callback: test_klp_callbacks_busy -> [MODULE_STATE_LIVE] Normal state
> +livepatch: 'test_klp_callbacks_demo': patching complete
>   % modprobe test_klp_callbacks_mod
>   livepatch: applying patch 'test_klp_callbacks_demo' to loading module
> 'test_klp_callbacks_mod'
>   test_klp_callbacks_demo: pre_patch_callback: test_klp_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
> +test_klp_callbacks_demo: post_patch_callback: test_klp_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
>   test_klp_callbacks_mod: test_klp_callbacks_mod_init
>   % rmmod test_klp_callbacks_mod
>   test_klp_callbacks_mod: test_klp_callbacks_mod_exit
> +test_klp_callbacks_demo: pre_unpatch_callback: test_klp_callbacks_mod -> [MODULE_STATE_GOING] Going away
>   livepatch: reverting patch 'test_klp_callbacks_demo' on unloading module
> 'test_klp_callbacks_mod'
>   test_klp_callbacks_demo: post_unpatch_callback: test_klp_callbacks_mod -> [MODULE_STATE_GOING] Going away
>   % echo 0 > /sys/kernel/livepatch/test_klp_callbacks_demo/enabled
> -livepatch: 'test_klp_callbacks_demo': reversing transition from patching to unpatching
> +livepatch: 'test_klp_callbacks_demo': initializing unpatching transition
> +test_klp_callbacks_demo: pre_unpatch_callback: vmlinux
> +test_klp_callbacks_demo: pre_unpatch_callback: test_klp_callbacks_busy -> [MODULE_STATE_LIVE] Normal state
>   livepatch: 'test_klp_callbacks_demo': starting unpatching transition
>   livepatch: 'test_klp_callbacks_demo': completing unpatching transition
>   test_klp_callbacks_demo: post_unpatch_callback: vmlinux
>
> ERROR: livepatch kselftest(s) failed
> not ok 1..2 selftests: livepatch: test-callbacks.sh [FAIL]
>
> which probably means that the consistency model is not in the best shape.
> There were not many livepatch changes in the latest pull request. Stack
> unwinder changes may be connected, so adding Thomas to be aware if it
> leads in this direction.
>
> Unfortunately, I'm leaving in a minute and will be gone till Wednesday, so
> if someone confirms and wants to investigate, definitely feel free to do
> it.

I will take a look today.  Thanks for reporting.  I hope it's something 
silly in the tests not the consistency model ...

-- Joe