Re: [paulmck-rcu:dev.2022.02.17a 73/73] make[3]: *** No rule to make target 'kernel/rcu/typesafe.o', needed by 'kernel/rcu/built-in.a'.

["Paul E. McKenney" <paulmck@kernel.org>]

On Tue, Feb 22, 2022 at 03:05:27AM +0800, kernel test robot wrote:
> Hi Paul,
> 
> First bad commit (maybe != root cause):
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2022.02.17a
> head:   f5b2eaf791ebbd6af881947ab7c40ed70681e534
> commit: f5b2eaf791ebbd6af881947ab7c40ed70681e534 [73/73] EXP torture: Add tests demoing SLAB_TYPESAFE_BY_RCU
> config: arc-allyesconfig (https://download.01.org/0day-ci/archive/20220222/202202220308.TNib9D2v-lkp@intel.com/config)
> compiler: arceb-elf-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://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=f5b2eaf791ebbd6af881947ab7c40ed70681e534
>         git remote add paulmck-rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
>         git fetch --no-tags paulmck-rcu dev.2022.02.17a
>         git checkout f5b2eaf791ebbd6af881947ab7c40ed70681e534
>         # save the config file to linux build tree
>         mkdir build_dir
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arc SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
> >> make[3]: *** No rule to make target 'kernel/rcu/typesafe.o', needed by 'kernel/rcu/built-in.a'.
>    make[3]: Target '__build' not remade because of errors.

This is the only commit involving kernel/rcu/typesafe.o, so...

One the one hand, I do not plan to upstream this, so maybe it doesn't
matter.

I have been building this using the rcutorture scripting for some time,
same RCU-related .config as you are using.  But when I pulled it into
a clone in a neighboring directory, it failed just as it did for you.
The problem was that the update to kernel/rcu/Makefile somehow didn't
come across, so this line was missing:

	obj-$(CONFIG_RCU_TYPESAFE_TEST) += typesafe.o

Which of course explains the build failure.

I blew away that clone and re-cloned it.  And it still failed, both
with "make" from the commandline and under rcutorture.

Hahahahahahaahaha!!!

I forgot "git add kernel/rcu/typesafe.c".

There is now a new typesafe.2022.02.21a tag with this file added.

Good catch!  That file happened to still be lying around.  The first
"git reset --hard" would have destroyed.  Thank you!!!

And with that fixed, my clone now builds correctly.  Does this fix
it for you?

							Thanx, Paul