Re: [PATCH 1/3] base: remove unused variable 'no_warn'

From: kernel test robot
Date: Wed Jul 14 2021 - 08:15:44 EST


Hi Bill,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on scsi/for-next]
[also build test WARNING on linux/master driver-core/driver-core-testing mkp-scsi/for-next ipvs/master linus/master v5.14-rc1 next-20210714]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Bill-Wendling/Fix-clang-Wunused-but-set-variable-warnings/20210714-172029
base: https://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git for-next
config: powerpc-redwood_defconfig (attached as .config)
compiler: powerpc-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/f6c4b007fc8c907719d883faae424f2cf3bb100c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Bill-Wendling/Fix-clang-Wunused-but-set-variable-warnings/20210714-172029
git checkout f6c4b007fc8c907719d883faae424f2cf3bb100c
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

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, 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, driver_name);
66 kfree(driver_name);
67 }
68 }
69

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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