Re: [PATCH] kernel/module.c: fix warning about unused nowarn variable

[Jessica Yu]

+++ Corentin Labbe [02/06/17 14:05 +0200]:

This patch fix the following warning:
kernel/module.c: In function 'add_usage_links':
kernel/module.c:1653:6: warning: variable 'nowarn' set but not used 
[-Wunused-but-set-variable]
 int nowarn;

Signed-off-by: Corentin Labbe <clabbe.montj...@gmail.com>
---
kernel/module.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index e3e9dbba6a5b..aed902bcb4aa 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1663,19 +1663,20 @@ static inline void remove_notes_attrs(struct module 
*mod)
}
#endif /* CONFIG_KALLSYMS */

-static void add_usage_links(struct module *mod)
+static int add_usage_links(struct module *mod)
{
+       int ret = 0;
#ifdef CONFIG_MODULE_UNLOAD
        struct module_use *use;
-       int nowarn;

        mutex_lock(&module_mutex);
        list_for_each_entry(use, &mod->target_list, target_list) {
-               nowarn = sysfs_create_link(use->target->holders_dir,
+               ret = sysfs_create_link(use->target->holders_dir,
                                           &mod->mkobj.kobj, mod->name);

ret will get overwritten with each iteration of the loop; we should return
ret as soon as we hit an error (while making sure we unlock
module_mutex).

        }
        mutex_unlock(&module_mutex);
#endif
+       return ret;
}

static void del_usage_links(struct module *mod)
@@ -1798,13 +1799,17 @@ static int mod_sysfs_setup(struct module *mod,
        if (err)
                goto out_unreg_param;

-       add_usage_links(mod);
+       err = add_usage_links(mod);
+       if (err)
+               goto out_unreg_usage_links;

Small nitpick: could you add an extra newline here?

        add_sect_attrs(mod, info);
        add_notes_attrs(mod, info);

        kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
        return 0;

+out_unreg_usage_links:

Can you rename this to `out_unreg_modinfo_attrs` (to better reflect
what's being done)?

+       module_remove_modinfo_attrs(mod);
out_unreg_param:
        module_param_sysfs_remove(mod);
out_unreg_holders:

Thanks,

Jessica