Messages in this thread | | | Date | Fri, 9 Feb 2018 13:59:22 +0100 (CET) | From | Miroslav Benes <> | Subject | Re: [PATCH v7 5/7] livepatch: Support separate list for replaced patches. |
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On Tue, 6 Feb 2018, Petr Mladek wrote:
> From: Jason Baron <jbaron@akamai.com> > > We are going to add a feature called atomic replace. It will allow to > create a patch that would replace all already registered patches. > > The replaced patches will stay registered because they are typically > unregistered by some package uninstall scripts. But we will remove > these patches from @klp_patches list to keep the enabled patch > on the bottom of the stack. Otherwise, we would need to implement > rather complex logic for moving the patches on the stack. Also > it would complicate implementation of the atomic replace feature. > It is not worth it. > > As a result, we will have patches that are registered but that > are not longer usable. Let's get prepared for this and use > a better descriptive name for klp_is_patch_registered() function. > > Also create separate list for the replaced patches and allow to > unregister them. Alternative solution would be to add a flag > into struct klp_patch. Note that patch->kobj.state_initialized > is not safe because it can be cleared outside klp_mutex. > > This patch does not change the existing behavior. > > Signed-off-by: Jason Baron <jbaron@akamai.com> > [pmladek@suse.com: Split and renamed klp_is_patch_usable()] > Signed-off-by: Petr Mladek <pmladek@suse.com> > Cc: Josh Poimboeuf <jpoimboe@redhat.com> > Cc: Jessica Yu <jeyu@kernel.org> > Cc: Jiri Kosina <jikos@kernel.org> > Cc: Miroslav Benes <mbenes@suse.cz> > --- > kernel/livepatch/core.c | 30 ++++++++++++++++++++++++------ > 1 file changed, 24 insertions(+), 6 deletions(-) > > diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c > index fccb603942f1..11632fe8716a 100644 > --- a/kernel/livepatch/core.c > +++ b/kernel/livepatch/core.c > @@ -47,6 +47,13 @@ DEFINE_MUTEX(klp_mutex); > > static LIST_HEAD(klp_patches); > > +/* > + * List of 'replaced' patches that have been replaced by a patch that has the > + * 'replace' bit set. When they are added to this list, they are disabled and > + * can not be re-enabled, but they can be unregistered(). > + */ > +LIST_HEAD(klp_replaced_patches);
It should be static, I think. It is used only in kernel/livepatch/core.c. And sparse complains about it.
With that fixed
Acked-by: Miroslav Benes <mbenes@suse.cz>
Miroslav
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