Re: [PATCH v5 3/3] livepatch: add transition notices

From: Petr Mladek
Date: Wed Sep 27 2017 - 07:49:14 EST


On Thu 2017-08-31 10:53:53, Joe Lawrence wrote:
> Log a few kernel debug messages at the beginning of the following livepatch
> transition functions:
>
> klp_complete_transition()
> klp_cancel_transition()
> klp_init_transition()
> klp_reverse_transition()
>
> Also update the log notice message in klp_start_transition() for similar
> verbiage as the above messages.
>
> Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
> ---
> kernel/livepatch/transition.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
> index 53887f0bca10..3d44a3cf27be 100644
> --- a/kernel/livepatch/transition.c
> +++ b/kernel/livepatch/transition.c
> @@ -82,6 +82,10 @@ static void klp_complete_transition(void)
> unsigned int cpu;
> bool immediate_func = false;
>
> + pr_debug("'%s': completing %s transition\n",
> + klp_transition_patch->mod->name,
> + klp_target_state == KLP_PATCHED ? "patching" : "unpatching");
> +
> if (klp_target_state == KLP_UNPATCHED) {
> /*
> * All tasks have transitioned to KLP_UNPATCHED so we can now
> @@ -163,6 +167,9 @@ void klp_cancel_transition(void)
> if (WARN_ON_ONCE(klp_target_state != KLP_PATCHED))
> return;
>
> + pr_debug("'%s': canceling transition, unpatching\n",

This sentence is a bit confusing. It is related to the Mirek's concern
about that the following message would be "completing unpatching transition".

What about using something like:

pr_debug("'%s': canceling patching transition, going to unpatch\n",


Best Regards,
Petr