Re: [ammarfaizi2-block:paulmck/linux-rcu/fastexp.2022.04.01a 117/158] arch/powerpc/include/asm/book3s/64/pgtable-64k.h:60:1: error: no return statement in function returning non-void

[Paul E. McKenney]

On Sat, Apr 02, 2022 at 02:50:42PM +0800, kernel test robot wrote:
> Hi Paul,
> 
> First bad commit (maybe != root cause):
> 
> tree:   https://github.com/ammarfaizi2/linux-block paulmck/linux-rcu/fastexp.2022.04.01a
> head:   d9f3e7d671416fdf5b61f094765754269b652db0
> commit: 33a6b5d291d49c64d5e5d53c9cb7032835fc3e7b [117/158] rcutorture: Allow rcutorture without RCU Tasks Trace
> config: powerpc64-randconfig-c003-20220402 (https://download.01.org/0day-ci/archive/20220402/202204021454.WDwBbwVL-lkp@xxxxxxxxx/config)
> compiler: powerpc64-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/ammarfaizi2/linux-block/commit/33a6b5d291d49c64d5e5d53c9cb7032835fc3e7b
>         git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
>         git fetch --no-tags ammarfaizi2-block paulmck/linux-rcu/fastexp.2022.04.01a
>         git checkout 33a6b5d291d49c64d5e5d53c9cb7032835fc3e7b
>         # 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=powerpc prepare
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>

I believe that these three commits on the -rcu tree's "dev" branch
fix this problem:

18fdcb727bcc ("rcutorture: Allow rcutorture without RCU Tasks Trace")
9028d6407050 ("rcutorture: Allow rcutorture without RCU Tasks")
675b486996d9 ("rcutorture: Allow rcutorture without RCU Tasks Rude")

Please let me know if you have further problems.

							Thanx, Paul

> All errors (new ones prefixed by >>):
> 
>    WARNING: unmet direct dependencies detected for TASKS_TRACE_RCU
>    Depends on RCU_EXPERT
>    Selected by
>    - BPF_SYSCALL
>    Selected by
>    - RCU_REF_SCALE_TEST && DEBUG_KERNEL
>    In file included from arch/powerpc/include/asm/book3s/64/pgtable.h:310,
>    from arch/powerpc/include/asm/book3s/64/mmu-hash.h:20,
>    from arch/powerpc/include/asm/book3s/64/mmu.h:38,
>    from arch/powerpc/include/asm/mmu.h:405,
>    from arch/powerpc/include/asm/lppaca.h:46,
>    from arch/powerpc/include/asm/paca.h:17,
>    from arch/powerpc/include/asm/current.h:13,
>    from include/linux/thread_info.h:23,
>    from include/asm-generic/preempt.h:5,
>    from ./arch/powerpc/include/generated/asm/preempt.h:1,
>    from include/linux/preempt.h:78,
>    from include/linux/spinlock.h:55,
>    from include/linux/ipc.h:5,
>    from include/uapi/linux/sem.h:5,
>    from include/linux/sem.h:5,
>    from include/linux/compat.h:14,
>    from arch/powerpc/kernel/asm-offsets.c:12:
>    arch/powerpc/include/asm/book3s/64/pgtable-64k.h: In function 'get_hugepd_cache_index':
> >> arch/powerpc/include/asm/book3s/64/pgtable-64k.h:60:1: error: no return statement in function returning non-void
>    60 | }
>    | ^
>    cc1: some warnings being treated as errors
>    Makefile arch include kernel nr_bisected scripts source usr [scripts/Makefile.build:121: arch/powerpc/kernel/asm-offsets.s] Error 1
>    Target '__build' not remade because of errors.
>    Makefile arch include kernel nr_bisected scripts source usr [Makefile:1190: prepare0] Error 2
>    Target 'prepare' not remade because of errors.
>    make: Makefile arch include kernel nr_bisected scripts source usr [Makefile:219: __sub-make] Error 2
>    make: Target 'prepare' not remade because of errors.
> 
> Kconfig warnings: (for reference only)
>    WARNING: unmet direct dependencies detected for TASKS_TRACE_RCU
>    Depends on RCU_EXPERT
>    Selected by
>    - BPF_SYSCALL
>    Selected by
>    - RCU_REF_SCALE_TEST && DEBUG_KERNEL
> 
> 
> vim +60 arch/powerpc/include/asm/book3s/64/pgtable-64k.h
> 
> a9252aaefe7e721 Aneesh Kumar K.V 2016-04-29  53  
> fadd03c615922d8 Aneesh Kumar K.V 2018-06-14  54  /*
> fadd03c615922d8 Aneesh Kumar K.V 2018-06-14  55   * This should never get called
> fadd03c615922d8 Aneesh Kumar K.V 2018-06-14  56   */
> fadd03c615922d8 Aneesh Kumar K.V 2018-06-14  57  static inline int get_hugepd_cache_index(int index)
> fadd03c615922d8 Aneesh Kumar K.V 2018-06-14  58  {
> fadd03c615922d8 Aneesh Kumar K.V 2018-06-14  59  	BUG();
> fadd03c615922d8 Aneesh Kumar K.V 2018-06-14 @60  }
> fadd03c615922d8 Aneesh Kumar K.V 2018-06-14  61  
> 
> :::::: The code at line 60 was first introduced by commit
> :::::: fadd03c615922d8521a2e76d4ba2335891cb2790 powerpc/mm/hash/4k: Free hugetlb page table caches correctly.
> 
> :::::: TO: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
> :::::: CC: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://01.org/lkp