Re: [PATCH v3] livepatch: Don't block removal of patches that are safe to unload

From: Petr Mladek
Date: Thu Mar 17 2022 - 14:38:51 EST


On Sat 2022-03-12 23:22:20, Chengming Zhou wrote:
> module_put() is not called for a patch with "forced" flag. It should
> block the removal of the livepatch module when the code might still
> be in use after forced transition.
>
> klp_force_transition() currently sets "forced" flag for all patches on
> the list.
>
> In fact, any patch can be safely unloaded when it passed through
> the consistency model in KLP_UNPATCHED transition.
>
> By other words, the "forced" flag must be set only for livepatches
> that are being removed. In particular, set the "forced" flag:
>
> + only for klp_transition_patch when the transition to KLP_UNPATCHED
> state was forced.
>
> + all replaced patches when the transition to KLP_PATCHED state was
> forced and the patch was replacing the existing patches.
>
> Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>

The patch has been committed, with the proposed wording changes,
into livepatching/livepatching.git, branch for-5.18/fixes,
see
https://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching.git/commit/?h=for-5.18/fixes&id=2957308343fa7c621df9f342fab88cb970b8d5f3

Best Regards,
Petr