On Thu 2018-02-22 22:00:28, Miroslav Benes wrote:
> On Wed, 21 Feb 2018, Petr Mladek wrote:
> > This patch allows the late initialization.
> >
> > diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
> > index ad508a86b2f9..da1438d47d83 100644
> > --- a/kernel/livepatch/core.c
> > +++ b/kernel/livepatch/core.c
> > @@ -984,7 +988,12 @@ static void klp_free_patch(struct klp_patch *patch)
> >
> > static int klp_init_func(struct klp_object *obj, struct klp_func *func)
> > {
> > - if (!func->old_name || !func->new_func)
> > + if (!func->old_name)
> > + return -EINVAL;
> > +
> > + /* NOPs do not know the address until the patched module is loaded. */
> > + if (!func->new_func &&
> > + (!klp_is_func_type(func, KLP_FUNC_NOP) || klp_is_object_loaded(obj)))
> > return -EINVAL;
>
> If we changed the order of klp_init_func() and klp_init_object_loaded()
> calls in klp_init_object(), the hunk would not be needed. Is that correct?
Not really. klp_init_object_loaded() would set func->new_func only
when the object was loaded. But we want to proceed here and create
the kobject for NOPs even when it was not loaded.
> > INIT_LIST_HEAD(&func->stack_node);
> > @@ -1039,6 +1048,9 @@ static int klp_init_object_loaded(struct klp_patch *patch,
> > return -ENOENT;
> > }
> >
> > + if (klp_is_func_type(func, KLP_FUNC_NOP))
> > + func->new_func = (void *)func->old_addr;
>
> Is there a reason why you left the same assignment in
> klp_alloc_func_nop()? This one is enough, no?
Good point! I am going to replace the obsolete assignment
with a comment in v8.
Best Regards,
Petr
--
To unsubscribe from this list: send the line "unsubscribe live-patching" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
