Re: [PATCH v2] jump_label: fix jump_label update

Jason Baron
2011-06-21T15:48:13Z

On Tue, Jun 21, 2011 at 11:44:55AM +0200, Jiri Olsa wrote:
> On Tue, Jun 21, 2011 at 10:35:55AM +0800, Xiao Guangrong wrote:
> > The key of module is out of __stop___jump_table, it causes the events
> > of modules does not work
> >
> > Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> > ---
> > kernel/jump_label.c | 14 +++++++++-----
> > 1 files changed, 9 insertions(+), 5 deletions(-)
> >
> > diff --git a/kernel/jump_label.c b/kernel/jump_label.c
> > index fa27e75..a8ce450 100644
> > --- a/kernel/jump_label.c
> > +++ b/kernel/jump_label.c
> > @@ -375,15 +375,19 @@ int jump_label_text_reserved(void *start, void *end)
> >
> > static void jump_label_update(struct jump_label_key *key, int enable)
> > {
> > - struct jump_entry *entry = key->entries;
> > -
> > - /* if there are no users, entry can be NULL */
> > - if (entry)
> > - __jump_label_update(key, entry, __stop___jump_table, enable);
> > + struct jump_entry *entry = key->entries, *stop = __stop___jump_table;
> >
> > #ifdef CONFIG_MODULES
> > + struct module *mod = __module_address((jump_label_t)key);
> > +
> > __jump_label_mod_update(key, enable);
> > +
> > + if (mod)
> > + stop = mod->jump_entries + mod->num_jump_entries;
> > #endif
> > + /* if there are no users, entry can be NULL */
> > + if (entry)
> > + __jump_label_update(key, entry, stop, enable);
> > }
> >
> > #endif
> > --
> > 1.7.5.4
>
> That works for me, but in order to test it I needed to export
> jump_label_inc/jump_label_dec functions.
>
> Not sure I'm missing something, but to manage a key that is local
> to the module, we need to call jump_label_inc/jump_label_dec
> from within the module code, so we need some of the jump_label
> functions exported.. it'd be probably:
>
> jump_label_inc/jump_label_dec/jump_label_enabled
>

You're not missing anything, right now all the enabling/disabling is
done in the core kernel, hence no need for the export. I'd prefer to
keep them non-exported until we had a real use-case that required them
to be exported. But I don't feel that strongly about it.

Thanks,

-Jason