| Message ID | 20240322132014.906097-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | module: silence warning about unused 'no_warn' variable | expand |
On Fri, Mar 22, 2024 at 02:20:05PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > The sysfs_create_link() return code is marked as __must_check, but the > module_add_driver() function tries hard to not care, by assigning the > return code to a variable. When building with 'make W=1', gcc still > warns because this variable is only assigned but not used: > > drivers/base/module.c: In function 'module_add_driver': > drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable] > > Add an explicit cast to void to prevent this check as well. > > Cc: Luis Chamberlain <mcgrof@kernel.org> > Cc: linux-modules@vger.kernel.org > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: "Rafael J. Wysocki" <rafael@kernel.org> > Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/") > See-also: 4a7fb6363f2d ("add __must_check to device management code") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > I'm not entirely sure what bug the __must_check on sysfs_create_link() > is trying to prevent, or why the module loader code is allowed to > ignore this. It would be nice to have an Ack from the sysfs maintainers > on this. No, let's fix this properly and unwind if we can't create the link. You are pointing at something from 2006, so I guess we always thought "this can not fail" and never did anything about it since then. thanks, greg k-h
diff --git a/drivers/base/module.c b/drivers/base/module.c index 46ad4d636731..0180dbcf2240 100644 --- a/drivers/base/module.c +++ b/drivers/base/module.c @@ -67,6 +67,8 @@ void module_add_driver(struct module *mod, struct device_driver *drv) driver_name); kfree(driver_name); } + + (void)no_warn; } void module_remove_driver(struct device_driver *drv)