2021-05-27 15:14:43

by Baokun Li

[permalink] [raw]
Subject: [PATCH -next] driver core: Remove set but not used variable 'no_warn'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/base/module.c: In function 'module_create_drivers_dir':
drivers/base/module.c:36:6: warning:
variable ‘no_warn’ set but not used [-Wunused-but-set-variable]

It never used since introduction.

Signed-off-by: Baokun Li <[email protected]>
---
drivers/base/module.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/base/module.c b/drivers/base/module.c
index 46ad4d636731..07ecd66b12b0 100644
--- a/drivers/base/module.c
+++ b/drivers/base/module.c
@@ -33,7 +33,6 @@ static void module_create_drivers_dir(struct module_kobject *mk)
void module_add_driver(struct module *mod, struct device_driver *drv)
{
char *driver_name;
- int no_warn;
struct module_kobject *mk = NULL;

if (!drv)
@@ -59,12 +58,12 @@ void module_add_driver(struct module *mod, struct device_driver *drv)
return;

/* Don't check return codes; these calls are idempotent */
- no_warn = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
+ sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
driver_name = make_driver_name(drv);
if (driver_name) {
module_create_drivers_dir(mk);
- no_warn = sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
- driver_name);
+ sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
+ driver_name);
kfree(driver_name);
}
}
--
2.25.4


2021-05-27 15:44:41

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH -next] driver core: Remove set but not used variable 'no_warn'

Hi Baokun,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on next-20210526]

url: https://github.com/0day-ci/linux/commits/Baokun-Li/driver-core-Remove-set-but-not-used-variable-no_warn/20210527-170758
base: f6b46ef27317b3441138b902689bd89e4f82c6f4
config: um-x86_64_defconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/c41d30a4b7791bb76211dd1ddb7b467d555ad596
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Baokun-Li/driver-core-Remove-set-but-not-used-variable-no_warn/20210527-170758
git checkout c41d30a4b7791bb76211dd1ddb7b467d555ad596
# save the attached .config to linux build tree
make W=1 ARCH=um SUBARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>

All warnings (new ones prefixed by >>):

drivers/base/module.c: In function 'module_add_driver':
>> drivers/base/module.c:61:2: warning: ignoring return value of 'sysfs_create_link', declared with attribute warn_unused_result [-Wunused-result]
61 | sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/base/module.c:65:3: warning: ignoring return value of 'sysfs_create_link', declared with attribute warn_unused_result [-Wunused-result]
65 | sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
66 | driver_name);
| ~~~~~~~~~~~~


vim +/sysfs_create_link +61 drivers/base/module.c

32
33 void module_add_driver(struct module *mod, struct device_driver *drv)
34 {
35 char *driver_name;
36 struct module_kobject *mk = NULL;
37
38 if (!drv)
39 return;
40
41 if (mod)
42 mk = &mod->mkobj;
43 else if (drv->mod_name) {
44 struct kobject *mkobj;
45
46 /* Lookup built-in module entry in /sys/modules */
47 mkobj = kset_find_obj(module_kset, drv->mod_name);
48 if (mkobj) {
49 mk = container_of(mkobj, struct module_kobject, kobj);
50 /* remember our module structure */
51 drv->p->mkobj = mk;
52 /* kset_find_obj took a reference */
53 kobject_put(mkobj);
54 }
55 }
56
57 if (!mk)
58 return;
59
60 /* Don't check return codes; these calls are idempotent */
> 61 sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
62 driver_name = make_driver_name(drv);
63 if (driver_name) {
64 module_create_drivers_dir(mk);
65 sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
66 driver_name);
67 kfree(driver_name);
68 }
69 }
70

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]


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