Re: [PATCH 2/2] kobject: wait until kobject is cleaned up before freeing module

From: Ming Lei
Date: Fri Nov 05 2021 - 10:55:40 EST


On Fri, Nov 05, 2021 at 10:10:07PM +0800, kernel test robot wrote:
> Hi Ming,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on driver-core/driver-core-testing]
> [also build test ERROR on v5.15 next-20211105]
> [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/Ming-Lei/kobject-avoid-to-cleanup-kobject-after-module-is-unloaded/20211105-144026
> base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git 27e0bcd02990f7291adb0f111e300f06c495d509
> config: mips-buildonly-randconfig-r003-20211105 (attached as .config)
> compiler: mipsel-linux-gcc (GCC) 11.2.0
> 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/4a9e015dd3d3e39d5723ea46579ba21f5394806a
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Ming-Lei/kobject-avoid-to-cleanup-kobject-after-module-is-unloaded/20211105-144026
> git checkout 4a9e015dd3d3e39d5723ea46579ba21f5394806a
> # save the attached .config to linux build tree
> mkdir build_dir
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=mips SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All errors (new ones prefixed by >>):
>
> lib/kobject.c: In function 'kobj_module_callback':
> >> lib/kobject.c:741:20: error: 'MODULE_STATE_GOING' undeclared (first use in this function)
> 741 | if (val != MODULE_STATE_GOING)
> | ^~~~~~~~~~~~~~~~~~
> lib/kobject.c:741:20: note: each undeclared identifier is reported only once for each function it appears in

Hello,

Thanks for the report!

This must be triggered when CONFIG_MODULES is off, and the following patch
should kill the failure:


diff --git a/lib/kobject.c b/lib/kobject.c
index f5fd6017d8ce..c054dca0001a 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -738,8 +738,10 @@ static int kobj_module_callback(struct notifier_block *nb,
{
LIST_HEAD(pending);

+#ifdef CONFIG_MODULES
if (val != MODULE_STATE_GOING)
return NOTIFY_DONE;
+#endif

spin_lock_irq(&kobj_cleanup_lock);
list_splice_init(&kobj_cleanup_list, &pending);


Thanks,
Ming